CHARACTERIZATION OF CHEESE-MAKING PROPERT IES OF INDIVIDUAL LACAUNE EWE MILK SAMPLES WITH A FORMAGRAPH

The present study aimed at defining a method using the Formagraph appa ratus with non-standardized individual ewe milk samples. Rheological ( R, k20, k30, aR) and chemical (pH, protein and fat contents) parameter s were determined on 146 individual whole milk samples from 20 Lacaune ewes sampled all along the lactation. Respective effects of pH and la ctation stage were estimated simultaneously with the repeatability of different traits from ewes recorded all along their lactation, and the phenotypic correlations between all the measurements, using a mixed m odel. Without milk Standardization, ft is essential to measure pH and rheological parameters at the same time, because pH is one of the main factors of variation of rheological results. Phenotypic correlations between rheological parameters and milk composition were in agreement with those published in cow milk In particular, curd firmness is posit ively correlated with protein content (+0.59). Individual variability and repeatability of results of rheological parameters, comparable wit h those of the protein and fat contents, are discussed from a genetic point of view.