Abstract #T2

# T2
Pair housing of dairy calves in modified individual calf hutches.
L. Whalin*1, M. A. G. von Keyserlingk1, 1Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada.

The objective of this study was to determine if pair housing using a modified calf hutch on a commercial dairy farm would provide similar benefits to those previously described in research settings. Despite many benefits (e.g., weight gain, social behaviors, less fearfulness) of housing calves in small groups, individual calf hutches are still the predominant housing type in North America - perhaps because hutches are designed for one calf. Our modified hutch consisted of 2 individual hutches placed next to each other where both calves had access to both hutches and a common run. This study took place on a commercial farm in the Fraser Valley of British Columbia from May to November 2016. A week after birth, calves were randomly assigned to individual (n = 14) or paired (n = 8 pairs) hutches and fed milk 2/d using a nipple bottle. Calves were fed 6 L/d from d 1 to d 6, 10 L/d d 7 to d 35, and 6 L/d until d 56 (weaning). At each transition, milk volume changed over 48 h. Ad libitum access to calf starter, and water was offered beginning d 2. Feed intake was measured weekly until calves were 67 ± 5 d, while BW and health measures were recorded weekly until the calves were 85 ± 5 d. When the calves were 56 d a novel food test occurred where the amount of food consumed in 30 min was measured. Mixed model and independent t-tests were conducted in SAS (version 9.3, SAS Institute Inc., Cary, NC) to assess the effect of housing on the intake of starter and novel feed. Starter intake did not differ during high milk allowance (P > 0.5), but pair housed calves ate more starter after the first reduction in milk (pair: 1.72 ± 0.20 kg/d; individual: 1.02 ± 0.15 kg/d; P < 0.01), and during the post-weaning period (pair: 3.51 ± 0.27 kg/d; individual: 1.71 ± 0.21 kg/d; P < 0.01). Pair housed calves also ate nearly 3 times as much novel feed (pair: 170.92 ± 37.75 g; individual: 57.69 ± 10.55 g; P < 0.02). In conclusion, joining adjacent hutches is a viable option for pair housing; providing social contact during the milk feeding period increases calves’ willingness to consume different feeds resulting in increases in solid feed intake and potentially reducing weaning stress.

Key Words: novelty, feed intake, commercial farm