The effect of severe nutritional deprivation in early post-natal life on tissue and cellular responses during subsequent growth of lambs to the age of 4 months

Author:

Tulloh N. M.,Brimblecombe Helen,Dennis Carolyn

Abstract

SUMMARYThe growth of 16 ram lambs was severely restricted for the first 6 weeks of post-natal life. Subsequently, these lambs (group R) were fed ad libitum. The diet was based on reconstituted cows' whole milk and lucerne chaff. A control (group C) of 16 similar lambs was fed ad libitum on the same diet from birth.Lambs were weighed regularly and, in group C, four lambs were killed at the age of 1 day and then two at each of the following body weights: 10, 15, 20, 25, 30, 35 kg. In group R, five lambs were killed at the commencement of ad libitum feeding (age 43 days) and two each at the same body weights as in group C, except that only one lamb was available at 20 kg. After slaughter, the brain, liver, kidneys and the semitendinosus and gastrocnemius muscles were removed, weighed, stored and, with the exception of the liver, were analysed later for the following components: DNA, RNA and protein. Carcass weight and the weight of the kidney and channel (KC) fat were recorded. The femurs and metacarpals were removed from each carcass and cleaned, weighed and measured.During the 6 weeks of restricted feeding, group R gained 0·9 kg while the ad libitum group C gained 13·5 kg. However, during recovery, group R grew faster than group C (0·37 ν 0·34 kg/day), reducing the weight for age difference near the end to 29 days at mean body weights of 30 kg.Because of the design of the experiment, at the same age all measurements on group R animals, after the commencement of ad libitum feeding, were smaller than in group C. For this reason, the interpretation of the results has been based on differences between regression equations relating the various measurements to empty-body weight or to one another.At the start of ad libitum feeding, brain weight, carcass weight, femur weight and femur length were bigger, while liver weight and KC fat weight were smaller in group R than in group C. At the end of the experiment, there were no significant differences between treatments for these measurements. Metacarpal shape differed between groups, the bone being relatively longer and narrower in group R than in group C, throughout the period of ad libitum feeding.There were no significant differences between treatments in the relationships between DNA and corresponding tissue weights. However, the RNA was significantly less in both muscles in group R than in group C at the beginning of ad libitum feeding, but this difference had disappeared by the end of the experiment.The brain protein: DNA and the brain weight: DNA ratios did not differ between treatments nor did they change significantly during the experiment. The semitendinosus was the only other tissue for which protein content was available and the protein: DNA ratio for this muscle differed between treatments, reflecting an acceleration of division by cell nuclei during the recovery period. The other tissue weight: DNA relationships did not differ between treatments and all ratios increased to values similar to those reported elsewhere. RNA:DNA ratios differed between treatments for both muscles, suggesting that high rates of protein synthesis occurred in group R during the recovery period.In spite of the apparent normality of group R when measurements were related to EBW or tissue weights at the end of the experiment, only a long-term investigation would determine whether the weight-for-age difference of the type reported here would persist in adult life.

Publisher

Cambridge University Press (CUP)

Subject

Genetics,Agronomy and Crop Science,Animal Science and Zoology

Cited by 7 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

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