Majority of calves are not getting enough colostrum
Too many dairy farms are failing to get enough good quality colostrum into calves soon enough after calving and are unwittingly putting their newborn calves at risk from potentially fatal neonatal scours, Merial Animal Health says – as well as contributing to an annual £15m drain on British agriculture.
Just 19% of calves were found to have ingested sufficient amounts of colostrum, Merial revealed, following the publication of results from a new service rolled out to users of Trivacton® 6 scour vaccine earlier this year. Available through vets, the test focused on young calves of between two and five days to give an indication of the calf's level of 'passive immunity' obtained from their dam via colostrum consumed within the first 24 hours of life
"The test analyses a blood sample taken from the calf and measures the concentration of an important antibody, known as IgG, which is passed to the calf in colostrum from its mother," explains Warwickshire vet Steve Borsberry, who used the test with his clients earlier this year.
"IgG antibody concentrations of 15g/l or more are considered adequate," he says, "so in cases where we found levels below this, we were able to offer advice on colostrum management and incorporate it into the herd health plan."
According to Merial's Brian Rice, 81% of the calves tested had IgG antibody levels below the amount considered adequate. "In fact, the average level in the calves tested was indicative of inadequate transfer of passive immunity. It's a worrying discovery, suggesting that in the majority of herds there is inadequate colostrum absorption in a calf's first 24 hours," Mr Rice points out.
"Ideally, calves should be fed at least three litres of good quality colostrum within the first six hours, with the first feed within an hour of birth, as the ability of the gut to take up the IgG antibodies declines rapidly after birth and eventually stops when calves are 24 hours old. As a rule of thumb, it will take around 20 minutes for a calf to suckle three litres when feeding continuously."
Neonatal scours account for up to 75% of early calf deaths in the UK and are estimated to cost the whole industry £15m every year. Good hygiene and colostrum management, including vaccination of dams with a neonatal scour vaccine, such as Trivacton® 6, ensures protective antibodies are available to the calf via colostrum.
Close attention to colostrum intake paid off for Stuart Boothman, livestock business manager for Cogent Breeding. "A heifer's first few hours of life can determine her eventual performance," he says. "Immediately after calving, we milk all our newly-calved heifers for their colostrum and manually feed 5-6 litres to the calf. The aim is to ensure that by one hour old, calves take around 10 per cent their own weight in colostrum from a teat feeder.
"A calf's early attempts to suckle – in the straw, on the cow's leg and so on – provide it with the ideal opportunity to ingest unfavourable pathogens such as E. coli," Mr Boothman warns. "A good intake of colostrum within the first six hours ensures immunity from the dam is passed to the calf.
According to Mr Boothman, the implementation of the new strategy has significantly reduced calf scour in the herd. "The calves respond better to everything, whether that's nutrition or vaccines. Another major benefit is an improvement in growth rates," he points out, "with calves now averaging an additional 0.2kg per day."
"Colostrum from healthy cows should contain adequate levels of antibodies to pathogens present on the dam's farm," points out Mr Borsberry, but he believes it's prudent to consider vaccination prior to calving to get the most from an active colostrum feeding policy.
