Influence of chicken growth hormone (cGH) SNP genotypes on morphometric and growth traits of three chicken breeds in Nigeria

This study was conducted to identify the diversity of chicken growth hormone (cGH) single nucleotide polymorphs’ (SNP) and their association on morphometric and growth traits of three Nigerian chicken breeds namely Funaab Alpha (FA), Shikabrown (SB) and Nigerian local chicken (NLC). Morphometric traits measured include shank length (cm), breast girth (cm) and breast width (cm) while growth traits measured were final body weight, av. weight gain, feed intake and feed conversion ratio all at laying stages respectively. Morphometric and growth traits were significantly influenced (P<0.05) between the different breeds. The SNP panel showed two base pair substitution mutation (GT and CA) on locus 5 chromosome for the FA and locus 6 chromosome for the SB and NLC respectively. The G-T alignment produced genotypes GG and GT, with TT not observed. Also C-A alignment produced genotypes CC and CA, with AA not observed. The NLC breed had the highest number of haplotypes of 6 while FA and SB had 4 haplotypes each implying that the local breed had more allelic variation than the other two breeds. Also FA had heterozygosity of 0.48 while SB and NLC had a value of 0.44, indicating higher genetic variability of FA breed than the rest with negative theta value (−0.0843) of F-statistics indicating high level of outbreeding. The conducted association of SNP genotypes showed no significant association effects (P>0.05) on the morphometric traits, except for SB breed where CA genotypes was significantly associated with CC for bodyweight, and in NLC breed where CC genotype was also significantly associated with CA genotypes for shank length.