Effects of different milk allowances on the behavior and liveweight of Holstein-Friesian bull calves.

Dairy calves reared for beef are commonly fed restricted milk allowances preweaning, which may negatively influence their welfare and growth. We investigated the effects of 2 milk allowances on the behavior and liveweight of 22 Holstein-Friesian bull calves in a pasture-based system. Calves were managed indoors in 1 group and individually offered 5 or 10 L of milk/d via an automatic milk feeder until 5 wk of age (n = 11 calves/treatment) when they were transferred onto pasture. Behavior (at meal, milk, hay and bentonite feeders, ruminating, exploring, drinking, lying, grooming, play running and cross-suckling) was recorded for 48.5 h at 4 wk of age using video cameras and leg-based accelerometers. Milk feeder data were automatically recorded over 2 wk (number of visits, milk consumption, and drinking speed). Liveweight was recorded weekly until 18 wk of age and monthly thereafter until 1 yr of age. At 4 wk of age, calves offered 10 L had fewer unrewarded visits to the milk feeder (3.1 vs. 38.2 visits/d), fewer visits to the meal (0.7% vs. 2.8% of observations) and hay feeders (0.4% vs. 0.8% of observations) and drank the milk slower (388 vs. 473 mL/min) than calves offered 5 L. Calves offered 10 L/d also spent more time (78 min/24 h) lying, but took more steps (303 vs. 245/24 h), and engaged more in self- and allogrooming behavior (self-grooming: 3.2% vs. 1.8%, receiving: 1.0% vs. 0.5% of observations) compared with calves offered 5 L. Calves offered 10 L/d were, on average, 4.3 kg heavier at 5 wk of age compared with the calves offered 5 L/d even though they did not always drink their full allowance (average milk intake: 6.6. vs 4.9 L/d). Liveweights of the 2 treatment groups were similar at 1 yr of age. Calves offered more milk grew faster preweaning and showed indications of being less hungry and more content, thus confirming previous research that feeding calves higher milk allowances is associated with enhanced welfare and early growth.