Scour survey reveals high disease levels
Poor colostrum management and low vaccination rates are the two key factors contributing to high calf scour disease levels in the UK.
Independent national survey feedback from over 1,100 farmers representing more than 160,000 cows highlights both the extent of the disease problem and some of the reasons why some units find it so difficult to stamp out scours.
"According to the survey, over 70% of farmers have had calves dying from scour in the last year, with more than one in five rearers reporting that anywhere between 10% and 30% of their calves have been affected by the disease in some way over the last 12 months," reports Rosemary Booth MRCVS, from the survey sponsor Intervet/Schering-Plough Animal Health.
One of the key reasons behind the disease problem is the fact that calves do not appear to be getting enough high quality colostrum.
"Only half the respondents claimed to be getting more than three litres of colostrum into their calves in the first 24 hours of life. Yet, the recognised gold standard feeding protocol now is to get three litres into the calf within six hours of birth. Indeed, over 20% of farmers had no idea how much colostrum their calves were receiving because they didn’t intervene at all, only allowing calves to suck from the cow," Rosemary Booth says.
However, the survey findings do show that the majority of farmers recognise the importance of bottle-feeding and stomach tubing. But is the colostrum they are feeding of good enough quality?
"In a lot of cases, colostrum quality is poor," Rosemary Booth says. "Remember that quality and quantity are not necessarily the same thing. Higher yielding cows may produce more colostrum, but the higher volume often leads to lower antibody concentration. Heifer colostrum quality is also poor. Consequently, it’s a good idea to periodically assess your colostrum quality, using a colostrometer, and asking your vet to check the adequacy of your colostrum feeding regime by measuring antibody levels in calf blood."
When it comes to trying to prevent scour problems, the survey findings suggest most farmers seem to recognise the importance of good hygiene and colostrum feeding, but Rosemary Booth says that it is likely to be infection spread from calf to calf that lies at the root of many disease problems. For example, despite widespread acknowledgement of the necessity of good hygiene, only 59% of respondents are able to rest their pens between calf batches.
One of the most concerning findings is that only 11.4% of farmers are using a vaccination regime to prevent scour problems. This despite the fact that the common scour-causing organisms rotavirus, coronavirus and E.coli K99 had been identified on many respondents farms. For example, over 30% of those questioned said rotavirus had been identified on the farm.
"Rotavirus is the leading infectious cause of scours on UK farms, but as a virus it can’t be treated with antibiotics. The best way of protecting calves from rotavirus scours – and indeed those caused by coronavirus and E.coli K99 – is to vaccinate the dam," Rosemary Booth advises.
"On many farms, normal colostrum does not provide sufficient antibodies. Vaccination of the calf’s mother with a single shot of Rotavec Corona, 12 to three weeks before calving, boosts the antibodies in her colostrum against rotavirus, coronavirus and E.coli K99. It is these antibodies that confer immunity on the calf and act as a protective barrier to infection in the gut. With such prevalence of disease and studies suggesting every case of scour costs at least £44 per calf, the money spent on a vaccination regime is very quickly recouped many times over."
