THE QUANTITY AND THE HYGIENIC QUALITY OF MILK - OBSERVATIONS IN THE ILE-DE-FRANCE REGION (A STUDY USING INFORMATION COLLECTED IN 63 DAIRY-COW HERDS)

An analysis using the economic and technical management data from 63 d airy herds in the Ile-de-France region was performed (year 1990-1991). The following variables were studied: '' milk '' (= milk production p er cow present in the herd per year or milk production per cow milked per month), '' cells '' (= number of cells per millilitre of milk test ed) and '' germs '' (= number of germs per millilitre in bulk milk fro m ther herd storage tank). Overall analysis of the results showed that there was a negative linear correlation (-0.455) between the variable '' milk '' and the logarithm of the variable '' cells '' for the aver age yearly values. When analysed month by month this correlation was o bserved for six of the twelve months studied (end of autumn and spring ). There were significant differences between two groups of farms : fa rms which tested the milking machine had higher milk production and lo wer logarithm of '' cells ''. However, farms which tested their milkin g machine three years in a row did not improve their results.