ChileanJAR

ln 10 dairy farms of the Region Metroplitana (Chile), samples of the water used to sanitize the milking equipment were collected at the same time with milk samples, that were kept for 48 hr at 4ºC, simulating the process that takes place in a cooling tank. Methylene blue reduction tet (MBRT), total bacterial (TBC), psychrotrophics (PC) and coliforms (CC) counts were determined in the milk samples; the same analysis were practiced in the water samples, with exception of MBRT. Correlation analysis between bacteriological variables in milk and water samples were made; also, milk samples were stratified, according to the water sanitary quality levels (good and poor), performing a t test for each of the variables. Averagewater counts were 13,834/ml (TBC), 1,816/ml (PC) and 5,239/100 ml (CC); ussing different standards, the levels of hygienic acceptable samples fluctuated between 16.6 - 86.7, 36.7 - 80.0, and 0 - 50% for TBC, PC and CC, respectively. A significant relationship was obtained only between water PC and milk TBC (r = 0.275; P < 0.001); the milk bacterial concent/ml and MBRT (hr) corresponding to poor and good water sanitary qualities were; TBC: 56,742a and 38,020a; PC: 27,1 78a and 43,208a; CC: 1 ,123a and 1 ,133a; MBRT: 6.19a and 6.41b (P < 0.05). Water did not fulfill the quality requirements for use in sanitizing milking equipments; in spite of this fact, it was not possible to isolate its effect on milk bacteriological quality.