Determinação genética da paternidade em leitões nascidos de inseminação artificial heterospérmica cervical e pós-cervical

Abstract

Post-cervical artificial insemination (AI) with reduced sperm concentration allows the use of semen from few boars on a high number of females, but the common use of pooled semen in commercial AI programs masks the subfertility of individual boars. This study compared the reproductive performance of post-cervical and cervical heterospermic AI, in commercial farm conditions and through paternity tests. Each AI method was conducted in two groups of 150 sows. Sperm concentration was 3.0 x 109/85mL for cervical AI and 1.5 x 109/60mL for post-cervical AI. Conception and farrowing rates for post-cervical AI (90.7% and 85.3%, respectively) were lower (P<0.05) than for cervical AI (98.7% and 94.7%, respectively). Total litter size did not differ (P>0.05) for post-cervical (12.8 ± 0.3) and cervical AI (13.5 ± 0.3), but it was greater (P<0.05) for parity-two females than for those having 3-5 parities. The paternity test used nine microsatellite markers to genotype 300 piglets from 25 litters, but paternity exclusion was achieved for only 95 piglets, which did not differentiate boars across AI methods. Keywords: Post-cervical AI, paternity test, micro-satellites, swine.