Protein polymorphisms and coagulation properties of Cilentana goat milk

The study was carried out on 86 ‘Cilentana’ goats, distributed in four herds. Milk samples were collected during morning and evening milking, and pH, dry matter, fat, protein and lactose percentage as well as the lactodynamometric profile were detected to determine enzymatic phase duration, coagulation speed and curd consistency. Polymorphism of the s1-casein protein was detected. Four alleles (designated A, B, E and F) and nine genotypes were detected. The association of these nine genotypes with chemical composition and lactodynamometric characteristics was investigated. The BF genotype was the most frequent (35.5 %), followed by EE (15.1 %) and AF and BB (10.4%). The F allele showed the highest frequency and it negatively influenced cheesemaking as it was associated with a low s1-casein content. Goats with the AB genotype produced milk with higher dry matter, protein and fat content compared with the FF genotype. Moreover, milk from the AB genotype has a lower enzymatic phase duration and a higher coagulation speed than the BB genotype. Curd consistency is higher for milk from the AA genotype, when compared with the EF genotype. All the chemical and lactodynamometric characteristics varied with herd and months of control; furthermore, the milk obtained from morning milking showed better coagulation properties.