Pre- and postweaning performance and health of dairy calves fed milk replacers with differing protein sources

Three studies were conducted to evaluate the effect of partially replacing milk replacer (MR) protein with alternative sources on calf performance and health. Sources evaluated included wheat gluten (WG), soy protein concentrate (SPC), spray dried animal plasma (PL), and plant peptide powder (PP). The control treatment (CON) across all studies was 100% milk protein MR. In study 1, WG and SPC (replacing up to 50% of MR milk protein) decreased (P < 0.05) preweaning and overall (0.78 vs. 0.70 kg of BW/d) ADG compared with CON. Milk replacer intake was similar (P > 0.05) across treatments. Preweaning and overall calf starter intake were reduced (P < 0.05) for calves fed MR with WG or WG and SPC compared with CON calves. In study 2, partial replacement (50%) of MR CP with WG, PL, or SPC did not affect pre- or postweaning ADG, hip height gain, or MR or calf starter intake compared with CON calves (P > 0.05). In study 3, there were no differences (P > 0.05) in performance or health between CON calves or those fed MR with PL or PP. Across treatments, calves gained 0.78 kg of BW/d, grew 11.19 cm in hip height, and consumed 51.66 kg of calf starter DM d 1 to 56. In summary, studies 1 and 2 indicate WG and SPC used in these studies can be fed in combination with PL to minimize calf performance effects. Study 3 suggests PL and PP used in these studies can successfully replace up to 25% of milk protein in calf MR.