Abstract: 501 goat individuals in seven populations were detected by PCR-RFLP. The results showed the polymorphisms of XspⅠ existed in every population and the number of the individuals with genotype AG was more than that with genotype AA while the number of genotype AA was more than that of GG in all the populations. At the same time, the results of χ2 test indicated that all the populations were at Hardy-weinberg equilibrium (P>0.05) and genotype distributions were not relative to populations (P>0.05). We also found that frequency of allele A was higher than that of allele G and the frequencies of allele A and G were nearly invariable in all populations. PCR products were sequenced and the result showed that the sequence contains partial exon2, complete intron2, exon3 and partial intron3. The homology of the gene sequences with and dairy goat, sheep, dairy cattle, were 99.1%, 98.1% and 94.1%, respectively. The correlations between genotypes at the gene locus and weaning weight, rib eye area, 10th month body length, 10th heart girth and 12th month body length were significant (P<0.05) and the associations were significant for 3rd month body length and 3rd heart girth (P<0.01). The genetic effects of genotype AG were significantly higher than those of genotype GG (P<0.05 for weaning weight and rib eye area while P<0.01 for above five physical measure traits). Further more, the effects of genotypes for above traits were AG>AA>GG.

Key words: goat, IGFBP-3 gene, PCR-RFLP, genetic analysis, economic trait