RELATIONSHIP BETWEEN MILK GENETIC POLYMORPHISM AND PHYSICO-CHEMICAL AND NUTRITIONAL QUALITY OF SHEEP MILK

Individual milk samples (n = 72) were collected from Massese ewes bred in Central Italy. Milk phenotypes were typed by isoelectrofocusing. Milk samples were analysed for the physico-chemical composition. The lipid fraction was evaluated by the morphometric analysis of milk fat globules and by the determination of the fatty acids composition. The relationships between the genetic polymorphism of s1-casein (s1-cn) and -lactoglobulin (-lg) and the qualitative properties of milk were statistically evaluated. The comparison was performed between genotypes s1-cn AC vs CC, and -lg AA vs AB. Some interesting relationships were found between milk protein genotypes, fat globule morphometric characteristics, and fatty acid composition. A higher amount of smaller milk fat globules was associated to s1-cn AC (vs CC) and -lg AB (vs AA) genotypes, and a higher content of long-chain fatty acids was associated to -lg AA (vs AB) genotype