ANALYSE DES NUMÉRATIONS CELLULAIRES SOMATIQUES DU LAIT ET DES FACTEURS DE RISQUE DE MAMMITES BOVINES CHEZ DE PETITES UNITÉS HORS SOL DANS LA RÉGION DE MAHDIA (TUNISIE)

Abstract

The objective of this study was to assess the health status of mammary cows from individual cell counts and assess risk factors for subclinical mastitis in small dairy farms in the region of Mahdia in Tunisia under semi-arid. The periodic removal of samples were made for 250 dairy cows on 23 farms aboveground adhering to the control milk during the period spanning January 2007 to May 2008. A monitoring progress of projects implemented and the maintaining operation of milking machines adopted has been undertaken. It appears that the arithmetic averages (MA) and geometric (MG) of individual cell counts (ICC) were respectively 578000 and 180000 cell./ml. The diagram of the quartiles of the distribution of ICC showed that the median (Q2) is close to the MG ICC, which confirms the usefulness of using the MG instead of MA in the analysis of values ICC. The rate of healthy cows, with an average ICC 200000 cell./ml was 45% according to the MA and 56% by MG. The study of the conditions of milking cows showed several failures on plans hygienic, technical and technological. The statistical study revealed that the correlation was significantly high ICC with operating parameters of milking machines; however, it was not significantly associated with practices of milking.