The Relationship Between the Genetic Marker DIK20 and A Range of Physiological and Productive Traits in Holstein Cattle

Abstract

The use of gene markers in livestock breeding plays a crucial role in enhancing productivity. Specific genetic markers can be identified, facilitating the task of breeders in selecting desired traits, such as milk production, disease resistance, and growth monitoring, which in turn leads to improving the overall productivity of animals. This research aims to study the linkage among the genetic marker DIK20 and several physiological and productive features in Holstein cattles, which includes milk production, mastitis, and percentages of fat, lactose, and protein. The research was conducted in one milk production season, starting from October 2022 to April 2023, using 60 Holstein cows aged between 4-6 years. The results showed that cows had two genotypes of DIK20, with sizes of 190/181 and 180/170 base pairs, with distribution rates of 36.21 and 63.79%, respectively. Results obzerved highly significant differences (P≤0.01) between the genetic variants. The study also found significant differences (P≤0.05) between the genetic polymorphisms 180/170 and 190/181 in the California mastitis test. However, no statistically significant differences noticed in the genetic polymorphisms related to fat, protein, lactose, and solid non-fat in milk elements, with percentages of 3.60% and 3.48% for fat, 2.90% and 3.1% for protein, 4.18% and 4.31% for lactose, and 7.94% and 8.26% for solid non-fat for the two genetic polymorphisms 180/170 and 190/181, respectively. It is concluded that there is a correlation between the genetic marker DIK20 and various physiological and productive traits in Holstein cows.