Effects of Using Wheat Gluten and Rice Protein Concentrate in Dairy Calf Milk Replacers

There is a limited amount of peer reviewed data on feeding milk replacers (MR) containing either hydrolyzed wheat gluten (HWG; 80% CP) or rice protein concentrate (RPC; 80% CP) to calves under 2 mo of age. Male Holstein calves less than 7 d old from multiple farms (trial 1) and 2- to 3-d-old calves from one dairy farm (trials 2 and 3) were used. Trial 1 compared feeding 0.454 kg/d of 20% CP, 20% fat MR powders that contained 0 and 4.3% HWG for 42 d. Trial 2 compared feeding 0.681 kg/d of 26% CP, 17% fat MR powders that contained 0, 6, and 12% HWG for 42 d. Trial 3 compared feeding 0.681 kg/d of 26% CP, 17% fat MR that contained 0, 8, and 16% RPC for 28 d. Within trial, the MR were formulated to have equal concentrations of major nutrients and be adequate in essential amino acids. In trial 1, preweaning ADG, starter intake, feed efficiency, and hip width changes were greater in calves fed the MR with 0 vs. 4.3% HWG. In trial 2, preweaning ADG, starter intake, and hip width change decreased linearly with increasing concentration of HWG in the MR. In trial 3, ADG and feed efficiency declined linearly as RPC increased in the MR. In these 3 trials, preweaning ADG of calves less than 2 mo old was reduced when either HWG or RPC replaced whey protein in a MR.