Effect of Ambient Temperature on Daily Milk Yield and Blood Flow to the Mammary Gland in Lactating Goats Treated With Growth Hormone

Authors

  • A.E. Pereka Department of Veterinary Physiology, Biochemistry, Pharmacology and Toxicology, P. O. Box 3017, SUA, Morogoro

Keywords:

Physiology, Animal, Caprine, Mammary Gland

Abstract

The study was done with the objective of studying the effect or high temperature on the mammary gland production in terms or its blood supply and synthetic capacity. Growth hormone was injected to see whether high temperature has an interaction with the galactopoietic effects of the hormone in the mammary gland. Eight, one year old goats in  their  6th week  of lactation  (1st  lactation)  were put into  two climatic chambers,  four  in  a  chamber  at  12°C and four  in  a  chamber  at 30°C. After four weeks of exposure to their respective temperatures two goats in each chamber were injected with bovine somatotropin (BST) daily for fifteen days. Daily milk yield was recorded. Blood flow rate was calculated from velocities measured using the Doppler Ultrasound Technique.  Milk yield in goats at 30°C was 78% of milk yield of goats at 12°C at all times. With BST treatment milk yield increased by 9% and 13% at 12°C and 30°C respectively. Blood flow rate (L/day) to the mammary gland was in accordance to the milk yield with  a  blood flow rate:  milk  yield (CBF MY)  ratio  of  572 ± 166:  1  and  760  ± 180  : 1  at   12°C and 30°C respectively. With  BST treatment  the  BF:MY ratio was 1059  ± 263 : 1  and 89 ± 38: 1  at 12°C  and   30°C  respectively. It is herewith concluded that blood flow to the mammary gland is a factor contributing to increased milk yield as it supplies the necessary nutrients for milk synthesis in the udder. The depressive effects of high ambient temperature can be counteracted by BST  treatment  as  this  increases  milk  yield not only through increased blood flow but also increased efficient nutrient extraction  and  utilization  by the  mammary gland  cells  for milk synthesis

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Published

30-09-1990

How to Cite

Pereka, A. (1990) “Effect of Ambient Temperature on Daily Milk Yield and Blood Flow to the Mammary Gland in Lactating Goats Treated With Growth Hormone”, Tanzania Veterinary Journal, 10(3), pp. 83–89. Available at: https://tvj.sua.ac.tz/vet2/index.php/TVJ/article/view/361 (Accessed: 14 February 2025).

Issue

Section

RESEARCH ARTICLES

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