Improvement in milk production of first calf heifers by multiple suckling

Abstract

Thirty Friesian heifers were alternately allocated to two groups as they calved at 2½–3 years of age. Calves were left with the heifers for 36 hr after calving, then machine-milked twice daily (group 1) or machine-milked at 0600 hours and suckled at 1500 hours (group 2) by an average of 1½ calves for the first 8 weeks of lactation. Heifers were restricted in a race while suckling. Heifers in group 2 (suckled) produced 16% more milk during the 300 day lactation than group 1 (milked) heifers. The difference in milk production was in excess of that removed by the calves whilst suckling. Suckling appears to promote a more complete milk 'let-down' in early lactation, thus preventing milk accumulation in the udder. Milk accumulation at this critical stage is believed to adversely affect subsequent milk production by damaging secretory tissue. The concentration of prolactin in peripheral blood was lower during suckling than during milking, and the degree of udder infection (mastitis) in the two groups did not differ significantly. Multiple suckling of cows in early lactation appears to be a worth-while practice, particularly with animals showing a nervous disposition. It also provides a convenient calf-rearing system, as milk is provided at an optimal temperature to the calf and with minimum chances of contamination.