J. Anim Sci.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Landis, M. D.
Right arrow Articles by Smith, S. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Landis, M. D.
Right arrow Articles by Smith, S. B.

Journal of Animal Science, Vol 80, Issue 3 591-601, Copyright © 2002 by American Society of Animal Science

JOURNAL ARTICLE

Ontogenic development of brown adipose tissue in Angus and Brahman fetal calves

M. D. Landis, G. E. Carstens, E. G. McPhail, R. D. Randel, K. K. Green, L. Slay and S. B. Smith
Department of Animal Science, Texas A&M University, College Station 77843, USA.

Brahman calves experience greater neonatal mortality than Angus calves if cold-stressed. To establish a developmental basis for this, three fetuses of each breed type were taken at 96, 48, 24, 14, and 6 d before expected parturition, and at parturition. Overall fetal BW tended (P = 0.08) to be greater for Angus than for Brahman fetuses. There was no difference between breed types in total brown adipose tissue (BAT) mass or grams of BAT/kg BW. Brown adipocyte density decreased 56%, whereas lipogenesis from acetate and glucose in vitro decreased 97% during the last 96 d of gestation in both breed types. Glycerolipid synthesis from palmitate declined by 85% during the last trimester but still contributed 98% to total lipid synthesis at birth. The fetal age x breed interaction was significant for lipogenesis from glucose (P = 0.05) and palmitate (P = 0.005); rates were higher at 96 d before birth in Brahman BAT but declined to similar rates by birth. Uncoupling protein-1 (UCP1) mRNA tripled during gestation in both breed types (P = 0.002), whereas mitochondrial cross-sectional area did not change (P = 0.14) during gestation. Neither the breed nor the age x breed effect was significant (P > or = 0.24) for UCP1 mRNA concentration or mitochondrial cross-sectional area. In both breed types, a marked decrease in BAT UCP1 mRNA between 24 and 14 d prepartum was associated with a similar reduction in lipogenesis from palmitate and a noticeable change in BAT mitochondrial morphology, as the mitochondria became more elongated and the cristae became more elaborate. Uncoupling protein-1 mRNA initially was elevated in Angus tailhead s.c. adipose tissue, but was barely detectable by birth, and tended to be greater overall (P = 0.09) in Angus than in Brahman BAT. If uncoupling protein activity in s.c. adipose tissue persists after birth, then s.c. adipose tissue may contribute more to thermogenesis in Angus newborn calves than in Brahman calves. In contrast, we did not observe differences in ontogenic development of perirenal BAT that could explain the documented differences in thermogenic capacity between Angus and Brahman newborn calves.


This article has been cited by other articles:


Home page
 J ANIM SCIHome page
S. B. Smith, G. E. Carstens, R. D. Randel, H. J. Mersmann, and D. K. Lunt
Brown adipose tissue development and metabolism in ruminants
J Anim Sci, March 1, 2004; 82(3): 942 - 954.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2002 by the American Society of Animal Science.