Performance of Bos taurus X zebu crossbreds under village conditions

Data on first lactation performance of 751 Holstein X zebu and Jersey X zebu crossbred heifers of various grades were collected under rural field conditions in Maharashtra. The heifers were the progeny of seven Danish Holstein (Sortbroget Dansk Malkekvoeg) sires, 33 homebred Holstein sires, six Danish Jersey sires and 35 homebred Jersey sires. The least-squares analysis showed that the location and genetic group within the two classes of crossbreds significantly affected the milk yield. In pooled data the 7/8 Holstein crossbreds produced by homebred sires were significantly superior to other genetic groups of either Holstein or Jersey inheritance. The milk yield increased with increasing level of homebred Holstein inheritance and with Jersey inheritance. Danish Holstein sires were the best to produce the halfbred Holstein crosses. The differences in the genetic groups accounted for 20% of the phenotypic variance in 305-day milk yield and for 2% of the variance of the lactation length in the crossbred population. It is inferred that the optimum level of exotic breed inheritance in Maharashtra would be above 50% and that the genetic group of the dams needs to be considered when evaluating the performance of a sire's progeny.