Efecto de la Variante Genética de la k-Caseína sobre la Producción y Composición de la Leche de un Rebaño Holstein en el Trópico

Abstract

To evaluate the effect of k-casein polymorphism on milk yield and composition in a Holstein herd located in the central region of Venezuela, different k-casein genetic variants present in the herd were determined by the isoelectric focusing technique. A total of 294 milk samples were analyzed using a completely randomized statistical design with a 23 factorial arrangement. The allele A of casein was found in 92% of the cows in the herd, while the allele B was found in 52%. When the levels of milk yield of each animal were compared, it was found that those animals with allele A had a higher daily milk yield. The statistical analysis of the results of milk composition from milk samples showed that the k-casein polymorphism found in the Holstein herd has no effect on the content of the main components of milk.