Effects of Enrichment Tools on Dairy Calves Housed in Hutches

Housing and feeding young calves individually is a common management practice to increase weight gain, improve feed conversion and allow for dairy cows to yield more milk. Calves, as herd animals, have increased stress when separated from their mothers and other calves. Previous research has examined enrichment usage in group housed and feedlot cattle to examine effects on weight gain. Enrichment has been shown to be a welfare-friendly solution to decrease stress levels in large groups, but little research has examined effects on individually housed animals. The current study focused on individually housed dairy calves with enrichment to examine enrichment preference and effects on feed conversion ratio. Six Holstein calves, 4 males and 2 females, were used in a 3 by 3 Latin square with 2 calves in each of 3 treatments. Treatment A was stationary brushes mounted on a post for calves to scratch on. Treatment B enrichment had movable bottles wrapped in AstroTurf. Treatment C was the control group with no enrichment. Every 14 d the enrichment was moved to a new group until each group experienced all treatments. Each calf was observed for 5 h/wk. During wk 1, a difference was noted with brushes being favored over bottles, 827.5 s and 482.5 s respectively (P=0.096). However, no difference was noted between brushes (487.5 s) and bottles (470.0 s) in wk 2 (P=0.615). Feed conversion had no differences in wk 1 (P=0.647) or wk 2 (P=0.586) when comparing treatment to the control. However, brushes (7.913) and bottles (7.117) during wk 2 had a difference in feed conversion ratios (P=0.057). Decreased feed conversion of the preferred enrichment could be due to increased energy and decreased resting time of the calf with the preferred enrichment and a decrease of stereotypical behaviors in the non-favored enrichment.