413ASSOCIATION BETWEEN GENETIC POLYMORPHSIM OF EXON 10 OF PROLACTIN RECEPTOR GENE AND LITTER SIZE OF SHEEPImprovement of reproductive traits in livestock species has become of increasing interest, especially in Sheep where moderate increases in litter size can gains large profit. Prolactin receptor (PRLR) is an anterior pituitary peptide hormone involved in different physiological activities and is essential for reproductive success. The associations of PRLR gene with litter size in 4 Chinese sheep breeds was studied using PCR-SSCP. Genotypes and alleles frequency of PRLR gene among four sheep breeds at locus P2 were at HWE equilibrium (P>0.05) while the genotype at locus P3 were significantly deviated from HWE (P<0.01) except for Altry sheep. At P2 locus Sheep with genotype CC had a larger litter size than sheep with BB and BC genotype, while at locus P3 sheep with DD genotype had a larger litter size compared with DE genotype, although the results for P2 and P3 were statistically non significant (P>0.05). Hu sheep with DD genotype had a larger litter size than that of DE genotype. However, the association of prolactin receptor gene with litter size was non significant (P>0.05). Our results showed that PRLR gene couldn’t be selected as a candidate gene for the prolificacy of sheep.dkxmsunwei@163.comResearch5122015Sheep, PRLR gene, Litter sizeW.Gao,X.Y. Lv,X.N. Zhang,Q.Z.Wang,Hassan H. Musa, H.S.Xu,W.H.Hua,Q. Liu,W.Z. Liu,W. Sun Animal Science and Technology College, Yangzhou University, Yangzhou 225009, China., Animal Science and Technology College, Yangzhou University, Yangzhou 225009, China., Animal Science and Technology College, Yangzhou University, Yangzhou 225009, China., Animal Science and Technology College, Yangzhou University, Yangzhou 225009, China.,Faculty of Veterinary Science, University of Nyala, Nyala155, Sudan.,Xuhou Huayang sheep industry Co., Ltd., Suining 225009.,Zhengjiang Wanshanhongbian Agricultural Parek, Jvrong 2142400, China,Zhengjiang Wanshanhongbian Agricultural Parek, Jvrong 2142400, China,Zhengjiang Wanshanhongbian Agricultural Parek, Jvrong 2142400, China, Animal Science and Technology College, Yangzhou University, Yangzhou 225009, China.