Endocrine patterns in two strains of Japanese black cattle with growth retardation.

Endocrine patterns were compared in 2 strains of Japanese black cattle with growth retardation; MHO- and HSK-paternal strains (MHO and HSK cattle, respectively). MHO cattle (n=8) displayed lower serum concentrations of insulin-like growth factor-1 (IGF-1), triiodothyronine (T3), thyroxine (T4), and cortisol (31.1+/-20.7 ng/ml, 73.9+/-51.9 ng/dl, and 2.9+/-2.9 microg/dl, 1.3+/-0.7 microg/dl, respectively) than those in both HSK cattle (n=5) (64.9+/-47.6 ng/ml, 97.8+/-40.7 ng/dl, 4.1+/-2.1 microg/dl and 1.8+/-1.1 microg/dl, respectively), and the controls (n=6) (314.7+/-197.2 ng/ml, 140.2+/-21.3 ng/dl, 5.8+/-1.7 microg/dl, and 3.0+/-1.4 microg/dl, respectively). The area under the concentration curve of growth hormone (GH-AUC 0-600 min) in MHO cattle (22210+/-18951 ng.min/ml) tended to be greater than those in HSK (7887+/-6340 ng.min/ml) and the controls (2811+/-1275 ng.min/ml). MHO cattle showed a high GH-AUC0-600 min in contrast to a low serum IGF-1 concentration, as well as lower serum T3, T4, and cortisol concentrations. HSK cattle exhibited the same secretory patterns, but much more moderately. Growth retardation in Japanese black cattle exhibits some variations based on pedigree.