Up footbathing frequency
By Marianne Curtis
GONE are the days when footbathing cows once at housing was enough to keep digital dermatitis at bay.
Deeper modern lesions mean producers should expect to repeat the treatment several times over winter for it to be effective in controlling this painful disease.
Although antibiotic aerosol spray remains the best treatment, when more than 5-10% of the herd is infected antibiotic footbathing makes sense, says ADAS Bridgets vet researcher Richard Laven.
"Antibiotic sprays take five minutes an animal rather than the 30 seconds a cow required for foot-bathing. Footbathing also offers a method of control, meaning all susceptible animals are picked up rather than just those where signs of the disease are visible."
Results from Mr Lavens research published recently in Vet Record, provide a convincing argument for footbathing. In his experiment, two groups of cows with digital dermatitis were either footbathed immediately or left untreated for four days.
"Four days after treatment, exudation, reddening and creaminess of lesions were significantly improved in treated, compared with untreated, cows." In the treated group, 11% of cows were lame after four days compared with 27% in the untreated group, he adds.
Despite Mr Lavens enthusiasm for the merits of footbathing, producers often report lack of success. This is likely to be because they are doing it wrong, he says.
"Do not expect one footbath to work; lesions are deeper and more chronic than they used to be, meaning the infection is further away from the skin and more difficult to penetrate. Repeat footbathing after 24 hours."
Other points to keep in mind are hosing cows feet before foot-bathing to reduce dilution of the solution with faeces and restricting numbers of cows through the foot-bath. "Expect to put 100 cows through a 300-litre footbath, then either top it up with a stronger solution or change the solution. For a 200-cow herd, change the solution completely after 100 cows."
Cows should stay in the footbath for about five seconds and stand on a clean surface afterwards to prevent the antibiotic solution from becoming diluted by slurry.
At ADAS Bridgets, where about 80% of its 700 cows will become infected with digital dermatitis at some time during their lactation.
"We have a high stocking density and a high incidence of mild digital dermatitis. Of cows with the disease, 10% are lame and footbathing reduces the number of lame cows, although it wont eliminate them. We were going to footbath cows monthly this winter, but trials on non-antibiotic footbaths mean this wont be possible."
Antibiotic footbathing costs about £50 a bath, but the cost of each case of digital dermatitis is much higher at £68 a case, according to Mr Laven. "Animals in pain produce less milk and fertility is also adversely affected – there is also the cost of treatment."
Digital dermatitis is a growing problem, with 70% of UK herds infected. "Unless you operate a closed herd, the chances are your cows will get it. Herds without digital dermatitis should try to buy replacement stock and bulls from other uninfected herds.
Although cows standing in slurry – unavoidable on many dairy units – lies behind digital dermatitis, there are steps which can be taken to reduce disease risk. "With automatic scrapers, running scrapers more often reduces foot contact with slurry. Also, ensure that collecting yards are scraped frequently."
Tread carefully… More care with footbathing and keeping cows feet clean could help conquer digital dermatitis.
• Footbath more than once.
• Scrape slurry frequently.
• Seeking good antibiotic alternatives.