Genetic parameters for milk traits in Egyptian native cows

الملخص EN

The aim of this study is to estimate the genetic parameters and the effect of non-genetic factors for some milk traits including total milk yield (TMY), Lactation period (LP), number of services per conception (NSC), days open (DO), calving interval (CI) and dry period (DP).

Data were collected from two farms.

Experimental Farm belonging to (APRI) data included 1829 records.

The statistical analysis has been adopted using animal models.

Actual means of TMY/kg, LP/day, NSC/services, DO/day, CI/day and DP/day were 791.3, 171.1, 1.8, 109, 402.7 and 79.3 respectively.

Estimated heritability (h2 ) of TMY, LP, NSC, DO, CI, and DP were 0.18± 0.01, 0.15± 0.001, 0.07± 0.016, 0.05± 0.001, 0.09± 0.041 and 0.09±0.001 respectively.

While the range of BV of the cows was the highest for all traits TMY/kg, LP/day, NSC, /services, DO/day, CI/day and DP/day were 776.3, 26.7, 6.7, 13.4, 77.1 and 11.5 respectively.

The estimated Predicted Breeding Value PBV for all traits varied widely.

The genetic trends of cow breeding values were significant for all studied traits.

This confirms that the genetic improvement of these traits leads to increased milk production traits.

The study recommends preserving the Native Egyptian dairy cattle because they represent a national wealth that must be preserved from extinction through inventorying the genetic resources, characterization and evaluation of this local breed to benefit from it in improving animal breeds of high economic value.

Due to the distinction of Egyptian domestic cows for their resistance to various environmental conditions.