Reproductive and economic evaluation of sexual stimulation during the anestrous period in a commercial farm with neonatal lamb losses

ABSTRACT This study was performed during the anestrous, involving 140 Akkaraman Kangal ewes whose lambs had died in the neonatal stage due to pneumonia and enteritis. Intravaginal sponge containing progesterone was placed to the animals (Group 1, n = 70) on day 0 and removed after 7 days, following which 263 µg PGF2α and 500 IU eCG were administered to the sheep. Ram introduction was performed for 7 days (days 8-14), starting from the day after the removal of the intravaginal sponge (day 8). The animals in Group 2 (n = 70) were not exposed to any treatment. Ram introduction was performed simultaneously in both the groups. To determine the reproductive response, reproductive parameters such as estrous, pregnancy, multiple pregnancy, and embryonic mortality rates, number of births, number of offspring, and fertility, as well as their economic implications, were compared between groups. Each reproductive parameter exhibited a statistical difference between groups. An economically positive trend was observed in the study group compared with the control group. It was concluded that in case of lamb losses in commercial farms that derive profit from lambing, pregnancy of ewes can be achieved via sexual stimulation without waiting for the next breeding season.

摘要 本研究于乏情期开展，共纳入140只Akkaraman Kangal品种母羊，其羔羊均因肺炎与肠炎在新生阶段死亡。第1组（n=70）于第0天为受试母羊植入含孕酮的阴道海绵栓，7天后取出，随后注射263 μg 前列腺素F2α（PGF2α）与500 IU 孕马血清促性腺激素（eCG）。自取出海绵栓的次日（第8天）起，开展为期7天的公羊配种诱导（第8至14天）。第2组（n=70）未接受任何药物处理，两组均同步实施公羊配种诱导。为评估繁殖应答效果，本研究比较了两组间的发情率、妊娠率、多胎妊娠率、胚胎死亡率、产羔数、产仔数、繁殖效率及其经济效益等各项繁殖相关参数。结果显示，两组间所有繁殖参数均存在统计学差异；与对照组相比，试验组呈现出经济正向效益趋势。本研究得出结论：对于以羔羊生产为盈利来源的商业牧场而言，若母羊的新生羔羊发生死亡，无需等待下一个繁殖季，即可通过性刺激手段实现母羊妊娠。