Performance evaluation of Jersey cattle at Islamabad

Abstract

Performance data (from 1985 to 2000) of Jersey cattle imported from USA and maintained at Islamabad, Pakistan were evaluated. The purpose of this study was to assess the genetic merit of Jersey breed under Pakistani environment for further propagation. Cows with at least two calvings were considered for this study; records on 50 daughter-dam pairs were available on production and reproduction performance traits for genetic evaluation. The average age at first calving in parents was 25.2±2.4 m as compared to 23.9±6.6 m in progeny. Calving interval in parents and progeny was 416±74 and 446±105 d; lactation length 301±51 and 325±73 d; lactation milk yield 2,908±669 and 2,707±903 lit respectively. All these differences were found to be statistically significant except lactation length. The correlations between age at first calving and total lactation milk was -0.25, between calving interval and total lactation milk yield was 0.14, and between lactation length and total lactation milk yield was 0.79. The h2 of these traits were low indicating important role of environment in expressing the genetic potential of animals. The S.E of h2 of all the traits was high due to large variation in data.