Association Of Polymorphisms Of The Leptin Gene With Seminal Quality In Carora Breed Bulls

The presence of bulls with poor seminal characteristics causes considerable failures in the reproductive performance of farms, due to decrease in the number of pregnant cows, being more marked in systems under artificial insemination (AI) programs. Seminal quality (SQ) traits can be an important criterion for the selection of breeding males used in AI. The identification of molecular markers associated with SQ in the bull could facilitate the selection for these traits. The objective of this study was to evaluate the association of the polymorphisms of the Leptin gene on the SQ of Carora breeding bulls. The variables ejaculate volume (EV), mass motility (MM), individual motility (IM) and sperm concentration (SC) were evaluated in 43 Carora breeding bulls from an AI Center, organized into 8 age groups. The single-nucleotide polymorphisms (SNPs) of the Leptin gene evaluated were rs29004487 (SNP1), rs29004488 (SNP2), rs29004501 (SNP3) and rs29004508 (SNP4). An analysis of variance was used using a generalized linear model (GLM). The genotype factor had 10 levels and the age factor 8 levels. There was no effect of SNP1 on any of the variables evaluated, while SNP3 had a significant effect on SC. SNP2 and SNP4 showed a highly significant effect on IM and SC. Finally, the variables EV and MM were not affected by any of the SNPs studied. The results of the present study suggest potential markers for the genetic evaluation and selection of breeding cattle.