Influence of milk protein polymorphism of Italian Brown and French Holstein cows on curd yield

The influence of protein polymorphism on curd yield from the milk of 16 Italian Brown (IB) and 18 French Holstein (FH) primiparous cows was evaluated. The cows were bred on the same farm and fed with the same ration ad libitum. The chemical composition and protein polymorphism were determined in individual milk samples. The amount of real curd yield was monitored at 72 h and evaluated by micro cheese-making. For the same κ-CN genotype, FH primiparous cow produced more milk (+36.13%) with lower protein content than IB primiparous cow, resulting in a lower curd yield. IB primiparous cows presented a higher frequency of κ-CN BB genotype and preserved a better body condition score (BCS) (+0.57 BCS points P < 0.0008) at the end of lactation.