| 摘要: |
| 为阐明奶牛血浆瘦素、能量状况和生殖机能之间的关系,随机选取年龄、胎次、泌乳量相近的奶牛60头,分别在产后1、14、28、42、56和70 d时颈静脉采血,根据血糖浓度在6个时间点分为低血糖组(L)和对照组(CK)。同时调查和检测奶牛的生产性能 (体重、泌乳量和干物质摄入量)、繁殖性能(首次配种间隔、情期受胎率、发情率和配种指数)、血液生化指标(血糖、β-羟丁酸和游离脂肪酸)和内分泌指标(胰岛素、胰高血糖素、瘦素、雌二醇和孕酮)。结果显示:奶牛泌乳早期存在不同程度的能量负平衡,产后14 d最高。能量负平衡(negative energy balance,NEB)能使奶牛产后干物质摄入量(DMI)、体重(BW)和泌乳量(MY)减少,首次配种间隔延长,情期受胎率和发情率降低,配种指数增高,血浆胰岛素(Ins)、胰高血糖素(Gn)、瘦素(leptin)、雌二醇(E2)和孕酮(P4)浓度降低,呈现低血糖(Glu)、高血浆游离脂肪酸(NEFA)和β-羟丁酸(BHBA)生化特性;能量负平衡时,奶牛血浆瘦素与血浆Glu、E2、P4之间呈显著正相关,与BW损失、血浆NEFA之间呈明显负相关;能量平衡时,奶牛血浆瘦素与DMI、Glu、Ins之间呈显著正相关,与BW损失呈显著负相关,与血浆E2和P4之间相关不显著。 这些结果提示,奶牛泌乳早期易发能量负平衡不仅与干物质摄入量、体重、泌乳量密切相关,而且与机体内分泌未完全协调发挥作用有关。能量负平衡明显降低泌乳早期奶牛的生产性能和繁殖性能。血浆瘦素与生产性能指标、血浆生化指标的相关性分析证实瘦素在奶牛能量平衡、生产性能和繁殖性能之间起到一个平衡纽带的作用。 |
| 关键词: 奶牛 瘦素 泌乳早期 能量平衡 生殖机能 生产性能 |
| DOI：10.11841/j.issn.1007-4333.2010.03.012 |
| 投稿时间：2009-11-17 |
| 基金项目:中国博士后科学基金资助项目(20070420895); 黑龙江省教育厅学术骨干基金资助(1151G029)第一作者:郑家三,讲师,主要从事兽医外科学研究,E-mail:zjs3399@yahoo.com.cn通讯作者:夏成,教授,博士,主要从事动物营养代谢病研究, E-mail:xcwlxyf@sohu.com |
|
| Correlation between leptin with energy balance and reproductivefunction of dairy cows during the early lactation |
|
ZHENG Jia-san, XIA Cheng, ZHANG Hong-you, XU Chuang
|
| (College of Animal Science and Technology,Heilongjiang Bayi Agricultural University,Daqing 163319,China) |
| Abstract: |
| To ascertain the relationship between plasma leptin,energy balance and reproductive function,sixty dairy cows were randomly divided into hypoglycemia group (L) and control group (CK) according to the levels of plasma glucose on postpartum 1,14,28,56 and 70 day,respectively.The production performances (BW,MY,and DMI),dairy breeding traits (first conception interval,conception rate in estrus,estrus rate,breeding index),blood biochemical parameters (Glu,BHBA,and NEFA) and endocrine parameters (Ins,Gn,Lp,E2 and P4) were investigated.The results indicated that there was different degree of negative energy balance(NEB) during early lactation of cows,and reached to the highest levels on postpartum 14 day,which is related to low energy diet and high milk yield (MY) and made postpartum cows have a low plasma concentrations of Ins,Gn,Lp,E2 and P4,a low body weight (BW),MY,dry matter intake (DMI),a biochemical character of hypoglycemia,high plasma NEFA and BHBA,and a low reproductive traits.As NEB,there was a significant positive correlation with plasma leptin and plasma Glu,E2 and P4;a notable negative correlation with plasma leptin and BW lose,NEFA during early lactation.As energy balance,a significant positive correlation between plasma leptin and plasma Glu,Ins,and DMI,a notable negative correlation between plasma leptin and BW lose during early lactation.These results suggested that cows’ NEB easily occurred during early lactation,which was not only related to a low energy diet,high milk yield,low DMI,and rapid BW lose,but also related to the no-fully coordinated endocrine function in energy metabolism regulation in the body.Furthermore NEB can cut down production performance and reproductive traits of dairy cows.Analysis between plasma leptin and the index related to the productive performance and blood plasma biochemical character suggested that Leptin plays a balanced role in the energy balance,productive performance and reproductive performance. |
| Key words: dairy cows leptin early lactation energy balance reproductive traits productive performances |
