摘要
本试验旨在研究稀土(RE)对奶牛尿中嘌呤衍生物排出量、奶牛产奶性能、及氮排泄的影响。选取年龄、体重、产奶量、乳成分及泌乳期相近(45±15 d)的荷斯坦奶牛40头,分为4组,对照组和试验1组、2组、3组每千克体重分别添加稀土0、20、35、50 mg。预试期15 d,正试期60 d。结果表明:RE能提高干物质采食量,提高幅度以试验2组较显著(P<0.05);试验组尿嘌呤衍生物排出量极显著高于对照组(P<0.01),试验1组、2组、3组,分别比对照组提高10.83%、19.77%、17.25%;试验组产奶量极显著高于对照组(P<0.01),分别比对照组提高6.05%、14.73%、11.55%;RE能显著或极显著提高乳脂和乳蛋白率(P<0.05或P<0.01);显著或极显著降低乳体细胞数(P<0.05或P<0.01),以试验2组最低;在氮总排泄量上,试验组极显著低于对照组(P<0.01),试验1组、2组、3组分别降低3.40%、14.11%、11.38%。由此可见,本试验条件下,综合考虑奶牛尿中嘌呤衍生物排出量、产奶量、乳成分含量及氮排泄等指标,RE添加量以每千克体重35 mg最有利。
This experiment was conducted to determine the effects of Rare earth （RE） on purine derivatives excretion, milk performance and nitrogen excretion. A total of 40 Holstein lactating cows with similar age, weight, milk yield and lactation stage （45±15 d in milk） were divided into 4 groups. The supplement level of RE in the control and 3 test groups was O, 20, 35 and 50 mg/kg BW, respectively. The pretest lasted for 15 d, and the test lasted for 60 d. The results showed that the dry matter intake in treatment group 2 was increased （P〈0.05）. The purine derivatives excretion in treatment groups was significantly increased by 10.83%, 19.77%, 17.25% compared with that in control group （P〈0.01）. The cows in treatment groups 1, 2 and 3 had 6.05%, 14.73% and 11.55% greater daily yields of milk than those cows in the control （P〈0.01）. RE significantly increase milk fat percentage and milk protein concentration （P〈0.05 or P〈0.01）, and significantly reduced milk somatic cell count （P〈0.05 or P〈0.01）, especially the treatment group 2. Compared with control group, total nitrogen excretion in test groups was significantly reduced （P〈0.01）, and was reduced by 3.40%, 14.11%, 11.38% test groups 1, 2 and 3, respectively. Based on the data of purine derivatives, milk yield, milk composition content and nitrogen excretion, it could be concluded that the suitable supplement level of RE in dairy cow was 35 mg/kg BW for the present study.
出处
《中国畜牧杂志》
CAS
北大核心
2016年第15期42-47,共6页
Chinese Journal of Animal Science
基金
山东省现代农业产业技术体系牛产业创新团队(SDAIT-09-08)
关键词
稀土
尿中嘌呤衍生物
产奶性能
氮排泄
rare earth
purine derivatives excretion
milk performance
nitrogen excretion
