@article{MAKHILLJAVA2003291199, title = {Genetic Variants of Milk Proteins and Indexes of Milk Performance Dairy Cows of Slovak Spotted Breed on Different Lactations}, journal = {Journal of Animal and Veterinary Advances}, volume = {2}, number = {9}, pages = {519-523}, year = {2003}, issn = {1680-5593}, doi = {javaa.2003.519.523}, url = {https://makhillpublications.co/view-article.php?issn=1680-5593&doi=javaa.2003.519.523}, author = {A. K?bek,J. itn?,J. Bujko and}, keywords = {}, abstract = {The genetic structure of polymorphic milk proteins in alphas1-casein, beta-lactoglobulin, beta-casein and kapa-casein systems were analysed by the method of starch gel electrophoresis. The homozygotic and heterozygotic genotype combinations of dairy cows of Slovak spotted breed (n=345) were evaluated for dairy parameters. Data used in protein index calculation were obtained from lactation records of 1250 standardized lactations. 1. In polymorphism alpha s 1-casein with genetic variant BC highly significance has occurred (++P=0,01) in milk production on the first lactations 719 kg (BC>BB) and in beta-lactoglobulin system within second and following lactations 150,6 kg of milk (AB>AA+BB, +P=0,01). 2. Protein content (kg) tested between groups of heterozygote and homozygote genotypes of polymorphic milk protein was significantly higher (+P=0,01) by 5,4 kg on second and following lactations in group of AB genotypes of beta-lactoglobulin (AB>AA+BB). 3. Within first lactations significantly high difference of 28 kg of fat has occurred between genotypes BC and BB of alpha s1-casein (++P=0,01, BC>BB). The paper is reporting also index of protein production , which is on the first lactations 116,7%, on second and following lactations 105,9% and over all lactations 107%. Selection criteria used in index of protein production calculated for first calved cows as well as for cows of Slovak spotted breed are listed in section Material and methodology.} }