Evaluation of passive immunity absorption in Holstein Heifers

Abstract

Colostrums considered of good and very high quality are considered colostrums with a BRIX of ≥25%, so the first weeks of a neonate's life are considered critical, showing a greater susceptibility to diseases. In this sense, the objective was to evaluate the quality of colostrum and the transfer of passive immunity in Holstein heifers. The experiment was carried out on a milk producing property, located in the municipality of Olho D'agua das Flores, Alagoas, from October 2021 to April 2022, where 181 crossbred heifers were used. To measure the quality of the colostrum, an optical Brix refractometer was used, if it showed a quality lower than 25% BRIX, this colostrum was corrected and offered to the calf. The collected blood was stored in a tube without anticoagulant and left to rest until the serum was obtained, later, a drop of this serum was applied to the refractometer prism and, similarly to colostrum, a reading was performed to determine the concentrations of proteins. totals. For Pearson's correlation study, correlation coefficient analysis (r) was performed, assuming intervals of -1 (negative linear association) and 1 (positive linear association). Serum protein showed a negative correlation with the time of colostrum supply after birth (r = -0.16) and positive with calf weight at birth (r = 0.15). The adequate program of colostrum and evaluation of transfer of passive immunity allied to the proper management collaborate for the success in the productive indexes of the properties.