Changes of physico-chemical characteristics, somatic cell count and curd quality during lactation and their relationships in Lacaune ewes

The aim of research was to evaluate changes of physico-chemical characteristics, somatic cell count and curd quality during lactation and their relationship in Lacaune ewes. The study was carried out on eighteen ewes of the second lactation on an organic farm in Valašská Bystřice (Czech Republic). It was found that the stage of lactation significantly affected almost all monitored traits except pH value, titratable acidity, somatic cell count and curd quality. The content of total solids, fat, total protein, casein, Ca and P was significantly increased, while daily milk yield and the content of lactose were decreasing with the advancement of lactation. The stage of lactation had a significant effect on the coagulation time that was extended with advanced lactation. Length of the coagulation time was positively correlated with contents of total protein, casein and Ca. In contrast, the curd quality was not affected by the stage of lactation and no significant correlation between the curd quality and other parameters were found, except for the coagulation time (r=0.40). It could be concluded that Lacaune ewes had a satisfactory milk yield and physico-chemical and technological characteristics of milk under relatively extensive nutrition.