非常规蛋白饲料原料对泌乳山羊氮代谢和微生物蛋白合成的影响

文章旨在研究不同蛋白质来源精饲料对泌乳山羊氮代谢及微生物蛋白合成的影响。试验选择平均初始体重为(43.62±2.35)kg的泌乳期山羊72头,随机分为3组,每组4个重复,每个重复6头。各组分别饲喂以豆粕、大豆浓缩蛋白和豆科植物(银合欢)为基础的精料,试验为期8周。结果:大豆浓缩蛋白组尿液和尿素氮排泄量较豆科植物组显著提高21.41%和23.31%(P<0.05),但大豆浓缩蛋白和乳尿素氮排泄量最低(P<0.05)。大豆浓缩蛋白组尿液和尿素氮排泄量占体重的比例也显著高于豆科植物组(P<0.05)。大豆浓缩蛋白组氮摄入量最低(P<0.05)。大豆浓缩蛋白组尿氮含量显著高于豆粕和豆科植物组(P<0.05)。豆科植物组微生物氮、微生物蛋白量及合成效率也显著高于豆粕组(P<0.05)。结论:在本研究条件下,以大豆浓缩蛋白为蛋白源的精饲料饲喂哺乳期山羊,尿液氮排泄量更大,导致负氮平衡,而以豆科植物(银合欢)为蛋白源时,可以提高乳山羊瘤胃微生物蛋白合成能力。

Effects of unconventional protein ingredients on nitrogen metabolism andmicrobial protein synthesis in lactation goats

The aim of this study was to investigate the effects of different protein sources on nitrogen metabolism and microbial protein synthesis of lactation goats.Seventy-two lactation goats with an average initial weight of(43.62±2.35)kg were randomly divided into 3 groups with four replicates and six replicates.Each group was fed with soybean meal,soybean protein concentrate,and legume based concentrate for 8 weeks.Results:The urinary and urea nitrogen excretion of soybean protein concentrate group was significantly increased by 21.41%and 23.31%(P<0.05)compared with that of legumes group,but the soybean protein concentrate and urea nitrogen excretion of dairy were the lowest(P<0.05).The excretion of urine and urea nitrogen as a percentage of body weight in the soy protein concentrate group was also significantly higher than that in the leguminous group(P<0.05).The nitrogen intake in soybean protein concentrate group was the lowest(P<0.05).The urine nitrogen content of soybean protein concentrate group was significantly higher than that of soybean meal and leguminous plant group(P<0.05).The amount of nitrogen,protein and synthesis efficiency of the legumes group were also significantly higher than that of the soybean meal group(P<0.05).Conclusion:Under the conditions of this study,the concentrate fed with soy protein concentrate as protein source led to greater urinary nitrogen excretion,resulting in negative nitrogen balance,while the concentrate fed with leguminous plants(acacia)as protein source could improve the rumen microbial protein synthesis ability of lactation goats..