The Effect of Pregnancy on the Body Weight of Dairy Cows

Abstract

A study was made of the effect of pregnancy on the body wts. of dairy cattle. 56 Ayrshire cows, during their first 3 periods of gestation, were used in the study. The gain in wt. over and above normal wts. was not great before the 5th month of pregnancy. From 75 to 85% of the gain came during the last 4 mos. of pregnancy. The first calf heifers showed a more uniform gain in wt. from month to month than did the older animals. The animals in the last month of pregnancy were on the average 151 lb. heavier than open animals of the same age. The av. monthly gain made during the 8th month of pregnancy was less than in the months immediately preceding and following.