Monitoring Passive Transfer of Immunity in Neonatal Calves by Measuring Levels of IgG in Blood Using Immunoassay Method and Refractometer Measures of Serum and Colostrum

IgG Check calf test has been used in this study to identify if a failure of passive transfer occurs in neonatal calves by measuring the level of IgG in blood. An adequate level of IgG measured in all calves at 48 hours, 7 days and 14 days after birth showed level of IgG 1000 mg/dl. This level indicated that they have good passive transfer of immunity. Also, in this study colostrum quality fed to calves was detected using Brix Refractometer. The colostrum is of high quality as it contains 50 mg/ml of IgG. This Brix refractometer can be used on the farm level to estimate colostrum IgG content and monitoring colostrum feeding practices. Colostrum with high quality IgG could provide calves with enough IgG to attain successful passive transfer of immunity. Brix and Obione refractometers provide simple, rapid method for estimating IgG concentration on calf serum, thus considered to be the most common method for determining passive transfer failure.