GENETYCZNE ASPEKTY SYNTEZY LAKTOZY U BYDŁA MLECZNEGO

Abstract

Market requirements, dictated by the growing needs of consumers, make it necessary to conduct breeding works to improve the performance characteristics of farm animals. The effectiveness of the breeding goal depends on both the genotype of the animals and the environmental conditions. Genomic selection using single nucleotide polymorphism (SNP) is increasingly used in the selection and evaluation of dairy cattle breeds. In recent years, many experiments have been carried out to determine the relationship between the occurrence of the genotype and performance traits of livestock. The analysis of milk composition carried out so far focused mainly on such milk production traits as milk yield (kg), fat yield (kg), fat content (%), protein yield (kg) and protein content (%). So far, no largescale experiments have been carried out to test the content of lactose in milk and evaluate possible relationships with other milk performance traits. Lactose synthesis in the epithelial cells of the mammary gland serves as a major factor influencing milk volume production. Due to that conducting such an analysis seems to be beneficial for milk producers for economic reasons. An additional advantage may be the use of the obtained results in marker-assisted selection (MAS). The present review summarizes knowledge about lactose synthesis by covering and linking several aspects of cow’s milk.