Effects of level and frequency of feeding milk replacer and of protein level of supplement on calf growth to six months of age.

Abstract

Proc. Aust. Soc. Anim. Prod. (1978) 12: 227 EFFECTS OF LEVEL AND FREQUENCY OF FEEDING MILK REPLACER AND OF PROTEIN LEVEL OF SUPPLEMENT ON CALF GROWTH TO SIX MONTHS OF AGE I.J.R. BYFORD*, G.A. CHAMBERS** and R.J. MOSS** Once,. rather than twice daily milk feeding of dairy calves is now generally accepted and high growth rates are not required for dairy replacements. Calf rearing aims at early rumen development and early weaning onto concentrates and pastures to reduce both labour and costs. Feeding low levels of milk plus dry energy and protein concentrates may accelerate this process. However, low initial growth rate and early weaning may affect subsequent calf performance. Heifers weaned at light weights onto tropical pastures of moderate digestibility may grow too slowly for early mating. At Kairi Research Station in North Queensland 48 Friesian calves were fed a proprietary milk replacer (Buchanan's Calf Starter) in a 2 x 2 x 2 factorial experiment. Calves were fed replacer once or twice . daily at 7% or 10% of liveweight and either maize or a 4:l maize: bloodmeal mix ad. lib. to weaning at eight weeks of age. Calves were weaned onto green panic-glycine pas ures and fed maize or maize: E bloodmeal supplement at 0.9 kg day- to six months of age. BirthTwice daily feeding gave highfr growth rates to weaning (0.48 kg day ') than once daily (0.37 kg day- ) (P(O:Ol). Restricting milk feeding level from 10% to 1% of liveweight reduced daily growth rate from 0.48 to 0.36 kg day- (P(O.01). The combination twice daily feeding and higher rate o replacement feeding further increased growth rate to 0.56 kg day- f (P(O.05). Protein supplementation did not increase calf growth prior to weaning. Weaning to six months. Protein supplementation (maize v maize: bloodmeal) increased weaner growth rates from 0.45 to 0.56 kg/day (PCO.01). Previous milk feeding level and frequency had no effect on subsequent calf performance. Although other work has shown that grain supplementation can enable reduction of milk intake without serious lowering of calf growth rate, a 30% decrease in milk feeding level reduced growth rate by 25% in this instance. Post weaning growth on pasture plus maize was less than desired for rearing herd replacements (Cowan et-al. 1974). Provision of a high protein supplement improved this growth performance to a satisfactory level of 0.56 kg/day. Post weaning growth was not affected by restricted growth rate to weaning, indicating that rumen development at eight weeks of age was advanced in calves under all feeding regimes. It is concluded that provided calves are healthy and reared in clean, warm, dry surroundings, dairy replacements can be reared at low levels ,, of milk intake with supplementary feeding, Dryland tropical grass legume pastures do not provide sufficient protein, and early weaned calves should receive a high protein supplement. Cowan, R.T. O'Grady, P., and Moss, R.J. (1974). Qld. J. agric. and anim. Sci. 31~367. * Dept. of Primary Industries, Breakfast Creek Road, .Newstcad, Q. ** Dept. of Primary Industries, Research Station, Ayr, Q. 4802. I 227, 4006 2. .