[Effect of some environmental physiological and genetic factors that affect the productive behaviour in crossbred cows of the Hacienda "La Esperanza"]

animal physiology breeds cows crossbreds environmental factors facteur du milieu factores ambientales fisiologia animal genetica genetics intervalle entre parturition intervalo entre partos lactation duration parto parturition parturition interval physiologie animale productos del cruzamiento produit de croisement race razas vaca vache zulia (venezuela)