Abstract

Milk yield and composition were measured weekly throughout lactation, and daily dry matter intake (DMI) on 7 occasions, for Friesian (n=16) and Jersey (n=16) heifers calving at either high (H) or low (L) liveweights. During the 8 weeks pre-partum, heifers were fed to achieve calving liveweights of 404 (H Friesian), 354 (L Friesian), 334 (H Jersey) and 277 (L Jersey) kg. All heifers were fully fed on pasture as one group for the whole of lactation. Calving liveweight had no effect on average DMI over the season. Average DMI was higher for Friesians than Jerseys while average liveweight- corrected DMI was slightly greater for Jersey than Friesians. Average daily milk yields and yields of lactose were lower for L than H heifers. Solids- corrected milk yields and yields of milkfat and protein were unaffected by calving liveweight, but milkfat % and protein % were higher for L than H heifers. The Friesians had higher milk yields, and yields of protein and lactose, but lower milkfat % and protein % than Jerseys. No effect of restricted feeding during late pregnancy in heifers was demonstrated on milk solids production in the subsequent lactation.

TR, Mackle, CR Parr, GK Stakelum, AM Bryant, KL Macmillan, and MJ Auldist

Proceedings of the New Zealand Society of Animal Production, Volume 56, , 260-262, 1996