Influence of herd relocation upon production and endocrine traits of dairy cows.

Effects of potential stress encountered by two Holstein herds relocated into a new double-six herringbone parlor and free-stall facility were studied by evaluating alterations of milk yield and fat percentage, mastitis status, corticosteroids, and heat detection. One-half of one herd (18 cows) was moved 100 m to new facilities (Merged), and the remaining 18 cows were maintained in their original tie-stall barn (Control). The same day, the second herd of 50 cows (Moved) was transported via stock trailer 7 km to new facilities. Milk yield by Merged and Moved cows was decreased at first milking, but subsequent milk yields were similar to yields prerelocation. Milk fat percentage was decreased for only 3 days for Moved cows but was unchanged for Merged cows. Across groups, older cows and cows in late lactation tended to have greatest decreases in milk yield. Corticosteroids in serum were increased in Merged cows for only 2 days after relocation. No changes in milk somatic cell count or percentage heats detected were associated with relocation. Detrimental effects of herd relocation were slight and indicate that dairy herds can be moved without adversely affecting production traits.