Abstract

LIMA, J.A.M et al. Effects of increasing milking frequency in early lactation on milk production, milk composition and reproductive parameters of crossbred Holstein Zebu cow. Arq. Bras. Med. Vet. Zootec. [online]. 2011, vol.63, n.5, pp. 1160-1166. ISSN 0102-0935.  http://dx.doi.org/10.1590/S0102-09352011000500017.

Fifty three multiparous crossbred Holstein Zebu cows were distributed in four groups with the purpose of evaluating the effects of four daily milking until lactation day 21 and after this day two milking, with or without suckling by the calf, on milk yield and composition, cows and calves weights and the reproductive parameters. Milk production and composition were measured each four days until the 33th day of lactation, then each 15 days until the end of lactation. The animals were weighed at birth, and weekly until two months postpartum and then each 30 days until the end of lactation. The experiment was completely randomized in a 2x2 factorial design. The average milk productions were 16.7, 17.2, 19.0, and 18.9kg/day (P<0.01), for cows milked twice or four times a day with or without suckling by the calf, respectively. Fat and total solids percentages, 3.5% fat corrected milk, and total solids corrected milk were higher in the groups of cows milked four times a day. The increase in milking frequency at the beginning of lactation increased the production of milk (P<0.01), but did not influence the weight of cows and calves or reproductive parameters (P>0.05).

Keywords : number of milking; presence of the calf; milk yield; reproductive efficiency; suckling.