Iman N Y, Slyter A L
Department of Animal and Range Sciences, South Dakota State University, Brookings 57007-0392, USA.
J Anim Sci. 1996 Aug;74(8):1765-9. doi: 10.2527/1996.7481765x.
Cumulative lifetime (five lamb crops) lamb production and wool production of 681 ewes were evaluated in this study. Lamb production and wool production from each ewe at the end of age 2, 3, 4, 5, and 6 yr were added to the previous year's production and analyzed within age of ewe. If a ewe failed to lamb, died, or was culled, it received a zero for that year and subsequent years. Main effects in the model included ewe breed and management system. Per ewe entering the study, Finn-Dorset-Targhee (FDT) ewes had a higher (P < .01) number of lambs born (7.42 vs 5.70), number of lambs weaned (5.39 vs 4.48), and total lamb weight weaned (131.7 vs 110.5 kg) than did Targhee ewes. Targhee ewes produced more (P < .01) wool (16.1 vs 13.6 kg) than FDT ewes. Range flock ewes had a higher number of lambs born (6.74 vs 6.38; P < .05), number of lambs weaned (5.39 vs 4.48; P < .01), and total lamb weight weaned (135.8 vs 106.5 kg; P < .01) than did farm flock ewes. Farm flock ewes produced more (P < .01) wool (15.2 vs 14.5 kg). A second analysis based on only those ewes retained at the start of each subsequent breeding season showed FDT ewes had a higher (P < .01) number of lambs born (9.96 vs 8.11), number of lambs weaned (7.61 vs 6.57), and total lamb weight weaned (183.8 vs 165.7 kg) after five lamb crops. Targhee ewes produced more (P < .01) wool (22.5 vs 17.6 kg). Farm flock ewes had a higher (P < .10) number of lambs born (9.18 vs 8.89) and produced more (P < .01) wool (21.1 vs 19.0 kg) than range flock ewes. Range flock ewes weaned more (P < .05) lambs (7.27 vs 6.92) and had more (P < .01) total lamb weight weaned (184.3 vs 165.2 kg) than farm flock ewes.
本研究评估了681只母羊的累计终生(五胎羔羊)产羔量和羊毛产量。将每只母羊在2、3、4、5和6岁末的产羔量和羊毛产量与上一年的产量相加,并按母羊年龄进行分析。如果一只母羊未产羔、死亡或被淘汰,那么该年度及后续年度的产量记为零。模型中的主要效应包括母羊品种和管理系统。每只参与研究的母羊中,芬多塞特-塔吉(FDT)母羊的产羔数(7.42只对5.70只)、断奶羔羊数(5.39只对4.48只)和断奶羔羊总重(131.7千克对110.5千克)均高于塔吉母羊(P < 0.01)。塔吉母羊的羊毛产量(16.1千克对13.6千克)高于FDT母羊(P < 0.01)。与农场羊群的母羊相比,草原羊群的母羊产羔数更多(6.74只对6.38只;P < 0.05)、断奶羔羊数更多(5.39只对4.48只;P < 0.01)、断奶羔羊总重更高(135.8千克对106.5千克;P < 0.01)。农场羊群的母羊羊毛产量更高(15.2千克对14.5千克;P < 0.01)。基于每个后续繁殖季节开始时留存的母羊进行的第二次分析表明,经过五胎产羔后,FDT母羊的产羔数(9.96只对8.11只)、断奶羔羊数(7.61只对6.57只)和断奶羔羊总重(183.8千克对165.7千克)均高于塔吉母羊(P < 0.01)。塔吉母羊的羊毛产量更高(22.5千克对17.6千克;P < 0.01)。与草原羊群的母羊相比,农场羊群的母羊产羔数更多(9.18只对8.89只;P < 0.10)、羊毛产量更高(21.1千克对19.0千克;P < 0.01)。与农场羊群的母羊相比,草原羊群的母羊断奶羔羊更多(7.27只对6.92只;P < 0.05)、断奶羔羊总重更高(184.3千克对165.2千克;P < 0.01)。