A survey was conducted from August to December 1978, at 32 dairy farms with mechanical milking equipment, in the Metropolitan Area (surrounding the city of Santiago), Chile.
Bacterial count, time of Reductase Test, and temperature of the milk were measured at each farm; and the first two measurements were repeated on arrival of the same milk to the dairy processing plant.
According to initial bacterial count, the dairies were stratified as follows: first strata, with 7,000 bacteria/ mi at the outlet of the milking equipment, and 17,000,000 bacteria/mi when arriving to the plant; second strata, with 48,000 bacteria/mi at the farm and 48,000,000 bacteria/mi at the plant, and third strata, with 300,000 bacteria/mi at the farm and 1,580,000,000 at the plant.
With samples collected at each dairy, a factorial experiment showed the effect of time and temperature on the Reductase Test. For the first, second andthird strata, the Reductase Test time diminished, on the average, 13,65, 13,41 and 19,28 min per hour, respectively; the higher values for the first hour were 564,506, and 441 min, respectively. For the first and third strata, this test time diminished in 5 and in 2 min. respectively, per each Celsius degree increase in the milk temperature. |
ChileanJAR
