Short communication: Factors affecting coagulation properties of Mediterranean buffalo milk

The aim of this study was to investigate sources of variation of milk coagulation properties (MCP) of buffalo cows. Individual milk samples were collected from 200 animals in 5 herds located in northern Italy from January to March 2010. Rennet coagulation time (RCT, min) and curd firmness after 30 min from rennet addition (a(30), mm) were measured using the Formagraph instrument (Foss Electric, Hillerød, Denmark). In addition to MCP, information on milk yield, fat, protein, and casein contents, pH, and somatic cell count (SCC) was available. Sources of variation of RCT and a(30) were investigated using a linear model that included fixed effects of herd, days in milk (DIM), parity, fat content, casein content (only for a(30)), and pH. The coefficient of determination was 51% for RCT and 48% for a(30). The most important sources of variation of MCP were the herd and pH effects, followed by DIM and fat content for RCT, and casein content for a(30). The relevance of acidity in explaining the variation of both RCT and a(30), and of casein content in explaining that of a(30), confirmed previous studies on dairy cows. Although future research is needed to investigate the effect of these sources of variation on cheese yield, findings from the present study suggest that casein content and acidity may be used as indicator traits to improve technological properties of buffalo milk.