Abstract

Six nutritional regimes were imposed on Friesian heifers (n=270) from weaning to 22 months of age to determine the effect of level of feeding during rearing on subsequent milk production. Nutritional treatments resulted in groups weighing 480, 406, 455, 376, 398, and 342 kg (P<0.05) at 22 months of age. However, once the heifers entered the herd differences liveweight were lost. By 28 months of age the difference between the heaviest and lightest treatment groups was only 44 kg (P<0.05). Level of feeding from 90 to 200 kg liveweight had no effect on subsequent milkfat or protein yield (P>0.05). Heifers offered a high feeding level after 200 kg produced 9.6 kg more milkfat (P<0.01) and 6.6 kg more protein (P<0.01) than heifers offered the low feeding regime. These data suggest that Friesian heifers produce an additional 0.12 kg MS over their first lactation for each additional 1 kg liveweight gained during rearing.

JW, Penno, KA MacDonald, and AM Bryant

Proceedings of the New Zealand Society of Animal Production, Volume 57, , 176-178, 1997