Dissertations / Theses on the topic 'Hormones in animal nutrition'

Reproductive neuroendocrine activity and appetite are modulated at the hypothalamus by both nutritional status and photoperiod in the seasonal animal. The objectives of this work were (1) to measure circulating hormones and/or metabolites that relay information about peripheral nutritional status to the hypothalamus, (2) to identify which hypothalamic neuropeptides and receptors that are responsive to photoperiodic and nutritional feedback and (3) to establish which changes in peripheral signals and/or hypothalamic neuropeptides are associated with alterations in the activity of the reproductive neuroendocrine axis. Three main experiments were carried out. The first experiment (Chapter 1) utilised a 2 x 2 design to examine the separate and interactive effects of photoperiod and food restriction on hypothalamic neuropeptide and receptor mRNA expression and on GnRH/LH secretion. In the second experiment (Chapter 2), two components of nutritional status, BC and increased food intake were investigated since both are positively related to reproductive performance in sheep. In the final experiment (Chapter 3) the approach was to use an exogenous treatment to artificially raise plasma insulin in an attempt to "drive" some of the foregoing effects. Collectively these studies have lead to the first localisation AgRp, MCH, orexin, Mc3R, Mc4R gene expression in the ovine hypothalamus. They indicate that circulating insulin and leptin are major factors relaying information about nutritional status to the hypothalamus. In addition, they have dissociated BC and food intake as signals to the hypothalamus. Moreover these studies have provided no evidence that NPY, AgRp, POMC, MCH and ObRb play a role in driving seasonal changes in appetite and gonadotrophin secretion. However they do suggest NPY-ergic and melanocortin pathways are important in maintaining appetite/bodyweight/energy homeostasis or restoring energy balance following perturbation. Furthermore the results show that changes in nutrient-sensitive hypothalamic neuropeptide and receptor gene expression may not necessarily lead to alterations in the activity of the reproductive neuroendocrine axis. However, they do indicate that increased NPY biosynthesis during food restriction may be involved in the inhibition of pulsatile GnRH/LH release.

Thesis (Ph. D.)--University of Adelaide, Dept. of Animal Science, 1998.
Corrigenda inserted behind title page. Copies of author's previously published articles inserted. Includes bibliographical references (leaves 193-210).

Foram utilizadas 24 ovelhas da raça Santa Inês para coleta de tecido adiposo, sendo 16 lactantes e 8 secas. Oito ovelhas lactantes foram tratadas in vivo com bST (160 mg, em duas doses em intervalo de 14 dias) iniciando a injeção subcutânea de hormônio no 13 o dia de lactação, sendo que os animais restantes receberam somente vitamina E. Outros 8 animais encontravam-se em período seco, para que fosse verificada também a diferença das taxas lipolíticas em diferentes estados fisiológicos. Foi verificada a hipótese de que ocorra uma atuação da ST através de mudança na resposta do sistema antilipolítico da proteína Gi ligada a receptores da adenosina. O tratamento com ST exógena aumentou o ganho de peso das ovelhas lactantes (P<0,05) e também o peso dos cordeiros oriundos do grupo tratado ao final do período experimental, no entanto, não foi verificado aumento na produção de leite. As concentrações de AGNE diminuíram no decorrer da lactação para os dois grupos de ovelhas lactantes, chegando no 36 º dia de lactação a concentrações similares ao do grupo de ovelhas secas. A concentração de IGF-I sérico das ovelhas aumentou após tratamento com bST, sendo 8 dias após a segunda dose do hormônio (36 dias de lactação) superior à concentração observada para ovelhas secas. A lactação não teve influência na lipólise basal entre os diferentes estados fisiológicos. Houve um aumento significativo (P<0,01) da taxa lipolítica do tecido adiposo quando estimulada por b adrenérgico (ISO) para animais em quaisquer dos estados fisiológicos. Todavia, a taxa estimulada por ISO foi significativamente (P<0,01) mais elevada no tecido das ovelhas tratadas com bST. Na presença de ADA, ocorreu um aumento da taxa em relação à basal, mas não ultrapassou àquela estimulada por isoproterenol. O estímulo lipolítico pela eliminação de adenosina no meio através da ADA apresentou-se significativamente (P<0,01) mais elevado para ovelhas lactantes, sendo este efeito amenizado pelo tratamento com bST. O uso do análogo da adenosina PIA quando colocado no meio de cultura do tecido que foi tratado in vivo com bST teve seu efeito diminuído. Os resultados indicam um aumento da taxa lipolítica em resposta a agonista b-adrenérgico no tecido adiposo do omento de ovelhas lactantes tratadas com bST in vivo, bem como confirmam a hipótese de diminuição da ação inibitória da adenosina na cascata lipolítica naquele tecido.
Bovine somatotropin (bST) treatment in vivo alters adipose tissue metabolism by enhancing lipolytic response to adrenergic agonists. We examined the impact of bST and lactation on basal and stimulated lipolytic rates with isoproterenol (ISO; 10 -5 nM), adenosine deaminase (ADA; 0.75 U/mL), ISO plus ADA in short-term (2h) incubations of ovine adipose tissue. The anti-lipolytic effect of phenylisopropyladenosine (PIA; non-hydrolyzable adenosine analog) was evaluated at various concentrations (0.5, 1.5, 3, 100 nM). Sixteen lactating Santa Ines ewes were randomly assigned to two groups. They received two s.c. injections, with a 14 day interval, starting at d 13 postpartum with either bST (160 mg) or Vitamin E (control). Eight similar nonlactating ewes received vitamin E. Omental adipose tissue biopsies were taken on d 8 after the second bST or vitamin injection. The performance of weight and milk production were taken. The serum IGF-I was analyzed. The lipolytic rate was determined by NEFA release in serum and media as mEq of oleic acid.2h -1 g -1 tissue. Basal lipolytic rates did not change with lactation or with bST treatment in vivo (P>0,05). ISO stimulated lipolytic rate increased compared to basal and was higher for the adipose tissue from lactating ewes treated with bST (P<0,01).The lipolytic rate for adipose incubated with ADA was higher than basal for lactating ewes, with the greater response for the control. The ADA treated tissue from lactating ewes receiving bST showed intermediate lipolytic rates. Maximum lipolytic rate with ISO+ADA was also higher for lactating ewes treated with bST (P<0.01), and there was no difference between lactating and nonlactating ewes. The PIA effects were evaluated by the inhibition of ISO+ADA lipolysis, and adipose tissue from lactating ewes treated with bST showed a reduced response to PIA. The results demonstrate that in vivo somatotropin treatment increases maximal lipolytic rates stimulated by adrenergic agonist and decreases the antilipolytic effect of PIA in omental adipose tissue in ewes.

Orientador: Jose Luiz Moraes Vasconcelos
Banca: Ky Garrett Pohler
Banca: Gustavo Resende Siqueira
Banca: Ocilon Gomes de Sá Filho
Resumo: Os hormônios metabólicos IGF-1, GH e leptina são alterados de acordo com o status nutricional dos animais. O objetivo desse trabalho foi determinar as concentrações desses hormônios em vacas paridas e novilhas Nelore entre 12 e 16 meses de idade e seus efeitos na reprodução nos experimentos do Capítulo 2. No Capítulo 3, vacas primíparas, multíparas e novilhas Nelore de dois anos foram suplementadas ou não com milho moído durante o protocolo de IATF até o diagnóstico de gestação com o intuito de avaliar a alteração nos hormônios metabólicos e seus impactos na reprodução. No Capítulo 4, multíparas Nelore de duas fazendas foram suplementadas ou não com virginiamicina adicionada ao sal mineral. Em todos os experimentos as fêmeas foram submetidas a protocolos de IATF e colocadas com touro até o fim da estação de monta, sendo que apenas nos experimentos do Capítulo 3, as fêmeas receberam segunda IATF caso estivessem vazias antes da entrada dos touros. No experimento 1 do Capítulo 2 e no experimento 1 do Capítulo 3 houve efeito linear positivo da concentração de IGF-1 no dia da inseminação na probabilidade de prenhez a IATF. Em todos os experimentos realizados, também houve efeito linear positivo da concentração de IGF-1 no dia da inseminação na probabilidade de prenhez ao final da estação de monta, exceto no experimento 2 do capítulo 2. A concentração de IGF-1 no diagnóstico de gestação apresentou efeito linear negativo na probabilidade de prenhez em quatro estudos. O efeito do GH ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The metabolic hormones IGF-1, GH and leptin change according to nutritional managmentof the herd. The aim of these trials was to measure the concentration of these metabolic hormones in 12-16 months old Nellore heifers and multiparous cows and associate with the reproduction performance in experiments of Chapter 2. In Chapter 3, 2-years old heifers, primiparous and multiparous Nellore cows received or not ground corn starting in the begginning of TAI protocol until pregnancy check on day 30 to associate with metabolic hormones and reproduction. In Chapter 4, multiparous Nellore cows of two farms were supplemented or not with virginiamycin in mineral salt and the association with metabolic hormores and reproduction was evaluated. In all studies TAI was performed and bulls stayed from 7 days after TAI until the end of breeding season, except on trials of Chapter 3, which second TAI was performed in open cows before being exposed to bulls. In experiment 1 of Chapter 2 and experiment 1 of chapter 3 there was a linear positive effect of IGF-1 concentration on day of insemination on TAI pregnancy rate. In all trials, IGF-1 concentrations on insemination had a linear positive effect on pregnancy rate in the end of breeding season, except in experiment 2 of chapter 2. The IGF-1 concentrations on pregnancy rate had a linear negative association with TAI pregnancy rate in 4 studies. Concentraions of GH and leptin had no consistent association with reproduction rates. Corn supplementation did not alter TAI pregnancy rate, but tended to improve pregnancy rate on second AI and increased final pregnancy rate in primiparous cows, reduced final pregnancy rate in multiparous cows and increased weaning rate of primiparous calves supplemented with corn. Virginiamycin supplementation did not increase TAI and... (Complete abstract click electronic access below)
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This work was developed to determine the effects of feed restriction on rearing gilts on their reproductive efficiency as primiparous sows. Were used 80 gilts C40 (Dalland, Pietran x Large White), with 149.8 ± 3.2 days and 93.1 ± 6.0 kg of live weight, divided in eight lots of 10 animals, being each lot housed in collective pens of 15m2. The animals were submitted to two different treatments during 150 days of age until seven days after first mating. In treatment 1, gilts received 2,6 kg of feed (2945 Kcal ME, 14% CP, 0.6 lysine) a day, while in the treatment 2 the gilts received 2,2 kg (feed restriction 15%) of the same feed a day. Seven days before the first mating gilts of both treatments received 3,0 kg of lactation feed a day (flushing). The gilts had the backfat thickness (BF) measured at 170, 190 and 210 days and were weighted at 210 days of age. At 215,6 ± 6,7 days gilts were artificially inseminated. There were no differences (P>0,05) on BF at 170 (12,3 ± 1,6 vs 11,6 ± 1,3 mm), 190 (12,8 ± 1,3 vs 12,2 ± 1,1 mm) and 210 (13,4 ± 1,3 vs 12,9 ± 1,1 mm) days, as well as in the weight at 210 days of age (131,4 ± 7,1 vs 128,6 ± 9,8 kg) among the animals of the treatments 1 and 2, and both treatments were effective in preparing the replacement gilts inside the patterns of weight and BF at the first breeding. The treatment did not influence the rate of estrus return, but gilts of treatment 1 had a better (P <0,05) performance as primiparous sows than gilts of treatment 2 (11,6 ± 1,6 vs 10,6 ± 2,3 total piglets born). Feed restriction 15%, resulting in a daily intake of 6479 kcal ME and 13.2 g lysine, showed negative effects on reproductive performance, although it was not accompanied of alterations in the weight and in BT at 210 days. The parameters weight and BF were not safe to determine the reproductive efficiency of gilts as primiparous sows, once different results were observed at first farrow under same weight and BF patterns at first mating. Gilts s metabolic status at the insemination seems to be as important as the weight and BF at first mating.
Este trabalho foi desenvolvido com o objetivo de determinar os efeitos da restrição alimentar em marrãs de reposição sobre sua eficiência reprodutiva ao primeiro parto. Foram utilizadas 80 marrãs C40 (Dalland, Pietran x Large White), com idade média de 149,8 ± 3,2 dias e peso vivo médio de 93,1 ± 6,0 quilos, divididas em oito lotes de 10 animais, sendo cada lote alojado em baias coletivas de 15m2. Os animais foram submetidos a dois tratamentos distintos dos 150 dias de idade até 7 dias antes da cobertura. No tratamento 1, as marrãs receberam 2,6 kg de ração (2945 Kcal EM, 14% PB, 0,60 lisina digestível) por dia, enquanto no tratamento 2 as marrãs receberam 2,2 kg (restrição alimentar de 15%) da mesma ração por dia. A partir de sete dias antes da cobertura as marrãs de ambos os tratamentos receberam 3,0 kg de ração lactação por dia (flushing). As marrãs tiveram a espessura de toucinho (ET) mensurada aos 170, 190 e 210 dias e foram pesadas aos 210 dias de idade. Aos 215,6 ± 6,7 dias as marrãs foram artificialmente inseminadas. Não foram encontradas diferenças (P>0,05) na ET aos 170 (12,3 ± 1,6 vs 11,6 ± 1,3 mm), 190 (12,8 ± 1,3 vs 12,2 ± 1,1 mm) e 210 (13,4 ± 1,3 vs 12,9 ± 1,1 mm) dias, bem como no peso aos 210 dias de idade (131,4 ± 7,1 vs 128,6 ± 9,8 kg) entre animais dos tratamentos 1 e 2, sendo que os dois tratamentos foram eficazes em preparar a fêmea de reposição dentro dos padrões de peso e ET à primeira cobertura. O tratamento não influenciou a taxa de repetição de estro, porém as marrãs do tratamento 1 tiveram um melhor (P<0,05) desempenho ao primeiro parto em relação as marrãs do grupo 2 (11,6 ± 1,6 vs 10,6 ± 2,3 total de leitões nascidos). A restrição alimentar de 15%, resultando em um consumo diário de 6479 Kcal de energia metabolizável e 13,2 g de lisina digestível, mostrou ter efeitos negativos no desempenho reprodutivo das marrãs ao primeiro parto, embora não fosse acompanhada de alterações no peso e na ET aos 210 dias. Os parâmetros peso e ET não foram seguros em determinar a eficiência reprodutiva das marrãs ao primeiro parto, uma vez que foram observados diferentes resultados ao primeiro parto sob mesmos padrões de peso e ET à cobertura. O status metabólico da marrã ao momento da inseminação parece ser tão importante quanto o peso e a ET à primeira cobertura.

To evaluate the effect of two different cooling systems on production, physiological, and hormonal responses, 37 Holstein and 26 Brown Swiss dairy cows were allotted to three treatments. A control group of cows had access to only shade (C). A second group was cooled with spray and fan (S/F) and the third group was under an evaporative cooling system called Korral Kool&circR; (KK). The trial lasted from May to September with a daily maximum temperature-humidity index from 73 to 85. Milk production differences in Holstein cows were significantly increased by KK and S/F. No treatment differences in milk production were observed in Brown Swiss cows. Protein percentages were higher in C group compared to Korral Kool group only in Brown Swiss cows, while fat percentage were similar among treatments in Holstein cows. Rectal temperatures and respiration rates of the C group were higher than S/F and KK in both Holstein and Brown Swiss cows. Triiodothyronine levels in milk were significantly higher in KK group compared to S/F and C groups, while cortisol levels were lower in C group than S/F and KK. Similar differences were observed in body weight and body condition score changes between treatments in Holstein or Brown Swiss cows. Pregnancy rate was increased in the groups under the cooling systems in Holstein cows, however this effect was not observed in Brown Swiss cows where C group had a higher pregnancy rate than cooled groups. The cows under cooling systems spend more time eating and outside of the shade in the early afternoon (12:00 to 15:00) than control group. Cows injected with bST (bovine somatotropin) increased milk yield significantly only in Brown Swiss cows, whereas respiration rates were increased in both breeds by bST but rectal temperatures were similar between bST and non-bST cows. These results demonstrate that both cooling systems are an alternative to increase productive and reproductive performance and comfort of Holstein cows during summer in hot-dry climates. The physiological responses of Brown Swiss cows indicated a better adaptation to a hot climate, however their milk production was lower than in Holstein cows.

Many of the anabolic effects of growth hormone (GH) are indirect, occurring through GH-stimulated production of insulin-like growth factor-I (IGF-I) by the liver. As well as being GH regulated, plasma IGF-I concentrations have been demonstrated to be dependent upon protein nutrition, with low protein diets being associated with reduced plasma IGF-I concentrations. This effect cannot be reversed by GH, suggesting that liver sensitivity to GH is impaired. To investigate the mechanisms through which protein supply affects GH sensitivity, primary cultures of ovine hepatocytes were grown in defined media. In a first experiment the media contained various fractions (0.2, 1.0, 5.0) of portal vein amino acid concentrations in fed sheep. In the second 24h incubation period, unstimulated IGF-I secretion was highly sensitive the concentration of amino acids in the media, with significantly greater release of basal IGF-I in 5x compared to either 1x (P<0.05) or 0.2x amino acid containing media. In a second series of experiments the effects of specific amino acid depletions was examined. Methionine depletion of 0.2x portal amino acid concentrations ablated the GH response second 24h of culture without affecting basal IGF-I release. By comparison ³H-leucine incorporation into secreted protein, following 20 hours of culture in defined media was significantly reduced in 0.2x aa (P<0.01) and 1.0x aa (P<0.05) media compared with 5.0x aa media, however secretory protein synthesis was unaffected by methionine depletion to 0.2x portal concentrations. The results suggest that amino acid availability regulates both basal and GH stimulated IGF-I release in ovine hepatocytes. Furthermore reducing methionine concentrations in the culture media to 0.2x portal concentrations diminishes GH response without compromising protein secretion.

The loss of bone mineral density (BMD) plays a major role in the increased incidence of osteoporosis in aging women and, consequently, strategies to maintain BMD are critical to quality of life for these women. The role of vitamin D in the accrual and maintenance of bone mineral and its relationship to the incidence and severity of osteoporosis is not well understood. By measuring serum and intake levels this study investigates the relationship of vitamin D to baseline BMD and changes in regional and total body BMD over 1 y. The role of sex hormone binding globulin (SHBG) is also investigated. Because SHBG binds with both estrogen, an antiresorptive agent, and testosterone, a bone formation agent, lower serum SHBG concentrations may promote a greater bioavailability of estrogens and androgens, which could decrease resorption, stimulate formation and increase BMD. Women who were 3-10 y postmenopausal, aged 55 ± 5.1 y, and taking or not taking hormone replacement therapy (HRT) were randomized into exercise and non exercise groups: (1) No HRT, no exercise; (2) HRT, no exercise; (3) No HRT, exercise; and (4) HRT, exercise. The number of subjects per group at the end of one year was 25, 19, 27 and 20, respectively. The thrice weekly exercise regimen, consisting mainly of weight lifting and weight bearing activities, lasted for 1 y. Vitamin D deficiency was found in 3% of the subjects, Serum 25(OH)D₃ concentrations had inverse relationships with changes in BMD in the femoral neck (P < 0.05) and trochanter (P = 0.07). When subjects were grouped according to HRT status, BMD at baseline and one 1 y was never positively related to serum 25(OH)D₃ concentrations in HRT users, Subjects having greater than 80 nmol/L 25(OH)D₃ had significantly decreased concentrations of serum osteocalcin and urinary deoxypyrodinoline (Dpd) crosslinks (P < 0.05). Exercise had no effect on serum content of 25(OH)D₃. Serum concentrations of SHBG were not significantly related to BMD at any site, nor did they show a decrease with exercise even when HRT status was taken into account. Significant inverse relationships (P < 0.05) were found between SHBG, sex hormone indices (Estrone/SHBG; Estradiol/SHBG) and bone turnover markers, osteocalcin and Dpd crosslinks/creatinine.

Los objetivos de la tesis fueron el estudio y revisión de los actuales conocimientos sobre el metabolismo y las acciones de IGF-I en la producción porcina y más específicamente la investigación de los efectos que un suplemento alimenticio proveniente de la fermentación de la proteína de patata puede tener sobre los niveles de IGF-I en diferentes estadios productivos, y si estas modificaciones tienen alguna repercusión práctica sobre la producción. En el estudio realizado con las cerdas lactantes, el objetivo fue estudiar si la adición en la dieta de las cerdas lactantes durante 5 días antes del destete y 5 días post destete de la proteína fermentada de patata con o sin glucosa tenía algún efecto sobre los días no productivos entre el destete y su cubrición, sobre la fertilidad y sobre el número de lechones nacidos totales en el subsiguiente parto y si estos parámetros productivos estuvieron relacionados con niveles plasmáticos de IGF-I. Para ello se eligió una granja altamente productiva con un alto status sanitario porque se consideró que era la mejor opción para conocer los efectos de la proteína fermentada de patata sobre los parámetros estudiados. Se usaron un total de 183 cerdas de 3 grupos de cerdas destetadas de forma consecutiva y se distribuyeron en 4 grupos de tratamiento teniendo en cuenta el ciclo de parto, el número de lechones destetados en el ciclo anterior y el número de lechones paridos en el ciclo actual. El tratamiento consistió en la adición de la proteína de patata fermentada, con y sin glucosa, que se consideró como el control positivo y un grupo de cerdas que actuó como control negativo al que no se le suministró ningún producto. Los tratamientos se iniciaron 5 días antes del destete y concluyeron 5 días post destete. Se registraron todos los parámetros productivos para alcanzar los objetivos y se obtuvieron muestras de sangre de un subgrupo de cerdas para determinar el nivel de IGF-I. No se encontraron diferencias significativas en cuanto a los niveles de IGF-I al finalizar los tratamientos ni tampoco se encontraron diferencias significativas en los parámetros productivos estudiados. Un hallazgo no contemplado en el estudio pero encontrado en el análisis fue que las cerdas que fueron nodrizas durante la lactación en la que se inició el tratamiento tenían mayor nivel de IGF-I que las que no lo fueron. Este hallazgo confirma que el nivel de IGF-I depende el status nutricional y metabólico de los animales ya que las cerdas que actuaron como nodrizas tuvieron un gasto metabólico menor que las que no lo fueron y pudieron recuperar mejor su status metabólico. A pesar de ello no existieron diferencias de productividad tras el subsiguiente parto. En el estudio con los lechones lactantes el objetivo fue estudiar el efecto de la administración oral de la proteína fermentada de patata a lechones durante las primeras 12 horas tras el nacimiento sobre los niveles plasmáticos de IGF-I, sobre la mortalidad y sobre la ganancia de peso vivo desde el nacimiento al hasta el destete. Este estudio se realizó en una granja con productividad media, con una sanidad considerada como habitual en la producción porcina y que podía ser catalogada como una granja estándar. Se usaron 542 lechones nacidos en 3 grupos consecutivos de parto. Los lechones fueron clasificados según su peso al nacimiento entre lechones grandes, con 1,2 kg de peso o más al nacimiento y lechones pequeños con menos de 1,2 kg de peso al nacimiento porque se consideró que el peso al nacimiento podría ser una variable que influyera en el estudio. Se distribuyeron en 4 grupos de tratamiento dentro de cada grupo de peso. Los tratamientos consistieron en el suministro oral de la proteína de patata fermentada bien en una sola dosificación (primer grupo) o bien partida en media dosis separadas de un intervalo de 12 h (segundo grupo) suministrando a un tercer grupo de animales glicerol en una sola toma, grupo que se consideró como el control positivo. El cuarto grupo fue el control negativo y los lechones de este grupo no recibieron ningún tratamiento. No se encontraron diferencias significativas de forma global ni dentro de cada grupo de peso en ninguna de las variables estudiadas. Los niveles de IGF-I fueron mayores en los animales del grupo de peso grande cuando se compararon con los lechones pequeños a los 7 días del estudio, pero no al finalizar el mismo. En el estudio con los lechones destetados, el objetivo fue estudiar si la adición en la dieta de lechones de proteína fermentada de patata tras su destete en diferentes proporciones podía reemplazar el uso de plasma porcino y si las modificaciones estaban relacionadas con los niveles plasmáticos de IGF-I. Este estudio se realizó en una granja de destete de lechones. Los lechones provenían de la granja utilizada en el estudio de lechones lactantes. Se realizaron dos estudios consecutivos, el primero para conocer los efectos de la proteína de patata fermentada sobre los lechones y el segundo para conocer el nivel necesario de incorporación a las dietas para substituir al plasma porcino. Se usaron 200 lechones en el primer estudio distribuyéndose homogéneamente según su peso y edad al destete y su sexo. Se distribuyeron en 5 grupos de tratamiento donde un grupo fue el control negativo sin plasma ni proteína de patata fermentada, un grupo como control positivo con plasma en la dieta y 3 dosificaciones crecientes de proteína de patata. En el segundo estudio se usaron 1036 lechones distribuidos homogéneamente según su peso y edad al destete y su sexo. Se distribuyeron en 6 grupos de tratamiento donde un grupo fue el control negativo sin plasma ni proteína de patata fermentada, un grupo como control positivo con plasma en la dieta y 4 grupos con cantidades crecientes de proteína de patata fermentada. Los lechones alimentados con plasma en el primer estudio tuvieron el día 4 del mismo un nivel mayor de IGF-I que el resto siendo los lechones que fueron alimentados con la dosis inferior de proteína de patata fermentada los que tuvieron el nivel de IGF-I inferior teniendo el resto de grupos un nivel intermedio de IGF-I. Los lechones que más pienso consumieron fueron los lechones que consumieron el menor nivel de proteína de patata y los que menos los del grupo control negativo. Estas diferencias de consumo no se vieron reflejadas en un mayor crecimiento diario ni en una mejor conversión alimenticia al final del estudio. Los lechones que consumieron proteína de patata tuvieron mayor peso y ganancia media diaria que los animales del control negativo al finalizar el segundo estudio. En cuanto al consumo, los animales con las 3 dosis más bajas de proteína de patata tuvieron mayor consumo que el resto teniendo una mejor conversión alimenticia los lechones que consumieron bien proteína de patata o plasma que los lechones del control negativo. Los resultados de la presente tesis demuestran que el suministro de un suplemento alimenticio derivado de la fermentación de la proteína de patata i) no mejora la productividad de las cerdas en el subsiguiente parto, ii) no mejora la mortalidad de los lechones durante la lactación ni tampoco su peso a destete y iii) puede reemplazar al plasma animal en las dietas de lechones destetados. El nivel de IGF-I no se ve modificado en ningún estudio al suministrar la proteína de patata fermentada por lo que el modo de acción de este producto debe ser investigado con estudios futuros.
Els objectius de la tesi van ser l'estudi i revisió dels actuals coneixements sobre el metabolisme i les accions d'IGF-I en la producció porcina i més específicament la investigació dels efectes que un suplement alimentari provinent de la fermentació de la proteïna de patata pot tenir sobre els nivells d'IGF-I en diferents estadis productius, i si aquestes modificacions tenen alguna repercussió pràctica sobre la producció. En l'estudi realitzat amb les truges lactants, l'objectiu va ser estudiar si l'addició a la dieta de les truges lactants durant 5 dies abans del deslletament i 5 dies post deslletament de la proteïna fermentada de patata amb o sense glucosa tenia algun efecte sobre els dies no productius entre el deslletament i la cobrició, sobre la fertilitat i sobre el nombre de garrins nascuts totals en el subsegüent part i si aquests paràmetres productius van estar relacionats amb nivells plasmàtics d'IGF-I. Per a això es va triar una granja altament productiva amb un alt estatus sanitari perquè es va considerar que era la millor opció per conèixer els efectes de la proteïna fermentada de patata sobre els paràmetres estudiats. Es van usar un total de 183 truges de 3 grups de truges deslletades de forma consecutiva i es van distribuir en 4 grups de tractament tenint en compte el cicle de part, el nombre de garrins deslletats en el cicle anterior i el nombre de garrins parits en el cicle actual. El tractament va consistir en l'addició de la proteïna de patata fermentada, amb i sense glucosa, que es va considerar com el control positiu i un grup de truges que va actuar com a control negatiu al qual no se li va subministrar cap producte. Els tractaments es van iniciar 5 dies abans del deslletament i van concloure 5 dies post deslletament. Es van registrar tots els paràmetres productius per assolir els objectius i es van obtenir mostres de sang d'un subgrup de truges per determinar el nivell d'IGF-I. No es van trobar diferències significatives pel que fa als nivells d'IGF-I en acabar els tractaments ni tampoc es van trobar diferències significatives en els paràmetres productius estudiats. Un resultat no contemplat en l'estudi però trobat en l'anàlisi va ser que les truges que van ser alletants durant la lactació en què es va iniciar el tractament tenien major nivell d'IGF-I que les que no ho van ser. Aquesta troballa confirma que el nivell d'IGF-I depèn l'estatus nutricional i metabòlic dels animals ja que les truges que van actuar com dides van tenir una despesa metabòlica menor que les que no ho van ser i van poder recuperar millor el seu status metabòlic. Malgrat això no van existir diferències de productivitat després del subsegüent part. En l'estudi amb els garrins lactants l'objectiu va ser estudiar l'efecte de l'administració oral de la proteïna fermentada de patata a garrins durant les primeres 12 hores després del naixement sobre els nivells plasmàtics d'IGF-I, sobre la mortalitat i sobre el guany de pes viu des del naixement al fins al deslletament. Aquest estudi es va realitzar en una granja amb productivitat mitjana, amb una sanitat considerada com habitual en la producció porcina i que podia ser catalogada com una granja estàndard. Es van usar 542 garrins nascuts en 3 grups consecutius de part. Els garrins van ser classificats segons el seu pes al naixement entre garrins grans, amb 1,2 kg de pes o més al naixement i garrins petits amb menys de 1,2 kg de pes al naixement perquè es va considerar que el pes al naixement podria ser una variable que influís en l'estudi. Es van distribuir en 4 grups de tractament dins de cada grup de pes. Els tractaments van consistir en el subministrament oral de la proteïna de patata fermentada bé en una sola dosificació (primer grup) o bé partida en mitja dosi separades d'un interval de 12 h (segon grup) subministrant a un tercer grup d'animals glicerol en una sola presa, grup que es va considerar com el control positiu. El quart grup va ser el control negatiu i els garrins d'aquest grup no van rebre cap tractament. No es van trobar diferències significatives de forma global ni dins de cada grup de pes en cap de les variables estudiades. Els nivells d'IGF-I van ser majors en els animals del grup de pes gran quan es van comparar amb els garrins petits als 7 dies de l'estudi, però no al finalitzar el mateix. En l'estudi amb els garrins deslletats, l'objectiu va ser estudiar si l'addició a la dieta de garrins de proteïna fermentada de patata després de la seva deslletament en diferents proporcions podia reemplaçar l'ús de plasma porcí i si les modificacions estaven relacionades amb els nivells plasmàtics d'IGF-I. Aquest estudi es va realitzar en una granja de transició. Els garrins provenien de la granja utilitzada en l'estudi de garrins lactants. Es van realitzar dos estudis consecutius, el primer per conèixer els efectes de la proteïna de patata fermentada sobre els garrins i el segon per conèixer el nivell necessari d'incorporació a les dietes per substituir al plasma porcí. Es van usar 200 garrins en el primer estudi distribuint homogèniament segons el seu pes i edat al deslletament i el seu sexe. Es van distribuir en 5 grups de tractament on un grup va ser el control negatiu sense plasma ni proteïna de patata fermentada, un grup com a control positiu amb plasma en la dieta i 3 dosificacions creixents de proteïna de patata. En el segon estudi es van usar 1036 garrins distribuïts homogèniament segons el seu pes i edat al deslletament i el seu sexe. Es van distribuir en 6 grups de tractament on un grup va ser el control negatiu sense plasma ni proteïna de patata fermentada, un grup com a control positiu amb plasma en la dieta i 4 grups amb quantitats creixents de proteïna de patata fermentada. Els garrins alimentats amb plasma en el primer estudi van tenir el dia 4 del mateix un nivell major d'IGF-I que la resta sent els garrins que van ser alimentats amb la dosi inferior de proteïna de patata fermentada els que van tenir el nivell d'IGF-I inferior tenint la resta de grups un nivell intermedi d'IGF-I. Els garrins que més pinso consumir van ser els garrins que van consumir el menor nivell de proteïna de patata i els que menys els del grup control negatiu. Aquestes diferències de consum no es van veure reflectides en un major creixement diari ni en una millor conversió alimentària al final de l'estudi. Els garrins que van consumir proteïna de patata van tenir més pes i guany mitjà diari que els animals del control negatiu al final del segon estudi. Pel que fa al consum, els animals amb les 3 dosis més baixes de proteïna de patata van tenir major consum que la resta tenint una millor conversió alimentària dels garrins que van consumir bé proteïna de patata o plasma que els garrins del control negatiu. Els resultats de la present tesi demostren que el subministrament d'un suplement alimentari derivat de la fermentació de la proteïna de patata i) no millora la productivitat de les truges en el subsegüent part, ii) no millora la mortalitat dels garrins durant la lactació ni tampoc el seu pes a deslletament i iii) pot reemplaçar al plasma animal en les dietes de garrins deslletats. El nivell d'IGF-I no es veu modificat en cap estudi al subministrar la proteïna de patata fermentada per la qual cosa la manera d'acció d'aquest producte ha de ser investigat amb estudis futurs.
The objectives of this thesis were the study and review of the current knowledge about the metabolism and actions of IGF-I in pig production. The thesis also studied the effects that an additive coming from the fermentation of the potato protein can have on the IGF-I levels in the different pig production phases and if these modifications have some practical consequence in the pig production. In the lactating sows study, the objective was to assess if the introduction of the fermented protein potato in the diet of the sows 5 days before and 5 days after weaning, with or without glucose, had some effect on the non-productive days between weaning and mating, the fertility and the number of piglets total born in the subsequent litter, and if these productive parameters were in relation with plasma IGF-I levels. It was chosen a high productive sow farm with a high health status because it was considered the best option to assess the effects of the fermented protein potato over the studied parameters. 183 sows coming from 3 consecutive weaned batches sows were distributed in 4 treatment groups taking into account the parity, the number of piglets weaned in the former litter and the number of piglets born in the current litter. The dietary treatments were arranged as a 2x2 complete factorial design with the factors being the addition or not of fermented protein potato and with or without glucose. The treatment started 5 days before weaning and ends 5 days after weaning. There were recorded all the production parameters to get the targets and blood samples were obtained from a subgroup of sows to analyze IGF-I level. No statistical differences were found in IGF-I levels at the end of the treatment nor in the productive parameters recorded. An outcome not considered in the design of the study was that nursing sows had higher IGF-I levels. This finding confirms that IGF-I level depends on the nutritional and metabolic status. Sows that were nursing an extra litter (small piglets) in the current lactation had lower metabolic expense that normal sows during the nursing time and there could recover their metabolic status. In spite of, there were not found productive differences in the next parity. In the study with milking piglets the objectives were to assess if the oral administration of the fermented potato protein in piglets during the first 12 h of live had some effects on the plasma levels of IGF-I, the pre weaning mortality and the average daily gain from birth to wean. This study was carried out in a sow farm with the country average production, with a standard health status. 542 piglets from 3 consecutive batches were used. Piglets were classified into two groups depending on their weight at birth because it was considered that weight at birth could influence the results. The cut-off weight was 1.2 kg. The treatments were: a single oral dose of fermented protein potato, a split half dose in 12 h interval of fermented protein potato, and a group of piglets that received glycerol as positive control group. One group of piglets with no treatment was considered negative control group. No differences were found in any group neither of treatment nor within the weight groups. IGF-I levels were higher in heavier piglets at 7 day of study but not at the end. In the study with weaned piglets the objectives were to assess if the introduction in the diet of the fermented potato protein in weaned piglets at different ratios could substitute the use of animal plasma and if this modification was linked with the plasma level of IGF-I. This study was carried out in a nursery using piglets from the sow farm used in the milking piglets study. There were conducted 2 consecutive experiments. The first of them was carried out to assess the effects of the fermented protein potato on the productive parameters and the second to assess the level to substitute animal plasma. In the first experiment, 200 piglets were distributed taking into account their age, sex and weight at weaning in 5 experimental groups. One group was considered as negative control group with neither fermented protein potato nor animal plasma, one group was the positive control group with animal plasma and 3 other groups with different levels of fermented protein potato. In the second experiment, 1036 piglets were distributed taking into account their age, sex and weight at weaning in 6 experimental groups. One group was the negative control group without animal plasma or fermented protein potato, one group as positive control group with animal plasma and 4 groups with increasing ratios of fermented protein potato. IGF-I levels at day 4 of the first study were higher in piglets fed with animal plasma being the lowest IGF-I level for the piglets fed the lower ratio of fermented protein potato. The rest of the groups had intermediate IGF-I levels. The highest daily feed intake was achieved by the piglets fed with the lowest ratio of fermented protein potato. This high daily feed intake was not achieving a high daily gain or a better feed conversion ratio at the end of the study. Piglets fed with fermented protein potato were heavier and growth faster than piglets in the negative control group at the end of the second study. The highest daily feed intake was achieved by the piglets fed the 3 lower doses of fermented protein potato. Feed conversion ratio was improved in piglets fed either fermented protein potato or animal plasma than piglets in the negative control group. The results of the studies of this thesis show that feeding a fermented protein potato i) do not improve the productivity of the sows in the subsequent parity, ii) do not improve pre weaning piglet mortality nor their weaning weight, iii) can substitute animal plasma in the post weaning diets. The IGF-I levels were not modified in any study when fermented potato was administered orally either to weaned sows, pre weaning piglets or weaned piglets. The mode of action of fermented protein potato should be researched in future experiments.

L’Ovum Pick-Up (OPU) et la production d'embryons in vitro représentent une voie d’accélération du progrès génétique par la voie femelle. Ces techniques impliquent en autre la collecte d’ovocytes de qualité pour produire des embryons transférables. La qualité des ovocytes et les taux de développement embryonnaire in vitro sont impactés par la nutrition des donneuses avant OPU, les effets étant médiés par plusieurs métabolites et hormones impliqués dans la régulation du métabolisme énergétique. Les niveaux plasmatiques d'insuline et d’IGF1 accrus sont corrélés aux niveaux des apports énergétiques chez les génisses laitières. Les régimes augmentant les concentrations d'insuline influencent négativement la qualité des ovocytes. Néanmoins, une augmentation des concentrations d'insuline stimule en quelques jours le nombre des petits follicules. Ces résultats ont conduit à formuler l’hypothèse d’une modulation transitoire des concentrations d'insuline chez les donneuses d’ovocytes basée sur l'administration orale de propylène glycol (PG). En effet, le PG augmente les concentrations d'insuline et d’IGF-1 dans le plasma chez la vache au cours du post-partum. L’hormone antimüllérienne (AMH) est un marqueur endocrinien de la réserve de follicules ovariens sensibles aux gonadotrophines chez la vache. Il a été récemment établi que les concentrations plasmatiques d'AMH aident à prédire la réponse des donneuses d’embryons collectés in vivo. Dans cette thèse, nous avons étudié l'effet de l'administration de PG à court terme sur les niveaux d'insuline, la croissance folliculaire, la réponse à la stimulation de la croissance folliculaire au traitement FSH et la production d'embryons in vitro après OPU chez les génisses avec différents profils d’AMH circulante (haut H vs bas B). La relation entre la dose de PG chez les génisses laitières et la réponse à l'insuline a été établie, ainsi que les relations avec les concentrations plasmatiques d’hormones et métabolites du métabolisme énergétique. Puis, le nombre et la qualité morphologique des ovocytes et des embryons produits ont été déterminés chez les génisses donneuses ayant une alimentation restreinte. Enfin, les profils d'expression de gènes du système IGF dans les ovocytes et les cellules du cumulus et de gènes candidats de survie embryonnaire chez des blastocystes ont été évalués.Nos données ont montré que l'administration de PG chez les génisses laitières est associée à une élévation des concentrations plasmatiques d’insuline, d'IGF1 et de glucose et à une diminution de celles de β-hydroxybutyrate (BHB) et d’urée. Les concentrations d’IGF1 dans le liquide folliculaire ont augmenté. De plus, l’administration de PG a été associée à un nombre plus élevé de petits follicules (2- 3mm) le 2ème jour du cycle œstral par rapport au lot contrôle. Cet effet positif a été maintenu sur le nombre de follicules moyens (4-8mm) le 5ème jour du cycle, après stimulation de la croissance folliculaire dans le groupe AMH H. En outre, une augmentation significative du taux de blastocystes de qualité 1 après 7 jours de culture in vitro (exprimés en pourcentage d'ovocytes fécondés) a été observée chez les génisses du lot PG par rapport au lot contrôle. L’administration de PG a conduit au développement d’un nombre plus élevé de blastocystes épanouis le 7ème jour du cycle par rapport au contrôle, uniquement dans le groupe AMH H. De plus, le PG a modifié les profils d'expression des gènes du système IGF dans les cellules du cumulus et des gènes de survie étudiés chez les blastocystes. Par conséquent, nos données montrent que l'administration de PG a amélioré la production et la qualité des embryons in vitro, peut-être en raison des modifications du système IGF1 induites par le PG en début de vague folliculaire. Celles-ci pourraient moduler l'environnement folliculaire et impacter l’expression des gènes y compris jusqu'au stade blastocyste, l’effet étant cependant plus marque chez les génisses a profil haut d’AMH
The ovum pick-up and in vitro embryo production method in heifers can accelerate the speed of genetic progress through the female line. However, to be effective it requires high numbers of usable oocytes to be collected and high numbers of transferable embryos and high embryo survival after cryopreservation to ensure the maintenance of pregnancy after transfer. The variability in the quality of oocytes and embryo development rates in vitro may be influenced by the dietary intake of donor cattle before oocyte recovery and may be related to the concentrations of metabolites and hormones involved in regulating energy metabolism: in particular, increased levels of insulin and IGF1 were associated with high energy intake in dairy heifers. Moreover, in heifers, it was shown that diets that increase insulin concentrations negatively influence the quality of oocytes. However an increase in insulin concentrations over a short lapse of time has a positive effect on the growth of small follicles prior to superovulatory treatment. These findings support the idea that it may be possible to modulate insulin concentrations transiently to improve reproductive success. The addition of propylene glycol (PG) to the diet increases the concentrations of insulin and IGF1 in plasma in cows during the post-partum period. Anti-müllerian hormone (AMH) is an endocrine marker of the size of the pool of ovarian gonadotrophin-responsive follicles in the cow, and plasma AMH concentrations measured before stimulation of follicular growth with FSH hormone treatment can help predict the response of individuals. In this thesis, we investigated the effect of shortterm PG administration to modulate the levels of insulin, follicular growth, the superovulatory response and in vitro embryo production after OPU in heifers with different pre-experimental circulating AMH profiles (high, H vs. low, L). Firstly, the relationship between the dose of propylene glycol in dairy heifers and the insulin response was established. Secondly, the number and morphological quality of oocytes and embryos produced with and without a supplement of propylene glycol in feed-restricted heifers were determined. Thirdly, the gene expression patterns of the IGF system in oocytes and cumulus cells and the expression profile of selected candidate genes that are important for in vitro embryo development were evaluated. Plasma concentrations of some hormones and metabolites and their relationship with PG were also studied.Our data show that administration of PG increased plasma insulin, IGF1 and glucose concentrations and decreased plasma β-hydroxybutyrate (BHB) and urea concentrations in feed-restricted heifers. PG as an oral drench also increased IGF1 concentrations in follicular fluid. In addition, PG increased the number of small (2–3mm) follicles on Day 2 during the first follicle wave in both AMH groups (H and L) compared with the control treatment (water drench). PG only continued to have a positive effect on the number of medium (4–8mm) follicles on Day 5 after stimulation of follicular growth in the AMH H group. Additionally, there was a significant increase in Day 7 Grade 1 blastocysts (expressed as a percentage of fertilized oocytes) after PG compared with control treatment in both AMH groups of heifers. PG increased the number of expanded blastocysts at Day 7 compared with control but only in AMH H and not AMH L heifers. Additionally, PG modified the gene expression pattern of the IGF system in cumulus cells and produced changes in gene expression in blastocysts. Consequently, our data showed that PG administration is effective in improving in vitro embryo production probably due to the existence of epigenetic regulation induced by PG during follicular growth in the IGF1 system. This regulation system may modulate the follicular environment and level of gene expression up to the blastocyst stage more markedly in heifers with high compared to low AMH levels

The metabolic hormones ghrelin, growth hormone, and insulin-like growth factor I are influenced by developmental age, sex, and nutritional status in domestic and free-ranging species. However the role these hormones play has not previously been explored in sub-tropical/ tropical mammals. Furthermore, the seasonality of species with less dynamic environmental cues, such as the West Indian manatee, have not been studied. The West Indian manatee is and endangered species distributed in the southeastern United States and throughout the Caribbean basin, and its nutritional physiology is influenced by environmental factors. Understanding the hormone response to nutritional status in this species and its seasonality will enhance our knowledge of the links between season, nutrition, and life history. The purpose of this research is to understand the biology and seasonal patterns of metabolic hormones in free-ranging manatees which will allow us to assess the nutritional status of wild populations. The research objectives include validation assays to accurately quantify hormone concentrations in manatees. Hormones were quantified in manatee serum using heterologous radioimmunoassay. Hormones were then evaluated between summer, fall, and winter and compared to body composition. Developmental patterns were also assessed. Lastly, hormones were examined between Florida and Antillean manatee populations. Manatees exhibited differences in GH, IGF-I, and body composition demonstrating seasonality similar to other species. Manatees exhibited differences between age classes suggesting decreased growth rate as the animals age. Differences were detected between populations. This research suggests that ghrelin, GH, and IGF-I can be used to indicate nutritional status and detect seasonality and developmental age in the manatee. This could prove to be a valuable tool in rehabilitation facilities and during captures and health assessments to provide better veterinary care and further improve overall health and body condition to better manage the survival of the species.

The lifespan of an organism is determined by a complex array of genetic, environmental and nutritional factors. Yet single gene manipulations have been shown to significantly extend lifespan in several model organisms. Of all the genes that have been studied thus far, components of the insulin/IGF-1 signaling (IIS) pathway have emerged as the most robust regulators of longevity. In addition, IIS also regulates development, energy metabolism and the response to stress in a conserved manner. In Caenorhabditis elegans, signaling through this pathway is initiated by activation of the insulin/IGF-1 receptor tyrosine kinase DAF-2, which then activates a PI3-kinase signaling pathway involving additional downstream serine/threonine kinases such as PDK-1, AKT-1, AKT-2 and SGK-1. The concerted action of these kinases results in the negative regulation of the single FOXO transcription factor homolog DAF-16. Under reduced signaling conditions, active DAF-16 is able to translocate into the nucleus and regulate the expression of hundreds of genes regulating longevity, stress resistance, metabolism and development. The PTEN phosphatase homolog DAF-18, which antagonizes IIS at the level of PI3-kinase, is a major negative regulator of the pathway. However, not much was known about additional phosphatases that negatively regulated the kinases in the pathway. Dephosphorylation is a critical regulatory mechanism by which cellular signaling homeostasis is maintained. Aberrant hyper-activation of growth factor signaling pathways, including IIS, has been implicated in several cancers. In addition, deregulation of IIS is also closely linked to Type II diabetes. Therefore, the identification phosphatases that balance kinase activity will provide a better understanding of the regulation of the IIS pathway under normal as well as disease conditions. A directed RNAi screen using dauer diapause was conducted in our lab to identify serine/threonine phosphatases that modulated IIS. My work in the Tissenbaum Lab has primarily focused on characterization of the top three candidates from this screen, the genes pptr-1, pdp-1 and fem-2. From these studies, we have also uncovered novel crosstalk between the IIS and TGF-β signaling pathways. In Chapter 2, we demonstrate that PPTR-1, a PP2A phosphatase regulatory subunit negatively regulates the IIS pathway by modulating AKT-1 dephosphorylation. PPTR-1 modulates several outputs of IIS similar to DAF-18. In addition, PPTR-1 co-localizes and physically interacts with its substrate, AKT-1. PPTR-1 modulates dephosphorylation of AKT-1 at a conserved threonine site and we show the molecular conservation of this interaction in mammalian adipocytes. Ultimately, this negative regulation by PPTR-1 results in increased DAF-16 nuclear localization and transcriptional activity. Next, in Chapter 3, we show how PDP-1 is a novel link between the IIS and TGF-β signaling pathways. Similar to DAF-18 and PPTR-1, PDP-1 regulates multiple outputs of the IIS pathway and promotes DAF-16 activity. Interestingly, PDP-1 acts at the level of DAF-8 and DAF-14, two R-SMAD proteins that function in a TGF-β pathway. Our data suggests that PDP-1 may negatively regulate TGF-β signaling to downregulate the expression of several insulin(s). Without the insulin ligands, there is less activation of the IIS pathway, and DAF-16 is more active, thereby promoting transcription of genes that act to enhance longevity and stress resistance. In Chapter 4, we investigate possible crosstalk between IIS and the TGF-β signaling pathways, as the latter was previously considered as a parallel independent pathway. From our studies on PDP-1, we knew that this phosphatase, despite acting in the TGF-β pathway, was a robust modulator of multiple outputs of IIS. Using double mutant combinations as well as RNAi we unravel complex and extensive crosstalk between the two pathways. Importantly, our results suggest that DAF-16 is likely to be the most downstream component of the two pathways. In Chapter 5, we describe genetic characterization of fem-2, and its regulation of the IIS pathway. RNAi of fem-2 results in robust suppression of dauer formation, similar to pptr-1 and pdp-1 RNAi but this phenotype is only observed in the e1370 allele of daf-2. While knockdown of pptr-1 and pdp-1 suppress dauer formation of additional alleles of daf-2, fem-2 RNAi has no effect. These results reveal a complex genetic interaction between fem-2 and the daf-2 receptor. Taken together, our results identify several novel regulators of IIS that modulate this pathway by distinct mechanisms.

Breast cancer is a leading cause of cancer and the second leading cause of cancer death among women in the US. Although many risk factors for breast cancer are known, few are modifiable and little is known about ways to prevent its incidence. Early-life body size is inversely associated with both premenopausal and postmenopausal breast cancer risk, suggesting an excess risk in lean girls. In a prospective analysis within the Nurses’ Health Study (NHS) II, Chapter 1 examines whether adolescent physical activity mitigates the excess risk of breast cancer associated with early-life body leanness. Lean girls were at higher risk of breast cancer, regardless of the level of adolescent physical activity; however, the association was slightly, though not significantly, attenuated among the most active girls. Breast cancer is hormone-related cancer; estrogen metabolites (EM) are both estrogenic and genotoxic, suggesting factors that alter the pattern of estrogen metabolism may contribute to breast carcinogenesis. With the application of advanced technology that measures 15 different individual estrogens and EM in urine, Chapter 2 examines the associations of dietary fiber and macronutrients intake with detailed estrogen metabolism in a cross-sectional analysis within the NHSII. Few significant associations were identified: a positive association between total fiber intake and 4-methoxyestradiol, an inverse association between total fiber intake and 17-epiestriol, and inverse associations for polyunsaturated and trans-fat intakes with 17-epiestriol. The tissue-specific responsiveness to potentially carcinogenic hormones, estrogen and progesterone, is partially regulated by the tissue expression of receptors that bind these hormones. Using benign breast biopsy samples collected in a nested case-control study within the NHS and NHSII, Chapter 3 assesses estrogen receptor (ER), progesterone receptor (PR), and proliferative marker Ki67 expression in normal breast tissue in relation to subsequent breast cancer risk. In this case-control analysis, PR expression in normal breast tissue was significantly positively associated with breast cancer risk in premenopausal women. ER and Ki67 expression was not significantly associated with breast cancer risk; however, our power was limited. Results of this dissertation help elucidate the underlying biologic mechanisms of breast cancer and enhance our understanding of the link between risk factors and breast cancer risk.

Once seen as a disease of wealthy nations, type 2 diabetes mellitus is now showing unprecedented growth throughout the world, fueling increases in microvascular and macrovascular complications. A compelling and growing body of evidence suggests that glucose intolerance and insulin resistance, hallmarks of the diabetic patient, may be driven by chronic inflammation. In particular, a predominance of visceral fat has been associated with enhanced inflammatory cytokine secretion that may contribute to enhanced risk of diabetes and comorbid cardiovascular disease in these individuals. As a function of its potency and wide environmental and biological distribution, we hypothesized that bacterial lipopolysaccharide (LPS, also known as endotoxin) may promote adipose inflammation and concomitant metabolic dysfunction. Indeed, expression of the LPS receptor CD14 is enhanced on visceral adipocytes of ob/ob mice, paralleling enhanced IL-6 secretion ex vivo. Furthermore, rosiglitazonefed ob/obmice demonstrated a reduction in CD14 that coordinated with diminished IL-6 secretion, suggesting a basis for the touted anti-inflammatory effects of this commonly employed type 2 diabetes medication. Mice deficient in components of the LPS signaling cascade, namely CD14, TLR4, and MyD88, yielded adipocytes with markedly attenuated IL-6 secretion, corroborating the central importance of LPS in adipocyte inflammation and supporting the role of this signaling pathway in depot-specific inflammation. Despite the prominent role of LPS signaling in adipocyte inflammation, CD14-, TLR4-, and MyD88-deficient mice failed to show resistance to diet induced obesity. Surprisingly, cd14-/- and tlr4-/- mice had marked glucose intolerance without alteration in total weight or adipose accumulation. In contrast, myd88-/- mice revealed minor glucose intolerance only with high fat diet challenge at an advanced age despite being overtly obese. In cd14-/- and tlr4-/-, but not myd88-/-, mice, an exaggerated rebound to hypoglycemia was associated with enhanced norepinephrine secretion, which could be abrogated by the adrenergic β-blocker propranolol. The overlay of these mouse models reveals a divergence of phenotypes that demonstrate LPS signaling disruption may lead to glucose intolerance and insulin resistance in part due to enhanced sympathoadrenal tone, uncovering an essential role of innate immunity in physiological stress and its impact upon glucose homeostasis.

Bibliography: leaves 186-200. Analyses feed intake and growth data from cattle, which indicates that genetic variation exists in post-weaning effiency and growth. Concludes with a consideration of how post-weaning feed intake information can be used in genetic improvement programs.

Nutrition has profound effects on reproductive performance in cattle. Although these effects have been documented, the underlying mechanisms are not yet fully understood. The aim of this project was to investigate the role of metabolic hormones, in mediating these nutritional effects, by studying bovine folliculogenesis. The interaction of metabolic hormones and gonadotrophins on granulosa cell function in vitro was also investigated. To determine the effect of nutrition on ovarian follicular development, twenty-eight heifers were allocated to different dietary treatments. Small follicle number (< 4 mm) was increased by 37% on days 1 and 2 of the oestrous cycle in heifers consuming twice maintenance requirements (2M). Insulin concentrations were higher in 2M than in control or feed-deprived heifers. The increased small follicle number was independent of changes in peripheral FSH and insulin-like growth factor-I (IGF-I), negatively associated with growth hormone (GH) but positively associated with circulating insulin. Number of medium-sized (4 to 8 mm) and large (> 8mm) follicles and FSH concentrations were not different among treatments. The relationship between follicular development postpartum and endocrine and metabolic changes in lines selected for high or low predicted breeding value for milk yield (PVB) was investigated. PVB was strongly correlated with milk production during a 305 day-lactation. This was associated with higher peripheral GH and β-hydroxybutyrate and lower insulin and glucose concentrations in high genetic merit cows. Although no differences were seen in follicular development between selection lines, changes in body weight influenced follicle number, and day to first ovulation postparum was delayed in cows selected for high milk production. To gain an insight into the mechanisms underlying the nutritional effect of folliculogenesis, a serum-free (SF) bovine granulose cell culture system was developed. In the presence of FSH, granulosa cells from small follicles differentiated in vitro and oestradiol (E₂) secretion increased with time. Cells from medium-sized large follicles secreted E₂ throughout the culture period. Insulin and FSH promoted proliferation and E₂ production in a dose-responsive manner. The inclusion of IGF-I enhanced proliferation and E₂ production, even in the absence of FSH. Furthermore, cultured granulosa cells formed clumps of spherical cells with ultrastructural characteristics that resembled those of granulosa cells in vivo. In contrast, granulosa cells growing either in the base of the clump, or as monolayers on serum-coated wells, possessed morphological characteristics suggestive of early luteinisation.

Master of Science
Department of Animal Sciences and Industry
Timothy G. Rozell
Timothy G. Rozell
An increase in pre-mating dietary energy positively influences ovulation and lambing rates, and this practice is known as nutritional flushing. The mechanisms of flushing, however, are still unknown. Increasing dietary energy approximately two weeks before breeding likely increases the production of insulin-like growth factor I (IGF-I) within the ovary, which stimulates the synthesis of follicle stimulating hormone receptor (FSHR). Several alternatively spliced transcripts of the FSHR have been identified in sheep. Each variant form is believed to be produced according to the stage of follicle development. This study was carried out to evaluate expression patterns of the FSHR variant forms (FSHR-1, FSHR-2 and FSHR-3) in the sheep ovary in response to different flushing diets. For this experiment, yearling Rambouillet ewes (n=93) were allocated among 6 different energy type treatment diets, either prairie or alfalfa hay based, for at least two weeks in combination with the insertion of a controlled internal drug releasing device (CIDR). Two of the treatment groups had commercially available block supplements provided and two had rolled corn supplemented. Mid-ventral laparotomy was performed on each ewe 3.5 to 4 days after CIDR removal. Follicles 4 mm and greater were aspirated and categorized as either medium (M; 4 to 6 mm) or large (L; > 6 mm). Total RNA was extracted from granulosa cells (GC) and reverse transcribed followed by qPCR of the resulting cDNA using specifically designed primer sets for each variant of the FSHR and for the LH receptor. Changes in live weight were different (P < 0.01) between treatment diets but there were no statistical differences for NEFA concentrations between any of the treatments nor were there differences for body condition (mean = 3.0) or lambing rate. Therefore, it is likely a flushing response did not occur in this study. Expression of FSHR-1was different between M and L follicles (P < 0.01) and tended to be different for ewes fed alfalfa hay (P = 0.05). Overall mean expression of FSHR-3 was greater than expression of FSHR-1 or FSHR-2 (P < 0.01), although there was no difference between M and L follicles, or between treatment diets. The concentration of estradiol in follicular fluid was not different between the treatment diets or follicle sizes nor was expression of lutenizing hormone receptor (LHR), indicating that follicles were similar developmentally. The FSHR-1 form seemed to be the variant most likely to be involved in later stages of follicular development, and is potentially involved in follicle rescue. For all follicles, FSHR-3 was the more highly expressed form of the FSHR and may likely be essential throughout antral follicle development. Further research is required to determine the exact mechanism whereby initial energy status of ewes seems critical for the increased ovulation rate that occurs after energy supplementation (i.e. the flushing response).

The concentrations of calcium and phosphorus were determined in 12 llamas from the Condoriri Agricultural Experiment Center (Oruro Technical University) of Oruro, Bolivia during two seasons (wet and dry) and at three ages (newborn, juvenile, and adult). Samples of flesh were taken from the arm, leg, back, rib, and neck. Pasture samples (grassland and prairie) were used to determine the rate of biting of each animal studied. The blood samples were taken by extracting blood from a jugular vein. The minerals (Ca and P) in the flesh are highest in the wet season, 113.78 mg/100 g. The newborns were found to have the highest concentrations of minerals during the wet and dry season, 113.78 and 93.98 mg/100 g. The mineral concentrations of calcium and phosphorus for the newborns and adults were 120.58 and 144.5 mg/100 g. The lower concentration of juveniles had 7.52 mg/100 g of calcium in the meat and reported a 9.59 mg/100 g concentration during the wet season and 6.78 mg/100 g for the dry season. The juveniles and adults recorded higher concentrations of calcium with 9.2 and 8.78 mg/100 g with the newborns having a lower value of 6.58 mg/100 g. The phosphorus in the flesh was reported to be 9.59 mg/100 g for the wet season and 6.78 mg/100 g for the dry season. The concentration of the calcium and phosphorus in the grazed pasture during the wet and dry seasons was 0.56 and 0.12 % respectively. The females recorded higher concentrations of calcium and phosphorus with 0.38% while the males recorded only a 0.30% concentration. The calcium content is higher in the pasture (0.55%) than the phosphorus (0.13%). In the wet season the biomass contains 0.91% calcium and 0.22% phosphorus. During the dry season the high calcium content was 0.19% and for phosphorus it was 0.04%. The calcium and phosphorus exist in smaller quantities in the blood during the wet season (7.25 mg/dl) and greater quantities during the dry season (9.88 mg/dl). Juvenile females have a higher quantity of calcium (10.15 mg/dl) while newborns and adults have a lower quantity (9.52 and 7.2 mg/dl).

Metabolic complications of obesity are mainly linked to body fat distribution. Since body fat distribution is sex-linked, understanding the role of sex hormones in body fat distribution and storage is important. The acylation stimulating protein (ASP) is a novel lipogenic factor that is suggested to be influenced by hormonal changes. The aim of the present study was to investigate the effect of sex steroid hormones on ASP production and related gene expression, by using adipose tissue explants isolated from ovariectomized rats and the 3T3-L1 cell line generated from mouse embryonic fibroblast cells. In ex vivo studies, 3-way ANOVA analysis showed an effect of hormones, fat depots and chylomicrons interactions on ASP production (p=0.005). Further analysis demonstrated that progesterone and estrogen (P&E) treatment stimulated ASP production (p=0.006) in comparison to estrogen group in subcutaneous adipose tissue explants. In the presence of chylomicrons, visceral adipose tissue explants incubated with P&E showed increased ASP secretion by 54% (p=0.003). The same treatment led to a significant reduction of ASP concentration in subcutaneous explant media (32% lower, P=0.03). C5L2 protein expression were more affected by hormone and chylomicrons interaction (p=0.025). The expression of C5L2 protein increased significantly by P&E treatment (p=0.04) in comparison to the control group in subcutaneous tissue explants. Fat depots and chylomicrons interaction showed a significant effects on effect on ASP’s precursors C3 (p=0.003), factor B (p=0.009) and adipsin (p=0.001) mRNA expressions. DGAT1 have shown to be influenced by hormone and chylomicrons interactions (p=0.3) with no interaction effect on LPL mRNA expression. Using 3T3-L1 cells, high doses of progesterone in the presence of estrogen significantly induced ASP production (p< 0.001). C5L2 protein expression increased in dose-dependent manner with progesterone or estrogen treatments. Treatment of 3T3-L1 adipocyte cells with P&E and chylomicrons had no effect on ASP production. Estrogen receptors (ERs) blockade increased the gene expression of C5L2 and PLC significantly by 5-fold. In summary, female steroid hormones (P&E) may regulate fat distribution through their effects on ASP and C5L2 in subcutaneous adipose tissue. Chylomicrons modulated the ASP responses to P&E treatment in this tissue. P&E interaction with ASP was proven to be regulated through their receptors (PR and ERs) in 3T3-L1 adipocytes. These results demonstrated an important role of female sex steroid in fat distribution and adipocyte lipid metabolism by mediating ASP- C5L2 pathway. Therefore ASP is an important lipogenic factor that, under normal female hormonal states, may reduce the metabolic health risk in women.

Ce travail se propose d'étudier l'impact de modifications nutritionnelles imposées à des femelles gestantes sur le statut peptidique et le bilan hormonal des descendants. Pendant la deuxième moitié de leur gestation, des rates sont nourries la nuit avec un régime équilibré recevant les deux tiers de leur besoin energetique. Le jour, elles ont la possibilité de compléter leur prise calorique par un régime riche en glucides (groupe G), ou en lipides (L), ou équilibré (Cr). Un autre groupe est nourri ad libitum jour et nuit avec le régime équilibré (Ca). Les ratons Cr et G naissent avec un déficit pondéral. Les rats Cr gardent toute leur vie une tendance à être plus maigres. Les animaux G parviennent à rattrapper leur déficit pondéral et montrent même une propension à l'obésité à l'âge adulte. Les rats L ne soufrent d'aucun problème de poids. Au sevrage, les animaux G surexpriment NPY et AgRP. Adultes, ces rats G présentent des taux plasmatiques élevés de glucose, d'insuline et de leptine. Malgré ces concentrations élevées, le système à NPY et AgRP du noyau arqué de l'hypothalamus n'est pas inhibé, contrairement aux neurones produisant la POMC. Ces rats possèderaient donc une resistance centrale aux hormones periphipheriques
We studied the consequences of nutritional manipulations during gestation on hormones and peptides offsprings status. From half gestation, female rats were fed on an adequate well-balanced diet for two third of their energy needs. They were offered the possibility to complete their energy intake through the ingestion of a diet either rich in carbohydrate (HC group) or in fats (HF) or the well-balanced diet (Cr). A other group (C) was fed ad libitum on the balanced diet. At birth, HC and Cr pups were lighter than C and HF pups. At adult age, Cr rats remained lighter while HC tended to be heavier. HF animals did not have any weight problem. At weaning, NPY and AgRP mRNA expression in the arcuate nucleus was significantly higher in the HC pups. In these rats at adulthood, glucose, insulin and leptin plasma levels were increased. Despite this, NPY and AgRP hypothalamic system was not down-regulated while POMC neurons were. We concluded that a central leptin and insulin resistance could exist in these overweight HC rats

Kyoto University (京都大学)
0048
新制・課程博士
博士(人間・環境学)
甲第18366号
人博第679号
新制||人||163(附属図書館)
25||人博||679(吉田南総合図書館)
31224
京都大学大学院人間・環境学研究科共生人間学専攻
(主査)教授 林 達也, 教授 森谷 敏夫, 教授 石原 昭彦, 教授 津田 謹輔
学位規則第4条第1項該当

An increasing amount of people have their work hours displaced to the night and there are indications that shift work and other irregular working schedules are associated with an increased risk of developing the metabolic syndrome and other pathological conditions. It is therefore important to address the consequences of eating at irregular hours, especially nighttime. Papers I-III refer to a study in which 7 males were given a high-carbohydrate diet (HC) or a high-fat diet (HF), using a cross-over design. Subjects were kept awake for 24 h and food was provided as 6 equally spaced isocaloric meals. Higher energy expenditure and non-esterified fatty acids (NEFA) concentration, as well as lower glucose and triacylglycerol (TAG) concentrations were observed with the HF-diet, compared to the HC-diet. With the HF-diet, fat oxidation, heat release, heart rate, glucose, NEFA and TAG concentrations differed depending on time of day. The highest postprandial TAG concentrations were seen after the 04.00 meal with both diets. Insulin and leptin responses to meal intake differed with respect to diet and time of day. Time of day affected glucagon, thyroid stimulating hormone, free thyroxin, total triiodothyronine (tT3), cortisol, chromogranin A and pancreatic polypeptide (PP) concentrations. PP’s postprandial increase was greater during 08.00 – 16.00 compared to 20.00 – 08.00. Furthermore, the subjects felt less irritated when eating the HF-diet but hunger was not related to macronutrient composition. Hunger and thirst decreased throughout the 24 h period despite constant activity and energy intake; and were correlated with several endocrine and metabolic variables. In paper IV 7 males were studied twice during 24-h either given 6 isocaloric meals throughout the 24-h period, or 4 isocaloric meals from 08.00 to 20.00, followed by a nocturnal fast. Energy expenditure, glucose, TAG, insulin and glucagon concentrations were lower; and NEFA concentrations were higher during the nocturnal fast compared to nocturnal eating; although no 24 h differences between the protocols were apparent. The subjects were more passive during the fasting period compared to when food was given. Stepwise regression showed that correlations between metabolic variables and hormones differed between daytime and nighttime. The decreased evening/nocturnal responses of cortisol and PP to meal intake suggest that nocturnal eating might have health implications and that the body reacts unfavorably to nocturnal eating. Smaller meals around the clock, however, showed marginally better effects on postprandial TAG concentrations and mental energy compared to larger meals during daytime. Further studies (long term) are needed before dietary guidelines can be given to shift workers, especially regarding the impact of nocturnal eating on gastrointestinal response and cortisol.

The effect of a low-Cu diet supplied to gilts during pregnancy and early lactation on dams and their offspring was obtained in seven pairs of first littermate gilts. They were housed in stainless steel metabolism cages in a controlled environment and fed semi-purified diets containing either 2.13 or 12.25 ppm Cu from 30 days of gestation through two weeks of lactation. Feed intake was restricted to 2 kg/day during pregnancy and 4 kg/day in the first two weeks of lactation. Reproductive performance of gilts was measured. Balance studies were conducted at 30, 60 and 100 days of gestation. Mineral levels in the plasma of gilts and piglets, and in colostrum and milk were determined. The low-Cu diet did not affect (p $>$ 0.05) weight changes during pregnancy. The duration of parturition was shorter for low-Cu than for control gilts (3.19h vs 5.71h, p 0.05). Low-Cu gilts had lower plasma Cu in early- and mid-gestation and farrowed piglets with lower plasma Cu and higher plasma Zn concentrations (p 0.05). Plasma Cu and Fe levels of newborn piglets were lower than those of their dams (p 0.05). Low-Cu gilts had lower Cu and higher Zn content in colostrum and also lower Cu in milk than control gilts (p 0.05). Colostrum was richer in Cu and Zn than milk (p 0.05). Higher dry matter digestibility was observed in low-Cu gilts during early gestation (p 0.05). Compared to control gilts, the low-Cu gilts tended to have higher Cu and Zn retention which was achieved by reduction of fecal Cu and Zn excretion. Utilization of minerals appeared to increase as pregnancy progressed.

The interaction effects of genotype and nutrition on the performance of sows during lactation is still poorly understood; this series of experiments explored the factors contributing to breed differences in lactational performance and the development of appropriate feeding strategies. Two extreme types of sow were used in these experiments; lean pure-bred White sows (W: Large White and Landrace) and a prolific but fatter Meishan synthetic damline (M: 50% Meishan genes). M sows had higher numbers of piglets, a different feed intake curve and produced more milk with a higher fat content compared to W breed types. Their response to dietary protein was different for the two breeds; the Meishan sows, with higher initial levels of body fat reserves, used the extra protein to increase milk production. The White sows did not partition the extra protein into milk but used it to conserve their own maternal body reserves and improved their weaning to conception interval. The breed differences in sows performance were found not to be solely due to differences in litter size or piglet genotype or maternal body fat reserves. M sows showed better maternal behaviour with lower activity and shorter suckling intervals. It can be concluded from these experiments that Meishan synthetic sows are inherently better mothers, and the way in which sows of different breed types partition feed nutrients during lactation is very different. A dietary lysine concentration of 9 g/kg (giving daily intakes of 53-61 g/day at 98-111 MJ DE/day) optimised lactational and rebreeding performance in both breed types.

Three experiments were conducted to study the sensitivity of the pH-stat (in vitro) method in the prediction of true digestibility (TD), as measured by amount of base added, of plant proteins, either alone or in the presence of specific additives (nitrogen-free mixture, vitamin mixture and/or mineral mixture) as part of a complete diet of plant proteins that had been subjected to various levels and forms of heating. The in vitro TD values were then compared with TD values obtained in. vivo (Wistar rats). In experiment 1, the effect of temperature (dry-heating at 80, 100, 120, 150, 180 and 240° C or autoclaving at 121° C) and time (30, 60, 120 and 240 minutes) of heat application on in vitro base consumption (BC) was measured in 3 grains (wheat, barley and sorghum) and whole defatted soybeans. The largest increase in BC measured by the pH-stat method was that of soybeans in response to 30 minutes of autoclaving. Dry heating had various effects on the BC by soybeans, depending upon temperature and time of application, but none of the treatments was as beneficial as autoclaving. Mild, dry-heating of grains at 80-120° C improved BC slightly. The improvement was most marked for wheat. Both dry-heating of grain at temperatures above 120° C and autoclaving reduced the BC significantly for all durations. In experiment 2, the effect of inclusion of non-protein dietary components (minerals, vitamins and a nitrogen-free mixture, singly and in combination) on in. vitro BC measured by the pH-stat method of wheat and fat-extracted soybeans (both proteins in the raw and autoclaved forms) was monitored. For the wheat treatments, the inclusion of a mineral mixture significantly (p<0.001>) increased digestibility. This effect was greatest with autoclaved wheat. It was concluded that, in general, the presence of minerals increased the rate of hydrolysis. With raw soybeans, the distinction between treatments was less well-defined. The treatments containing vitamin or nitrogen-free and mineral combination mixtures were digested to a significantly greater extent than the raw soybeans alone. With autoclaved soybeans, additives had no effect. This lack of response to additives may have been due to the rather large amount of base required by the autoclaved soybean protein alone. In experiment 3, a series of rat-feeding trials were conducted in conjunction with in. vitro digestions. Diets were fed to groups of Wistar rats to determine TD, Biological Value (BV), and Net Protein Utilization (NPU) in vivo. Although BV was measured it was not relevant for this work. Concurrently, the same diets were tested for in. vitro TD by the pH-stat method. Specific regression equations were developed for each protein-type tested, after it was determined that a much lower correlation coefficient was obtained when one general equation was utilized. The newly-developed equations followed the format y = a + bx, where y = TD (as a part of one), a = the y-intercept, b = slope of the function and x = ml 0.10N NaOH added during the 10-minute digestion. Regression equations, correlation coefficients (r) and standard errors for each regression (s) between in. vitro and in vivo true digestibility of proteins were as follows; Soybean, soybean (autoclaved), soybean/wheat combinations (n = 6) r = 0.93 TD = 0.7868 + 0.2175x s = 0.018 Sorghum (raw, autoclaved, 90° C, 120° C, 180° C dry-heated, steamed) (n = 6) r = 0.92 TD = 0.4575 + 1.8841x a = 0.058 Alfalfa pellets/hay in combination with either wheat or barley (n = 13) r = 0.91 TD = 0.3446 + 1.0356x s = 0.046Alfalfa hay and barley combinations (n = 5) r = 0.96 TD = 0.2360 + 1.3194x s = 0.048 Grains (19 barleys, 10 triticales, 6 sorghums, and 2 wheats) (n = 37) r = 0.74 TD = 0.7419 + 0.4759x s = 0.044 In general, it can be stated that the pH-stat method is a useful method for screening proteins for the effect of various treatments on digestibility. Damage due to abnormally severe processing conditions (i.e. heating) is readily detected by the pH-stat technique as indicated by a decrease in the amount of base consumed during enzymatic hydrolysis.
Land and Food Systems, Faculty of
Graduate

Objectives were to determine net uptake or release of α-amino N (AAN), ammonia N (NH₃N) and urea N (UN) across portal-drained viscera (PDV), liver, splanchnic (PDV + liver) and mammary tissues of lactating cows fed differently processed sorghum or corn. Cows were fitted with catheters in blood vessels (artery and portal, hepatic and mammary vein), and received in a switchback design TMR containing 40% dry-rolled (DR; 643 g/L or 50 lb/bu) or steam-flaked (SF; 360 g/L or 28 lb/bu) sorghum (Exp. 1), and steam-rolled (SR; 489 g/L or 38 lb/bu) or SF corn (Exp. 2). Neither daily intake of DM and nutrients nor milk yield and efficiency of milk production were altered by feeding processed sorghum or corn. Milk fat yield was lowered (P=.03) by SF vs. DR sorghum; SF vs SR of corn tended to increase (P=.07) concentration but not yield of milk protein. Blood flows in portal (1988 ± 109 L/h) and hepatic vein (2368 ± 215 L/h) were not altered by diets. Steam-flaked vs. DR sorghum tended (P=.18) to increase UN cycling (162 vs. 95 g/d), and reduced (P≤.09) absorption of AAN (223 vs. 269 g/d) and NH3N (257 vs. 318 g/d) by PDV. Flaking vs. rolling of sorghum increased (P≤.07) estimated uptake (83 vs. 67 g/d) and extraction ratio (14.5 vs. 11.1%) of AAN by mammary tissues. Net uptake and release of AAN and NH3N across splanchnic tissues of cows were not altered by corn processing; however, SF vs. SR corn increased (P=.08) UN cycling to PDV by 143% (212 vs. 87 g/d). Steam-flaked vs SR corn increased (P≤.02) estimated uptake (88 vs. 61 g/d) and extraction ratio (14.7 vs. 11.0%) of AAN by mammary tissues. It is concluded that feeding of steam-flaked sorghum or corn compared to dry-rolled sorghum or steam-rolled corn improves N utilization of dairy cows by increasing urea transfer to the gut and uptake of amino acid by the mammary gland.

Sex differences have been identified in both external appearance of faces (e.g. Bulygina et al., 2006; Weston et al., 2007) and the way information about faces is extracted by our brains, that is in face processing (e.g. Tahmasebi et al., 2012; Hampson et al., 2006). The mechanisms leading to the development of such sex differences are not well understood. This thesis explores the role of sex hormones in face development and face processing. Data from two large-scale studies (Saguenay Youth Study and Imagen, with n=1,000 and 2,000, respectively) and four smaller datasets (Cycle-Pill Study, n=20; Pill Study, n=20; First Impression Study, n=120, and Twin Study, n=119) were used to explore the effects of sex and sex hormones on face development (head MR images, MRI-face reconstruction) and face processing (functional MRI data, eye-tracking data). Shape of male and female faces was influenced by both prenatal and pubertal androgens. Facial signature of prenatal androgens, identified by the sex-discordant twin design, was found also in an independent dataset of female adolescents (singletons) and we showed that prenatal androgens, indexed indirectly by the facial signature, were associated with larger brain size. We propose that this facial signature might be used, similarly to digit ratio, as an indirect index of prenatal androgens. Variability in postnatal sex hormones due to the use of oral contraception and the phase of menstrual cycle influenced brain response to faces. Using the same dynamic face stimuli as in the functional magnetic resonance imaging (fMRI) study, we showed that eye-movements scanning the face did not differ between the users and non-users of oral contraception. We conclude that effects of sex hormones can be observed in both the face and the brain and that these effects help us understand sex differences in face shape and face processing. **This version does not contain the previously published journal articles reproduced in the printed thesis (appendices 1-3). For details see p. 188. **

This experiment evaluated rumen protein:energy synchronization in steers fed either gamagrass (Tripsacum dactyloides) or orchardgrass (Dactylis glomerata) hays with or without a soybean hull/corn supplement. A N balance trial was conducted to compare the effects of the supplement and hay on N intake, N digestion, and N metabolism. The supplement consisted of 50:50 corn: soybean hulls mix with 50 g molasses per kg of corn: soybean hulls mixture. The supplement contained 11.3% CP, 34.2% NDF, 22.9% ADF, and 0.87 kg was fed at 0830 and 1600 followed by hay offered in two equal portions. Steers had ad libitum access to water and a trace mineralized salt block throughout the study. Hay compositions were 8.3% CP, 71.8% NDF, and 37.8% ADF for gamagrass and were 11.9% CP, 70.5% NDF, and 36.6% ADF for orchardgrass. Steers were individually fed, blocked into two weight groups, and randomly assigned to either gamagrass or orchardgrass hay (4 steers per hay). Within hays, steers were assigned to receive supplement or no supplement in a crossover design. Ad libitum DM intake for each steer was equal to their intake during the last 8d of the 21-d ad libitum period. Steers were then placed in metabolism crates for an 8-d adjustment followed by a 5-d balance trial. During the balance trial, steers were fed 90% of ad libitum intake. Compared with gamagrass, orchardgrass had similar true IVDMD (64.2 vs 62.2%), similar leaf true IVDMD (58.2 vs 63.2%), and similar stem true IVDMD (46.7 vs 51.7%). Effects were significant at P < 0.10. Compared with gamagrass, orchardgrass had a lower ad libitum DM intake (4.62 vs 5.37 kg/d), higher N intake (96.6 vs 81.1 g/d), similar fecal N (36.1 vs 34.5 g/d), higher N digestibility (62.4 vs 57.4 %), similar N retained (27.2 vs 27.7 g/d), and lower digestible DMI (3.20 vs 3.53 kg/d). Compared with no supplement, supplement increased digestible DM intake (3.70 vs 3.03 kg/d), total DM intake (5.87 vs 5.07 kg/d), N intake (96.9 vs 80.8 g/d), fecal N (39.4 vs 31.1 g/d) and N retained (31.7 vs 23.2 g/d). Supplement (1.74 kg/d) decreased hay ad libitum intake by 0.73 kg/d. Supplement decreased, blood urea N, urine urea N and urine urea N as a percentage of urine N more for orchardgrass than for gamagrass. Supplement tended (P < 0.11) to improve N retained as a percentage of N intake or percentage of N digested more for orchardgrass than for gamagrass hay. Blood urea N was reduced (2.21 vs 0.14 mM)more for steers fed orchardgrass hay than for steers fed gamagrass. We believe that the increase in digestible OM intake is due in part to the presence of soybean hulls in the supplement.

Dairy slurry and poultry litter have increased in popularity as fertilizers in the agriculture industry. However, residual effects of these manures on voluntary intake of forages from subsequent harvests are not well known. The objectives of this two part study were to determine if moisture level of alfalfa silage and the use of dairy slurry as a fertilizer have an effect on intake and digestibility by sheep, and if forage species and the use of poultry litter as a fertilizer have an effect on intake by horses. Eighteen ewes (47.6 ± 5.34 kg) were used in experiment 1 and were allocated randomly to 1 of 6 treatments arranged in a 2 × 3 factorial treatment arrangement. Treatments consisted of high (HM; 46.8%) or low (LM; 39.7%) moisture alfalfa silage at baling after no slurry application (NS), slurry applied to stubble immediately after removal of the previous cutting (S0) or 14 d after the previous cutting (S14). Experiment 2 used 5 mature geldings (480.3 ± 52.89 kg) in a balanced incomplete block design to evaluate preference for bermudagrass (B) or teff (T) hay that was harvested after no litter application (NL), litter applied immediately after the removal of the previous cutting (L0) or 14 d after the previous cutting (L14). Animals were housed individually: sheep were housed in 1.4 × 4.3 m pens and horses were housed in 3.6 × 3.6 m indoor stalls with access to 3.6 × 7.6 m outdoor runs. All animals were offered mineral and had ad libitum access to water. Intake by sheep did not differ (P ≥ 0.13) across treatments. Dry matter and OM digestibility by sheep tended (P < 0.10) to be greater for LM compared with HM. In horses, intake was greater (P < 0.01) for bermudagrass and NL and L0 treatments compared with teff and L14. Therefore, the use of manure as a fertilizer may not affect voluntary intake in sheep, but application time may affect intake in horses.

The interaction between dietary crude protein and amino acid levels in weaner pigs in an antibiotic-free environment with or without Bacillus amyloliquefaciens supplementation Natasha van Niekerk High crude protein (CP) diets cause a myriad of digestive problems in weaner pigs due to incomplete digestion. This is caused by an immature digestive system at weaning. These problems present themselves as increased diarrhoea and reduced growth performance in weaner pigs. Many of the negative consequences could in the past be rectified through the use of antibiotic growth promoters (AGPs). However, AGPs are becoming more closely scrutinised by the general public and government officials and it is therefore imperative that alternative feed additives and dietary strategies are explored so that weaner pig performance is not impaired in the face of AGP bans. The effect of a 3% dietary CP reduction and 10% elevation of lysine, methionine, threonine, tryptophan and valine and/or Bacillus amyloliquefaciens was investigated in weaner pigs of 28 days old. The experiment was performed on 162 pigs with six dietary treatments; comprising of two CP levels (21% or 18% in the pre-starter diets and 18% or 15% in the starter diets), two amino acid levels (recommended amino acid level or elevated by 10%) and with or without the supplementation of a probiotic additive (Bacillus amyloliquefaciens). The total trial period was 42 days, divided into a pre-starter phase and starter phase, both of 21 days each. Growth performance and faecal score was measured for the entire trial period. In addition, after 21 days of the trial, 54 pigs were humanely euthanised to determine the gut health effects of the dietary treatments. Crude protein level resulted in significant effects on body weight (BW), average daily gain (ADG) and gain to feed ratio (G: F) in both the pre-starter and starter phase. The pigs consuming the HP diets had increased (p <0.05) BW at day 7, 14, 21, 28 and 35, and higher ADG (p <0.01) between days 7-14 and 7-21. In addition, high CP diets resulted in increased (p <0.05) G: F in the periods 7-14, 7-21, 21-42 and 7-42. This was due to the negative impact incurred as a result of deficiencies in certain essential AA and the standard ileal digestible (SID) Lys to CP ratio (SID Lys: CP) of 6.9% being exceeded when CP was reduced, and supplemental AA increased. The reduction in CP resulted in improved faecal scores. The supplementation of the probiotic did not result in any significant effects on performance but did exert a positive synergistic effect with the low CP diet on gut health, as observed through improved faecal score. Ileal villi height was significantly increased in high CP diets, possibly indicative of increased nutrient availability in the high CP diets. Crypt depth was also increased in the high CP diets, indicative of increased cell proliferation. There were no significant dietary effects on the pH and ammonia content of caecal digesta, or the presence and enumeration of Salmonella and Escherichia coli (E. coli) in ileal and caecal digesta. Interestingly, the supplementation of the probiotic increased the relative liver weights of the pre-starter pigs. Results of the study suggest that in order for the strategy of reducing CP in weaner pig diets to be successful, no deficiencies in essential or non-essential amino acids should be present. In addition, low CP diets in conjunction with a probiotic can improve faecal scores of weaner pigs, providing an effective solution to replacing AGPs.
Dissertation (MSc)--University of Pretoria, 2020.
Evonik Nutrition & Care GmbH
Animal and Wildlife Sciences
MSc (Agric) Animal Nutrition
Unrestricted

The processing of soya oilcake is important to ensure protein availability and high degradability of the soya proteins. Pig producers in South Africa are concerned about the quality of locally processed soya oilcakes and the effect that it may have on the intestinal health and lifetime production of the pig. The primary aim of this study was to compare the quality of locally processed soya oilcake to soya oilcake imported from Argentina. The trail consisted of two parts. In part one of the trail, eighty-eight samples of soya oilcakes from three different processing plants in South Africa and one from Argentina was analysed for their nutritive value and antinutritive factors. The results from the in vitro analyses were used to conduct the second part of this trail. Thirty-two piglets were divided into four treatment groups, the control group (diet containing no trypsin inhibitors), a low trypsin inhibitor group, a medium trypsin inhibitor group and a high trypsin inhibitor group. A digestibility trail was conducted to determine the effect of antinutritive factors on the digestibility of CP in pigs. The nutrient analyses suggested that the imported soya oilcake is of better quality than the locally produced product. All the results for the imported soya oilcakes were very consistent, with minor variations and had lower trypsin inhibitor activity. The results obtained from this study showed that some of the local soya oilcake processing plants in South Africa produced products of higher quality than others. One of the locally processed soya oilcakes, named soya oilcake 3 in this study, was identified as a good replacement for the imported soya oilcake. Soya oilcake 3 had a CP value of 53.11% which compared well with the imported soya oilcake with a similar CP value of 53.51%. The trypsin inhibitor concentration of the imported soya oilcake was the lowest and the second lowest in soya oilcake 3. Due to the high variance found in the results obtained from the in vivo digestibility study, it is not possible to make a conclusion on the effect of feeding lower quality soya oilcakes to weaner pigs. Further research is needed on the effect of trypsin inhibitor on gut health and digestibility of crude protein in weaner pigs.
Dissertation (MSc)--University of Pretoria, 2019.
Topigs, Evonik Africa (Pty) Ltd, Addesio
Animal and Wildlife Sciences
MSc
Unrestricted

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Aiming to evaluate feeding programs (FP) with different levels of calcium (Ca) and available phosphorus (aP) on rations containing phytase for piglets, one hundred sixty- eight barrows and females weighing 8.11 ± 0.61 kg were weaned at 28 days and blocked according to initial body weight. Inside each block, piglets were randomly distributed to one of seven feeding programs with eight replicates and three piglets per experimental unit.The treatments consisted of control FPwithout phytase and six with decreasing levels(%) of aP and calcium (Ca) with the addition ofphytase(2,000 FTU/kg), as follows: FP1: (aP: 0.435-0.385-0.315; Ca: 0.850-0.825-0.768); FP2: (aP: 0.370-0.320-0.250; Ca:0.850-0.825-0.768); FP3: (aP: 0.305-0.255-0.185; Ca: 0.850- 0.825-0.768); FP4: (aP: 0.435-0.385-0.315; Ca:0.690-0.665-0.608); FP5: (aP: 0.370- 0.320-0.250; Ca: 0.690-0.665-0.608); FP6: (aP: 0.305-0.255-0.185; Ca: 0.690-0.665- 0.608). The FP3, FP5 and FP6 resulted in higher average daily gain and feed intake in comparison to control,from 28 to 35 days. Only FP6 resulted in higher average daily gain in comparison to control, from 28 to 49 days. The FP6 resulted in lower verage daily gain when compared to FP1, from 28 to 63 days.The FP1, FP2, FP4 and FP5provided greater bone mineralization when compared to control. The FP1resulted in greater bone mineralization than FP3, FP5 and FP6. The FP3 resulted in less bone mineralization than FP1, FP2 and FP4. Bone Ca was lower on FP5 when compared to FP1. With the exception of the FP3, phosphorus (P) of the bone was higher on all treatments when compared to control, however, the FP3 treatment resulted in less bone P than FP1. The FP4, FP5 and FP6 resulted in lower bone Ca:P ratio when compared to control. The serum Pconcentrations were lower in FP3 and FP6 in comparison to control. Considering only treatments containing exogenousphytase, the FP3 resulted in lower serum P than FP1, FP4, FP5; and FP6 resulted in lower serum P in comparison to FP5 as well. In conclusion, the FP6 results in satisfactory performance of pigs from 28 to 63 days of agealthough providing lower growth rate when compared to FP5.
Objetivando-se avaliar planos nutricionais comdiferntesníveis de cálcio (Ca) e fósforo disponível (Pd) em rações contendo fitase, 168 leitões, machos castrados e fêmeas, com peso corporal inicial de 8,11±0,61kg foramdesmamados aos 28 dias de idade e distribuídos em delineamento em blocos ao acaso, conforme o peso corporal, em sete tratamentos, com oito repetições e três animais por unidade experimental. Os tratamentos foram planos nutricionais (PN), sendo um controle sem fitase e os demais com níveis (%) decrescentes de Pd e Ca com 2.000 FTU de fitase, conforme segue: PN1: (Pd:0,435-0,385-0,315; Ca: 0,850-0,825-0,768); PN2: (Pd:0,370-0,320-0,250; Ca:0,850-0,825-0,768); PN3: (Pd: 0,305-0,255-0,185; Ca: 0,850-0,825-0,768); PN4: (Pd: 0,435-0,385-0,315; Ca:0,690-0,665-0,608); PN5: (Pd: 0,370-0,320-0,250; Ca:0,690-0,665-0,608); PN6: (Pd: 0,305-0,255-0,185; Ca: 0,690-0,665-0,608). O ganho de peso e o consumo de ração diários dos 28 aos 35 dias foram maiores para o PN3, PN5 e PN6 em comparação ao plano controle. Dos 28 aos 49 dias, o ganho de peso diário proporcionado pelo PN6 foi maior em comparação ao controle. O ganho de peso diário foi menor no PN6 em comparação ao PN1, dos 28 aos 63 dias. Os tratamentos PN1, PN2, PN4, PN5 proporcionaram maior mineralização óssea comparados ao controle. O PN1 resultou em maior mineralização óssea que o PN3, PN5 e PN6. OPN3 proporcionou menor mineralização óssea que os PN1, PN2 e PN4. O PN5 resultou em menor Ca ósseo comparado ao PN1. Com exceção do PN3, todos os tratamentos resultaram em P ósseo maior em relação ao controle, mas o PN3 resultou em P ósseo menor que o PN1. O PN4, PN5 e PN6 resultaram em menor relação cálcio:fósforo ósseo em relação ao controle. O P sérico foi menor no PN3 e PN6 em relação ao tratamento controle. Dentre os tratamentos contendo fitase, o PN3 resultou em menor P sérico que o PN1, PN4, e PN5; e o PN6 em menor P sérico que o PN5. Conclui-se que oPN6, correspondente a 0,305-0,255-0,185 de Pd, 0,690-0,665-0,608 de Cae2000 FTU/kgde fitase, apesar de proporcionar menor taxa de crescimento em relação ao PN5, resulta em desempenho satisfatório de leitões dos 28 aos 63 dias de idade.

Il est maintenant bien établi que les hormones sexuelles jouent un rôle majeur dans les différences entre les sexes non seulement dans la perception de la douleur, mais également dans les processus d'inhibition de la douleur. En effet, les femmes ont des seuils de douleur moins élevés que les hommes et souffrent plus fréquemment de douleur chronique. Toutefois, le rôle des hormones sexuelles dans la douleur neuropathique a été relativement peu étudié jusqu'à présent. Des études récentes ont également démontré que les cellules gliales contribuaient à la douleur chronique, notamment à la douleur neuropathique. Dans le cadre de ce mémoire, l'implication des hormones sexuelles et des cellules gliales dans la douleur et l'analgésie a été étudiée à l'aide d'un modèle animal de douleur neuropathique. Dans la première partie du projet, des tests comportementaux ont été réalisés afin d'observer l'implication des hormones sexuelles dans les mécanismes excitateurs et inhibiteurs de la douleur neuropathique. Suite à une constriction chronique du nerf sciatique, des souris mâles et femelles, avec ou sans leurs hormones sexuelles endogènes ont été testées pour les deux composantes majeures de ce type de douleur, soit l'allodynie et l'hyperalgésie. Les résultats obtenus vont dans le même sens que ceux obtenus précédemment dans nos laboratoires à l'aide du test à la formaline. En général, les mâles ont moins de douleur que les femelles et ce autant pour l'allodynie que l'hyperalgésie. Alors que les femelles avec et sans hormones sexuelles ont un niveau d'allodynie comparable, les mâles castrés ont pour leur part un niveau d'allodynie et d'hyperalgésie plus élevé que les mâles avec testostérone. Ces résultats démontrent bien le rôle protecteur que semble jouer la testostérone dans la douleur. De plus, comme les hormones sexuelles modulent également les mécanismes d'inhibition de la douleur, nous avons voulu vérifier leur impact sur ces mécanismes à l'aide du test de nage forcée qui déclenche une analgésie similaire aux mécanismes endogènes de contrôle de la douleur chez l'humain. Les animaux avec hormones sexuelles semblent avoir une meilleure analgésie puisque les femelles et les mâles ont moins de nociception après la nage que les femelles ovariectomisées et les mâles castrés, respectivement. Les résultats obtenus démontrent clairement que les hormones sexuelles sont bien impliquées dans les mécanismes de modulation de la douleur neuropathique tant chez le mâle que chez la femelle. Dans la deuxième partie du projet, l'expression d'un marqueur d'activation des cellules gliales, le"Glial Fibrillary Acidic Protein" (GFAP), a été évaluée afin de voir si l'activation des cellules gliales au niveau spinal était en corrélation avec les résultats comportementaux. L'analyse immunohistochimique a confirmé que chez les animaux ayant eu une lésion au nerf périphérique, l'activation des cellules gliales était très évidente avec une induction encore plus marquée du côté de la lésion. Ces résultats confirment l'implication des cellules gliales dans la douleur neuropathique. Chez les animaux sans douleur neuropathique, un léger marquage était observé, indiquant la présence de cellules gliales non-activées. De plus, puisque quelques études ont démontré que l'activation des cellules gliales peut être modulée par les hormones sexuelles, nous avons voulu vérifier si ce même effet pouvait être observé dans la douleur neuropathique. Cependant, tous les groupes, indépendamment de leur statut hormonal, avaient une densité spinale comparable de cellules gliales, indiquant que le statut des hormones sexuelles ne semble pas influencer l'activation des cellules gliales dans la douleur neuropathique. Cette étude a donc permis de démontrer que les hormones sexuelles sont impliquées dans la douleur neuropathique et que les cellules gliales sont activées suite à l'insulte neuronale responsable de créer la douleur neuropathique. Par contre, la contribution des cellules gliales dans ce type de douleur ne semble pas être influencée par les hormones sexuelles. Évidemment, une meilleure caractérisation de l'implication des hormones sexuelles et des cellules gliales dans les processus douloureux permettra de mieux comprendre les bases physiologiques qui sont responsables de ces différences dans le but ultime d'orienter le traitement pharmacologique des douleurs chroniques en fonction du sexe.