Lavaggio dell’impianto di mungitura e qualita’ microbiologica del latte

Milking machine cleaning and microbiological quality of milk - Cleaning and maintenance of milking equipment is essential in order to obtain high quality milk. Many are the critical points of milking machine cleaning: water temperature, quantity and type of detergent and water turbulence. A total of 22 farms were visited three times in order to monitor milking machine cleaning using electronic flow meters (Lactocorder®). Cleaning process can be divided in three phases: pre-rinse, detergent phase and post-rinse. In our study the duration of detergent phase was 17.4±5.80 min, electrical conductivity of the detergent solution was 4.06±1.84 mS/cm and turbulence was 25.2±13.9 %. Maximum temperature detergent solution was on average 34.6±9.05°C, lower than the International guideline (43-77°C). The results underlines that farms using low water temperature (<35°C) had higher standard plate count in bulk tank milk than the others (4.12 log10/CFU vs 3.93 log10/CFU; P<0.05). Detergent phase duration had interesting effects on milking machine hygiene and bacterial quality of milk: 10 to 15 min seems to be the best time to reduce standard plate count in milk and standard plate count, thermoduric and psychrotrophic bacteria on milking equipment.