Interactions between Sires in Artificial Insemination and Management of Dairy Herds

Abstract

No interactions of practical importance were found between sires and herd environments classified by level of production, location, days dry, calving interval, or type of housing. The analyses included 8638 Holstein and 1872 Guernsey daughters of 193 and 139 A.I. bulls in 1211 Holstein and 356 Guernsey herds tested in Michigan DHIA (Dairy Herd Improvement Assoc). Small differential responses of daughters of A.I. bulls in different herds were found within classifications, but these appear unimportant in selecting between bulls in A.I. except to require a few more daughters for a specified accuracy in evaluating the genetic abilities of the bulls. The ranking of the sires will generally be the same in any of the environments examined.