Productive and reproductive performance of Friesian cows raised under the Egyptian condition

Abstract EN

The objectives of this study were to predict the influence of sire and some environmental factors on milk traits and reproduce ability and estimate heritability, genotypic correlation and breeding value of cows, sire and dam.

A total of 1976 records were collected for over 12 years from Alkarda farm (Government farm) located in Kafr El-sheikh governorate, the dairy herd belongs to Animal Production Research Institute (APRI), Egypt.

Studied traits were productive and reproductive traits including total milk yield (TMY, kg), 305-day milk yield (305-DMY, kg), lactation period (LP), days open (DO) and calving interval (CI).

The analysis was performed using : General linear model (GLM) procedure (SAS, 2003) to determine the fixed effects (parity, year and season of calving) and random effects of sire.

Data were analyzed by Multiple Traits Derivative Free Restricted Maximum Likelihood (MTDFREML) according to Boldman et al.

(1995) to estimate variance components, heritability and breeding value of cow, sire and dam using Best linear unbiased prediction (BLUP) calculated by back solution for all animals in the pedigree file.

Actual means of TMY, 305-DMY, LP, DO and CI were 3361.9 kg, 2939.1 kg, 310 day, 148.7 day and 451 day, respectively.

The study showed significant effects of sires selection on all traits, allows the possibility of selection to improve these traits through sires, also nongenetic effects of parity, year and season of calving affected (P ≤ 0.001) all traits.

Heritability estimates for TMY, 305-DMY, LP, DO and CI were 0.31, 0.34, 0.31, 0.03 and 0.04, respectively.

Rank correlation computed between predicted breeding values among TMY, 305-DMY and LP were highly significant (P ≤ 0.001) ranging from (0.40 to 0.89) showing that genetic improvement of one of the trait improve the rest of the traits.

Genetic correlations (rg) between milk and reproduce ability traits ranged from 0.001 to 0.078.

Wide range of cows breeding value was found for most of the studied traits for TMY, 305-DMY, LP, DO and CI were 3278 kg, 2726 kg, 329.9 day, 10.2 day, and 48.9 day, respectively.

Selection cows leads to high genetic improvement in the herd.