新疆牧区温性荒漠草原草群营养成分变化与放牧绵羊体重及产羔性能的关系

Relationship between nutrient composition changes in grass and body weight and lambing performance of grazing sheep in warm desert steppe of Xinjiang pastoral area

为了研究新疆牧区温性荒漠草原草群营养成分的变化对不同品种断奶母羊增重和繁殖性能的影响,试验以放牧的多胎萨福克羊、萨福克羊和中国美利奴羊(新疆军垦型)为研究对象,定期测量6—9月份断奶母羊的体重、牧草产量和草群营养成分(粗蛋白、粗纤维、粗脂肪、粗灰分、钙、磷、无氮浸出物等),记录母羊次年的窝产仔数及羔羊的初生窝重和断奶重,分析牧草产量、营养成分与母羊体重和繁殖情况之间的关系。结果表明:6—8月份,新疆牧区气温较高,降雨天数减少;进入9月份气温下降,降雨天数增多。6—9月份新疆牧区温性荒漠草原类沟羊茅、针茅和新疆绢蒿型草群牧草产量、干物质、粗灰分、粗脂肪和粗纤维含量均呈先下降后升高的趋势。多胎萨福克羊、萨福克羊和中国美利奴羊的体重从63.50 kg、91.33 kg、56.25 kg降至63.33 kg、86.00 kg、51.50 kg,分别下降0.27%、5.84%、8.44%。多胎萨福克羊的体重未恢复至初始体重与体重恢复至初始体重群体母羊的窝产仔数分别为1.83只、1.91只,萨福克羊为0.93只、1.00只,中国美利奴羊为0.95只、1.00只,均差异不显著(P>0.05)。多胎萨福克羊、萨福克羊和中国美利奴羊体重未恢复至初始体重群体母羊所产羔羊的初生窝重和断奶重均显著低于体重恢复至初始体重群体(P<0.05)。说明6—8月份随着气温的持续升高和降雨天数的减少,新疆牧区温性荒漠草原类沟羊茅、针茅和新疆绢蒿型草群牧草的产量呈下降趋势,进入9月份气温降低,牧草产量升高,多胎萨福克母羊放牧适应能力强,维持体重能力优于萨福克羊和中国美利奴羊。

In order to analyze the effects of the changes in the nutrient composition of the grass population on the weight gain and reproductive performance of different weaning ewes in the temperate desert steppe of Xinjiang pastoral area,the grazing multiparous Suffolk sheep,Suffolk sheep and Chinese Merino sheep(Xinjiang Army Reclamation Type)were selected as the research objects.The weight of weaning ewes,forage yield and nutrient composition of the grass population(crude protein,crude fiber,crude fat,crude ash,calcium,phosphorus,nitrogen free extract,etc.)were measured regularly from June to September.The litter size of ewes,litter weight at birth and weaning weight of lambs were recorded,and the relationship between the yield and nutrient composition of forage and the weight and reproduction of ewes was analyzed.The results showed that the temperature in Xinjiang pastoral area was higher and the number of rainfall days decreased from June to August,and the temperature dropped and the number of rainy days increased in September.From June to September,the forage yield,dry matter,crude ash,crude fat and crude fiber content of Festuca arundinacea,Stipa arundinacea and Seriphidium sericicum decreased first and then increased in the warm desert steppe of Xinjiang pastoral area.The weight of multiparous Suffolk sheep,Suffolk sheep and Chinese Merino sheep(Xinjiang military reclamation type)decreased from 63.50 kg,91.33 kg,56.25 kg to 63.33 kg,86.00 kg,51.50 kg,and the weight of the three breeds decreased by 0.27%,5.84%and 8.44%respectively.The litter size of multiparous Suffolk ewes that did not recover to the initial weight and that recovered to the initial weight were 1.83 and 1.91,respectively,and that of Suffolk sheep were 0.93 and 1.00,that of Chinese Merino sheep were 0.95 and 1.00,respectively,There was no significant difference among groups in the same variety(P>0.05).The litter weight at birth and weaning weight of lambs from multiparous Suffolk sheep,Suffolk sheep and Chinese Merino sheep that did not recover to the initial weight were significantly lower than those of lambs in ewes that returned to the initial weight(P<0.05).The results indicated that with the continuous increase of temperature and the decrease of rainfall from June to August,the yield of Festuca arundinacea,Stipa arundinacea and Seriphia sericea type grass groups showed a downward trend in the temperate desert steppe in Xinjiang pastoral area.With the decrease of temperature in September,the forage yield increased.The multiparous Suffolk ewes had strong grazing adaptability,and the maintenance ability to weight(fat)was better than that of Suffolk sheep and Chinese Merino sheep.