Association of polymorphisms in the GHRL, GAST, and SCTR genes with feed conversion and productivity indicators of meat chickens bred at the Smena Breeding Centre
The study was conducted to identify the genotypes of single-nucleotide polymorphisms (SNPs) in the GHRL, GAST, and SCTR genes for early performance assessment in Smena 9 poultry. The study was performed on 170 CM5/CM7 roosters and 750 final-hybrid CM5679 broiler chickens with individual feed intake monitoring at ages 36-42 days and 21-42 days, respectively. Groups were formed randomly. Polymorphisms were identified using genotyping using real-time PCR with fluorescently labelled probes. CM5 roosters homozygous for the T allele and heterozygous (TC) for the rs312295326 polymorphism demonstrated improved feed conversion in the 36-42-day period. The feed conversion ratio (FCR) for this period was 1.89 for birds with the TT genotype and 1.91 for TC. The CC genotype was associated with a 7.3-8.5% decrease in FCR (p<0.05). Statistically significant differences in feed conversion efficiency (FCR) were observed in broilers with polymorphic variants of the SCTR gene (rs314830059 and rs736374789). In birds of both sexes with the GG genotype of the rs314830059 polymorphic variant, a decrease in FCR by 8.6-16.9% was observed compared to the GT and TT genotypes from the 24th to the 33rd day (p<0.05). Females with the GG genotype of the rs736374789 polymorphism showed a lower FCR (2.18 to 2.48) compared to individuals with the GT genotype (2.41 to 2.89) on days 39, 40, and 42 (p < 0.05). The identified SNPs in the GHRL (rs312295326), SCTR (rs314830059), and SCTR (rs736374789) genes can be integrated into genomic selection programmes aimed at reducing FCR in meat-producing chickens.