Science - November 12, 2009

Cows fall sick to the tune of farmer's attitude

Why do cows suffer from udder infection more often in some dairy farms and not in others? The attitude of the dairy farmer has a lot to do with this, communication scientist Jolanda Jansen has discovered. 'The farmer who upkeeps health objectives performs better.'

Jansen examined the attitude and conduct of dairy farmers to see if these can influence the prevention of mastitis (udder infection) on the farm. Mastitis is very painful for the cow, costs the farmer time and money and is the main reason for using antibiotics in dairy farming. 'Every farmer wants to prevent mastitis', says Jansen. And yet, one farmer succeeds better than another. Epidemiologists fail to have their fingers on the pulse of the factors which cause such differences. 'Mastitis is a multi-factor disease and has to do with many small matters', adds Jansen.
Epidemiologists often use questionnaires to relate the conduct of the farmers - 'do you clean the udders before milking?' - to the number of cows with mastitis. These however do not provide any clear-cut answers. So Jansen questioned the farmers about their attitude, which determines their actual conduct - 'how important is hygiene?' And that provides a better explanation of the variation in the occurrence of mastitis in farms, she reports in the journal Preventive Veterinary Medicine this month.
Somatic cell counts
There are two types of mastitis: the clinical form in which the udders are visibly inflamed, and the subclinical form in which the signs are not obvious but results in an increase in the number of somatic cells in the milk. Milk processing plants inspect incoming milk for the presence of these somatic cells. Farmers are fined if their somatic cell counts in a certain period are higher than 400,000 cells/ml.
The attitudes of the farmers account for thirty percent of the variation in clinical mastitis among farms, according to Jansen's calculations. But she pointed out in particular the relation of the farmer's conduct in reducing the invisible form of mastitis. Attitudes account for 47 percent of high somatic cell counts.
'Dairy farmers who strive for a low somatic cell count have much fewer cases of mastitis in their farms than farmers who only see the problem when they reach the penalty limit of 400,000. The difference in attitude is that the first group has concrete goals concerning improving the health status on the farm.' The second group has other priorities. 'Farmers have many requirements to fulfill. If many problems arise in their work, they often do not know what to start with. With a good management overlooking their activities, farmers are able to work out their plans for improvement into concrete action.'
The wheel of five
What actions? The condition of the livestock, the milk machine, the feed, the hygiene of the stable, how to treat sick animals - all these are factors which together determine the number of udder infection cases. 'Problems can be different from farm to farm.'
Jansen has undertaken her graduate research work on assignment from the Udder Health Centre of the Netherlands. The centre has its 'Wheel of Five' - five themes which affect the health of cows. Together with advisors, such as veterinarians and feed suppliers, animal farmers can set up their health plans with the help of these themes.
Jansen's results are in line with the covenant in the animal farming sector to reduce the use of antibiotics. One of its contentions is that animal farmers have to improve their management to reduce the disease rate on their farms.