Alterations of growth, blood biochemical components and hormone profiles by intensified nutrition in growth retarded Japanese Black cattle.

In order to determine the clinical conditions of Japanese Black (JB) cattle with growth retardation, we determined the changes of body growth, blood profiles of metabolism and hormones caused by intensified nutrition (sufficient total digestible nutrients and digestible crude protein for a target daily gain set at 1.2-1.3 kg/day) in three cattle. The daily gain (DG) was increased during the intensified period (Intense) compared with the preparation period (Pre), but the DG in the Intense period was 36-66% of the target DG. Serum albumin, total cholesterol, insulin and IGF-1 increased during the Intense period compared with the Pre period. Serum GH showed high levels in the Pre period, whereas it showed lower levels in the Intense period. These results suggested that the present growth retarded cattle had abnormalities in their metabolic systems and lacked nutrient absorption.