Abstract #M157

# M157
Evaluation of milk replacer feeding rates on Holstein calves via a meta-analytical approach: 2. Carry-over effect on digestion and growth from 2 to 4 months of age.
W. Hu*1, T. M. Hill1, T. S. Dennis1, F. X. Suarez-Mena1, J. D. Quigley1, 1Nurture Research Center, Provimi, Cargill Animal Nutrition, Brookville, OH.

Objective of this study was to evaluate carry-over effects of feeding milk replacer at 2 rates on growth performance of dairy calves from 2 to 4 mo of age via a meta-analytical approach. A database was developed from 10 studies conducted at the Nurture Research Center, Provimi (Brookville, OH) from 2014 to 2016. Male Holstein calves (n = 485; 76.1 ± 7.0 kg BW at 2 mo of age) were previously assigned to 1 of 2 treatments: total milk replacer intakes of 29.7 ± 0.6 kg DM (MOD) and 48.8 ± 4.5 kg DM (HIGH). Milk replacer contained 24.8–28.6% CP and 17.6–20.2% fat on a DM basis. Calves were weaned at 6–7 wk, moved into pens by treatment on d 56, and then fed calf starter (19.4–22.3% CP and 3.4–4.6% fat, DM basis) blended with 5% hay until d 112. Statistical analysis was conducted using mixed-effects models. From 56 to 84 d, ADG (0.864 vs. 0.885 kg/d; P = 0.480) or DM intake (2.361 vs. 2.431 kg/d; P = 0.204) did not differ, but apparent digestibility of DM (78.6 vs. 75.9%; P < 0.001), OM (79.6 vs. 76.8%; P < 0.001), CP (80.9 vs. 78.5%; P < 0.001), and NDF (55.2 vs. 46.6%; P < 0.001) was greater for calves fed MOD vs. HIGH when estimated at a 5-d period between wk 11–13. From 56 to 112 d, ADG (1.015 vs. 0.976 kg/d; P < 0.001), gain/DMI (0.375 vs. 0.349 kg/kg; P < 0.001), and hip width change (0.089 vs. 0.081 cm/d; P < 0.001) was greater, but dry feed intake was less (2.797 vs. 2.923 kg/d; P = 0.008) for calves previously fed MOD vs. HIGH. Over the entire period of calf early life (d 0–112), ADG was 0.784 vs. 0805 kg/d (P = 0.004) and hip width change was 0.077 vs. 0.075 cm/d (P = 0.081) for calves previously fed MOD vs. HIGH. Feeding calves more than 0.681 kg/d (as-fed basis) of milk replacer in the nursery decreased BW gain and structural growth in the grower period (d 56–112). Reduced digestibility of DM, OM, CP, and NDF as result of more milk replacer in the nursery could cause calves to grow slower from 2 to 4 mo of age.

Key Words: calf, performance, digestibility