Zusammenhang zwischen κ-Casein und ß-Lactoglobulin-Varianten mit der Milchleistung und der Nutzungsdauer von Rindern der Rassen Schwarzbuntes Rind und Polnisches Rotvieh
Abstract. Title of the paper: Relations between genetic variants of κ-casein and ß-lactoglobulin and Performance of Black and White and Polish Red cattle
Performance of 184 cows from 4 herds of Black and White (SR) and 178 cows from 4 herds of Polish Red breed (RP) was compared due to genotype encoding milk proteins: κ-casein and ß-lactoglobulin. Frequence of inividual genotypes differend significantly both between herds within the breed. Statistically significant influence of genotype was found in relation to milk fat content in SR cattle (κ-CNAA> κ-CNBB and ß-LGBB >ß- LGAB > ß-LGAA) and in RP cattle milk protein yield (κ-CNBB > κ-CNAA) and fat content (ß-LGAA > ß-LGAB and ß-LG ). The highest protein content and protein yield in milk was found in cows of both breeds carrying KCNBB genotype (P>0.05). Significant relation with the age of first calving was stated in SR cows: κ-CNAA > KCNAB, in RP cows κ-CNBB > κ-CNAB and in SR cows ß-LGBB >ß-LGAB. Other traits such as longevity, life-time number of calvings and lactations, life-time yield were not found significantly related to searched genotypes although some trends were observed.