Effect of IGF-1 gene polymorphism and some non-genetic factors on milk yield and chemical composition in Awassi sheep

Abstract

The study was carried on 68 ewes of local Awassi sheep in the fields station the al-kafeel sheep station the Karbala For the period from 1/10/2017 to 1/8/2018 Genetic analyzes were carried out in the molecular genetics laboratory at the College of Agriculture / Basrah University in order to extract (DNA) and determine the genotype of the IGF-1 gene. Milk yieild were recorded and samples were also analyzed to determine fat, protein and lactose percentage in the laboratory of the College of Veterinary Medicine / AL-Qasim Green university. This study aimed to know the relationship between the genotypes of the ewes of IGF-1 gene, the age of dams and the sex of the kids on the of daily, monthly and total milk yield and lactation preiod and milk chemical composition, (fat, protein and lactose percentage). IGF-1 gene showed a significant effect on milk production, monthly, total milk and lactation length .the genotype GC had highest value 92.53 kg total milk production and 112.18 lactation length . The of genotype GC was significantly higher in protein (4.71%) but CC genotype had higher protein (5.31%). Age of dams had a significant effect on milk production, and lactation period , Ewes born male exceeded that born females in total milk production, on other hand ewes of two years old significantly produced highest fat percentage, sex of lamb did not significantly affect the milk component.Key word: sheep ,polymorphism IGF-1, milk yield