SOME MECHANICAL FACTORS AFFECTING MACHINE MILKING CHARACTERISTICS UNDER SEMI-ARID CONDITION

The effect of mechanical factors and season of the year on milking characteristics (milk yield, time of milking, rate of milk flow, stripping time and tripping milk) were studied on 26 Holstein Friesian cows, raised under Saudi Arabia environmental conditions. Cows were in the third and fourth lactation and reached the peak. Cows milked twice a day with equal intervals. Three vacuum levels (34, 38 and 42 cfm) and two pulsation ratios were used to form six vacuum-pulsation combinations. The study was carried during two seasons Autumn-Winter (S1) and Spring-Summer (S2). After absorbing the cow equations least square analysis was used to analyze the data. Vacuum level 38 cfm and pulsation ratio 70:30 was the best among all combinations of vacuum level-pulsation ratio. No significant effect (p < .01) for season, up to the seventh half minute, on the rate of milk flow. However, season of the year has a significant effect on total milk yield, stripping time and stripping milk.