Comparison of Breeding Scenarios in Open Nucleus Breeding System for Genetic Improvement of Iranian Native Buffaloes (Bubalus bubalis)

This study was aimed to compare the open nucleus breeding systems for Iranian buffaloes (Bubalus bubalis). To compare the genetic gain and inbreeding variations, three levels of nucleus size (5, 10, and 15), three levels of male transfer rate from the nucleus to commercial (0.25, 0.5, and 0.75), and two levels of female transfer rate from commercial to the nucleus (0.25 and 0.5) were simulated by QMsim software. Comparing different strategies, genetic improvement declined with the increase of the nucleus population in the total population. Our results showed that the optimal combination of total genetic value improvement and inbreeding was obtained for scenarios of the open nucleus breeding strategy with 10% herd size, 75% male transfer rate from the nucleus to commercial, and 25% female transfer rate from commercial to the nucleus. Results confirmed that describing breeding goals, determination of an appropriate selection index, and considering open nucleus breeding systems along with optimal scenarios of male and female transfer between the nucleus and commercial herds, can lead us to genetic improvement as well as reduced inbreed-ing, and thereby development in the traits performance of Iranian buffaloes.