Effects of Feeding Calves Different Rates and Protein Concentrations of Twenty Percent Fat Milk Replacers on Growth During the Neonatal Period

Abstract

<h3>Abstract</h3> Three trials were designed to examine how the feeding rate of a 20% fat milk replacer (MR) affected calf performance. Holstein bull calves (40 to 41kg average initial BW; < 7 d) were randomly assigned to MR treatments and fed fixed amounts of MR with free-choice starter for 42 d. Calves were weaned at 42 d and fed starter only from d 43 to d 49. A 20% CP, 20% fat MR fed at 0.45kg daily served as the control treatment in each trial. Feeding a 28% CP, 20% fat MR stepped-up to 1.13 (Trial 1) or 1.36 (Trial 2)kg daily resulted in similar BW gains, increased fecal scores, increased medical treatments (52 to 72%), and reduced starter intake (48%) by 49 d compared to the control. Feeding a 28% CP, 20% fat MR at 0.68kg daily (Trial 3) increased BW gains (55%) and tended to increase fecal scores and medical treatments (27%), but tended to decrease starter intake (11%) vs. the control by 49 d of age. Feeding a 20% CP, 20% fat MR at 0.68kg daily (Trial 3) did not increase daily gains, but tended to decrease starter intake (14%) vs. the control by 49 d of age. Increasing the CP level above 20% (to 28% in this case) was needed to promote BW gains when the MR feeding level was increased to 0.68kg.