Blood concentrations of growth hormone, insulin-like growth factor-1, thyroid hormone and vitamin A in Japanese Black calves with retarded growth.

摘要

Plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1), thyroid hormone (T3 and T4), and vitamin A concentrations were measured in Japanese Black beef calves with marked retarded growth associated with diarrhoea, pneumonia, coccidiosis orstrongyloidiasis. Plasma GH concentrations were significantly higher in calves with retarded growth (23 cases; 14.3±9.5 ng/ml) showing a cyclic change as compared with that in clinically healthy calves (6 cases; 2.9±1.0 ng/ml) showing steady secretion. Plasma IGF-1 and vitamin A concentrations were significantly lower in calves with retarded growth (30.1±15.7 ng/ml and 15.7±7.7μg/dl, respectively) as compared with those in clinically healthy calves (120.5±64.9 ng/ml and 29.2±5.4μg/dl, respectively). There was no difference in plasma T3 and T4 concentrations between the 2 groups. These findings suggested that the retarded growth resulted from some endocrinological disturbances and malnutrition due to diarrhoea, pneumonia or parasite infestations and that the estimation of plasma IGF-1 concentrations might be useful for prognosis.