Birth Weight, Weight Gain and Intestinal Disaccharidase Activities in Calves as Affected by Maternal Undernutrition in Late Pregnancy

Abstract

1. Fourteen pregnant cows were assigned to three experimental groups at about 130 days of gestation. These groups were given rations at levels for gaining body weight normally (MG), maintaining body weight (LG), and greatly reducing the body weight (VLG) in late pregnancy, respectively. The change in body weight from the begining of the experiment to parturition in each group was 52, 0 and-47kg, respectively. Al of the calves were fed on a milk substitute from 4 days after birth and were slaughtered at about one month of age. 2. The birth weight of the calves did not differ significantly between the MG and LG groups. On the other hand, the birth weight of VLG calves was significantly lighter than that of MG calves (P<0.05). Neither the daily weight gain nor the daily consumption of hay and a concentrate from birth to one month of age differed significantly among the three groups of calves. 3. The activities of lactase and maltase in the small intestinal mucosa were significantly higher in VLG calves than in MG and LG calves (P<0.05). These high enzyme activities in VLG calves were observed over nearly the whole length of the small intestine. The concentration of plasma glucose at 28 days of age reached a significantly higher level after drinking milk in VLG calves than in MG and LG calves (P<0.05). This seemed to be a reflection of the high lactase activity in VLG calves.