The incidence of mutation in three loci of GDF9, BMP15 and BMP15-1B and their effects on litter sizes was evaluated in Baluchi sheep. Wild-type alleles were detected for BMP15 and BMP15-1B loci and all individuals were found to be as non-carriers for FecB and $FecX^G$ mutations but, a G to A nucleotide substitution was found in GDF9 locus. The frequency of $FecG^+$ (0.82) wild type allele was higher than the frequency of $FecG^l$ (0.18) mutant allele and the frequencies of $FecG^+/FecG^+$, $FecG^+/FecG^1$ and $FecG^1/FecG^1$ genotypes were 0.72, 0.20 and 0.08, respectively in GDF9 locus. The heterozygous ($FecG^+/FecG^1$) and homozygous ($FecG^+/FecG^+$) non-carrier ewes had 0.35 and 0.21 more lambs than the homozygous ($FecG^1/FecG^1$) carrier ewes, respectively (p<0.05). In addition to the finding of segregation of non-additive gene effect on litter size in the previous study in Baluchi sheep, these findings for the first time shows that the $FecG^1$ gene has a major effect on litter size in this breed.