Abstract

Early solid food intake is key to a successful early rumen development system. In NZ, specialist bull-calf rearers tend to feed four-day-old calves restricted milk, ad lib pellets and wean early (5 to 6 weeks). A range of experiments examined the effect of protein %, feed form and the effect of changing protein source in older calves. There was no difference between 16% and 20% protein pellets in the first three weeks but between weeks three and six, feed intakes and liveweight gains were higher on 20% protein pellets (P<0.05). Weaning live weights were higher on a customised pellet (51.5% maize, 20.0% peas, 20.0% soy bean extract 48, 5% molasses, 1.5% limestone, 1.0% soybean oil, 0.8% salt, calf vitamin mineral premix (0.01%), Bovatec (0.006%) and Rumasweet palatant (0.00002%)) than on a commercial pellet (68.9 vs 64.8 kg, P<0.05). Feeding the customised formulation either in roller-milled, hammer-milled or pelleted form did not affect feed intake or liveweight gain. In weaned calves welladjusted to consuming concentrates, substituting a commercial meal with palm kernel significantly reduced feed intake when fed at 60% of the ration whilst copra meal substitution significantly reduced intake at 40% in calves accustomed to eating pellets. Pellet composition had a greater impact on feed intakes and growth rate than did the form in which the feed was offered. Keywords: calf; copra meal; palm kernel; protein content; artificially reared

PD, Muir, BC Thomson, and NB Smith

New Zealand Journal of Animal Science and Production, Volume 80, Online, 95-100, 2020