Milk efficiency and basic traits of dairy cow fertility of Improved Slovakian Spotted breed

analyse statistique aptitud lechera aptitude pour la viande breeds croisement cruzamiento dairy cows fertilidad fertilite fertility grasa de la leche intervalle entre parturition intervalo entre partos meat performance milk fat milk performance parturition interval performance de reproduction peso poids race razas reproductive performance reproductividad statistical analysis vacas lecheras weight