Milk is tricky to clean off surfaces. Hot water removed fat, but the heat can bake protein onto the surface. Fats and proteins form a nutrient-rich biofilm where bacteria grow. Feeders look clean but bacteria are happily growing on the surface. Cleaning needs to remove fat and protein to prevent the formation of biofilm. An alkali detergent is the best for this job.

• Milk bar detergent is ideal for removing the biofilm from teats and feeders.