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Effects of growth hormone administration on the body composition and hormone levels of genetically fat sheep

Published online by Cambridge University Press:  02 September 2010

S. M. Francis
Affiliation:
AgResearch, Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand
N. B. Jopson
Affiliation:
AgResearch, Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand
R. P. Littlejohn
Affiliation:
AgResearch, Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand
S. K. Stuart
Affiliation:
AgResearch, Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand
B. A. Veenvliet
Affiliation:
AgResearch, Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand
M. J. Young
Affiliation:
Animal and Veterinary Sciences Group, PO Box 84, Lincoln University, New Zealand
J. M. Suttie
Affiliation:
AgResearch, Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand
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Abstract

Coopworth sheep selected for low (lean) or high (fat) backfat have large differences in plasma GH profiles. Fat genotype ram lambs (5 months old) were treated with growth hormone (GH) to simulate the plasma GH profiles of lean sheep and investigate whether exogenous GH could modify carcass fatness. For 77 days, bovine GH was administered at 25 Uglkg live weight per day either as a single, daily subcutaneous bolus (fat bolus) or via portable pulsatile infusion pumps (fat pump) which delivered GH solution at 90-min intervals into a jugular catheter. Measurements of body composition were made by computed tomography (CT) and ultrasonic scanning during the trial, with linear carcass measurements and proximate analysis undertaken at the end of the experiment.

Before treatments began, mean plasma GH levels were lower (P < 0·01) in fat control (0·34 ugll) than in lean lambs (1·1 μg/l). Several weeks after the start of the trial, mean plasma GH had increased in both fat bolus (1·2 μg/l) and fat pump (0·45 μg/l) treatment lambs with major changes in the pulsatility relative to the fat control lambs. Although these changes were maintained in the fat bolus lambs, by the end of the trial there was no significant difference in mean plasma GH between fat pump and fat control sheep. Throughout the trial, plasma 1GF-1 levels were higher in fat bolus, fat pump and lean lambs than in fat control lambs. Analysis of body composition data over the GH treatment period revealed that the slope of the allometric equation for total fat relative to empty body weight was lower in the fat bolus lambs (1·07) than in the lean lambs (1·50) with fat control and fat pump treatment lambs intermediate (1·30 and 1·36, respectively). Subcutaneous fat was later maturing in lean lambs than in fat control and bolus treatment lambs when regressed against total fat, with the fat pump treatment lambs being intermediate. Linear carcass measurements revealed changes due to GH administration in the distribution of subcutaneous fat and eye muscle dimensions.

It is concluded that sheep from the fat genotype show physiological responses to exogenous GH. Increasing plasma GH levels of fat sheep increased plasma IGF-1 and had variable effects on carcass fatness. The change in body composition may be affected by the mode of administration of exogenous GH.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 1998

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References

Amselem, S., Duquesnoy, P., Duriez, B., Dastot, F., Sobrier, M. L., Valleix, S. and Goossens, M. 1993. Spectrum of growth hormone receptor mutations and associated haplotypes in Laron syndrome. Human Molecular Genetics. 2: 355359.CrossRefGoogle ScholarPubMed
Bass, J. J., Hodgkinson, S. C., Breier, B. H., Carter, W. D. and Gluckman, P. D. 1992. Effects of bovine somatotrophin on insulin-like growth factor-I, insulin, growth and carcass composition of lambs. Livestock Production Science 31: 321334.CrossRefGoogle Scholar
Bass, J. J., Oldham, J. M., Hodgkinson, S. C., Fowke, P. J., Sauerwein, H., Molan, P., Breier, B. H. and Gluckman, P. D. 1991. Influence of nutrition and bovine growth hormone (GH) on hepatic GH binding, insulin-like growth factor-I and growth of lambs. Journal of Endocrinology. 128: 181186.CrossRefGoogle ScholarPubMed
Bick, T., Hochberg, Z., Amit, T., Isaksson, O. G. P. and Jansson, J. O. 1992. Roles of pulsatility and continuity of growth hormone (GH) administration in the regulation of hepatic GH-receptors, and circulating GH-binding protein and insulin-like growth factor-I. Endocrinology. 131: 423429.CrossRefGoogle ScholarPubMed
Butterfield, R. M. 1988. New concepts of sheep growth. Department of Veterinary Anatomy, University of Sydney, Sydney.Google Scholar
Diggle, P. J. 1990. Time series: a biostatistical introduction. Clarendon, Oxford.CrossRefGoogle Scholar
Etherton, T. D., Louveau, I., Serensen, M.T. and Chaudhuri, S. 1993. Mechanisms by which somatotropin decreases adipose tissue growth. American Journal of Clinical Nutrition 58: (supplement) 287S295S.CrossRefGoogle ScholarPubMed
Fleming, J. S., Suttie, J. M., Montgomery, G. W., Gunn, J., Stuart, S. K., Littlejohn, R. P. and Gootwine, E. 1997. The effects of a duplication in the ovine growth hormone (GH) gene on GH expression in the pituitaries of lean and fat-selected sheep lines. Domestic Animal Endocrinology. 14: 1724.CrossRefGoogle ScholarPubMed
Foster, D. L. and Ryan, K. D. 1979. Endocrine mechanisms governing transition into adulthood: a marked decrease in inhibitory feedback action of estradiol on tonic secretion of lutenizing hormone in the lamb during puberty. Endocrinology 105: 896904.CrossRefGoogle Scholar
Francis, S. M., Veenvliet, B. A., Littlejohn, R. P., Stuart, S. K. and Suttie, J. M. 1995. Growth Hormone (GH) secretory patterns in genetically lean and fat sheep. Proceedings of the New Zealand Society ofAnimal Production. 55: 272274.Google Scholar
Francis, S. M., Veenvliet, B. A., Stuart, S. K., Littlejohn, R. P. and Suttie, J. M. 1997. The effect of photoperiod on plasma hormone concentrations in wether lambs with genetic differences in body composition. Animal Science. 65: 441450.CrossRefGoogle Scholar
Jopson, N. B., Thompson, J. M. and Fennessy, P. F. 1997. Tissue mobilization rates in male fallow deer (Dama dama) as determined by computed tomography: the effects of natural and enforced food restriction. Animal Science. 65: 311320.CrossRefGoogle Scholar
Kirton, A. H. and Johnson, D. L. 1979. Interrelationships between GR and other lamb carcass fatness measurements. Proceedings of the New Zealand Society of Animal Production 39: 194201.Google Scholar
Lord, E. A., Fennessy, P. F. and Littlejohn, R. P. 1988. Comparison of genotype and nutritional effects on body and carcass characteristics of lambs. New Zealand Journal of Agricultural Research. 31: 1319.CrossRefGoogle Scholar
McEwan, J. C., Clarke, J. N., Knowler, M. A. and Wheeler, M. 1989. Ultrasonic fat depths in Romney lambs and hoggets from lines selected for different production traits. Proceedings of the New Zealand Society of Animal Production 49: 113119.Google Scholar
Maiter, D., Walker, J. L., Adam, E., Moatsstaats, B., Mulumba, N., Ketelslegers, J. M. and Underwood, L. E. 1992. Differential regulation by growth hormone (GH) of insulin-like growth factor-I and GH receptor binding protein gene expression in rat liver. Endocrinology. 130: 32573264.CrossRefGoogle ScholarPubMed
Martini, J.-F., Villares, S. M., Nagano, M., Delehaye-Zervas, M.-C., Eymard, B., Kelly, P. A. and Postel-Vinay, M.-C. 1995. Quantitative analysis by polymerase chain reaction of growth hormone receptor gene expression in human liver and muscle. Endocrinology. 136: 13551360.CrossRefGoogle ScholarPubMed
Merriam, G. R. and Wachter, K. W. 1982. Algorithms for the study of episodic hormone secretion. American Journal of Physiology 243: E310–E318.Google Scholar
Morris, C. A., McEwan, J. C., Fennessy, P. F., Bain, W. E., Greer, G. J. and Hickey, S. M. 1997. Selection for high or low backfat depth in Coopworth sheep: juvenile traits. Animal Science 65: 93103.CrossRefGoogle Scholar
Muir, L. A. 1985. Mode of action of exogenous substances on animal growth—an overview. Journal of Animal Science 61: (suppl. 2) 154180.CrossRefGoogle Scholar
Pampori, N. A. and Shapiro, B. H. 1994. Subnormal concentrations in the feminine profile of circulating growth hormone enhance expression of female-specific CYP2C12. Biochemical Pharmacology 47: 19992004.CrossRefGoogle ScholarPubMed
Shapiro, B. H., Agrawal, A. K. and Pampori, N. A. 1995. Gender differences in drug metabolism regulated by growth hormone. International Journal of Biochemistry Cell Biology. 27: 920.CrossRefGoogle ScholarPubMed
Spencer, G. S. G., Schurmann, A., Berry, C., Wolff, J. E., Napier, J. R., Hodgkinson, S. C. and Bass, J. J. 1994. Comparison of the effects of recombinant ovine, bovine and porcine growth hormones on growth, efficiency and carcass characteristics in lambs. Livestock Production Science 37: 311321.CrossRefGoogle Scholar
Statistical Analysis Systems Institute. 1992. SAS/STAT software: changes and enhancements, release 6.07. SAS report P-229. SAS Institute Inc., Cary, NC.Google Scholar
Suttie, J. M., Kostyo, J. L., Ebling, F. J., Wood, R. I., Bucholtz, D. C., Skottner, A., Adel, T. E., Towns, R. J. and Foster, D. L. 1991a. Metabolic interfaces between growth and reproduction. IV. Chronic pulsatile administration of growth hormone and the timing of puberty in the female sheep. Endocrinology. 129: 20242032.CrossRefGoogle ScholarPubMed
Suttie, J. M., Lord, E. A., Gluckman, P. D., Fennessy, P. F. and Littlejohn, R. P. 1991b. Genetically lean and fat sheep differ in their growth hormone response to growth hormone-releasing factor. Domestic Animal Endocrinology 8: 323329.CrossRefGoogle ScholarPubMed
Suttie, J. M., Veenvliet, B. A., Littlejohn, R. P., Gluckman, P. D., Corson, I. D. and Fennessy, P. F. 1993. Growth hormone pulsatility in ram lambs of genotypes selected for fatness or leanness. Animal Production. 57: 119125.Google Scholar
Weller, P. A., Dauncey, M. J., Bates, P. C., Brameld, J. M., Buttery, P. j. and Gilmour, R. S. 1994. Regulation of porcine insulin-like growth factor I and growth hormone receptor mRNA expression by energy status. American Journal of Physiology 266: E776–E785.Google ScholarPubMed