杜蒙杂交母羊的繁殖规律研究

旨在研究杜蒙杂交母羊的繁殖规律。对内蒙古自治区乌兰察布市四子王旗范围内养殖的杜蒙杂交母羊（n=668）的首次发情时间、妊娠期、产羔率、产双羔率等指标数据进行整理;采用公羊试情方法,观察并记录杜蒙杂交母羊（n=302）的发情周期和发情持续时间。对上述指标数据进行分析,探究该地区杜蒙杂交母羊的繁殖规律。结果表明：杜蒙杂交母羊平均首次发情时间为8.5月龄（最早7.0月龄、最晚10.7月龄）,平均发情周期为16.0 d（最短13.5 d、最长18.5 d）,平均发情持续时间为24.0 h（最短20.0 h、最长27.5 h）,平均妊娠期为146.0 d（最短143.0 d、最长149.0 d）,产羔率为119.7%,产双羔率为19.7%。研究结果为掌握杜蒙杂交母羊自然发情规律,以及准确把握最佳配种时间提供了依据。

Characterization of Reproductive Regulation of Dorper Sheep and Mongolian Sheep Crossbred Ewes

This study aimed to characterize the reproductive regulation of Dorper sheep and Mongolian sheep crossbred ewes. The recorded data of first estrus, gestation period, lambing rate, twinning rate and other reproductive indicators of the crossbred ewes （n=668） raised in Siziwang Banner of Ulanqab City of Inner Mongolia were collected and collated; the estrous cycle and duration of estrus of the crossbred ewes （n=302） was observed by ram mating test. The data of the above reproductive indicators of the two ewe herds were analyzed to reveal the reproductive regulation of the crossbred ewes raised in this region. The results showed that the presence of the first estrus of the crossbred ewes was averagely observed at the age of 8.5 months （the earliest at the age of 7.0 months, the latest at the age of 10.7 months); the average estrous cycle of the crossbred ewes was 16.0 d （the shortest was 13.5 d, the longest was 18.5 d）; the duration of estrus of the crossbred ewes averagely lasted for 24.0 h （the shortest lasted for 20.0 h, the longest lasted for 27.5 h）; the average gestation period of the crossbred ewes was 146.0 d （the shortest was 143.0 d, the longest was 149.0 d）; the lambing rate and twinning rate of the crossbred ewes was 119.7% and 19.7%, respectively. The results obtained in this study provide a basis for understanding the natural estrus regulation of Dorper sheep and Mongolian sheep crossbred ewes and accurately grasping the best breeding time.