Title:Control of immunoglobulin absorption using the oesophageal tube feeding method on a Hungarian dairy farm
Failure of passive transfer in dairy calves has been linked to increased neonatal morbidity, mortality and long-term decreases in productivity. The aim of this study was to assess the control of immunoglobulin absorption on a Hungarian Holstein-Friesian dairy farm and compare it to studies from around the world. Newborn Holstein-Friesian heifer calves (n=235) were examined from the 1st January 2019 until the 31st May 2019. Calves were removed from the dams within 2h after birth and high-quality frozen colostrum (3 to 4 litres) after melting (38°C) was provided to the newborn calves by oesophageal tube connected with a plastic can by a calving assistant. Nine to 10 h after birth the calving assistant repeated colostrum feeding from a plastic bucket, which was repeated by a calf caregiver between 17 to 18 h after birth. Milk replacer was then fed from this point onwards, 2.5l twice daily. Blood samples were withdrawn from all calves between 24 and 72 h of life. The serum from these samples was used to assess immunoglobulin absorption by using a BRIX refractometer. Any animal with a BRIX% less than 7.8% was deemed to have failure of passive transfer. The highest recorded BRIX value was 11% with the lowest recorded value being 5.2%. The average BRIX value for the sample was 8.05% ± 0.08. Average BRIX% showed little variance between the months. Failure of passive transfer was recorded in 95 out of 235 samples (40.43%). Mortality status was also recorded for the period of the study with 5 out of 235 (2.12%) animals dying. Serum IgG levels were estimated using a formula devised by Quigley (2016) and showed that, 88 out of 235 (37.5%) of the sample group had failure of passive transfer defining failure of passive transfer as <10 g/dL. Thus, suggesting that the formula used was quite accurate in assessing serum IgG levels. We found the levels of failure of passive transfer very high when compared to other literature using similar feeding techniques, colostrum volumes and feeding times. We identified areas of our study that would need improving to reduce variables and improve accuracy in future studies.