Relationship of polymorphism of the DIO2 gene within exon2 to some growth and prolificacy traits in local black goats

Abstract

This study was conducted on 40 local goats, aged 2-3 years, during the period from October 15, 2024 to May 15, 2025, in the field of the College of Agriculture, University of Diyala. All molecular genetic analyses were performed in the College of Agriculture laboratory, as well as in the Rukan Al-Rawan (Al-Jadriya) .The aim was to study the relationship between of the DIO2 polymorphism gene and growth traits (birth weight, weaning weight, and total weight gain), as well as its relationship to body dimensions at birth and weaning for dams (does) and prolificacy. The results showed a change from glutamine to arginine, which was considered a missense mutation at the protein level. The results also showed that the genetic polymorphisms of the A9280G of the DIO2 gene, which two genotypes (AA and AG) appeared in the second exon, did not show significant differences between the genetic combinations with regard to the weight and dimensions of the dam body at birth. The same was the case with the growth traits of the kids, as no significant effects were shown in the weight at birth and weaning, the rate of weight gain, and the prolificacy, as the averages were close to each other. While, the results showed significant effects (P ≤ 0.05) of the two combinations in the traits of chest and abdominal circumference at weaning, with the individuals carrying AA being superior with an average of 45.13 and 48.16 cm compared AG type (42.5 and 45.33 cm) respectively.