Abstract #M163

# M163
Pre- and post-weaning performance and health of dairy calves fed milk replacers formulated with alternative blended protein and fat sources at different levels of protein.
D. Ziegler*1, H. Chester-Jones1, C. Soderholm2, B. Hansen2, 1University of Minnesota, Waseca, MN, 2Milk Specialities Global, Eden Prairie, MN.

One-hundred 3 (2 to 5 d old) individually fed Holstein heifer calves (39.1 ± 0.63 kg) from 2 commercial dairies were randomly assigned to 1 of 4 milk replacer (MR) treatments formulated with blended protein and fat sources to evaluate pre- (d 1 to 49) and post-weaning (d 50 to 56) calf performance and health. The study was conducted between May and August 2018. All calves were fed a medicated (Decoquinate at 45.4 g/ton) texturized calf starter (CS; 18% crude protein CP as fed). Water and CS were offered free choice from (d 1 to 56). All MR were fed at 0.34 kg in 2 L of water 2× daily from d 1 to d 42 and 1× daily from d 43 to weaning at d 49; supplemented daily with neomycin sulfate and oxytetracycline at 22 mg/kg BW/day (d 1 to 14). Milk Replacer treatments were as follows: 1) 20% CP:20% fat (all milk protein, MP, all animal fat, AF; CONAM20); 2) 25% CP:20% fat MP AF, (CONAM25); 3) 25% CP:20% fat AF formulated with blend of bovine plasma, soy isolate and hydrolyzed wheat gluten proteins (BP) replacing 35.6% of MP, (BP25); and 4) 25% CP:25% fat MR formulated with BP as in TRT 3 and a blend of AF and coconut oil (BF) replacing 15% of total fat, (BPBF25). There was an increase in ADG (P = 0.10) trend for calves fed CONAM25 and BPBP25 vs. those fed CONAM20 and BP25 (d 1 to 56) averaging 0.68, 0.65, 0.61 and 0.60 kg/d respectively. Hip height gain was similar across treatment groups averaging 10.95 cm gain (d 1 to 56). There were no differences in CS or dry matter intake (d 1 to 56) averaging 30.7 and 60.5 kg total intake respectively. No differences in gain:feed ratio (d 1 to 56) were observed. There were no differences in health costs or daily fecal scores across treatments. Scouring days (days ≥3, 1 = normal to 4 = watery) tended to be higher (P = 0.07) for calves fed BP25 vs. other treatment groups. Under conditions of this study there were no benefits to feeding a 25:20 MR BP25 compared with calves fed a 20:20 a.m. MR CONAM20. The substitution of coconut oil for animal fat did not benefit overall performance (d 1 to 56).

Key Words: calf performance, milk replacer protein sources, fat source