Abstract
Background:
Blood proteins have been widely used to characterize animal breeds, as most are genetically determined and follow simple genetic rules. Therefore, the transferrin protein has been studied based on its various alleles. Transferrin is a type of protein that binds two iron atoms to each transferrin molecule. Sheep meat production can be increased through genetic improvement.

Aim:
The aimed study to predict the live weight and growth hormone concentration lambs by identifying transferrin gene alleles and selecting them for meat production or breeding

Methods:
This study was conducted at the Research Station of the College of Agriculture, University of Basrah. Blood samples were taken from 74 Arabi sheep, and the genetic makeup of the iron transporter protein (transferrin) was studied using polyacrylamide gel electrophoresis (PGE) in a variable buffer solution with black amido dye. The relationship between gene expression, lamb live weight, and growth hormone (GH) concentration was investigated.

Results:
Results indicated the detection of six transferrin genotypes AA, AB, AC, BB, BC, and C were detected based on their electrophoretic mobility in basal medium. Three alleles A, B, and C accounted for these genotypes. The results showed that the AA and BB genotypes were associated with lamb live weight and GH concentration, accounting for 48.61% and 16.66 % of the genotypes, respectively. The average lamb weights were 38.15 and 37.22kg, and the growth hormone concentrations were 9.97 and 9.51 ng/ml, respectively. In contrast, the genotypes AB and AC accounted for 20.83 and 11.11 %, respectively, with an average weight of 36.20 and 36.05 kg, and a growth hormone concentration of 8.97 and 8.85 ng/ml, respectively. As for the genotypes AC, BC their percentage reached 1.33 %, with an average weight of 35.65 and 35.35 kg, respectively, and a growth hormone concentration of 8.75 and 8.45 ng/ml, respectively, as these traits are recessive.

Conclusion:
From the results we conclude that there is a correlation between body weight, growth hormone concentration in lambs, and the genotype AA and BB, indicating that it is the dominant trait over the other genotypes.

Key words: Genetic transferrin; Live weight; Growth hormones; Genetic polymorphism.