Development of a New Diagnostic Test for the Detection of Passively Acquired Immunoglobulin G 1 (IgG 1) in Newborn Calves Using Immunostick ELISA Technology

Abstract

It is generally accepted that there is no transfer of immunity in utero in the bovine. The calf is dependent on ingestion and absorption of immunoglobulins (antibodies) from colostrum by the endothelial cells of the small intestine for protection against neonatal disease. Absorption of immunoglobulins (lg) is maximal at birth, declines rapidly and ceases by 24 hours post-partum. Because of modern dairy herd management practices worldwide, a high percentage of calves receive insufficient amounts of colostrum, and thus are deficient in protective antibodies and very susceptible to neonatal disease, particularly colisepticemia and diarrhea. Currently the level of immunity can be assessed by measuring the levels of lgG 1 in the blood, but these tests frequently must be conducted in a veterinary laboratory. Because of the lag time in obtaining a result, the calf is often already 24 hours old, immunoglobulin absorption has ceased and it is too late to correct the deficiency by feeding additional colostrum. This new test is non-invasive and measures the level of IgG 1 in nasal mucus. The test can be conducted on the farm, and takes 35 minutes to complete. If immunity is minimal, then the calf can be immediately fed colostrum to boost its immunity.