Abstract: The polymorphism of GH gene was detected using PCR-SSCP in black Muscovy duck. The association between GH gene and body weight， butcher performance of black Muscovy duck was analyzed. The results showed that two SNPs were detected in intron 1 of GH gene， which included G945A and T1039G. The mutations formed CC， CD and DD genotypes. The homozygosity and PIC were 05036 and 03732， respectively. The body weight of CC male was highest at different weeks in process of black Muscovy ducks early growth. When the ducks were slaughtered at 13-week-old， the live weight， dressed weight， half-eviscerated weight， eviscerated weight， abdominal fat weight and glandular muscle stomach weight of CC male ducks was significantly higher than that of CD and DD male ducks （P＜0.05）. The heart weight of CC male ducks were significantly higher than those of CD male ducks （P＜0.05）. There was not significant difference in the percentage indexes of slaughter among the three genotypes （CC， CD and DD） （P＞0.05）. All of the female ducks indexes had no obvious difference among the three genotypes （P＞0.05）. The correlation analysis implied that allele C maybe were the favorable genes for body weight in male ducks.

Key words: black Muscovy duck, GH gene, body weight, butcher performance