西班牙苜蓿替代美国苜蓿对泌乳奶绵羊的影响

Effects of Spanish alfalfa replacing American alfalfa on lactating milk sheep

【目的】研究西班牙苜蓿替代美国苜蓿对东佛里生-湖羊杂交一代奶绵羊生产性能、血清生化指标和瘤胃微生物区系的影响。【方法】以48只东湖杂交一代奶绵羊(第2胎次、第2泌乳月)为试验动物,将其随机分为2组,每组6个重复,每个重复4只羊,预试15 d后进行为期45 d的正式试验。在正试期内,2组羊饲喂青贮玉米+颗粒饲料(苜蓿+燕麦+精料),除饲喂苜蓿种类不同外,其余成分保持一致。每天记录采食量和剩料量;试验期内每天10:00和18:00采用机器挤奶,记录每次产奶量;在正试期的第15,30和45天挤奶后,取少量奶样用于常规营养成分(乳脂肪、乳蛋白、乳糖、非脂固形物)测定;在正试期第45天颈静脉采血10 mL,用于测定血清生化指标(总蛋白、白蛋白、球蛋白、总胆固醇、甘油三酯、高密度脂蛋白、低密度脂蛋白、血糖、丙二醛含量,谷草转氨酶、谷丙转氨酶、超氧化物歧化酶、谷胱甘肽过氧化物酶活性和总抗氧化能力);于正试期第45天用瘤胃液采集管采集各组奶绵羊的瘤胃液,利用16S rDNA分析瘤胃微生物区系。最后对2组试验羊的经济效益进行分析。【结果】正试期第15,30和45天2组试验羊产奶量无显著性差异(P>0.05)。正试期第30天西班牙苜蓿组试验羊乳脂肪含量显著高于美国苜蓿组(P<0.05),其他指标间均无显著性差异(P>0.05)。西班牙苜蓿组试验羊血清中总蛋白含量显著高于美国苜蓿组(P<0.05)。西班牙苜蓿组试验羊瘤胃微生物的Chao1指数、Shannon指数以及Shannon指数/Simpson指数均显著高于美国苜蓿组(P<0.05),Simpson指数与美国苜蓿组无显著性差异(P>0.05),覆盖度显著小于美国苜蓿组(P<0.05)。2组试验羊瘤胃中优势菌门均为拟杆菌门和厚壁菌门,美国苜蓿组试验羊瘤胃中的变形菌门相对丰度极显著高于西班牙苜蓿组(P<0.01)。在属水平上,2组试验羊瘤胃中各菌属相对丰度均无显著性差异(P>0.05)。西班牙苜蓿组的奶绵羊日经济效益稍高于美国苜蓿组。【结论】西班牙苜蓿替代美国苜蓿对奶绵羊的生产性能、血清生化指标及瘤胃健康无负面影响。

【Objective】The effects of Spanish alfalfa replacing American alfalfa on performance,serum biochemical indexes and rumen microflora of East Friesian and Hu sheep crossbreed first-generation dairy sheep(DHF1)were studied.【Method】Forty-eight DHF1 sheep(second parity and second lactation month)were randomly divided into two groups,with 6 replicates in each group and 4 sheep in each replicate.After 15 days of pre-feeding,the formal experiment was conducted for 45 days.During the trial pe-riod,the two groups of sheep were fed on silage corn and pellet feed(alfalfa,oat and concentrate)with the same ingredients except for different alfalfa types.The feed intake and residual feed were recorded every day,and milk yields by machine at 10:00 and 18:00 every day were measured during the experimental period.On days 15,30 and 45 of the trial period,small amounts of milk samples were taken to determine routine nutritional components(milk fat,milk protein,lactose and non-fat solids).On day 45 of the trial period,10 mL blood was taken from jugular vein to determine serum biochemical indexes(total protein,albumin,globulin,total cholesterol,triglyceride,high-density lipoprotein,low-density lipoprotein,blood sugar,malondialdehyde,aspartate aminotransferase,alanine aminotransferase,superoxide dismutase,glutathione peroxidase activity and total antioxidant capacity).Rumen fluid of dairy sheep from each group was collected by rumen fluid collection tube on day 45 of the trial period,and rumen microflora was analyzed by 16S rDNA.Finally,economic benefits of the two experimental groups were analyzed.【Result】There was no significant difference in milk yield between the two groups on days 15,30 and 45(P>0.05).On day 30 of the trial period,the fat of dairy sheep in Spanish alfalfa group was significantly higher than that in American alfalfa group(P<0.05),and there was no significant difference among other indexes(P>0.05).The content of total protein in serum of Spanish alfalfa group was significantly higher than that of American alfalfa group(P<0.05).Chao1 index,Shannon index and Shannon/Simpson index of rumen microorganisms in Spanish alfalfa group were significantly higher than those in American alfalfa group(P<0.05),Simpson index was not significantly different from that in American alfalfa group(P>0.05),and coverage was significantly lower than that in American alfalfa group(P<0.05).The dominant bacteria in rumen of test sheep in the two groups were Firmicutes and Bacteroides,and the relative abunclance of Proteus in rumen of the American alfalfa group was significantly higher than that of the Spanish alfalfa group(P<0.01).At the genus level,there was no significant difference in the relative abundance of each genus in rumen between the two groups(P>0.05).The daily economic benefit of dairy sheep in Spanish alfalfa group was slightly higher than that in American alfalfa group.【Conclusion】Spanish alfalfa instead of American alfalfa has no negative effect on performance,serum biochemical indexes and rumen health of dairy sheep.