PERFORMANCE OF HALFBREDS AND 3-BREED CROSSES OF HARIANA WITH EXOTIC DAIRY BREEDS

Seven genetic groups produced at the Institute were compared for age a t first calving (AFC), first lactation 300 days milk yield (FLSMY), fi rst lactation length (FLL), first dry period (FDP) and first carving i nterval (FCI), lifetime milk yield (LTMY), herd life (HL), total days in milk (TDM), and total days dry (TDD). Different linear fixed models were used to study the effects of genetic groups, Season and year of birth/calving. Year of birth significantly influenced AFC in halfbreds and 3-breed crosses. In halfbreds, all first lactation traits were si gnificantly influenced by genetic groups. Three-breed crosses had high er AFC than halfbreds. Among halfbreds JH had lowest AFC. Among 3-bree d crosses cows with Jersey inheritance had lowest AFC. FH yielded more milk in first lactation and had longest FLL and shortest FDP than oth er halfbreds. FCI and FDP were shorter in halfbreds than in 3-breed cr osses. in first lactation, 3-breed crosses produced more milk than hal fbreds. Among halfbreds, LTMY was maximum in FH (13316+/-602 kg) follo wed by those in BH and JH. HL and TDM were maximum in cows with Brown Swiss inheritance. On an average, halfbred and 3-breed crosses spent a bout 50 and 39% of their life in milk production respectively. Halfbre ds produced more milk in lifetime and stayed more in herd than 3-breed crosses, indicating that the latter may be less adaptable to local tr opical agroclimatic and managemental conditions.