دور الوراثة السايتوبلازمية في مكونات الحليب الرئيسية لدى ماشية الفريزيان

Abstract EN

A total of 600 milk samples from 200 Friesian cow were analyzed.

These cows were randomly picked out from the herd of Al-Latifia Station (45 Km South of Baghdad ), over period from 1-1-2006 to 31-12-2006 .

The aim of this stady was to investigate the role of cytoplasmic inheritance ,maternal effect of parity , season of year on the percentage of milk components (fat, protein and lactose), and estimate of heritability by variouse methods.

The General Linear Model Procedure within SAS statistical program was used for statistical analysis.

Components of variance for the random effects in the employed mixed model was estimated by using the Restricted Maximum Likelihood procedure.

The overal means for fat, protein and lactose % were 3.22, 3.72 and 4.36%.

parity and season of year had significant (P<0.01) effect on fat and lactose%, significant (P<0.05) effect on protein% .

The heritability of the fat, protein and lactose % were 0.38, 0.47 and 0.26 respectively by using heritability estimate by half-sib whereas decreased to o.22, 0.36 and 0.19 respectively at the estimate by half-sib with adjusted of maternal effects.

The variance of maternal effect in fat, protein and lactose % were 19.35, 11.892, and 24.580, wheares the variance of cytoplasmic were 2.005, 1.907,and 15.24.