QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Peel, C. J. Articles by Gorewit, R. C. Search for Related Content PubMed PubMed Citation Articles by Peel, C. J. Articles by Gorewit, R. C.

Lactational Response to Exogenous Growth Hormone and Abomasal Infusion of a Glucose-Sodium Caseinate Mixture in High-Yielding Dairy Cows¹

Department of Animal Science, Cornell University, Ithaca, NY 14853-0281

Milk production responses to 1) growth hormone injections (51.5 IU/day), 2) a mixture of glucose (274 g/day) and sodium caseinate (441 g/day) infused into the abomasum, 3) a combination treatment, and 4) a placebo treatment were determined in 4 cows in a 4 x 4 Latin square design. Treatment periods were 10 days, and production responses were based on the last 5 days of each treatment. Growth hormone administration increased milk yield 15.2% without changing milk composition or feed intake. Infusions of glucose-sodium caseinate into the abomasum increased milk yield 3.9% and milk protein yield 6.4% but when combined with growth hormone treatment did not stimulate a greater response than observed for growth hormone alone. Plasma concentrations of growth hormone were increased 4-fold with growth hormone injections but were not affected by the infusion of glucose-sodium caseinate into the abomasum. There were no significant changes in plasma concentrations of glucose, free fatty acids, insulin, glucagon, prolactin, triiodothyronine, thyroxine or cortisol with any of the treatments. Growth hormone increased milk synthesis and the efficiency of milk production, but its effect was not enhanced by the postruminal supply of additional nutrients.

KEY WORDS: • growth hormone • casein • milk composition • milk yield

¹ Supported in part by Cornell University Agricultural Experiment Station, The Upjohn Company, U.S. Department of Agriculture/Science and Education Administration—Agricultural Research Dairy Forage Cluster, and National Science Foundation grant PCM 8108130. Portions of this paper were presented at the 75th Annual Meeting of the American Dairy Science Association in Baton Rouge, Louislana, 1981, Abstract no. P132, and at the Cornell Nutrition Conference in Syracuse, NY, 1981.

² On leave from Victorian Department of Agriculture, Ellinbank Dairy Research Institute, Warragul, Victoria 3820, Australia.

³ Present address: Carnation Milling Division, 327 East Mill Street, Circleville, OH 43113.

⁴ Author to whom reprint requests should be addressed.

Manuscript received 1 April 1982.