In 2015, a study using 4000 dairy calves from nine different regions across New Zealand indicated that the average prevalence of FPT at various intervals during the spring calving period was 33per cent, with prevalence on farm ranging between 5per cent and 80per cent.
This indicates many calves are not getting enough good quality colostrum soon enough after birth.
Why do calves get failure of passive transfer?
• Feeding colostrum with inadequate levels of immunoglobulin
• Feeding insufficient volumes of colostrum
• Feeding colostrum too late after birth
• Bacteria contaminating colostrum at harvest, during storage or at feeding. Coliforms (bacteria from faecal material) are the most detrimental of the bacteria for immunoglobulin absorption.
Why can feeding enough high-quality colostrum be a challenge?
• Time and staffing constraints at calving time, especially with highly compact calving patterns, can make it difficult to ensure newborn calves receive enough high quality colostrum shortly after birth. The 2015 study of 105 dairy farmers showed that only 22 per cent pick up calves twice a day
• Colostrum immunoglobulin concentrations and colostrum volumes are extremely variable in dairy cattle
• Pooling colostrum is common practice on New Zealand dairy farms, but individual cow variation can result in low immunoglobulin concentrations.
• In the 2015 study, colostrum quality was found to be poor. Only 10 per cent of the 298 colostrum samples, collected at multiple times during the calving season, had immunoglobulin concentrations over the recommended levels and only 11per cent of samples had acceptable bacterial contamination levels.
Leaving the calf on its mother versus tube-feeding - which is best?
Leaving a calf with its mother should ensure it gets fresh, warm, high quality colostrum very soon after birth, right? Not necessarily. National and international research indicates:
• The risk of FPT is higher when calves are left to suckle dams compared with when they are removed promptly and fed enough high-quality colostrum in the calf shed
• If colostrum feeding and storage equipment is hygienic and pooled colostrum is 'clean' (low bacteria counts) and managed well, calves may be less likely to get health problems since the mother is a source of infection.
• Tubing animals means calves get a known quantity of colostrum within a known time frame but:
- It can lead to milk pooling in the rumen which leads to a poorer immunoglobulin absorption.
- Tube feeding poor-quality, contaminated colostrum will increase the risk of FPT occurring.
Testing for failure of passive transfer
Regardless of whether calves are left on their mothers, every calf is tube fed or calves are put on to feeders, the following management steps can be taken to measure and prevent FPT:
• Step 1 - Test your calves for FPT:
You can test for the prevalence of FPT by blood sampling 12 healthy calves (not scouring or dehydrated), between 24 hours and seven days of age, for laboratory analysis of total protein. It is recommended that this is done both at the beginning and peak of calving when the prevalence of FPT is typically higher.
• Step 2 - test colostrum for quality:
You can use a BRIX refractometer to test your colostrum quality. BRIX readings of over 22per cent indicate high quality immunoglobulin colostrum.
You can start by testing the pooled colostrum. If this is of poor quality you will need to test individual cows as they will give very different results.
Testing individual cows only takes five seconds using a BRIX refractometer and can be easily worked into your management protocols.
KEY FINDINGS:
• Failure to absorb enough immunoglobulins from colostrum in the first 24 hours of a calf's life can make a calf susceptible to disease and death
• This failure known as Failure of Passive Transfer (FPT), is relatively common
• Good management practices can limit the chance of FPT
• Farmers can test for prevalence of FPT and for the quality of their cows' colostrum
- Article originally published in DairyNZ's Technical Series.
