Genetic polymorphism of β-lactoglobulin gene and effect on milk composition in Leccese sheep

The distribution of the two main genetic variants of LGB gene in 192 Leccese dairy ewes was analysed to evaluate the effects of the substitution of Tyr20 with His encoding variants on ovine milk composition.The main traits of milk production were measured every 2 weeks for over 5 months from morning and evening milking after lambs’ weaning (30 ± 3 days); in particular fat, protein and lactose, total nitrogen, casein content and casein number, whey protein and ash were analysed. Milk composition did not differ considerably among the LGB genotypes, the main differences were found for fat content (P > 0.01), with AA = AB > BB genotype, and whey protein content (P > 0.05) with BB = AB > AA genotype.