Use parlour washings as a footbath with caution

Dairy Farmers should act with caution when using parlour washings for footbathing, according to research scientist Marijntje Speijers of the Agri-Food and Biosciences Institute.

A study carried out by Dr Speijers at the institute showed the incidence of digital dermatitis (DD) increased when cows were footbathed with 2% hypochlorite.

The trial looked at the effect of footbathing cows with a 2% hypochlorite solution (representative of parlour washings) for four consecutive milkings a week. This was compared to cows being footbathed weekly with 5% copper sulphate and cows not being footbathed at all.

Results showed the hypochlorite treatment did not control digital dermatitis and actually resulted in a 27% increase in DD levels – a figure similar to cows that received no treatment (see table).

However, the copper sulphate treatment resulted in a 14% drop in DD levels. This treatment also had a significantly higher proportion of cows with healing DD lesions from week to week.

“These results show that hypochlorite or parlour washings must be used with caution,” says Dr Speijers.

“The question is, can you be sure of the strength of your parlour washings? I would not go as far as to say don’t use them, but farmers should be aware they may not work.

“With any method it is important to assess how well your footbathing routine is working – it may be time consuming, but it is well worth looking at DD levels once a week when cows come into the parlour – this should become as routine as brushing your teeth.”

A further study looked at the effect of varying concentration of copper sulphate showed the level of active DD lesions in cows with a high prevalence of the disease (more than 60% of cows in a group), decreased faster with the 5% treatment compared to 2%.

However, the level of lesions remained similar with both concentrations when cows with a low DD prevalence (below 25%) were treated.