Academic literature on the topic 'Sheep Lambs'

Six potential methods for fostering lambs were investigated. Three involved transferring soft paraffin, dilute detergent solution or a hessian coat from a ewe's own lamb to a potential foster lamb. The effectiveness of placing own lamb's wool in a mask worn by the foster ewe was also tested, together with washing lambs in detergent solution. In the sixth procedure, untreated foster lambs were merely confined with the foster ewe. The first 3 methods, which attempted to transfer odour between lambs were 80-93% successful, and transfer of soft paraffin and coats resulted in earlier acceptance of alien lambs than complete washing or confinement alone. The effectiveness of a ewe mask containing own lamb's wool was intermediate. The initial application of soft paraffin, prior to transfer, also appeared to increase the attractiveness of alien lambs to ewes. Some flock differences in ease of fostering were encountered.

Quantitative genetic analysis of variability and relationship of lambs body weight traits in indigenous pirot sheep population are done. The examined lambs had high variability which very suitable for selection on a larger weight. There is a high and very significant correlation between the body weight of lambs with 30 and 60 days (.969 **) and the weight with 30 and 90 days (.914 **). There is also a highly significant correlation between the weights of lambs with 60 and 90 days of age (.904 **). From our research, we can see that the first month of the lamb's life is very important for the further development of the body. There is different level of correlation between weight of lambs. This gives us an idea to say that many paragenetic factors are crucial for the growth of lambs from birth to weaning. The coefficient of multiple determination (R2) is 0.845 which means that 8.45% of the lamb's body weight variance at 90 days is determined by the variance of the set of predictor variables (PI-60, 30, 1). Each increase in lamb body weight during the observed periods of age is associated with an increase in the score of depending variable PI90. In particular, any increase in lamb body weight at birth by 1 kg is associated with an increase in lamb body weight from 90 days by 0.238 kg.

Abstract The effects of dietary energy source, energy level, sheep age, and sheep sex on flavor and off-flavor intensity were evaluated. Consumer panelists, with previous lamb-eating experience, assessed lamb flavor and off-flavor intensity on a 100-point, end-anchored scale (0 = very mild to 100 = very intense), with off-flavor being defined as anything different than lamb flavor. Lamb longissimus thoracis (LT) and whole, boneless ground shoulder (GS) formed into patties were evaluated. Trial 1 was a randomized complete block design with a 3 × 2 factorial arrangement of treatments. Sheep age (ewe lambs, yearling ewes, and mature ewes; n = 16/age) and ad libitum access to diets [alfalfa pellets (AP) or whole-shelled corn (WSC100)] were treatments. The LT from mature ewes had a greater (P ≤ 0.02) off-flavor intensity when compared with yearling ewes and ewe lambs. Ground shoulder from sheep raised on AP had a greater lamb flavor (P ≤ 0.04) and off-flavor (P ≤ 0.04) intensity than GS from sheep consuming WSC100. Trial 2 was a randomized complete block design with a 3 × 2 × 2 factorial arrangement of treatments. Three dietary treatments [AP, WSC100, and restricted intake of whole-shelled corn to 85% of ad libitum (WSC85)], lamb sex (ewes and wethers; n = 48/sex), and lamb age [short fed, 177 ± 16.6 d of age and 93 ± 20.5 d on feed (DOF); long fed, 294 ± 7.0 d of age and 219 ± 3.8 DOF]. Flavor intensity of the LT was greater (P ≤ 0.05) from lambs offered AP when compared with lambs offered WSC85, whereas lamb flavor of the LT from lambs fed WSC100 was intermediate and not different from the lamb flavor of the LT of lambs fed AP or WSC85. The LT of long-fed lambs had a greater (P ≤ 0.01) lamb flavor and off-flavor intensity when compared with short-fed lambs. Lambs offered AP resulted in a GS with greater lamb flavor intensity (P ≤ 0.01) when compared with lambs offered WSC85 and WSC100, with no diet influence on GS off-flavor intensity. Long-fed lambs produced GS with a greater lamb flavor (P ≤ 0.01) and off-flavor (P ≤ 0.01) intensity when compared with GS from short-fed lambs. Results from the two trials indicate lamb flavor and off-flavor intensity were greater from sheep offered a high-forage (AP) diet when compared with a high-concentrate (WSC) diet. Lamb flavor intensity increased as age of the sheep at harvest increased, suggesting dietary management and associated age-related effects at harvest will influence consumer perception of lamb flavor.

The objective of the study was to evaluate interaction effect of genotype and dam’s litter size on selected productive traits of origin Czech sheep breeds. The data was provided by the Union of Sheep and Goat Breeders in the Czech Republic and contained the whole active purebred population of Wallachian and Sumava sheep in the Czech Republic in 2015. Selected productive traits with affiliation to ewes ‘reproductive and lambs’ growth performance were analyzed. Statistical evaluation of was conducted using SAS 9.3. (SAS/STAT® 9.3., 2011), GLM procedure. No significant differences were detected among Wallachian sheep regardless theirs litter size. Significantly lower total number of lambs born (−0.26 to −0.30 lamb) or reared at 14 days (−0.15 to −0.21 lamb) and 100 days (−0.24 to −0.27 lamb) of age per ewe per lambing were observed in groups of Sumava sheep born as singles and twins in comparison to triplets and quadruplets group. Similarly, Sumava sheep of single and twins reached significantly lower total number of lambs born (−0.23 to −0.34 lamb) or reared at 14 days (−0.22 to −0.33 lamb) and 100 days (−0.28 to −0.41 lamb) of age per ewe per lambing to Wallachian sheep regardless their dam’s litter size. No significant decrease of group of Sumava sheep born as triplets and quadruplets was detected in comparison to Wallachian sheep. Moreover, higher (+2.6 kg, P < 0.05) total live weight of lambs at 100 days of age from total number of lambs reared at 100 days of age per ewe was detected in group of Sumava born as triplets and quadruplets in comparison to group of Wallachian sheep born as twins. Both sheep breeds are useable in the crossing with other sheep breeds in specified conditions. Results of presented study suggested also potential aim breeding process in Sumava sheep.

In recent years, an increasingly high proportion of the country's ewes have been housed indoors for lambing, penned at high population densities. When observing suckling, for other purposes (Horrell et al. , 1987), we noticed that there seemed to be frequent disturbances of the normal suckling routine. The general pattern of suckling in extensive conditions has been described (Ewbank 1967). It involves suckling at fairly regularly intervals, with uninterrupted sucking for a period of 1-5 mins (in the first week) declining to 10-25 seconds in older lambs, until either the ewe moves away or the lamb ceases spontaneously; lambs rarely attempt to suck at unrelated ewes and twins tend to suck together. In contrast, we saw many attempts by lambs in indoor pens to suck at unrelated ewes, and ongoing suckling often seemed to be disturbed early on by alien lambs intruding, aggression on lambs by the ewe, lambs knocked off by other ewes, and other external events. If these differences are considerable, Intensive lambing conditions may have important implications for the efficiency of milk interchange. This project was designed to compare systematically the pattern of suckling in extensive and intensive conditions and to quantify the Incidence of various disturbances of suckling.

AbstractSignificant breed differences in grazing, activity, social and other affiliative behaviours are known to exist in sheep. The roles of maternal and offspring genotype in determining the development of breed-specific behavioural differences in lambs were investigated using embryo-transfer. Two breeds of sheep (Suffolk and Scottish Blackface) were chosen as they differ markedly in social and affiliative behaviours. Sixty ewe-lamb pairs (15 each of the four combinations of ewe and lamb) were observed over the first 3 days after lambing, then when the lambs were aged between 2-5 months old and during the first 6 weeks after weaning. Lamb breed was the main factor affecting lamb activity at birth and play behaviour over the first postnatal days, with Blackface lambs being significantly more active than Suffolk lambs. Lamb sucking behaviour during this period, however, was significantly affected by ewe breed with a higher frequency of sucking interactions observed with Suffolk ewes. When out at grass the two breeds of ewe differed in their use of the field, with Blackface ewes using upland areas whilst Suffolk ewes were found almost exclusively in the lowland parts. Ewes also differed in their spatial relationship to their lamb, with Blackface ewes maintaining a closer relationship to their lamb than Suffolk ewes, regardless of lamb breed. Blackface ewes were also more active than Suffolk ewes and were more frequently observed grazing. The breed of their mother significantly influenced the behaviour of the lambs, and their spatial relationships to other sheep, both before and after weaning. Lambs with Blackface mothers were more active than lambs with Suffolk mothers and this difference persisted after weaning. Blackface-reared lambs also had a shorter nearest neighbour distance after weaning, aggregated into smaller subgroups and were significantly more likely to be in upland areas of the field, regardless of lamb breed, than lambs reared by Suffolk ewes. Maternal influence, therefore, plays an important role in shaping the behaviour of their offspring in sheep, although neonatal lamb activity is not affected by maternal behaviour.

This paper reports the results of 3 studies on variables associated with the use of neatsfoot oil for substitutive or additive fostering of lambs. In the first study, neatsfoot oil was applied at the rate of 60 mL/kg of liveweight to 3-day-old lambs from Merino and Border Leicester x Merino ewes, and the lambs were exchanged between pairs of ewes of the same breed 3.5, 7 or 24 h later. The proportion of ewes accepting the alien lamb from the other ewe of the pair within 17 h generally increased with the period from application to exchange. Crossbred ewes accepted the foster lambs more readily than did the Merinos. Acceptance rates with batches of neatsfoot oil produced by different methods were similar. We found no advantage in smearing the ewe's nose with neatsfoot oil at the time the oil was applied to the lamb. Additive fostering in 20 ewes that accepted the alien lambs and were left with their own lambs was 95% successful and appeared permanent. In the second study using similar methods, with lambs of 28 crossbred ewes anointed 24 h prior to exchange, no advantage was found in presenting the foster lamb to the ewe at night over presentation during the day. Most foster lambs were accepted within 12 h, and all ewes reaccepted their own lambs after a 13 h absence. The acceptance rate of foster lambs by the crossbred ewes ranged from 70 to 83%. In the third study, 27 Merino ewes whose lambs were anointed with neatsfoot oil 7-40 h after birth, were presented with freshly anointed foster lambs 24 h later. The rate of acceptance of the foster lambs within the next 24 h was 74%,but many ewes required prolonged restraint before reaccepting their own lambs after 5-26 h separation. The results show that most ewes can be induced to accept foster lambs 1-2 days post partum, if their offspring have been liberally coated with neatsfoot oil for 24 h, and then substituted with neatsfoot-treated foster lambs. For additive fostering, the ewes' offspring should be returned within a few hours.

Reproductive performance of ewes in a large Dorset stud flock is reported. The data included 2488 ewes with 10016 joining records over 25 years. Average performance for reproductive traits were: fertility 92%, litter size 1.31, neonatal lamb survival 91%, lamb survival to weaning 85%, with overall lambs born 1.20 and lambs weaned 1.02 per ewe joined. Differences between breeds (Poll Dorset and Dorset Horn), season of birth (spring and autumn) and season of joining (spring and autumn) were significant for most reproduction traits. Linear and quadratic regressions for age of ewe at joining were highly significant for all traits (P < 0.001) with maximum performance between three and six years of age. Estimates of heritability for ewe reproductive traits were: 0.062 � 0-02 for number of lambs born and 0.04 � 0.01 for number of lambs weaned per ewe joined, and component traits, 0.02 �0 -01 for fertility, 0 08 � 0 -02 for litter size and 0.00 � 0.01 for lamb survival. Estimates of repeatability were less than 0.14 for all the reproduction traits, which resulted in substantially higher predicted heritabilities when repeated records were used. Heritability estimates for average ewe lifetime performance, with approximately four records, were 0.08 � 0 06 for lambs born, 0.12 � 0.05 for lambs weaned, 0.08 � 0.04 for fertility, 0.l9 � 0 -04 for litter size and zero for lamb survival. The genetic correlations between litter size and lambs born and weaned were close to unity, whereas those for fertility were lower and declined from lambs born (0.6l � 0.22) to lambs weaned (0-45 � 0.30). The estimated heritability for ewe longevity, defined as the number of years the ewe remained in the breeding flock, was 0.00 � 0.03. The potential for genetic improvement in reproductive rate is discussed in relation to other reports in the literature and in the context of the roles of the Dorset breed in the Australian lamb industry. Increased reproductive rate in Dorset flocks impacts on stud profitability and the rate of genetic improvement from selection for other traits such as liveweight. The parameter estimates derived will be used in compiling breed-specific parameter sets for genetic evaluation in LAMBPLAN.

Recently, in many parts of the world, greater importance has been given to lamb meat as well as to the intensive production of lamb and sheep, due to demand for this type of meat at affordable prices. In Serbia, similar to most European countries, the structure of total sheep meat production comprises about 70% lamb meat and 30% sheep meat. This study assessed resource-based measures on 11 dairy sheep farms and investigated, in a total of 30 lambs, the effects of sex, the presence of bruises and pneumonia in carcasses, and carcass and meat quality. Carcass (carcass length, thigh length, croup width, subcutaneous fat thickness, presence of bruises) and meat quality (pH, temperature, drip, thawing and cooking losses, color, and meat quality classes) traits were measured post mortem. The most common deficiencies on farms were high stocking density, poor hygienic conditions, dirty drinkers, and lack of outdoor access. Regarding sex differences, higher prevalences of carcass bruises and severe pneumonia were recorded in male lambs. Meat pH (pH45min), sensory color score, and prevalence of dark, firm and dry (DFD) meat were higher in lambs with carcass bruises. The occurrence of quality defects (DFD meat) was higher in lambs with severe pneumonia. It can be concluded that it is necessary to improve the welfare conditions on the lamb farms and pre-slaughter conditions in order to achieve better lamb meat quality.

The present paper covers reproductive performance in an artificial-insemination (AI) program of the Sheep CRC Information Nucleus with 24 699 lambs born at eight locations in southern Australia across five lambings between 2007 and 2011. Results from AI with frozen semen compared well with industry standards for natural mating. Conception rates averaged 72%, and 1.45 lambs were born per ewe pregnant for Merino ewes and 1.67 for crossbreds. Lamb deaths averaged 21% for Merino ewes and 15% for crossbreds and 19%, 22% and 20% for lambs from ewes that were mated to terminal, Merino and maternal sire types, respectively. Net reproductive rates were 82% for Merino ewes and 102% for crossbreds. From 3198 necropsies across 4 years, dystocia and starvation-mismothering accounted for 72% of lamb deaths within 5 days of lambing. Major risk factors for lamb mortality were birth type (single, twin or higher order), birthweight and dam breed. Losses were higher for twin and triplet lambs than for singles and there was greater mortality at relatively lighter and heavier birthweights. We conclude that reproductive rate in this AI program compared favourably with natural mating. Lamb birthweight for optimum survival was in the 4–8-kg range. Crossbred ewes had greater reproductive efficiency than did Merinos.

9 pp.
As a general rule, lambs are not purchased until they are at least 8 weeks old and exceed 40lbs. in weight. The lamb should gain an average of .5 to .8 lbs. a day. This publication discusses how to feed a show lamb according to its nutrient needs.

Bibliography: leaves 281-316. Presents investigations on pubertal development in South Australian merino ram lambs and examines the effect of active and passive immunizations against oestradiol-17ℓ or oestrone on testicular maturation.

Five hundred, ninety-seven and 643 white face range ewes were used in a 2 year study, respectively, in a 3-way factorial arrangement to determine effect of supplemental linoleic oil on lamb serum metabolites, thermogenesis and lamb growth. During the last 45 ± 4 days of gestation ewes were group fed a daily supplement of either 0.23 kg•ewe-1•d-1 whole safflower seed (SS) or 0.34 kg•ewe-1•d-1 whole barley (C). Colostrum was collected from each supplement treatment and pooled according to treatment. At parturition, twin born lambs received either SS or C pooled colostrum. One h postpartum, lambs were placed in a 0°C dry cold chamber for 30 min. and lamb rectal temperature was recorded at one min intervals. Blood samples were taken prior to and after cold exposure. Lamb weights were taken at birth, turnout and weaning for growth. There was no difference (P > 0.10) in body temperatures between lambs born to ewes supplemented with SS vs. C or between lambs given pooled colostrum form SS or C supplemented ewes. At 0 minutes lambs born to SS supplemented ewes had lower glucose (P = 0.05), total protein (P = 0.05) and NEFA (P = 0.003) and higher BUN (P = 0.03) than lambs from C supplemented ewes. Lambs from SS supplemented ewes had lower NEFA (P = 0.01) after cold exposure (30 minutes). Total protein concentration was similar in year 1 but lower (P < 0.01) in year 2. Concentrations of aGP were higher in lambs from SS supplemented ewes at both 0 and 30 min in year 1. Lambs from SS ewes had higher (P < 0.01) blood aGP levels at both 0 and 30 min in year 1 than in year 2. No differences (P > 0.30) were detected between lambs from SS ewes vs. C for changes in any blood metabolites measured during cold stress period. No differences (P > 0.12) were detected for average date of birth, number of lambs born, number of lambs present at turnout and weaning or for weight of lambs at turnout or weaning for ewes receiving either SS or C supplements.

Includes bibliographical references (leaves 276-2970. Investigations presented involve 18 hour to 5 day old South Australian merino lambs. Some twin lambs were available for comparative studies. Examines the relationship between the strength of ewe-lamb bond and the lamb's ability to follow the mother, the energy availability and usage in the lamb, particularly for locomotion, and the metabolic and cardiorespiratory responses to locomotion.

Thesis (MScAgric)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: The aim of the study was to determine the effect of increasing levels of Maize silage in finishing diets for Merino lambs on their feed intake, production performance, feed conversion ratio, digestibility and meat quality. Concerns exist regarding the intake of high moisture and fibre containing silage in sheep due to the physical fill effect thereof. To determine the efficiency of silage as feed ingredient for sheep, maize was cut at 27% dry matter (DM), compacted into 220 litre plastic drums, sealed and left to ferment for 60 days. The silage produced was analysed for fermentation end products and the nutritive value determined. The silage produced had an optimum pH, starch and water soluble carbohydrate (WSC) content. The crude protein (CP) content (112.2 g/kg DM) was higher than expected. Four diets containing, on a dry matter (DM) basis either, 0, 20, 50 or 70% maize silage was formulated on an iso-nutrient basis with exception of neutral detergent fibre (NDF). The aim was to establish the effect of increasing levels of silage on animal production with regard to dry matter intake, growth, digestibility and meat quality. Diets were formulated on an iso-nutrient basis to match the 70% silage diet and therefore had relatively low specifications due to the high inclusion of silage from the 70% silage diet. A growth study and an in vivo and in vitro digestibility study were conducted to determine the effect of the different diets on feedlot sheep production. Meat quality was also determined to establish whether the experimental diets had an effect on meat quality. Forty lambs in a completely randomised block design, with four treatments, were used in a 60-day finishing study. The dry matter intake (DMI) of lambs decreased as silage inclusion increased above the 20% silage inclusion level. At the 20% inclusion rate, the feed intake of the animals was stimulated. This resulted in significant differences found between the cumulative intake of the low and the high silage diets. Feed conversion ratio (FCR) was poorer, however, for the control and 20% silage diets. The poor FCR most likely was related to the quality of the feed ingredients used in the formulation of the control feed and the concentrate in the 20% silage diet rather than the silage itself. Significant differences were also found in the dressing percentage of the slaughtered animals where the 20 and 50% silage diets had a higher dressing percentage than the control and 70% silage diets. It was concluded that silage can be successfully incorporated into sheep diets, especially at low levels where its inclusion stimulates intake. Eight animals per group were used in an in vivo digestibility study to determine the apparent digestibility of the experimental diets. Feed, faeces and urine samples collected during the trial period were analysed for the respective nutrients. The 20% diet, even though having the best overall apparent digestibility, did not result in better production responses. Lambs on the 20% silage diet had the highest daily DM intake, which resulted in them having the highest energy intake. There were no differences in total energy excreted between the silage-based diets. This resulted in the 20% silage diet also having the best energy retention. Nitrogen retention was the highest for the control and 20% silage diets. This can be ascribed to the low quality of the concentrate part of the diet. The 20% silage diet, as previously stated, had the highest apparent DM and organic matter (OM) digestibility, while the control diet showed the lowest overall nutrient digestibility. The low nutrient digestibility of the control diet can be ascribed to the relatively poor quality ingredients used. There were no differences in the crude protein (CP) digestibility between the control and the 20% diet. Both proved to be higher than the CP digestibility of the 50 and 70% silage diet. As the neutral detergent insoluble nitrogen (NDIN) was higher for the 50 and 70% diets, this observation was not surprising. Fibre content of the silage-based diets increased as the inclusion level of the silage increased, which resulted in a decrease in overall fibre digestion. Three cannulated sheep were adapted on each experimental diet for two weeks before rumen fluid was collected for the in vitro digestibility study. No differences between the silage based diets were found for in vitro true digestibility (IVTD). The IVTD of the 20, 50 and 70% diets were higher, however, than the IVTD of the control diet confirming earlier observations on the choice of ingredients used in the control diet to formulate iso-nutrient diets. Degradability coefficients were determined for the DM and NDF fractions of the different experimental diets and fitted to the non-linear model; p = a + b (1 – e-ct). The amount of DM that disappeared in a certain time (t) is represented by p. Constant a represents the fraction that was rapidly soluble, b represents the potential degradable fraction and c is the rate at which b was degraded. There were no differences between experimental diets for the rapidly soluble fraction. The silage-based diets had a higher potential degradable fraction (b) but did not differ in the degradability rate (c) from the control diet. Silage-based diets had higher overall effective degradability than the control but did not differ between one another. Constant a was not determined for NDF degradability since the NDF fraction did not have a rapidly soluble fraction. The control diet had the lowest potential degradable NDF fraction with the rate also being lower than the silage based diets. Effective NDF degradability was highest for the 50% silage diet. Lambs used in the finishing study were slaughtered and meat samples taken for meat quality tests. The pH, colour, drip loss, cooking loss, shear force and fatty acid composition were determined on the Longissimus dorsi samples collected at Roelcor (Malmesbury, Western Cape, South Africa). Proximate analysis was also conducted on the meat samples. The experimental diets did not have a significant effect on the proximate chemical composition of the meat. Colour differences were found; however no clear pattern could be established. There were no differences in fatty acid composition. It can be concluded that up to 70% maize silage can be included in the finishing diets of Merino lambs with no adverse effects on the meat quality. The study showed that 20% maize silage can be included in the finishing diets of Merino lambs without negatively affecting intake, production, digestibility or meat quality. Future research is needed to optimise the 20% silage diet, however, and to again look at the effect that it will have on animal production, including the effect thereof on total methane emissions.
AFRIKAANSE OPSOMMING: Die doel van die studie was om te bepaal of mielie kuilvoer doeltreffend gebruik kan word as ‘n komponent in die afronding van Merino lammers. Gedurende die proses is mielies gesny teen 27% droë materiaal (DM), en saamgepers in 220 liter plastiek dromme. Dit is toegelaat om te fermenter vir 60 dae. Die kuilvoer wat daaruit geproduseer is, is geanaliseer vir fermentasie eindprodukte, en die voedingstofwaarde is bepaal. Vier diëte met onderskeidelik 0 (kontrole), 20, 50 en 70% kuilvoer is geformuleer op ‘n iso-nutriëntbasis met die uitsondering van vesel (NDF). ‘n Groeistudie, tesame met ‘n in vivo en in vitro verteerbaarheidstudie is uitgevoer om die effek van die verskillende diëte op diere produksie te toets. Vleiskwaliteit toetse is ook gedoen om te kyk of die verskillende diëte ‘n effek op vleiskwaliteit het. Veertig lammers, in ‘n ewekeurige blokontwerp, is gebruik in ‘n 60 dae afrondingstudie. Dit is opgemerk dat die DM inname (DMI) afgeneem het soos die kuilvoer insluiting bo die 20% vlak toegneem het. By die 20% insluitingskoers, is voerinname by die diere gestimuleer. Dit het veroorsaak dat beduidende verskille gevind is tussen die kumulatiewe inname van die lae en die hoë kuilvoer diëte. Die voeromsetkoers (VOK) was egter hoër vir die kontrole en 20% kuilvoer diëte. Beduidende verskille is ook gevind in die uitslagpersentasie van die diere, waar die 20% en 50% kuilvoer diëte ‘n hoër uitslagpersentasie as die kontrole en 70% kuilvoer diëte gehad het. Agt diere is per groep gebruik in ‘n in vivo verteerbaarheidstudie om die skynbare verteerbaarheid van die eksperimentele diëte te toets. Voer, feses en urien monsters is gedurende die proefperiode ingesamel en geanaliseer. Die 20% kuilvoer dieet het die hoogste DM en organiese materiaal skynbare verteerbaarheid teenoor die kontrole diet wat die laagste gehad het. Daar was geen verskille in die ru- proteien (RP) verteerbaarheid van die kontrole en 20% kuilvoer diet nie. Beide was hoër as die RP verteerbaarheid van die 50% en 70% kuilvoer dieet. Die veselinhoud van die kuilvoergebasseerde diëte het toegeneem soos die insluitingsvlak van die kuilvoer toegeneem het, wat ‘n afname in veselvertering veroorsaak het. Lammers op die 20% kuilvoer dieet het die hoogste daaglikse DM inname gehad, wat die hoogste energie inname tot gevolg gehad het. Daar was geen verskille in die totale energie inname van die kuilvoergebasseerde diëte – dit het veroorsaak dat die 20% kuilvoer dieet ook die beste energie retensie gehad het. Stikstof retensie was die hoogste vir die kontrole en 20% kuilvoer dieet. Drie gekannuleerde skape is vir twee weke op elke eksperimentele dieet aangepas voordat rumenvloeistof ingesamel is vir die in vitro verteerbaarheidstudie. Geen verskille is gevind vir die in vitro ware verteerbaarheid (IVWV) tussen die kuilvoergebasseerde diëte nie. Hulle was egter hoër as die IVWV van die kontrole dieet. Degradeerbaarheid koëffisiënte is bepaal vir die DM en NDF fraksies van die verskillende eksperimentele diëte en is gepas in die model p = a + b (1 – e-ct). Die hoeveelheid DM wat verdwyn het binne ‘n sekere tyd (t) word voorgestel deur p. Die konstante a verteenwoordig die fraksie wat vinnig oplosbaar is, b verteenwoordig die potensieel degradeerbare fraksie en c is die koers waarteen b gedegradeer is. Konstante a is nie bepaal vir die NDF degradeerbaarheid nie, aangesien die NDF fraksie nie ‘n vinnig oplosbare fraksie gehad het nie. Daar was geen verskille in die vinnig oplosbare fraksie tussen eksperimentele diete nie. Kuilvoer gebasseerde diete het ‘n hoër potensieel degradeerbare fraksie gehad, maar daar was geen verskille in koers van degradering nie. Die kuilvoergebasseerde diëte het ‘n hoër DM effektiewe degradeerbaarheid as die kontrole dieet. Effektiewe NDF degradeerbaarheid was die hoogste vir die 50% kuilvoer dieet. Lammers in die studie gebruik is geslag en vleismonsters is geneem vir vleiskwaliteit toetse, insluitende pH, kleur, drupverlies, kookverlies en taaiheid. Proksimale analise is ook uitgevoer op die vleismonsters. Die eksperimentele diëte het nie ‘n beduidende effek op die proksimale chemiese samestelling van die vleis gehad nie. Kleur verskille is wel gevind, maar geen duidelike patroon kon vasgestel word nie. Daar was geen verskille in die vetsuur samestelling nie. Daar kan dus tot die gevolgtrekking gekom word dat mielie kuilvoer ingesluit kan word in die afrondingsdiëte van Merino lammers, tot by 70%, sonder enige negatiewe effekte op die vleiskwaliteit. Daar is tot die gevolgtrekking gekom dat mielie kuilvoer suksesvol geïnkorporeer kan word in skaapdiëte, veral teen lae vlakke (20%) waar die gebruik nie net inname stimuleer nie, maar ook geen negatiewe effekte het op produksie en verteerbaarheid nie.
Dr. Francois van de Vyver, Cape Wools and NWGA for providing funding in the form of post graduate bursaries

Spring-born ram lambs were used to examine: (1) sexual maturational changes in LH, FSH and prolactin (PRL) secretion, testicular gonadotropin receptors, and testicular size and function; (2) predictability of yearling ram reproductive function from juvenile testicular size and reproductive hormone measurements. Despite continuous increases in testis size, serum LH-profile characteristics became greatest between 2 and 4 months and declined thereafter. However, LH-peak frequency increased by about 2-fold between 6 and 7 months; this was associated with marked increases in testosterone (T) secretion and spermatogenic function. Mean FSH and PRL levels were maximum at 2 months and 3 to 5 months, respectively, and decreased thereafter. Increases in steroidogenic and spermatogenic function were due partly to increases in testicular content of LH and FSH receptors. Yearling ram testis size and spermatogenic function were predictable from testis size at 5 to 6 months, neonatal (50 days) secretion of LH and T, and pubertal (150 days) secretion of T. However, combinations of testicular size and reproductive hormone measurements provided greater predictive power.

Lamb production dominates in organic sheep production, while milk production is much less present and very rare. There are usually two basic systems of breeding in lamb production: fattening of lambs on pasture and combined fattening of lambs. In organic goat breeding, the most common is the organic production of milk and dairy products, primarily quality goat cheeses. The cultivation system is usually a combination of grazing (summer half of the year) and stable cultivation (winter half of the year). Such agriculture provides amortization of the negative effects of social development on the ecosphere and the human population as a whole.

To assess the quality of lamb meat after feeding young sheep with liposomal form of antioxidants is the key aim of the research. Chemical analysis of muscle tissue showed a significant (p≤0.05) increase in fat in the m. Longissimus dorsi and neck muscles by 5.3 % and 7.1 %, respectively. A significant increase in protein was observed in the average samples of leg (by 11.1%) and neck muscles (8.7 %). The calorific value of meat significantly increased in the carcasses of young animals of the experimental group. The average samples of the m. Longissimus dorsi and neck muscles showed an increase of this indicator by 3.6 and 7.6 % (p≤0.05), respectively

We have developed a method of estimating the aspect ratio of a pipe wall thickness to diameter (t/d) using a hollow cylindrical guided wave (HCGW). The HCGW is an ultrasonic guided wave in a pipe. The method is very useful for onsite and nondestructive estimation of pipe wall thickness. It is based on the change of the dispersion relation of the HCGW as a function of t/d. The group velocity of the primary wave (first arriving wave packet from an impulse source) of the HCGW ranges from the bar velocity to the sheet velocity as a function of t/d. The bar velocity is the velocity of the DC component of the guided wave propagating in a solid cylinder; the sheet velocity is that of the S0 mode Lamb wave. The first part of the paper describes the principle of the method. In the last part, a laser ultrasonic method was employed to verify the method in both time- and time-frequency domains. The experimental results for aluminum pipes with various t/d’s were in good agreement with the theory.

Abstract The entire electronics industry is now facing a much more insidious counterfeit threat than at any time in the past. The existence of cloned electronic components bearing the markings of major component manufacturers in today’s global supply chains has been clearly established within SMT’s labs over the past 3 years. The most worrisome aspect of these “made from scratch” fakes is their ability to easily pass current Industry-Standard counterfeit inspection processes and electrical testing to the manufacturers’ data sheet. My presentation will focus on several actual examples of this most concerning advanced counterfeiter capability and some of the processes utilized by SMT as an obsolescence component supplier and testing lab to mitigate this new and growing threat from making it to our OEM & CM customers.

The goal of this project was to develop a model for a Combined Photovoltaic/Thermal (PV/T) unit to ease in the assessment of potential changes to the unit before fabrication of actual parts. This process reduces the time to assess changes in the system; once the initial model is created changes are relatively simple. It also reduces cost incurred for actual testing by certified labs and can simulate output variations in different climate conditions, site locations and times of year. A commercially available PV/T unit was chosen for analysis, which utilizes two water channels under the photovoltaic assembly instead of the conventional sheet-and-tube design to actively cool the solar cells while also collecting thermal energy that can be used for heating water or air via a heat transfer system. The project described in this paper modeled the PV/T unit in two ways: (1) as a one-dimensional theoretical model and (2) modeling the system in ANSYS FLUENT and simulating the fluid flow, energy and radiation models using computational fluid dynamics (CFD). The baseline CFD model was correlated to published Solar Rating and Certification Corporation (SRCC) test data for pressure drop and thermal performance to gage accuracy of the model. Through a literature search of past work on similar modules and systems, several potential improvements to the unit were identified and a detailed analysis was conducted by individually adding each to the theoretical model, then comparing them to the output of the baseline model. Combinations of improvements were evaluated as well and assessed based on output improvement, technical feasibility and expected cost. The accuracy of the 1-D model was compared to the CFD model to assess the benefits gained from the added complexity of using computational fluid dynamics.