Relationship between Milk Protein Polymorphism and Selected Cows' Reproductive Indices

Area of Science:

• Animal Genetics
• Reproductive Biology
• Dairy Science

Background:

• Milk protein polymorphisms, specifically kappa-casein (CSN3) and beta-lactoglobulin (BLG), are investigated for their potential impact on cattle reproductive efficiency.
• Understanding genetic influences on reproduction is crucial for optimizing dairy herd management and productivity.

Purpose of the Study:

• To evaluate the association between CSN3 and BLG gene polymorphisms and key reproductive parameters in Polish Holstein-Friesian cattle.
• To determine if specific genotypes influence age at first calving, interpregnancy period, calving interval, and insemination index.

Main Methods:

• Analysis of reproductive data from 598 black and white Polish Holstein-Friesian cows.
• Genotyping for CSN3 and BLG polymorphisms.
• Contingency analysis using Pearson's chi-squared test to assess genotype effects on reproductive indicators.

Main Results:

• The BB genotype of the CSN3 gene was linked to the most favorable reproductive indicators, with significantly better calving intervals (p ≤ 0.05).
• Significant differences in the interpregnancy period were observed between AA and BB genotypes for CSN3.
• No significant effect of BLG gene polymorphism on any of the analyzed reproductive indices was found.

Conclusions:

• CSN3 genotype polymorphism, particularly the BB genotype, is a favorable genetic marker for enhanced reproductive performance in the studied dairy herd.
• BLG gene polymorphism does not appear to influence the reproductive parameters evaluated in this population.