Identification of QTL for litter size on chromosome 1 in Markhoz goats using SSR markers

The litter size is a threshold trait that is controlled by many genes. Due to the low heritability (0.10), of litter size, classical breeding methods lead to slow genetic progress. Hence it is essential to use new technology to improve this trait. Length of chromosome 1 in goat is approximately 186 cM. Based on previously published data in addition to a high genetic homology between goat and cattle choromosome 1, a region between 16 to 169 cM of chromosome 1 was selected for QTL detection of litter size in the Markhoz goat breed. Sample population included 8 paternal half-sib families. The numbers of half-sib offspring per buck ranged from 30 to 40. All individuals were genotyped by six microsatellites specific to chromosome 1. QTL analyses were performedusing multiple regression method under a half-sib model. Our study indicated that a QTL in position 165 cM on chromosome 1 affect litter size rate in Markhoz goats. Its location was near to CSSM19 marker and was able to explaining 2.20 percent of the genetic variance of litter size. The QTL detected in this research could be related with POU1F1 gene. Hence this gene could be a candidate for the associated QTL on goat chromosomes 1.