SITUATION SANITAIRE MAMMAIRE ET PERTES QUANTITATIVES LAITIÈRES GÉNÉRÉES PAR LES ÉLÉVATIONS CELLULAIRES DANS DES ÉLEVAGES BOVINS HORS SOL EN TUNISIE

Abstract

The objective of this work is to study herd cellular levels variations (TCT) and estimate quantitative losses of milk related to their elevations using a herd model established by SNGTV. The study was performed on a sample of 40 cattle farms, above ground, in the region of Monastir (Tunisia semi-arid) during 8 months (from September 2009 to April 2010). Breast health diagnosis was made by the direct cell count method of flock’s mixed milk. It appears that 85 % of farms were arithmetic averages (MA) TCT > 200 000 cell. /ml and 75 % of farms have geometric averages (GM) of TST > 200 000 cell. /ml. The MA of TST is 771 000 cell. /ml while the MG TST is lower (385 000 cell. /ml) and close to the median value of TCT (373 000 cell. /ml). It was found that young farms, where more than 50 % of primiparous cows are less affected by mastitis and their TCT are lower. It was also recorded that the MA and MG of TCT are higher during the autumn season. Quantitative losses of milk resulting from high cellular levels were significant. Average milk decreases related to the theoretical production, estimated from TCT, were evaluated at 382 l / VP / year, also it means 3440 l / herd / year.