The present study was undertaken to assess the genetic parameters for first lactation production traits in crossbred cattle. Data on 529 crossbred cattle spread over a span of 30 years (1990-2019) were collected from pedigree sheets of organised herd maintained at dairy farm of Govind Ballabh Pant University of Agriculture and Technology, Pantnagar. Various production traits studied were 305 days milk yield (305DMY), total milk yield (TMY), lactation length (LL), peak yield (PY) and days to attain peak yield (DAPY). Heritability, phenotypic and genetic correlations were estimated using least-squares analysis. Heritability estimates obtained were low to medium (0.04±0.02 to 0.30±0.09). The phenotypic and genetic correlations between TMY with LL were 0.72±0.08 and 0.77±0.37, 305DMY with LL were 0.42±0.12 and 0.30±0.95, LL with PY were 0.16±0.45 and 0.14±0.00, LL with DAPY were 0.09±0.77 and 0.10±0.05, 305DMY with TMY were 0.79±0.66 and 0.76±0.46, PY with TMY were 0.41±0.17 and 0.25±0.28, TMY with DAPY were 0.14±0.67 and 0.10±0.58, 305DMY with PY were 0.70±0.26 and 0.74±0.29, 305DMY with DAPY were 0.14±0.15 and 0.07±0.23 and DAPY with PY were 0.13±0.08 and 0.15±0.61. Positive and high genetic correlation between TMY with LL, 305DMY with TMY and 305DMY with PY suggested that tandem selection can improve both the traits simultaneously. Positive and high phenotypic as well as genetic correlation of 305DMY with other traits advocated that selection for 305DMY would be beneficial for enhancing the production in crossbred animals.

Highlights

• Genetic parameters like heritability and correlation affect first lactation production as well as reproduction traits in cattle.
• This study was conducted to know about the genetic parameters affecting first lactation traits and the results are summarised in this paper.