JDS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Journal of Dairy Science Vol. 74 No. 4 1250-1262
© 1991 by American Dairy Science Association ®
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 Johnson, H. D.
Right arrow Articles by Baile, C. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Johnson, H. D.
Right arrow Articles by Baile, C. A.

Effects of Somatotropin on Milk Yield and Physiological Responses During Summer Farm and Hot Laboratory Conditions

H. D. Johnson 1, R. Li 1, W. Manalu 1, K. J. Spencer-Johnson 1, B. Ann Becker 2, R. J. Collier 3, and C. A. Baile 3

1 Department of Animal Science, University of Missouri, Columbia 65211
2 USDA-ARS, Animal Physiology and Nutrition Unit, University of Missouri, Columbia 65211
3 Monsanto Company, Chesterfield, MO 63198

The effects of bST on performance and physiological responses of lactating cows was studied under farm summer and laboratory heat conditions. Twelve cows, 90 to 50 d postpartum, were injected with either bST or vehicle solution for 30 d under farm summer and 10 d under either laboratory thermoneutral or heat conditions. Somatotropin increased milk yield by 6.1 (21%), 8.1 (32%), and 7.3 kg (35%) under the farm summer, laboratory thermoneutral, and heat conditions, respectively. Somatotropin also increased milk fat by 15 and 19% and dry matter intake by 16 and 18% under laboratory thermoneutral and heat conditions, respectively. Somatotropin increased the efficiency of feed conversion into milk without any significant changes in body weight and temperatures. Somatotropin reduced plasma concentrations of triiodothyronine and cortisol and had no effect on plasma prolactin and insulin concentrations. Somatotropin did not increase water intake; however, hematocrit was decreased. The results suggest that stimulatory effects of bST on milk production are still observed on heat-stressed cows without any significant indications of additional heat stress.

Key Words: heat stress • somatotropin • milk yield

Submitted on December 18, 1989
Accepted on November 26, 1990




This article has been cited by other articles:


Home page
 J DAIRY SCIHome page
S. Dikmen, E. Alava, E. Pontes, J. M. Fear, B. Y. Dikmen, T. A. Olson, and P. J. Hansen
Differences in Thermoregulatory Ability Between Slick-Haired and Wild-Type Lactating Holstein Cows in Response to Acute Heat Stress
J Dairy Sci, September 1, 2008; 91(9): 3395 - 3402.
[Abstract] [Full Text] [PDF]

Home page
 J DAIRY SCIHome page
R. S. Settivari, J. N. Spain, M. R. Ellersieck, J. C. Byatt, R. J. Collier, and D. E. Spiers
Relationship of Thermal Status to Productivity in Heat-Stressed Dairy Cows Given Recombinant Bovine Somatotropin
J Dairy Sci, March 1, 2007; 90(3): 1265 - 1280.
[Abstract] [Full Text] [PDF]

Home page
 J DAIRY SCIHome page
F. D. Jousan, L. A. de Castro e Paula, J. Block, and P. J. Hansen
Fertility of Lactating Dairy Cows Administered Recombinant Bovine Somatotropin During Heat Stress
J Dairy Sci, January 1, 2007; 90(1): 341 - 351.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1991 by the American Dairy Science Association ®.