Passive immunity transfer in bovine calves: analysis methods and their correlations with maternal and colostral parameters

Failure of passive transfer of immunity (FPT) is a prevalent concern in veterinary practice and can be assessed through various methodologies. Hence, the aim of this study was to assess different methodologies for determining FPT in calves, along with correlating these parameters with maternal and colostral parameters, with the intention of identifying alternative methods for FPT evaluation. Forty-five cows (16 primiparous and 29 multiparous) and their respective colostrum and calves were selected. Blood samples were obtained at birth and 24 h post-colostrum ingestion for biochemical evaluation, including IgG, total protein (TP), albumin, alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), and triglycerides. A Brix refractometer was employed for assessing samples. Calves from both primiparous and multiparous cows exhibited increased ALP, GGT, globulins, IgG, and TP levels post-colostrum ingestion. Calves born from multiparous cows demonstrated greater increases in TP and IgG levels and lower ALP activity compared to those from primiparous cows. Colostrum from multiparous cows exhibited lower Brix values and higher ALP activity than that from primiparous cows. There was a positive correlation between IgG and globulin levels in calves and maternal globulin levels. Maternal ALP activity showed a negative correlation with calf globulin, IgG, and TP levels via both biochemical and refractometric methods. Maternal TP levels were positively correlated with calf globulin, IgG, and TP levels. Brix and colostral globulin from multiparous cows positively correlated with calf globulin, IgG, and TP levels. Cost-effective and practical methodologies such as refractometry and biochemical assays can serve as reliable tools for FPT assessment in calves. Brix refractometry demonstrated a strong correlation with conventional parameters.