低品质牧草日粮氮的添加量和频率对肉牛采食和代谢的影响  

Effects of nitrogen supplemental contents and frequency on intake and metabolism of beef cattle fed with low quality forage

作　　者：史正明 石福岳[2] SHI Zhengming;SHI Fuyue(GanSu PingLiang Vocational and Technical College,Pingliang,Gansu Province 744000,China;Gansu Institute of Animal Science and Veterinary Medicine,Pingliang,Gansu Province 744000,China)

机构地区：[1]甘肃省平凉职业技术学院,甘肃平凉744000 [2]甘肃省畜牧兽医研究所,甘肃平凉744000

出　　处：《中国饲料》2020年第20期57-61,共5页China Feed

摘　　要：本研究评估了氮补充量和频率对饲喂低品质牧草的牛的摄食和血液特性的影响。试验选择10头平均体重为(262±20)kg的肉牛,随机分为5组,每组2头。对照组(不添加氮),T1组为日提供110 g粗蛋白质,T2组为每隔3 d提供110 g粗蛋白质,T3组为日提供220 g粗蛋白质,T4组为每隔3天提供220 g粗蛋白质。氮补充物由酪蛋白、尿素和硫酸铵组成(粗蛋白质水平为1140 g/kg)。结果:与对照组相比,补充氮不影响饲料的摄入量(P>0.05)。在所有的养分摄入量中,氮补充量和频率之间存在显著交互作用(P<0.05),其中每隔3 d补充220 g粗蛋白质显著降低了养分摄入量(P<0.05)。补充氮显著改善了血清IGF-1浓度(P<0.05)。瘤胃氨氮和血清尿素氮均受日粮处理显著影响(P<0.05)。结论:对饲喂低品质牧草的肉牛补充氮可以通过代谢作用来改善动物的生产性能,使瘤胃氮平衡,提高氮的沉积和利用效率。给饲喂低品质牧草的肉牛每隔3 d补充1次氮并不影响其消化、氮利用和代谢,但高剂量补充会对采食量产生负面影响。This study evaluated the effects of nitrogen supplementation and frequency on feeding,and blood characteristics in cattle fed with low quality forage.To select 10 head of average weight is(262±20)kg of beef cattle,randomly divided into five process groups,each group 2.In the control group(without nitrogen),T1 group provided 110 g of crude protein every day,T2 group provided 110 g of crude protein every 3 days,T3 group provided 220 g of crude protein every 3 days,and T4 group provided 220 g of crude protein every 3 days.Nitrogen supplements are composed of casein,urea,and ammonium sulfate(crude protein levels are 1,140 g/kg).Results:compared with the control group,nitrogen supplementation did not affect the intake of feed(P>0.05).Among all nutrient intakes,there was a significant interaction between nitrogen supplementation and frequency(P<0.05),with 220 g of crude protein supplementation per 3 d significantly reducing nutrient intakes(P<0.05).Nitrogen supplementation significantly improved serum igf-1 concentration(P<0.05).Rumen ammonia nitrogen and serum urea nitrogen were significantly affected by dietary treatment(P<0.05).Conclusion:adding nitrogen to beef cattle fed with low quality forage can improve the animal’s production performance through metabolism,balance the rumen nitrogen,and improve the deposition and utilization efficiency of nitrogen.Nitrogen supplementation once every 3 d did not affect digestion,nitrogen utilization and metabolism of beef cattle fed with low quality pasture,but high dose supplementation had a negative effect on feed intake.

关 键 词：低品质牧草 氮 频率 肉牛 采食量 代谢 

分 类 号：S823[农业科学—畜牧学]