Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-27T12:10:41.508Z Has data issue: false hasContentIssue false
  • English
  • Français

Endogenous pulsing and stimulated release of growth hormone in dairy calves of high and low genetic merit

Published online by Cambridge University Press:  02 September 2010

J. A. Woolliams ,
K. D. Angus  and
S. B. Wilson
J. A. Woolliams
Affiliation:
Institute of Animal Physiology and Genetics Research, Edinburgh Research Station, Roslin, Midlothian EH25 9PS
K. D. Angus
Affiliation:
Institute of Animal Physiology and Genetics Research, Edinburgh Research Station, Roslin, Midlothian EH25 9PS
S. B. Wilson
Affiliation:
Institute of Animal Physiology and Genetics Research, Edinburgh Research Station, Roslin, Midlothian EH25 9PS
Get access

Abstract

Fifty-five calves aged 105 days of age, of both sexes, belonging to two genetic groups (H, high or L, low) differing in their predicted breeding value (PBV) by 78 kg for fat plus protein yield, were individually penned for 3 weeks with the final 2 weeks on a diet designed to provide energy close to their maintenance requirements. The calves were then cannulated in the jugular vein and blood was sampled every 15 min for 25 h. Following this a growth hormone releasing factor (GRF) preparation was administered on up to four occasions, being one of (per kg live weight) either 0·2 or 0·4 μg GRF (treatments SGRF or DGRF respectively) or 0·2 μg thyrotropin releasing hormone (TRH). On each occasion blood samples were taken at −15, 4, 8,12,16, 20 and 45 min relative to the time of administration and up to four further occasions, one prior to and three within 32 min of administration. Samples were assayed for growth hormone (GH).

GH concentration of troughs prior to an episode of GH release was 1·19-fold greater in H compared with L calves with concentrations decreasing to 0·9 of their previous values each h. Trough and peak concentrations had repeatabilities of 0·21 and 0·26 respectively (both P < 0·05). There was no association between PBV and either peak concentrations, number of pulses (4·84 per 25 h) or mean GH concentration (13·3 μg/l).

GH released was only 1·11-fold greater after DGRF than SGRF. The difference in the regression coefficients for PBV between SGRF and DGRF was small, as it was for the difference between coefficients for the two sexes. The pooled coefficient was 0·00342 loge units per kg (s.e. 0·00157; P< 0·05) indicating a 1·31-fold greater response in H than in L calves. The correlation between responses to SGRF and DGRF was 0·482 and the repeatability of SGRF was 0·338; a pooled repeatability was estimated as 0·362(P < 0·01). The regression of GH release on PBV for TRH was 0·00345 (s.e. 0·00330). For all secretagogues, response depended on prior concentrations.

It was concluded that GH release following GRF administration was positively related to PBV in dairy calves and response was moderately repeatable; furthermore, although aspects of endogenous secretion may be related to PBV they suffer from measurement difficulties.

Keywords

dairy calvesgenetic meritsomatotropin
Type
Research Article
Information
Animal Production , Volume 56 , Issue 1 , February 1993 , pp. 1 - 8
Copyright
Copyright © British Society of Animal Science 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agricultural Research Council. 1980 The nutrient requirement of ruminant livestock. Commonwealth Agricultural Bureaux, Slough.Google Scholar
Barnes, M. A., Kazmer, G. W., Akers, R. M. and Pearson, R. E. 1985. Influence of selection for milk yield on endogenous hormones and metabolites in Holstein heifers and cows. journal of Animal Science 60: 271–284.CrossRefGoogle ScholarPubMed
Bonczek, R. R., Young, C. W., Wheaton, J. E. and Miller, K. P. 1988. Responses of somatotropin, insulin, prolactin and thyroxine to selection for milk yield in Holsteins. Journal of Dairy Science 71: 2470–2479.CrossRefGoogle Scholar
Breier, B. H., Bass, J. J., Butler, J. H. and Gluckman, P. D. 1986. The somatotrophic axis in young steers: influence of nutritional status on pulsatile release of growth hormone and circulating concentrations of insulin-like growth factor I. Journal of Endocrinology 111: 209–215.CrossRefGoogle Scholar
Diggle, P. J. and Zeger, S. L. 1989. A non-Gaussian model for time series with pulses. Journal of the American Statistical Association 84: 354–359.CrossRefGoogle Scholar
Kazmer, G. W., Barnes, M. A., Akers, R. M. and Pearson, R. E. 1986. Effect of genetic selection for milk yield and increased milking frequency on plasma growth hormone and prolactin concentration in Holstein cows. Journal of Animal Science 63: 1220–1227.CrossRefGoogle ScholarPubMed
Lovendahl, P., Angus, K. D. and Woolliams, J. A. 1991a. The effect of genetic selection for milk yield on the response of growth hormone secretagogues in immature cattle. Journal of Endocrinology 128: 419–424.CrossRefGoogle ScholarPubMed
Levendahl, P., Woolliams, J. A. and Sinnett-Smith, P. A. 1992b. Response of growth hormone to various doses of growth hormone releasing factor and thyrotropin releasing hormone administered separately and in combination to dairy calves. Canadian Journal of Animal Science 71: 1045–1052.CrossRefGoogle Scholar
Mackenzie, D. D. S., Wilson, G. F., McCutcheon, S. N. and Peterson, S. W. 1988. Plasma metabolite and hormone concentrations as predictors of dairy merit in young Friesian bulls: effect of metabolic challenges and fasting. Animal Production 47: 1–10.Google Scholar
Moseley, W. M., Alaniz, G. R., Clafin, W. H. and Krabill, L. F. 1988. Food intake alters the serum growth hormone response to bovine meal fed Holstein steers. Journal of Endocrinology 117: 253–259.CrossRefGoogle ScholarPubMed
Patterson, H. D. and Thompson, R. 1971. Recovery of inter-block information when block sizes are unequal. Biometrika 58: 545–554.CrossRefGoogle Scholar
Tannenbaum, G. S. and Ling, N. 1984. The inter relationships of growth hormone (GH)-releasing factor and somatostatin in generation of the ultradian rhythm of GH secretion. Endocrinology 115: 1925–1957.CrossRefGoogle Scholar
Tannenbaum, G. S. and Martin, J. B. 1976. Evidence for an endogenous ultradian rhythm governing growth hormone secretion in the rat. Endocrinology 98: 562–570.CrossRefGoogle ScholarPubMed
Thomas, G. B., Mercer, J. E., Karalis, T., Rao, A., Cummings, J. T. and Clarke, I. J. 1990. Effect of restricted feeding on the concentrations of growth hormone (GH), gonadotropins, and prolactin (PRL) in plasma, and on the amounts of messenger ribonucleic acid for GH, gonadotropin subunits, and PRL in the pituitary of adult ovariectomized ewes. Endocrinology 126: 1361–1367.CrossRefGoogle ScholarPubMed
Woolliams, J. A. and Smith, C. 1988. The value of indicator traits in the genetic improvement of dairy cattle. Animal Production 46: 333–345.CrossRefGoogle Scholar