Effects of folic acid supplementation to basal diets of broilers on growth performance, slaughter performance, IGF2 gene expression and methylation

Folic acid (FA) is an important water-soluble vitamin and plays an important role as a cofactor and coenzyme in animal growth and development, and regulation of gene expression and methylation. A total of 270 female broiler chickens (1-day-old) were randomly allotted to three dietary treatments supplemented with 0 mg/kg (control group), 5 mg/kg, and 10 mg/kg FA in basal diets for 42 days, respectively. Each treatment had six replicate cages with 15 birds per cage. Dietary supplementation of 5 mg/kg FA significantly enhanced average body weight and average daily gain of 21-day-old broilers (P < 0.05), but significantly reduced subcutaneous fat thickness and widths of an intermuscular fat band of 42-day-old broilers by dietary FA treatments (P < 0.05). Also, a diet with 10 mg/kg FA supplementation significantly increased the relative heart weight of 42-day-old chickens (P < 0.05). Furthermore, dietary FA supplementation significantly improved the serum insulin-like growth factor 2 (IGF2) concentrations (P < 0.01) and IGF2 mRNA expression in the abdominal fat (P < 0.05), but no statistical differences were found in the methylation of IGF2 promoter (P > 0.05). The present study demonstrated that dietary FA supplementation may have positive effects on chicken growth through increased IGF2 gene expression.

PSIX-22 Assessment of the influence of IGF2 gene polymorphism in boars on economically significant traits

Studies of polymorphism in the IGF2 gene are of interest due to their association with economically useful traits in pigs. The aim of this work was to study the effect of IGF2 polymorphism on the variability of meat and fattening traits in pigs and to control the preservation of high reproductive qualities. The genotyping was performed using RT-PCR approaches were generated on the genetic resource collection of the L.K. Ernst Federal Research Center for Animal Husbandry. The total of 272 Large White (LW) and 301 Landrace (L) boars was investigated. Genotypes have been identified: at LW AA 73.5%, AG 23.2%, GG 3.3%; for L AA 10.3%, AG 35.2%, GG 54.5%. Reproductive performance evaluated on 22082 farrows from these boars. Analysis of productivity data was performed taking advantage of the model: y=μ+Breed+IGF2+Breed×IGF2+e, where y is the productivity index (for traits: weight at start of the test (BWs), weight at the end of the test (BWe), age of reaching 100 kg (AGE100), average daily gain (ADG), fat thickness (BF), litter size (LS), live-born (LB) and stillborn piglets (SB), the number of weaned piglets (Wean), the weaning weight (WWT), µ is the total average for a sample of n animals; Breed - the influence of the breed factor; IGF2 - gene factor effect; Breed×IGF2 - factor interaction effect; e - error. A significant effect of the IGF2 gene on variability was revealed at P < 0.001 BWe, ADG, LS, LB, Wean, WWT, at P < 0.01 on BWs, AGE100; when factors interact at P < 0.001 on ADG, AGE100, Wean, WWT, at P < 0.05 on LB. Revealed animals with genotype AA showed the best results in terms of meat and feeding qualities, as well as reproductive qualities. This research was supported by the Ministry of science and higher education No 0445-2021-0008.

Structure of insulin-like growth factor 2 (IGF2) gene from striped catfish (Pangasianodon hypophthalmus)

Gene coding Insulin-like growth factor 2 (IGF2) is one of genes relating the growth of many fish species, including striped catfish. In this study, cDNA coding to protein IGF2 was isolated from total RNA extracted from liver tissue of catfish, then was amplified through reverse transcription PCR and standard PCR with IGF2 specific primer pair to generate the 642bp-in-size PCR product. The sequence of this cDNA-IGF2 is similar up to 95% to the cDNA-IGF2 gene sequence of catfish included in family Ictalurus. Based on that sequence, 3 primer pairs were designed to amplify 3 regions of IGF2 gene from genomic DNA extracted from fins of catfish, which have 900bp, 1500bp and 1200bp in length. That 3 regions were sequenced and assembled to give the final sequence with 3387bp in length of IGF2 gene, which includes 4 exons coding to IGF2 protein, and is similar up to 96% to sequence of mRNA coding to IGF2 protein of channel catfish Ictalurus punctatus and that of blue catfish Ictalurus furcatus. Determining the structure of IGF2 gene of striped catfish Pangasianodon hypophthalmus enable us to further examine its function and genetic variation.