Genetic evaluation for body condition score in Italian Brown Swiss cattle

Abstract

Body Condition Score (BCS) evaluates the body energy reserve in a cow using a numeric classification. It is possible to use the BCS as an indirect indicator of fertility. The genetic evaluation for BCS in Italian Brown Swiss is performed on 73125 BCS evaluations on the same number of primiparous, daughters of 507 sires. Effect of herd by year goes from -1,02 to +0,94 indicating large differences among herds. The primiparous cows show about 3.2 BCS points at calving, their BCS decreases slightly during first 90 milking days but, after this period, the BCS increases until 3.5 BCS points at the end of first lactation. Sires with larger EBVs guarantee a slower decrease of BCS during the first part of lactation, which is preferred to the strong decrease exhibited by the daughter of low EBV sires. The pseudo-genetic correlations, correlations values estimated among EBV, confirmed the relationships between BCS and other important traits like milk yield (-0.20), final score, dairyness and udder. The correlations between BCS and functional traits, milking speed and functional longevity, is -0.14 and +0.17 respectively.

Keywords

• BCS, Dairy cattle, Brown Swiss, Fertility.