In recent years, lime washing of concrete surfaces – particularly those which are cracked or are difficult to clean fully with a power washer – has become a routine procedure as part of a drive to improve hygiene.

Powdered hydrated lime, when mixed with water, undergoes a chemical reaction that generates heat and raises the pH of the emulsion to 13 to 14, i.e. it is extremely caustic.

Not only does this mean that sensible precautions must be taken when mixing, handling and applying to avoid scalding of the skin, but also the reaction – which is itself temperature-dependent – can take up to three to four days to complete.

If pigs come into contact with it before it is 'cured', even if the surface is dry, scalding can occur particularly on the snout. The blisters and ulcers that result, are painful and potentially can become infected and mimic Foot and Mouth disease lesions.

Always let lime wash cure before restocking a pen.