在哺乳乳期乳牛中对后尿素的剂量反应
Journal of dairy science
|August 29, 2023
概括
向奶牛提供尿素并没有改善干物摄入量 (DMI) 或利用率. 增加尿素水平线性增加了牛奶尿素和尿液分泌,这表明后体内分娩无法克服DMI限制.
科学领域:
- 动物科学动物科学
- 类动物营养 类动物营养
- 乳牛的新陈代谢 乳牛的新陈代谢
背景情况:
- 乳牛饮食中食尿素的含量受到干物摄入量 (DMI) 的减少和体 (N) 的低效利用的限制.
- 为克服这些局限性,并增强尿素含量水平,建议服用体内尿素补充剂.
研究的目的:
- 对乳母牛的DMI,牛奶产量,营养物质利用和N平衡的后体尿素输液的影响进行调查.
- 确定腹腔尿素补充是否可以减轻高尿素水平对料摄入量和N效率的负面影响.
主要方法:
- 在4x4拉丁方形设计中使用了四只经过流的荷尔斯坦-弗里西亚奶牛.
- 尿素连续输入腹腔四个水平 (0,163,325,488g/d),增加饮食原蛋白 (CP) 0-6%.
- 测量包括DMI,牛奶产量和成分,营养物质消化能力,乳头发酵,N平衡和血成分.
主要成果:
- 干燥物质摄入量和能量校正的牛奶产量显示对尿素剂量的二次反应,没有整体改善.
- 牛奶中的尿素含量,明显的全通道CP消化能力和尿路N分泌量随着尿素输注的增加而线性增加.
- 在更高的含量水平下,静脉后尿素补充并没有缓解DMI抑郁症.
结论:
- 腹腔尿素输送并不能减轻增加尿素水平对奶牛干物质摄入量的负面影响.
- 虽然后尿素在一定程度上提高了的利用效率,但它并没有提高整体料摄入量或牛奶产量超过一定水平.
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