Genetic Evaluation of F₁, F₂ and F₃ Crosses of Hariana with Friesian, Brown Swiss and Jersey

Data on the first lactation performance traits of F₁, F₂ and F₃ crosses covering the period from 1972 to 1995 of a total of 803 dairy cows of three genetic grades maintained at Livestock Production Research Farm, Indian Veterinary Research Institute, Izatnagar were analysed Three genetic grades were 1/2 Friesian+1/2 Hariana (FH), 1/2 Friesian+1/4 Brown Swiss and 1/4 Hariana (FBH) and 1/2 Friesian+1/4 Jersey+1/4 Hariana (FJH). Age at first calving increased by 7% and 8% in F₂ and F₃, respectively, over the F₁ in FH. The reduction in age at first calving at F₂ and F₃ levels by 2-7% over the F₁ was observed in FBH and FJH. The lactation milk yield of F₁, F₂ and F₃ crosses was 1,943±100.3, 2202±120.5 and 1,925±123.2 kg in FH; 2,014±76.7, 2,264±91.5 and 2,096±123.9 kg in FBH and 2,005±87.0, 2,414± 94.4 and 2,093±121.1 kg in FJH, respectively. The lactation milk yield improved by 12-20% in F₂ crosses in various genetic grades. The performance of F₁ was, however, maintained in FH F₃ crosses, it improved by 4% in FBH and FJH F₃ crosses. The lactation lengths and calving intervals were nearly the same for F₁, F₂ and F₃ crosses in FH while lactation lengths and calving intervals were reduced by 3-11% in F₂ and F₃ crosses in FBH and FJH genetic grades. The milk yield/day of lactation length and milk yield/day of calving interval increased by 16-35% in F₂ and 2-14% in F₃ over the F₁ in various genetic grades. It is recommended that a sufficiently large effective population size of these three genetic grades be maintained by inter se matings and rigorous selection of sires so for developing a genetic base population for new breed development.