Assessment of Passive Immunity Transfer in Indigenous Algerian Cows

Introduction: The acquisition of passive immunity is essential for calf survival, as they are born agammagolobulinemic and must absorb maternal antibodies from colostrum. This immunity is especially fragile in calves from extensive farming systems where indigenous cattle face environmental challenges. The objective of the current study was to determine the prevalence of sufficient passive immunity transfer (PIT) in order to assess neonatal survival capacity under natural environmental conditions. Materials & Methods: For this purpose, ۶۲ blood samples were taken from the jugular vein of local calves born in the mountainous regions of northeastern Algeria, to measure serum total proteins (STPs) levels using a digital refractometer. Results: The Mean±SD of STP concentration in calves was ۱۸.۵۶±۱۵ g/L, and the Mean±SD serum Brix percentage was ۸.۸±۱.۳%. STP correlated strongly with% Brix (r=۱). ۵۸% of calves presented a STP concentrations >۱۰ g/L, showing sufficient transfer of passive immunity and ۴۲% had a STP concentrations <۱۰ g/L, indicating failure of passive transfer (FPT). Our study revealed that the rate of PIT was influenced by the calving score (P=۰.۰۳). However, the sex of the calf had no impact on the success of this transfer (P=۰.۰۷). Test characteristics were evaluated to assess the FPT determined as STP level below ۱۰ g/L. Receiver operating characteristic (ROC) curve analysis identified a best cutoff value of ۸.۴% Brix, which indicated a sensitivity of ۸۹% and a specificity of ۸۵%. Our results are compared with published data, considering the methods and populations studied. Conclusion: Farmers can use the digital refractometer to measure STP in calves to facilitate monitoring the success of passive transfer to calves born in mountainous regions with freerange grazing.

کلیدواژه ها:

bovine ، Brix ، colostrum ، Refractometer