在哺乳期的荷尔斯坦牛中,延长的质期是问题吗?
J Denis-Robichaud1, A P Oliveira2, A Sica3
1Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada V6T 1Z4.
Journal of dairy science
|May 24, 2024
概括
乳牛的更长的黄质阶段不仅仅是由于怀孕流产. 季节和黄体存在影响长期的黄体阶段,这表明高产荷尔斯坦牛的潜在特征.
科学领域:
- 牲畜中的生殖生理学
- 乳牛内分泌学 乳牛内分泌学
- 动物的繁殖和生育能力.
背景情况:
- 了解影响黄体阶段长度的因素对于乳牛群的繁殖管理至关重要.
- 之前的研究经常将延长的白色阶段归因于流产,但可能存在其他原因.
- 高产荷尔斯坦牛存在独特的生理挑战,可能会影响生殖周期.
研究的目的:
- 调查荷尔斯坦乳牛中延长黄质期的潜在原因,超出妊娠丧失.
- 为了确定与商业乳制品群体中延长的性阶段相关的风险因素.
- 为了评估人工授精 (AI) 与安慰剂授精 (PBO) 对黄体阶段长度的影响.
主要方法:
- 荷尔斯坦乳牛 (在牛奶中≥50天) 接受了基于雌醇的同步协议.
- 牛在第0天随机分配给AI或PBO,超声波监测黄体 (CL) 和雌性周期长度.
- 使用混合后勤回归分析,长时间的质期 (≥24天) 与平价,季节,DIM,牛奶产量,BCS和CL在入学时的存在有关.
主要成果:
- 总体而言,38%的雌性周期非常长 (≥31天),19%很长 (24-30天).
- 在AI和PBO组之间没有观察到较长的雌性周期类别的显著差异.
- 季节和CL在入学时的存在与延长的白质期有关;早期怀孕损失可能会影响AI中的CL寿命,但不会影响PBO组.
结论:
- 霍尔施泰因奶牛的延长黄体阶段并不仅仅是由于胚胎或妊娠损失造成的.
- 季节性和前同步性CL的存在是导致长期质阶段的重要因素.
- 延长黄体阶段的高患病率表明,它可能是高产哺乳荷尔斯坦奶牛中报告不足的特征,影响了CL功能生理学.
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