Akademik Veri Yönetim Sistemi
11th International Hippocrates Congress on Medical and Health Sciences, İstanbul, Türkiye, 3 - 04 Mart 2023, cilt.11, sa.108, ss.300-301
Genomic selection allows the identification of animals with superior characteristics accurately. The relationship between index values used in evaluating the genomic value and essential markers such as casein genes provides important information at the herd level. Therefore, this study aimed to determine the association between casein gene genotypes and the indices of genetic merit in Holstein-Friesians. A total of 805 cows were genotyped using the Affymetrix® Axiom® array system. We used the data consisting of TPI and NM values as well as PTA indices, including milk, fat, %fat, protein, %protein, CFP, PL, SCS, DPR, LV, and UDC of each animal. The statistical analysis was performed using the one-way ANOVA test followed by Tukey’s test. The A2A2 (n=372) and the AB (n=285) genotypes were predominant in the CSN2 and CSN3 genes, respectively. Results revealed that the A2A2 animals have higher TPI and NM values. Moreover, they exhibited higher PTA values for protein (P<0.05), CFP (P<0.05), and PL (P<0.01). On the other hand, the A1A1 genotype was significantly associated with the highest UDC (P<0.05). Concerning the CSN3 haplotypes, the BB animals had higher PTA protein and CFP (P<0.01) than alternative haplotypes. The AA, AB, and BB haplotypes were significantly associated with the SCS (P<0.001), DPR (P<0.01), and PL (P<0.01) values, respectively. In addition, the BE haplotype had the highest NM (P<0.001). Selection procedures focusing on casein genes in dairy cattle are becoming increasingly common worldwide, especially for A2 milk. However, herd-based dynamics are also fundamental to providing a desired genetic merit for the animals. This study shows how the starting gene frequency in the herd, the genomic values of dams and sires of particular genotypes, and the health and reproductive efficiency are critical when evaluating the economic implications of using single genes in commercial dairy herds.