棉茬地放牧对母羊繁殖性能及血液性状的影响

利用能繁母羊在棉茬地进行冬季放牧,探讨了棉茬地放牧对母羊繁殖性能及血液生化指标的影响。结果表明,棉茬地地上生物量为6 178.6 kg·hm-2,其中棉叶、棉桃壳等可采食部位约占65%。母羊的日均干物质采食量为1.98kg·只-1。与该区域舍饲母羊群相比,棉茬地放牧母羊后羔羊初生重偏低而死亡率高达12.87%,繁殖成活率降低(P0.05);随着放牧时间的推移,母羊血液游离棉酚浓度呈上升趋势,放牧结束时血液游离棉酚浓度达到131.70mg·L-1;放牧组母羊的血液中白细胞数量显著高于舍饲组(P0.05),而血小板数目、尿素氮浓度和镁浓度显著低于舍饲为主的母羊群(P0.05)。棉茬地作为冷季放牧利用地,能降低饲养成本,但对母羊的繁殖能力和健康有一定影响,建议在棉茬地放牧的同时进行适当补饲。

Effect of cotton stubble grazing on the reproductive performance and blood biochemicals of ewes

This study was conducted to determine the effects of cotton-stubble grazing on the reproductive per-formance,blood biochemicals,and free gossypol content of ewes.The results showed that the above-ground bi-omass of the cotton stubble was 6 178.6 kg?ha—1,and the proportion of edible parts was more than 65%.The average daily dry-matter intake of the ewes from the cotton stubble was 1.98 kg?(d?head)—1.Compared to the indoor feeding group,birth weight of lamb were lower than feeding group,mortality reached 12.87%,re-production rate reduced (P<0.05).The concentration of free gossypol in the serum increased with the increase in grazing time;at the end of grazing,the concentration of free gossypol in the serum was 131.70 mg?L—1, which was significantly higher than that of the feeding group (P<0.05).The white blood cell was significantly higher than feeding group (P<0.05).The blood platelet levels,serum concentrations of total proteins and magnesium in the grazing group were significantly lower than in the feeding group (P<0.05).The serum con-centrations of total proteins and magnesium were slightly higher in the grazing group than in the feeding group (P<0.05).Cotton stubble is used for grazing in the winter in Xinjiang.Grazing on cotton stubble can reduce the feeding cost of the ewes,but it affects their ability to reproduce.To consider the reproductive performance and health of ewes,we suggest appropriate supplementary feeding when the ewes graze on cotton stubble.