Impact of a dietary citrus extract on the behavior and milk yield of lactating dairy cows following regrouping
The objective of this study was to determine if feeding a citrus extract (CE; from Citrus sinensis) reduces the effect of regrouping on lactating dairy cows. Thirty-two cows were enrolled and housed in a tie-stall facility where they were fed a diet with 4 g/d of CE or not. Cows stayed for 7 d in the tie-stall facility, then moved to 1 of 2 free-stall pens (each containing 29 other cows) for 7 d. Primiparous cows fed CE had sustained rumination and lying time after regrouping and had greater feeding time, greater milk yield, lesser idle standing time, and initiated fewer aggressive interactions after regrouping compared to primiparous control cows. For multiparous cows there was little effect of CE on their response to regrouping. The results indicate that feeding a CE additive to mid-lactation primiparous dairy cows may have mitigated the negative effects of regrouping on behavior and milk yield.