Sheep & Goat Research Journal. Volume 28, 2013
Efficacy of Pregnancy-Specific Protein B Assay to Detect Pregnancy and Lambing Rates in Sheep
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Early and accurate identification of pregnancy and lambing rate provides sheep producers many advantages for management decisions that improve flock productivity. The objective of this study was to investigate the efficacy of a commercial pregnancy-specific protein B (PSPB) ELISA assay to predict pregnancy and lambing rate in sheep. On days 20, 25, 30, 40, and 60 postbreeding, blood samples were collected from Columbia and Hampshire ewes. Dorset and Katahdin ewes were sampled 49, 63, and 77 days post ram introduction. Lambing records were used to verify date of conception. Samples were processed using the quantitative BioPRYN®assay for sheep and goat. BioPRYN® classification was 99 percent accurate for pregnant ewes tested after the first month of gestation (i.e., greater than 30 days). For ewes that did not lamb, 90 percent were classified as open and the remaining 10 percent were either misdiagnosed or lost the pregnancy prior to parturition. Ewes carrying multiple pregnancies had greater serum PSPB concentrations than singleton pregnancies from d 40 to d 69 of pregnancy. Effect of breed was detected for serum concentrations of PSPB from d 40 to d 79 of pregnancy. This research indicates that the Bio-PRYN® test is an effective tool to identify pregnancy in sheep. This test could provide estimates of lambing rates; however, variation in PSPB concentrations due to stage of pregnancy and breed of sheep must be factored into this analysis.
Pregnancy-Specific Protein B, Sheep, Fetal Age, Pregnancy Rate, Breed
Growth and Performance of Meat Goat Kids from Two Seasons of Birth in Kentucky
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Little information is available on the impact of season of kidding on growth and performance of meat-goat kids. However, seasonal market trends have many producers in the southeastern United States kidding in the late fall and winter, when animals must be supplemented to meet nutritional needs. Because of this, a study was designed with the objectives being to evaluate the effect of season of birth and ther factors on kid survival to weaning and performance from birth to weaning in meat-goat kids. One hundred and twenty commercial-meat-type does were used in this study. The does were bred for kidding either in the fall (October, November, and December) or spring (March, April, and May) seasons. Data collected included birth weight, birth type, sex, 60 d weight, and 90 d weight. Season of birth had a significant effect on birth (P < 0.0001) and 90 d wt (P = 0.0063), and ADG between 60 d and 90 d (P = 0.0003), with fall-born kids being heavier and having higher daily gains. The interaction between year and birth type was significant (P = 0.0004) for birth weight and the sex by birth/rearing type interaction was significant for 60-d wt (P = 0.0003) and ADG to 60 d (P = 0.0002). These data indicate that season of birth has an impact on some performance traits in meat goat kids. These differences can impact profitability and need to be studied in more detail to determine specific impacts on productivity and profitability of the meat goat industry.
Key Words: Meat Goat, Season of Birth, Kid Performance, Preweaning Growth.
Accuracy of Ultrasonographic Diagnosis of Sex and Effect of Sex and Birth Type on Biparietal Diameter of Saanen Goat Fetuses
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The effects of sex and birth type on biparietal diameter (BPD) were examined from 6th to 14th weeks of gestation in 29 pregnant Saanen does by ultrasonography and after birth by observing the kids directly. Fifteen does delivered singles, 13 had twins and one goat had quadruplet males. Twelve of the twins were male and 13 were female; 7 singles were male and 8 were female. In twin pregnancies, the most accurate period for diagnosis of sex of the fetus by observation of the position of the genital tubercle was the 9th week of gestation. However in singles, two errors (13 percent) were made at the 9th week. Twoway anova analysis revealed that birth type did not affect BPD of Saanen goat fetuses, and sexes did not differ until the 14th week (P < 0.05). Even then, the difference was too small to be useful to predict the sex of the offspring. Chisquare test was applied to compare the success rates of ultrasonography for prediction of fetal sex in different weeks of gestation. Ratio for success of sex determination by ultrasonography was greater from the 9th week of gestation compared with earlier periods in twin pregnancies (P < 0.001). On the other hand, there were no significant differences among gestation weeks in terms of ratio for success of sex determination by ultrasonography in single pregnancies (P > 0.05). Thus it is concluded that sex of the fetus can be diagnosed directly at the 9th week, but one cannot establish the sex of the fetuses by using only ultrasonographic measurements of BPD in either twin or single pregnancies in Saanen goats.
Keywords: Biparietal Diameter, Birth Type, Saanen
Tail Length at Docking and Weaning of Lambs
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This study was conducted with crossbred lambs (n = 109 female and 120 male) to measure tail length at docking and weaning and to determine the change in length between docking and weaning. Lambs were born in April and weaned at approximately 125 d of age. Within 24 h after birth, lambs were weighed and ear tagged, and rubber rings were applied to dock tails. Rings were applied just past the distal end of the caudal folds of the tail, which is just beyond where the folds attached to the tail. Time of rubber ring application was considered time of docking. Using a specially designed device, tail lengths were measured immediately after rubber ring application and at weaning. Lambs were weighed at weaning. Sex and breed type affected (P < 0.005) BW at docking and weaning; male and black-faced × whitefaced lambs were heavier than female and white-faced × white-faced lambs. At docking, neither sex, breed type, nor the sex × breed-type interaction affected actual tail length or tail length adjusted for BW, although BW at docking was a significant (P < 0.0001) covariate. At weaning, the sex × breed type interaction affected (P < 0.002) actual tail length, which was greater (P < 0.002) for male, black-faced × white-faced lambs than for lambs of the other sexbreed-type classifications. At weaning, sex and sex × breed type affected (P < 0.01) tail length adjusted for the covariate BW at weaning. Breed type affected (P < 0.006) the change in actual tail length between docking and weaning (white-faced × white-faced, 2.4 cm, vs. black-faced × white-faced lambs, 2.7 cm). The data indicate clearly that tail length increased between docking and weaning.
Key words: Lambs, Tail Docking, Tail Growth
Technical Note: Effects of Supplementation of Expired Human Foodstuffs on Intake and Digestion of Wethers Fed a Base...
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There is potential for expired human foodstuffs to be used as an energy supplement for livestock. Sixteen crossbred wether lambs were used in a completely randomized design to investigate the effects of feeding supplemental expired human foodstuffs on DM, OM, ADF and NDF digestibility, and intake. Wethers were fed (DM basis) isocaloric amounts of the following treatments: whole barley served as the control (BAR: 0.20 kg·wether-1·d-1), potato chips (PC: 0.15 kg·wether-1·d-1), macaroni (MAC: 0.21 kg·wether-1·d-1), and donuts (DON: 0.15 kg·wether-1·d-1). Wethers were fed 0.60 kg·wether-1·d-1 alfalfa/barley pellets and allowed ad libitum access to chopped hay. Wethers were placed in confinement crates for a 7-d acclimation period, fitted with fecal bags on d 0 and fed twice daily. Following acclimation, daily intakes, refusals, and fecal outputs were used to determine DM, OM, fiber digestibility and intake. Measures of intake and digestibility did not differ (P > 0.23) among treatments. It is concluded that these expired human foodstuffs have the potential to be used in ruminant diets as an alternative to traditional feedstuffs.
Key Words: Digestibility, Expired Foods, Intake.