一种新型缓释非蛋白氮添加水平对奶山羊泌乳性能及血液生化指标的影响

摘要

本试验旨在探讨饲粮中添加不同水平的一种新型缓释非蛋白氮( srNPN)对奶山羊泌乳性能及血液生化指标的影响。选择2~3胎平均体重约为60 kg的健康西农萨能奶山羊泌乳羊48只,随机分为4组,每组12只。各组饲粮 srNPN 添加水平分别为0(对照组)、0.25%、0.50%、0.75%。预试期1周,正试期16周。结果表明：1)饲粮中添加不同水平的srNPN对奶山羊日均采食量无显著影响( P>0.05)。2)饲粮中添加srNPN可显著提高奶山羊日均产奶量(P<0.05),且0.50%组日均产奶量显著高于其他各组(P<0.05)。3)与对照组相比,srNPN显著提高了乳中乳脂含量(P<0.05),但试验组间无显著差异(P>0.05)；各组乳中乳蛋白、乳糖及乳非脂固形物含量差异不显著( P>0.05)。4)饲粮中添加srNPN可显著降低血液尿素氮含量(P<0.05),其中0.50%组羊血液尿素氮含量最低；各组奶山羊血液甘油三酯、总胆固醇及总蛋白含量差异不显著( P>0.05)。由此得出,饲粮中添加srNPN能够提高奶山羊乳中乳脂含量,降低血液尿素氮含量,添加水平为0.50%时奶山羊日均产奶量最高。%This experiment was conducted to investigate the effects of different supplemental level of a new slow-release non-protein nitrogen ( srNPN ) on lactation performance and blood biochemical indices of dairy goats. Forty-eight healthy lactating Xinong Saanen dairy goats with 2 to 3 parities and about 60 kg of average body weight were randomly assigned to 4 groups with 12 goats in each group. Goats in the 4 groups were fed diets supplemented with srNPN at 0, 0. 25%, 0. 50% and 0. 75%, respectively. There was a pretrial period of 1 week followed by an experimental period of 16 weeks. The results showed as follows:1 ) dietary supple-mentation of srNPN at different levels did not affect average daily feed intake of lactating goats ( P>0 . 05 ) . 2 ) The supplementation of srNPN significantly increased average daily milk yield ( P <0 . 05 ) , which in 0 . 50% group was significantly higher than that in the other groups ( P <0 . 05 ) . 3 ) Compared with that in control group, milk fat content in experimental groups was significantly increased (P<0. 05), but there was no significant difference among experimental groups (P>0. 05); besides, the contents of milk protein, lac-tose and milk solids-non-fat were not significantly affected by the supplementation of srNPN ( P>0 . 05 ) . 4 ) The supplementation of srNPN could significantly decrease blood urea nitrogen content ( P<0 . 05 ) , and that in 0. 50% group was the lowest; the contents of triglyceride, total cholesterol and total protein in blood were not significantly affected by the supplementation of srNPN (P>0. 05). In conclusion, dietary supplementation of srNPN can increase milk fat content and reduce blood urea nitrogen content. The average daily milk yield of lactating goats is the highest when srNPN supplemental level is 0 . 50%.