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Endocrine changes and their relationship with body weight in growing yaks

  • Tian Yongqiang (a1), Zhao Xingxu (a1), Wang Minqiang (a2), Lu Zhonglin (a2) and Zhang Rongchang (a1)...


The concentrations of growth hormone (GH), insulin (Ins), tri-iodothyronine (T3) and thyroxine (T4) in blood samples of growing yaks during different bimonthly seasons were determined by radioimmunoassay. The changes of body weight of growing yaks and composition of grass grazed were measured accordingly. The seasonal changes of hormones were significant (P < 0·01 or P < 0·05). Within season, the variances of hormones depended upon the different growing stages. The body-weight gains in the different groups varied in different seasons, increase being significant in May, July and September, decrease being significant from January to May. Correlation analysis indicated that T4 concentration had a significant positive correlation with the body weight of the growing yaks(r = 0·2509, P < 0·05) and other hormones did not have any significant correlation with body weight. The results showed that the annual cycle of weight loss and gain was attributed to the seasonal change of nutrition status. The seasonal change of the assayed hormones depended on the grass growth.


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Blum, J. W., Gingins, M., Vitins, P. and Bickel, H. 1980. Thyroid hormone levels related to energy and nitrogen balance during weight loss and regain in adult sheep. Acta Endocrinologica 93: 440447.
Blum, J. W., Schnyder, W., Kunz, P. C., Blom, A. K., Bickel, H. and Schurch, A. 1985. Reduced and compensatory growth: endocrine and metabolic changes during feed restriction and refeeding in steers. Journal Nutrition 115: 417424.
Breier, B. H., Bass, J. J., Butter, J. H. and Gluckman, P. D. 1986. The somatotrophic axis in young steers: influence of nutritional status on pulsate release of GH and circulating concentration of IGH-I. Journal of Endocrinology 111: 209215.
Breier, B. H., Gluckman, P. D. and Bass, J. J. 1988. Influence of nutritional status and oestradiol-17b on plasma growth hormone, insulin-like growth factors-I and –II responses to exogenous growth hormone in young steers. Journal of Endocrinology 118: 243248.
Breier, B. H., Gluckman, P. D., McCutecheon, S. N. and Davis, S. R. 1991. Physiological responses to somatotropin in the ruminant. Journal of Dairy Science 74: (suppl. 2) 2034.
Ellenberger, M. A., Johnson, D. E., Carstens, G. E., Hossner, K. L., Holland, M. D., Nett, T. M. and Nokels, C. F. 1989. Endocrine and metabolic changes during altered growth rates in beef cattle. Journal of Animal Science 67: 14461454.
Gregory, N. G., Truscott, T. G. and Wood, J. D. 1982. Insulin secretion in relation to fatness in cattle. Journal of the Science of Food and Agriculture 23: 276282.
Hayden, J. M., Willians, J. E. and Collier, R. J. 1993. Plasma GH, IGF-I, insulin and thyroid hormone association with body protein and fat accretion in steers undergoing compensatory gain after dietary energy restriction. Journal of Animal Science 71: 33273338.
Joakimsen, O. and Blom, A. K. 1976. Growth hormone concentration in jugular blood plasma in relation to growth rate and age in young bulls. Acta Agriculturae Scandinavica 26: 239242.
Kahl, S. 1978. Effect of synovex-S on growth rate and plasma thyroid hormone concentrations in beef cattle. Journal of Animal Science 46: 232237.
Kahl, S. and Bitman, J. 1983. Relation of plasma thyroxine and triiodothyronine to bodyweight in growth in growing male and female Holstein cattle. Journal of Dairy Science 66: 23862390.
Rumsey, T. S. 1981. Effect of roneel on growth, endocrine function and blood measurements in steers and rats. Journal of Animal Science 53: 217225.
Trenkle, A. 1976. Estimates of the kinetic parameters of growth hormone metabolism in fed and fasted cattle and sheep. Journal of Animal Science 43: 10351039.
Trenkle, A. 1977. Changes in growth hormone status related to body weight of growing cattle. Growth 41: 241347.
Verde, L. S. and Trenkle, A. 1982. Concentration of hormone in plasma from cattle with different growth potentials. Journal of Animal Science 55: (suppl. 1) 426432.



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