Effect of Genetic and Non-genetic Factors on First Lactation Production Traits in Crossbreds of Gir with Holstein Frieson and Jersey Cattle Breeds

The data on production traits of FG (50% Holstein Frieson (HF) + 50% Gir), IFG (interseof FG), FJG (50% HF + 25% Jersey + 25% Gir), IFJG (interseof FJG) and R (50% HF + 12.50% Jersey + 37.50% Gir) crosses maintained at Research Cum Development Project on cattle, Mahatma Phule Krishi Vidyapeeth, Rahuri, were collected for the years 1972 to 2015. The data were analysed for estimation of means of production traits, viz. lactation length (LL), lactation milk yield per day of lactation length (LMY/LL) and lactation milk yield per day of calving interval (LMY/CI), by considering effects of period/season of calving by adopting least-square technique. The overall mean first lactation length (days) was 327.22 ± 4.15 in FG, 352.21 ± 5.14 in IFG, 331.71 ± 3.97 in FJG, 358.33 ± 3.81 in IFJG and 343.37 ± 7.52 in R genetic group. The overall mean LMY/LL and LMY/CI (kg) of first lactation was 10.47 ± 0.17 and 8.45 ± 0.16 in FG, 8.03 ± 0.12 and 6.42 ± 0.13 in IFG, 8.79 ± 0.24 and 6.99 ± 0.26 in FJG, 8.14 ± 0.10 and 6.45 ± 0.11 in IFJG and 8.38 ± 0.20 and 6.63 ± 0.22 in R genetic group, respectively. The period of calving had significant (P< 0.05) effect on lactation length, LMY/LL and LMY/CI in IFG and IFJG groups in first lactation. The variation due to season of calving on lactation length, LMY/LL and LMY/CI was significantly higher in IFJG in first lactation as compared to other groups. The genetic group had significant effect on LL, LMY/LL and LMY/CI traits.