EFFECT OF TEMPERATURE ON COLOSTROMETER READINGS FOR ESTIMATION OF IMMUNOGLOBULIN CONCENTRATION IN BOVINE COLOSTRUM

Effect of temperature on colostrometer readings for estimation of immunoglobulin concentration in bovine colostrum was investigated. Twenty-five colostrum samples were collected within 24 h postpartum from Holstein cows. Immunoglobulin concentration of colostrum was measured using a colostrometer through 5-degrees-C increments from 0 to 40-degrees-C. Two technicians measured independently a total of 225 samples. The agreement between technicians' readings was high (r = .98); thus, readings were averaged and used in regression analysis. A final regression model explained 92.5% of the total variation: corrected reading at 20-degrees-C = uncorrected reading - 13.2 + .8 x temperature (degrees-C). The regression equation was used to develop a conversion chart for practical field use.