VARIABILITY OF MILK TRAITS IN THE POPULATION OF SIMMENTAL CATTLE IN SERBIA

Abstract

The work is the presentation of performance data and phenotypes of milk traits of Simmental cows in Serbia. The analysis of quantitative phenotypic parameters was carried out in four breeding areas and on dozen of large and small farms housing and rearing 1370 cows – first calving heifers. The obtained data were analysed using the method of Least Squares and analysis results were obtained by applying mathematical-statistical data analysis using mixed models. Mathematical - statistical analysis of data was performed using linear methods with fixed effects, using the method of Least Squares (LS method). Based on these results, it was established that the breeding area, statistically analysed, caused highly significant deviations (P <0.01) of production traits from the general population average. Calving season has influenced significantly (P<0.05), and the interaction of area and calving season has produced a highly significant variation in milk yield, milk fat and protein (P <0.01).