HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Brody, S. Search for Related Content PubMed Articles by Brody, S.

Interrelations between endocrines, metabolism, and productive efficiencies in farm animals^*

University of Missouri

Abstract

We are presenting several questions, with explanatory notes, on the interrelations of endocrines, metabolism, and productive efficiencies in farm animals. Orientations for these questions, including references to the literature, will appear in the March (1939) issue of the Journal of Nutrition.

The questions are illustrated by the best known endocrine, the thyroid, and the best known type of metabolism, that referred to as "basal metabolism", which is the minimum heat production. This "basal metabolism" is very important in computing productive efficiency because the digestible feed cost of maintenance is proportional to it. Productive gross efficiency is the ratio of the output, such as milk energy produced, to the input (the digestible nutrient energy consumed) which includes the maintenance cost.

1. What is the relation between the rate of endocrine activity and the rate of metabolism, that is, heat production?
   Quantitative and causal relations between endocrine activity and heat production have been established only for the thyroids. About 1895 Magnus-Levy and others discovered that loss of the thyroids reduces the basal heat production to about half the normal level, and that feeling thyroid increases the basal heat production up to about twice the normal level. It was thus established the thyroxin is a powerful metabolic (especially heat-producing) catalyst.
   
2. Has it been established that thyroxin influences the rate of productive processes in farm animals?
   

^* Paper No. 186 in the Herman Frasch Foundation for Research in Agricultural Chemistry. Paper No. 588 in the Missouri Agricultural Experiment Station Journal Series.