Academic literature on the topic 'Santa gertrudis cattle'

AbstractCarcass traits of two indigenous African (Sanga) breeds (Afrikaner and Nguni), one indigenous African composite breed (Bonsmara), one foreign composite breed (Santa Gertrudis) and two continental European breeds (Brown Swiss and Pinzgauer) were compared. Treatment means were adjusted to the mean overall subcutaneous fat proportion (47 g/kg). Despite differences in maturity type, only the Afrikaner dressed out significantly (P < 0·05) lower than the foreign breeds. Both Sanga breeds and the Bonsmara had significantly higher muscle yields than the Santa Gertrudis and Pinzgauer, mainly due to the high intermuscular fat of the latter two breeds. When muscle yield was expressed per unit of bone, the Afrikaner and Bonsmara compared favourably with the larger breeds, due to their low bone and intermuscular fat yield, while the Nguni had a relatively high bone yield. The Santa Gertrudis had the lowest muscle yield due to its high bone and intermuscular fat yields, especially when compared with the smaller Bonsmara composite. Both Sanga breeds had significantly higher (P < 0·05) proportions of total weight, meat and bone (Afrikaner P > 0·05) in the high-priced cuts compared with the other breeds at the same subcutaneous fat level. Despite the statistical significance, differences were small in magnitude and probably of little commercial value. At the same time mean subcutaneous fat proportion, tissue yield and distribution patterns expected of late maturing breeds were observed for smaller indigenous breeds, suggesting that it was specific breed effects rather than maturity type effects, which were evident.

An analysis of some reproductive perfor­mance traits was carried out for the period 1983 to 1985, in a herd of 168 Santa Gertrudis beef cattle imported from Okla­homa, U.S.A. in 1981 into lkyogen cattle ranch in Nigeria. Three calf crops were obtained during the period. Mean pregnancy rate and calving percentage were 63.24 and 55.72% respectively; with pregnancy rate increasing from 54.23 to 70,41% while calving percentage increased from 48.42 to 61.11% during the period. Mean calf mortality rate of 40.83% was high and increased from 36.34 to 45.15%. Mean adult mortality rate was 5.68% of which 16.99% was recorded in the first year of introduction but this declined sharply to 0O2% in the next two years. Mean weaning rate was 50.08% and this declined from 55.71 to 44.32% during the period under study. Mean birth weight, weaning weight and calving interval were 27.8 t 0.29 kg, 174 ± 4.6kg and 451 days respectively It was concluded that with the exception of weaning weight, the reproductive traits of the imported Santta Gertrudis cattle reported in this study were not superior to those of the predominant indigenous cattle breeds of Nigeria. The implications of these results in the beef cattle industry of Nigeria are discussed.

We aimed to evaluate environmental effects on pre-weaning traits of Santa Gertrudis cattle. We used 213 standardized records for adjusted 205-day weight at weaning (W205), average daily gain from birth to weaning (AGD), and number of days to gain 160 kg from birth to weaning (D160), obtained from the Santa Gertrudis Breeders' Association for animals born between 1990 and 1997. The files were edited with information regarding cow age at calving (CAC) and contemporary group (CG), for which the effects of year and season of birth, animal category, herd, and sex were considered. It was observed that cow age at calving, which had linear and quadratic effects, and effect of contemporary group were significant (P < 0.0001) for the evaluated traits. Estimated averages were 198.05 ± 40.64 kg, 0.790 ± 0.198 kg day-1, and 288.05 ± 67.18 days for W205, ADG, and D160, respectively. Males were 4.67 kg heavier (197.17 kg) than females, on average. Regarding the animal category effect, the classified females were 2.3% heavier than the unclassified, on average. On average, animals born in the dry season were 1.6% lighter than those born in the rainy season (197.18 kg). Thus, environmental effects are important and should be considered in any analysis model.

This research aimed to compare carcasses of purebred and crossbred Nellore females reared uniquely on pasture (Brachiaria decumbens and Brachiaria brizantha cv. Marandu). Breeds assessed consisted of purebred Nellore (16) and Nellore x Santa Gertrudis crossbred (16), being 32 ± 1.5 months old. All animals were slaughtered as they reached 450 kg. Crossbred females showed higher slaughter, hot and cold carcass weights and longer lengths (P < 0.05). Conversely, purebred animals attained greater carcass yields (P < 0.05). Nonetheless, crossbred females had higher primal cut weights and plate/ flank percentage (P < 0.05). Also, non-carcass components as kidneys, liver, kidney-pelvic-heart fat showed higher weights for crossbred females (P < 0.05). Thus, regarding beef cattle reared and finished exclusively on grazing areas, crossbred females (Nellore x Santa Gertrudis) may be the most profitable ones for cattle raisers, since they produce heavier slaughtering carcasses. Notwithstanding, they might be interesting for meat industry, for yielding more in prime cuts than purebreds, even if raised at the same conditions and slaughtered at same age.

The objective of this experiment was to quantify differences in feed efficiency and feeding behaviour of 470 heifers and steers by Brahman, Belmont Red, Santa Gertrudis, Angus, Hereford, Shorthorn, Charolais and Limousin sires mated to Brahman dams. Animals were bred in subtropical Queensland and finished in a temperate New South Wales feedlot. Animals averaged 598 days of age and 425.8 kg at the start of the feed intake test period. Sire breeds did not differ for eating rate, feed conversion ratio or relative growth rate. Generally, higher daily feed intakes (DFI) corresponded with higher average daily gains (ADG). Straightbred Brahmans fed the most frequently (16.6 ± 0.8 sessions/day; P < 0.05) but spent the least time eating of all breeds (67.4 ± 2.7 min/day; P < 0.001). Least squares means for Brahman, Belmont Red, Santa Gertrudis, Angus, Hereford, Shorthorn, Charolais and Limousin sired progeny, respectively, for residual feed intake (RFI; P < 0.05) were 0.02 ± 0.16, 0.14 ± 0.13, –0.10 ± 0.23, 0.54 ± 0.17, –0.27 ± 0.18, 0.29 ± 0.18, –0.46 ± 0.16 and –0.21 ± 0.13 kg/day, and for ADG (P < 0.001) were 1.06 ± 0.05, 1.17 ± 0.04, 1.52 ± 0.08, 1.47 ± 0.06, 1.46 ± 0.06, 1.46 ± 0.06, 1.35 ± 0.06 and 1.38 ± 0.05 kg/day. While straightbred Brahmans did not differ from all other sire breeds for RFI, their lower appetite relative to crossbred contemporaries resulted in the lowest DFI (P < 0.001) and lowest ADG (P < 0.001) overall. Angus sired crosses were the least efficient feeders and spent the most time eating, consumed the most feed and had the highest RFI, but were not significantly different to Santa Gertrudis and Shorthorn crosses for these traits. Angus sired crosses spent 24.1 and 15.4 min/day more time eating (P < 0.001) than straightbred Brahmans and Charolais crosses, and consumed 35 and 13% more feed (P < 0.001) respectively. Charolais sired crosses were the most feed efficient with the lowest RFI and intermediate DFI, and did not differ significantly from the highest ranking sire breeds for ADG or Kleiber ratio. While Belmont Red crosses did not differ from all breeds for RFI, they had significantly lower DFI than British and Santa Gertrudis crosses resulting in lower ADG (P < 0.001) relative to these sire breeds. Therefore, selection of Charolais, Hereford, Limousin and Santa Gertrudis sire breeds would result in the most feed efficient (low RFI) crosses with Brahman without any sacrifice in ADG.

The genotypes for k-casein (<FONT FACE="Symbol">k</FONT>-CN), <FONT FACE="Symbol">b</FONT>-lactoglobulin (<FONT FACE="Symbol">b</FONT>-LG) and growth hormone (GH) were determined by polymerase chain reaction (PCR) and restriction enzyme digestion in seven breeds of cattle (Nelore, Gyr, Guzerá, Caracu, Charolais, Canchim and Santa Gertrudis). <FONT FACE="Symbol">k</FONT>-Casein had two alleles with the A allele occurring at a higher frequency in Bos indicus breeds (0.93, 0.92 and 0.91% for Gyr, Guzerá and Nelore, respectively). The <FONT FACE="Symbol">b</FONT>-lactoglobulin locus had two alleles in all of the breeds. European breeds had a higher frequency of the <FONT FACE="Symbol">b</FONT>-LG A allele than Zebu breeds. The GH locus had two alleles (L and V) in Bos taurus and was monomorphic (L allele only) in all of the Bos indicus breeds evaluated. The highest frequency for the V allele was observed in Charolais cattle. The markers used revealed a considerable similarity among breeds, with two main groups being discernible. One group consisted of Zebu and Santa Gertrudis breeds and the other consisted of European and Canchim breeds.

In the first study, non-genetic influences on pre- and post-weaning growth traits of a tropically adapted beef breed in the arid sub-tropical environment of Southern Africa were investigated. Production data of Santa Gertrudis cattle for a ten-year period were analysed. The herds were managed extensively under harsh arid environmental conditions in the northern thornveld region of Namibia. The cattle were divided into summer and winter breeding seasons, which were limited to 90 days for each group. The effect of sex, herd, season, calf birth year and cow parity group on birth weight, pre-weaning average daily gain, weaning weight, yearling weight, eighteen month weight and post-weaning growth rate were analysed. Sex was a highly significant (p < 0.001) source of variation for birth weight, weaning weight, 12 month weight, 18 month weight and significantly influenced (p < 0.05) pre and post-weaning weight gain. Bull calves were 3.05, 13.75, 123.37 and 238.99 kg heavier than the heifer calves at birth, weaning, yearling and eighteen months respectively and grew faster by 0.07 kg/day from birth to weaning and 0.65 kg/day from weaning to 12 months of age. The effect of season on birth weight, weaning weight, 18-month weight and pre-weaning growth rate was highly significant (p < 0.001). Calves born in the summer season had a lower birth weight compared to calves born in the winter season. However, the summer season calves were heavier by 17.67 kg at weaning but only by 1.7 kg at 12 months of age. They grew faster by 0.16 kg/day from birth to weaning. Calf birth year significantly influenced (p < 0.001) all traits measured with no fixed trend over time for the traits. Herd effects were highly significant (p < 0.001) for birth weight and 12-month weights and significantly influenced (p < 0.05) weaning weight, 18-month weight and growth rate from weaning to 12 months of age. The effect of cow parity was not significant on birth weight, 12-month weights, 18-month weights and post-weaning growth rates, but was significant (p < 0.05) for weaning weight and pre-weaning growth rates. Sex, herd, season of calving, calf birth year and herd x season x calf birth year significantly influenced growth traits and should be taken into consideration when evaluating the genetic merit of cattle during selection. The second study was conducted to determine the associations between lifetime cow fertility and cow frame size, also between lifetime cow fertility and pre-weaning as well as post-weaning calf growth in tropically adapted Santa Gertrudis cattle. A total of 2 506 Santa Gertrudis cows were divided according to their average lifetime calving interval (CI) into short calving interval (SCI, < 400 days, n = 914 cows) and long calving interval (LCI, > 400 days, n = 1 592 cows) groups. Calves were weighed at weaning at approximately 7 months of age. Hip height of cows and pre-weaning gain of calves of the SCI cows (135 cm and 1.01 kg/day) were significantly (p < 0.05) lower than those of the LCI cows (141 cm and 1.25 kg/day). Calves from SCI cows were born significantly earlier in the calving season than calves from LCI cows as measured by age at weaning (221 versus 189 days). As a result of compensatory growth there was no significant difference for yearling weight between progeny of SCI and LCI cows (348 kg versus 349 kg). It is concluded that SCI cows are smaller in size, with significantly lighter calves at weaning. A negative correlation exists between fertility and pre-weaning calf growth. High post-weaning calf growth is compatible with high cow fertility. In the third study, the effects of heifer frame size (FS) on their subsequent performance and the pre-weaning growth of their calves were evaluated using records collected from 1989 to 1998 from the Waterburg Estates at Otjiwarongo, Namibia. Based on hip height at 18 months of age, heifers were assigned to three different frame size (FS) groups: small (< 124 cm), medium (125 to 135 cm), or large (>136 cm). Calving rate (CR), calving date (CD), calf survival rate (CSR), reproductive efficiency (SANDEX), weaning rate (WR), birth weight (BW), weaning weight (WWT), pre-weaning ADG (P-ADG), and kilograms of calf produced per cow bred (KCB) were collected from first –(n = 830), second (n = 623) and third and greater-parity (n = 571) cows. Frame size of heifers significantly influenced (p < 0.001) their calving rate as second-parity cows with small and medium FS cows having higher CR than large FS cows. In spite of heavy culling of cows that had large FS as heifers, calving rates of second parity cows in this category were 41% less than that of second parity cows that had small and medium FS as heifers. In third or greater-parity cows, CR was greater (p < 0.05) for small FS than for medium and large FS. CSR was similar for heifers with a small, medium and large FS for the first, second and third and greater parity groups. Weaning rates of large FS (34.2 ± 11.27), second-parity cows were less (p < 0.001) than those of small (82.9 ± 5.58) and medium (79.0 ± 4.67) FS animals. Among all parity groups, BW of calves born to large FS were significantly higher (p < 0.05) than those of small and medium FS cows. Calves weaned by small FS animals as first parity cows, had lower (p < 0.05) WWT than those weaned by medium and larger FS, but large FS weaned heavier calves (p < 0.05) than small and medium FS in the third and greater-parity group. In first parity cows, calves of large FS had greater P-ADG (p < 0.05) than those from small FS, but in second parity cows the calves from medium FS (p < 0.05) out performed those of small and large FS, while calves from third and greater parity cows of medium and larger FS had greater (p < 0.05) P-ADG than cows with a small FS. Male calves were heavier (p < 0.05) at birth, at weaning and grew faster (P-ADG) than their female counterparts. KCB was similar among small and medium FS cows, but both tended to be greater (p < 0.05) than KCB of large FS cows and as second parity cows the small and medium FS cows had an even greater (p < 0.001) advantage over the large FS animals. Small and medium FS females calved earlier, and had greater calving rates and weaning rates, as well as greater kilogram of calf produced per cow exposed than the large FS females. The performance (fertility and the growth performance of their calves to weaning) traits of the large FS were generally similar to those of smaller cows in the third and greater parity group. The reproductive efficiency (SANDEX) of large FS at first, second, third and greater parity were lower (p < 0.001) compared to the small and medium FS, due to the later calving dates. Therefore, selecting cattle for the hot and dry climatic regions of Southern Africa, under extensive management conditions and with limited supplementary feeding, the recommended cow frame size should be a medium frame. These animals have similar levels of fertility compared to small framed cows, but with similar or even better growth performances than large framed cows. In the fourth study, the objective was to determine the effect of traits such as age, sex, body weight, body length and height, body condition score (BCS), coat score (CS), skin thickness and average skin surface temperature on tick burdens of a tropically adapted beef breed. Bonsmara cattle (n= 143) were used to measure visible tick counts, body condition score, coat score, skin thickness, body height and length, body weight, body surface temperature, gender and inter calving period. Measurements were taken for a period of eight months from April to December. All animals were managed extensively on natural and cultivated pastures near George in the Southern Cape. Female animals had significantly (p<0.05) greater tick infestation (37.9±2.7) compared to male animals (16.5±1.2). Age was a significant factor p<0.001) with the younger animals below two years having (46.4±5.26) more ticks than those of two years and older (20.1±2.44). A significant negative correlation (r = -0.29; p<0.001) was reported between the infestation of ticks on the animals and the age of the animal. Animals with an average body weight below 250kg had 42% (p<0.05) more ticks compared to animals with a body weight above 250kg. Age of the animal and weight were highly correlated (r = 0.70; p<0.001), while the correlation between the number of ticks per cow and the mean weight was negatively correlated (r = -0.37; p<0.001). Skin surface temperature significantly influenced tick infestation on the animals (p<0.001). The degree of infestation increased as body surface temperature exceeded 30º Celsius. Coat score, skin thickness, body condition score and inter calving period did not significantly influence tick infestation on the animals. The infestation of ticks on the animals was significantly influenced by body height (p<0.019) and body length (p<0.001). Animals smaller than a 130cm in height had a significantly (p<0.05) greater tick infestation (36.5±5.0) compared to animals taller than 130cm (21.2±1.5). This trend was also observed for body length. Animals with a body length shorter than 145cm had a greater (p<0.05) average tick infestation of 41.3±4.5 compared to 23.2±1.3 for animals longer than 145cm, indicating a 44% greater tick infestation for the shorter animals. The selection of cattle for adaptability and thus increased production under tropical conditions, through resistance to ticks should be for animals of medium frame sizes having smoother coats that are able to dissipate heat effectively. In the fifth study, the relationship between growth parameters, scrotal circumference and sheath area in tropically adapted beef bulls was investigated. The relationship between growth parameters such as initial weight at the start of the trial, average daily gain for the trial period (ADG), average daily gain per day of age (ADA), feed conversion ratio (FCR), final weight at the end of the trial, scrotal circumference (SC) and age and sheath area in Santa Gertrudis bulls were examined. To investigate the relationship between growth parameters and scrotal circumference, growth test data of 97 on-station performance tested Santa Gertrudis bulls were used while growth results of 55 Santa Gertrudis bulls tested under semi-intensive conditions were used to investigate the relationship of sheath area with growth performance. Bulls were divided into two groups according to their average sheath area (470 cm2). 28 Bulls were assigned to the small sheath group (SSA) below 470 cm2 while 27 bulls were assigned to the large sheath group (LSA) above 470 cm2. The LSA group possessed a 15% (66 kg; p < 0.05)heavier final weight than that of the SSA group. The LSA group had a 64% (241 cm2; p < 0.05) larger sheath area (378 ± 60 vs 619 ± 161 cm2) than the SSA group. A significant phenotypic correlation between ADG (r = 0.31, p < 0.05) and sheath area was found. The correlations between sheath area and initial weight (r = 0.42, p < 0.001) and between sheath area and final weight (r = 0.45, p < 0.001) were also highly significant. A highly significant correlation (p < 0.001) was observed between initial weight and SC and between final weight and SC, while significant correlations (p < 0.05) were also observed between SC and age and between SC and ADA for bulls tested intensively on station. It appears that SC and faster growth rate are compatible in young bulls. In addition, giving careful attention to sheath area in bulls, selected as yearlings is possible without necessarily sacrificing growth performance. In the sixth study, associations among growth and quantitative testicular traits of tropically adapted yearling bulls fed different dietary energy levels were investigated. High energy (HE), medium energy (ME) and low energy (LE) diets were fed to young Bonsmara bulls post-weaning and the subsequent effects on scrotal circumference (SC), average daily gain over an 84 day performance test trial period (ADG), average daily gain per day of age (ADA), body condition score (BCS), testicular histology and seminal traits were examined. Bulls fed the HE diet were significantly heavier and had a greater ADA, with the HE bulls (999.1 ± 7.13 g) out-performing the ME (804.1 ± 12.61 g) and LE (713.2 ± 12.95 g) bulls in terms of growth rate over the duration of the experimental period. Diet influenced (p < 0.001) BCS with the HE bulls (3.9 ± 0.05) having more body fat compared to the ME (3.3 ± 0.06) and LE (3.0 ± 0.08) bulls with the same effect (p < 0.001) observed in the carcass dressing percentage of the bulls fed different levels of energy. SC did not differ significantly between HE, ME and LE fed bulls. Seminal traits, such as semen concentration were significantly (p < 0.001) lower in bulls fed the HE diet (1.3 ± 0.134) compared to those fed the ME diet (2.4 ± 0.18) and LE diet (2.6 ± 0.16). Similarly, linear movement of sperm was also affected by diet and movement was slower (p < 0.05) in bulls fed the HE diet (1.7 ± 0.30) compared to bulls fed the ME diet (2.2 ± 0.31) and LE diet (3.1 ± 0.23). The percentage total major (p < 0.001) and total minor (p < 0.05) sperm defects were also greater in the HE fed bulls (27.1 ± 6.82 and 7.4 ± 0.91% compared to 9.7 ± 1.45 and 5.5 ± 0.87% for the ME fed bulls and 5.4 ± 1.26 and 3.9 ± 6.58% for the LE fed bulls). Dietary energy level significantly (p < 0.001) influenced the percentage inactive seminiferous tubuli, with bulls fed the HE diet having 35% more seminiferous tubules classified as inactive compared to those bulls fed ME and LE diets. Scrotal fat deposits were higher (p < 0.05) in bulls fed the HE diet (243.4 ± 21.59 g) compared to those fed the ME (110.0 ± 12.1 g) and LE (88.4 ± 9.65 g) diets. Correlation coefficients between SC and growth traits were generally favourable for the different dietary treatments. Correlations between live weight and SC were 0.51, 0.45 and 0.52 (p < 0.05) for the HE, ME and LE groups respectively. A negative association was observed between BCS and progressive sperm motility in bulls fed the HE diet (r = -0.54, p < 0.05). The percentage major seminal defects was negatively correlated with live weight in bulls fed the LE diet (r = -0.46, p = 0.008) and ME diet (r = -0.40, p = 0.08), while this characteristic was negatively correlated with mass movement of sperm (r = -0.63; p < 0.05) and percentage live sperm (r = -0.60; p < 0.05) in HE fed bulls. The present results suggest that feeding HE diets to young bulls influenced their testicular development and reduced their reproductive potential. In the seventh and last study, the relationship between scrotal circumference, quantitative testicular traits and growth performance in tropically adapted yearling beef bulls differing in age was investigated. The bulls were fed a high energy diet and the effect on average daily gain (ADG), average daily gain per day of age (ADA), body condition score (BCS), feed conversion efficiency (FCE), scrotal circumference (SC), seminal traits and testicular histology were examined in Bonsmara bulls (n = 34). The high energy diet contained not less than 11 MJ ME / kg DM and 13.8% CP. Bulls were fed the HE diet from an average starting age of either 210 (YB; n = 17) or 257 days (OB; n = 17) for a total of 112 days. Despite the age difference, growth and carcass traits were similar for the bulls irrespective of starting age. Scrotal weight, scrotal skin weight and scrotal skin thickness were greater (p < 0.001) in the YB (2223.4 ± 11.68g; 576.6 ± 25.17g and 4.5 ± 0.15mm) compared to that of the older group (1010.15 ± 50.10g; 255.9 ± 13.55g and 4.0 ± 0.13mm). The weight of the epididymal / spermatic cord (WESC) was heavier (p < 0.05) in the older bulls (70.2 ± 3.53g) compared to that of the younger group (47.2 ± 3.17g) with a similar trend observed when the volume of the epididymal / spermatic cord (VESC) was measured. Scrotal fat deposition was significantly (p < 0.001) increased by initial age (YB = 1164.7 ± 102.20g vs OB = 263.5 ± 27.52g). Age of the bulls also influenced (p < 0.05) the percentage inactive seminiferous tubuli, with the young bulls having 9.7% more seminiferous tubules classified as inactive compared to the older bulls. Seminal quality showed a similar trend and was generally of a lower standard than that of the group tested at an average of 369 days of age. Semen concentration (p < 0.05) and percentage linear sperm motility (p < 0.08) were the traits most affected by age. A negative correlation was evident between BCS and testis weight (r = - 0.51; p = 0.0342), testis volume (r = -0.52; p = 0.0318) and SC of dissected testis (r = -0.49; p = 0.042) in the young bulls. Correlation coefficients between SC and testis traits such as testis weight and testis volume were high (p < 0.05) for both the groups (YB; r = 0.87 and r = 0.87 and OB; r = 0.77 and r = 0.81). The relationship between SC and scrotal fat (r = 0.85) was highly significant (p < 0.001) only in the younger group. The results suggest that when bulls are fed a high energy diet, the age at which such feeding commences is of importance as regards their subsequent fertility. Copyright
Thesis (PhD)--University of Pretoria, 2006.
Animal and Wildlife Sciences
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O experimento foi conduzido objetivando-se avaliar a substituição parcial da fração protéica do concentrado por subproduto da produção de lisina (SPL) sobre a composição corporal e exigências nutricionais de tourinhos Santa Gertrudes, terminados em confinamento. Foram utilizados 33 animais com idade média de 10 meses e peso médio inicial de 242 kg, confinados em baias individuais por 115 dias, após 56 dias de adaptação. Seis animais foram abatidos no início do período experimental e constituíram os animais-referência. Os animais receberam dietas contendo 80% de concentrado, sendo testados os níveis de 0; 4,5; e 9,0% de inclusão do SPL na matéria seca da dieta. Os tratamentos sem e com 4,5% de SPL não diferiram para nenhum dos parâmetros avaliados. Já os tratamentos sem e com 9,0% de SPL diferiram quanto ao ganho de peso do corpo vazio, composição final em água e taxas de deposição e composição do ganho de peso vazio em minerais. Os tratamentos com 4,5 e 9,0% de SPL diferiram entre si quanto ao peso de carcaça e de corpo vazio finais, ganho de peso de carcaça e de corpo vazio, composição do corpo vazio em proteína e em minerais, taxas de deposição e composições do ganho para proteína e minerais. Os valores observados foram 243,6; 247,3 e 226,5 kg para peso final de carcaça; 392,7; 398,7 e 365,7 kg para peso final de corpo vazio; 0,64; 0,69 e 0,51 kg/dia para ganho de peso de carcaça; e 1,03; 1,11 e 0,82 kg/ dia para ganho de peso do corpo vazio, respectivamente para os tratamentos sem, com 4,5 e 9,0% de SPL. vi Em relação às exigências, verificou-se que, a exigência de energia líquida encontrada para ganho de 1 kg foi de 3,65; 4,17 e 4,63 Mcal, e a exigência de proteína metabolizável foi de 218,55; 216,19 e 202,19 g, respectivamente para animais de 300, 400 e 500 kg de peso corporal. O valor de exigência líquida para mantença encontrada...
The objective was to evaluate the effects of replacing part of the protein fraction of the concentrate by concentrated lysine production byproduct (LBP) on body composition and nutritional requirements of Santa Gertrudis young bulls, fattened in feedlot. Thirty-three 10-month-year-old animals, with initial body weight of 242 kg, were kept in individual pens during 115 days after 56 days of adaptation. Six animals were slaughtered after adaptation and were considered reference-animals. The concentrate proportion on diet was 80%, on dry matter basis, and the levels of LBP studied were: 0, 4.5 or 9.0%. There were no significant differences among treatments without and with 4.5% of LBP on diet. Empty body daily weight gains, final body composition on water and daily rates of deposition and gain composition on ash were significant different among treatments without and with 9.0% of LBP. The treatments with 4.5 and 9.0% of LBP showed significant differences for final carcass and empty body weights, empty body and carcass daily gains, body chemical composition on protein and ash, daily rates of deposition and gain compositions on protein and ash. The LBP can be used as food for fattening bovines receiving diets with high concentrate proportion, substituting part of protein fraction, the level of 4.5% of LBP on dry matter diet was more indicated. In relation to the requirements it was verified that, the net energy requirement observed for weight gain of 1 kg was 3.65, 4.17 and 4.63 Mcal, and the metabolizable protein requirement was 218.55, 216.19 and 202.19 g, viii respectively to animals with 300, 400 and 500 kg of body weight. The estimated maintenance energy requirement observed was 75.6 kcal/ LW0.75/ day.

Resumo: O experimento foi conduzido objetivando-se avaliar a substituição parcial da fração protéica do concentrado por subproduto da produção de lisina (SPL) sobre a composição corporal e exigências nutricionais de tourinhos Santa Gertrudes, terminados em confinamento. Foram utilizados 33 animais com idade média de 10 meses e peso médio inicial de 242 kg, confinados em baias individuais por 115 dias, após 56 dias de adaptação. Seis animais foram abatidos no início do período experimental e constituíram os animais-referência. Os animais receberam dietas contendo 80% de concentrado, sendo testados os níveis de 0; 4,5; e 9,0% de inclusão do SPL na matéria seca da dieta. Os tratamentos sem e com 4,5% de SPL não diferiram para nenhum dos parâmetros avaliados. Já os tratamentos sem e com 9,0% de SPL diferiram quanto ao ganho de peso do corpo vazio, composição final em água e taxas de deposição e composição do ganho de peso vazio em minerais. Os tratamentos com 4,5 e 9,0% de SPL diferiram entre si quanto ao peso de carcaça e de corpo vazio finais, ganho de peso de carcaça e de corpo vazio, composição do corpo vazio em proteína e em minerais, taxas de deposição e composições do ganho para proteína e minerais. Os valores observados foram 243,6; 247,3 e 226,5 kg para peso final de carcaça; 392,7; 398,7 e 365,7 kg para peso final de corpo vazio; 0,64; 0,69 e 0,51 kg/dia para ganho de peso de carcaça; e 1,03; 1,11 e 0,82 kg/ dia para ganho de peso do corpo vazio, respectivamente para os tratamentos sem, com 4,5 e 9,0% de SPL. vi Em relação às exigências, verificou-se que, a exigência de energia líquida encontrada para ganho de 1 kg foi de 3,65; 4,17 e 4,63 Mcal, e a exigência de proteína metabolizável foi de 218,55; 216,19 e 202,19 g, respectivamente para animais de 300, 400 e 500 kg de peso corporal. O valor de exigência líquida para mantença encontrada... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The objective was to evaluate the effects of replacing part of the protein fraction of the concentrate by concentrated lysine production byproduct (LBP) on body composition and nutritional requirements of Santa Gertrudis young bulls, fattened in feedlot. Thirty-three 10-month-year-old animals, with initial body weight of 242 kg, were kept in individual pens during 115 days after 56 days of adaptation. Six animals were slaughtered after adaptation and were considered reference-animals. The concentrate proportion on diet was 80%, on dry matter basis, and the levels of LBP studied were: 0, 4.5 or 9.0%. There were no significant differences among treatments without and with 4.5% of LBP on diet. Empty body daily weight gains, final body composition on water and daily rates of deposition and gain composition on ash were significant different among treatments without and with 9.0% of LBP. The treatments with 4.5 and 9.0% of LBP showed significant differences for final carcass and empty body weights, empty body and carcass daily gains, body chemical composition on protein and ash, daily rates of deposition and gain compositions on protein and ash. The LBP can be used as food for fattening bovines receiving diets with high concentrate proportion, substituting part of protein fraction, the level of 4.5% of LBP on dry matter diet was more indicated. In relation to the requirements it was verified that, the net energy requirement observed for weight gain of 1 kg was 3.65, 4.17 and 4.63 Mcal, and the metabolizable protein requirement was 218.55, 216.19 and 202.19 g, viii respectively to animals with 300, 400 and 500 kg of body weight. The estimated maintenance energy requirement observed was 75.6 kcal/ LW0.75/ day.
Orientador: Alexandre Amstalden Moraes Sampaio
Coorientadora: Wignez Henrique
Banca: Guilherme Fernando Alleoni
Banca: Alexandre Rodrigo Mendes Fernandes
Banca: Mauro Dal Secco de Oliveira
Banca:Atushi Sugohara
Doutor