| dc.description.abstract | 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 Blood samples were withdrawn from all calves between 24 and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. | en_US |
