Effect of lactation on the hygiene quality and some milk physicochemical traits of the Wielkopolska mares

The objective of this research project was to ascertain the hygiene quality and some physicochemical properties of milk obtained from mares of the Wielkopolska breed at different periods of lactation. Colostrum and milk for analyses were collected on days: 1, 2, 3, 4 and 5 of lactation and afterwards at 15-day intervals up to day 150 of lactation. A significant influence of lactation on levels of the examined traits was found. Depending on the period of lactation, titrable acidity was found to be at the level of 4.6oSH (from 8.6 to 2.5), the mean temperature of milk freezing was –0.541oC, whereas electrical conductivity fluctuated in the interval of 3.8-4.6 mS x cm. The mean somatic cell count during the lactation period amounted to 62 x 10/cm and ranged from 194 x 10 on the first day of lactation to 41 x 10 during the last month of lactation. The total count of microorganisms remained within the interval from 33 x 10/cm to 51 x 10/cm.