Analysis of lactoferin gene polymophism and its association to milk quality and mammary gland health in Holstein-Friesian cows

Abstract

Lactoferrin (LTF) is a glycoprotein, a member of transferrin gene family which plays an important role in immune mechanisms in the mammary glands of cows. The amount of lactoferrin increases during inflammatory processes and viral infections. The aim of this investigation was to monitor the distribution of lactoferrin gene genotypes and its connection to milk quality and the occurrence of mammary gland diseases in 46 Holstein-Freisian cows of different age (2-7 years) on a farm near Belgrade. DNA was isolated from blood samples, and the polymorphism of lactoferrin gene was deterimined by PCR-RFLP method using the restriction enzyme Eco RI. We found two alelic forms of this gene in cows included in these experiments (A and B) and two genotypes (AA and AB) in a ratio 71.7% to 28.3%. The genotype BB was not found in this sample. In order to determine the degree of differences between genotypes we used discriminant analysis which has shown that there is a statistically significant difference between genotypes AA and with respect to productive parameters. When analyzed separately, the only parameter which differed significantly (p=0.021) between two genotypes was total milk production. Individuals with observed genotypes are most similar for the amount of milk fat (p=0.271). There is no statistically significant difference in the number of somatic cells in milk samples between the examined genotypes. [Projekat Ministarstva nauke Republike Srbije, br. III46002]