Conditions d'élevage et de traite associées aux élévations cellulaires collectives chez des unités bovines laitières hors sol dans la région de Monastir (Sahel Tunisien)

High Herd Cellular levels (TCT), usually linked to the breast infections may have many origins. Through this work, we have deducted some of the responsible factors for these elevations. To do this, we interested in a sample of 40 dairy cattle farms of the same breed (Holstein Friesian), conducted in above ground system in a semi-arid environment of the coastal Tunisia (Monastir Region). For each herd, mixed milk was sampled periodically, analyzing the collective somatic cell counts by using direct counting through the use of cell counter Fossomatic 4000. In addition, farm and milking visits were accomplished at least twice per herd. TCT and corresponding farming and milking conditions analysis has identified such as milking machines cleaning with only water and pulse rate greater than 60 beats/Min are two conditions that have considered a significant effect on the elevation of TCT in the context of this study. These conditions can be considered as mastitis risk factors. Although all TCT readings are high (> 674 000 cell./mL), analysis of the rest of the conditions studied didn’t show a significant effect.