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 Engster, H. M. Articles by Scanes, C. G. Search for Related Content PubMed PubMed Citation Articles by Engster, H. M. Articles by Scanes, C. G.

Growth Hormone Metabolism in Essential Fatty Acid-deficient and Pair-fed Nondeficient Chicks^1,2,3,4,

Bioresearch Center, Department of Animal Sciences, Vermont Agricultural Experiment Station, University of Vermont, Burlington, Vermont 05401, and Department of Animal Physiology and Nutrition, Kirkstall Laboratories, Vicarage Terrance, Leeds, LS5 3HL, England

Day-old White Leghorn cockerels were fed a purified essential fatty acid (EFA)-deficient basal diet (0.03% linoleic acid) ad libitum for 1 week. They were then fed one of the following treatments for 7 weeks: 1) basal diet ad libitum, 2) basal +4% corn oil pair-fed to 1, 3) basal +4% corn oil ad libitum, or 4) corn-soybean diet. Chicks fed the deficient diet exhibited marked reductions in weight gain, energy efficiency, and comb and testes weights, increases in liver size, and characteristic changes in tissue fatty acids at 8 weeks of age. Depressions in weight gain, tibial length, epiphyseal plate width, pituitary growth hormone (GH) activity, elevated plasma GH, and a tendency for reduced nitrogen retention, point to an impairment in GH metabolism in EFA-deficient chicks. Results with pair-fed control chicks suggest that smaller tibial length and width, smaller epiphyseal plate width, reduced nitrogen retention, elevated plasma GH and, to a partial extent, reduced body weights, smaller combs and testes, and larger pituitary glands are a result of reduced appetite and food intake rather than a direct biochemical effect of EFA per se. Changes due directly to the EFA deficiency, independent of reduced food intake, were decreased energy efficiency, increased liver weight, elevated trienetetraene fatty acid ratio, and reduced hypophyseal GH. These results demonstrate the importance of equalizing food intake in studies of this nature. Hypophyseal GH content was not affected by treatments in the same fashion as was plasma GH concentration. This indicates that different hypothalamic-hypophyseal mechanisms operate to increase plasma GH in EFA-deficient and pair-fed control chicks.

KEY WORDS: • essential fatty acids • pituitary • growth hormone • appetite regulation • pair-feeding

¹ Part of a thesis submitted to the Graduate College of the University of Vermont as partial fulfillment of the requirement for the Ph.D. degree.

² Presented in part at the 66th Annual Meeting of the Poultry Science Assoc., Inc. at Auburn University, Auburn, Alabama.

³ Vermont Agricultural Experiment Station Journal, Article No. 396.

⁴ Financial support from Agway, Inc. is greatly appreciated. Materials were generously donated by Commercial Solvents Corp., Monsanto Chemical Co., Hoffman-LaRoche, Inc., and Proctor and Gamble Co.

⁵ Present address: Ralston Purina Company, Poultry Research Department, Checkerboard Square, St. Louis, Missouri 63188. Send reprint requests to this address.

⁶ Present address: Department of Zoology, University of Hull, Hull, Yorkshire, England HU6 7RX.

⁷ Present address: Department of Physiology, Thompson Hall, Cook College, Rutgers University, New Brunswick, New Jersey 08903.

Manuscript received 20 April 1978.