关键词: 母羊, 产羔数, 采食量, 羔羊, 增重

Abstract: [Objective] Investigate the impact of ewes giving birth to twin and triplet lambs on their feed intake, body condition, and lamb weight gain under consistent nutritional levels and feeding management conditions. [Methods] Xinggao mutton sheep were selected as the experimental animals, and five ewes that had given birth to twin lambs and five ewes that had given birth to triplet lambs during the lactation period were chosen for the feeding experiment. The experimental sheep were housed in individual pens, each equipped with an attached supplementary feeding area for lambs, and the ewes were fed once in the morning and once in the evening for a 45 days trial period. Ewes are monitored for feed intake and body weight, while lambs are monitored for lactation, starter feed consumption, and weight gain. [Results] During the experiment, there was no significant （P>0.05） difference in the average daily feed intake between ewes with twin lambs and ewes with triplet lambs. The weight loss of ewes with triplet lambs was greater than that of ewes with twin lambs. The average birth weight and average total weight gain of lambs in the twin-lamb group were greater than those in the triplet-lamb group, but the differences were not significant （P>0.05）. The average daily weight gain of lambs in the twin-lamb group （on a 5-day cycle） was greater than that of the triplet-lamb group. Notably, the difference in average daily weight gain between the two groups at ages 16-20 days and 21-25 days reached an extremely significant level （P<0.01）. Similarly, the average daily milk intake of lambs in the twin-lamb group was higher than that of the triplet-lamb group, with a significant （P<0.01） difference observed at ages 1-5 days. Conversely, the average daily intake of starter feed in the triplet-lamb group at 8-10 days was significantly higher （P<0.05） than that of the twin-lamb group. In contrast, the twin-lamb group demonstrated significantly higher （P<0.05） average daily starter feed intake than the triplet-lamb group at ages 31-35 days, 36-40 days, and 41-45 days. Furthermore, the average daily milk intake of lambs in the twin-lamb group exhibited an extremely significant negative correlation with the average daily intake of starter feed （R=-0.94, P=0.002）. In the triplet-lamb group, the average daily weight gain was significantly positively correlated with the average daily intake of starter feed （R=0.86, P=0.024）, while it was significantly negatively correlated with the average daily milk intake （R=-0.79, P=0.048）. [Conclusion] Under identical nutritional and feeding management conditions, the weight loss experienced by three-lambing ewes of Xinggao mutton sheep during the lactation period is greater than that of two-lambing ewes. Additionally, the average birth weight, average daily gain, and average daily milk intake of three-lambing lambs are lower than those of two-lambing lambs. When the number of lambs exceeds two, reliance solely on breast milk becomes insufficient to support the growth and development of the lambs; therefore, it is essential to implement scientific and reasonable early supplementary feeding measures.

Key words: ewes, number of lambs, feed intake, lambs, weight gain