Influence of Preceding Dry Period and of Mineral Supplement on Lactation

Abstract

Summary A dry period of 31 to 60 days has been found in this study to allow maximum milk yields by Jersey cows. A dry period of longer than 91 days appeared to result in lower milk production than did shorter dry periods. Dry periods of less than 30 days appeared to cause an early decline in milk yield, corresponding perhaps to the stage of withdrawal of stored nutrients in the body. The use of bonemeal as two per cent of the concentrates in supplementing rations that contained roughages grown on acid sandy soils resulted in a 45 per cent increase in milk production with 73 records, over that of 218 lactations on the low-calcium rations. A statistically significant difference was found in rates of decline in milk production between the groups on low-calcium and on adequate-calcium rations.