Plasma metabolite and hormone concentrations in Friesian cows of differing genetic merit measured at two feeding levels

Author:

Flux D. S.,Mackenzie D. D. S.,Wilson G. F.

Abstract

ABSTRACTPhysiological differences between cows in hormone and metabolite concentrations were sought that may account for genetic differences in milk production.Two groups of New Zealand Friesian cows, differing in genetic merit for fat production (high breeding index (HBI) and low breeding index (LBI)) by approximately 23 breeding index units (20 kg fat on the United Kingdom improved contemporary comparison scale), were each divided into two further groups, one of which was given freshly cut pasture to appetite and in the other intake was restricted to 70% of appetite. Eighteen blood samples were collected over a 24-h period from each of 16 cows fitted with indwelling jugular catheters. Samples were analysed for growth hormone, insulin, free fatty acids and β-hydroxybutyrate. Mean concentration of insulin was significantly higher in the HBI underfed group than in any other group (P< 0·01). Glucose concentration was significantly lower in the LBI group (P< 0·05), whose intake was restricted. The concentration of (3-hydroxybutyrate was significantly higher in the cows whose intake was restricted (P< 0·01) and the concentration fell markedly after feeding. Growth hormone concentrations were higher in the cows on restricted intake (P< 0·05) and in HBI cows but the differences were not statistically significant.It was concluded that different patterns of blood metabolites and hormones are associated with cows that differ in genetic merit. Aspects of insulin and glucose metabolism, particularly at low planes of feeding, appear to offer most promise as indicators of high milk-solids production.

Publisher

Cambridge University Press (CUP)

Subject

Animal Science and Zoology

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3