Growth and behaviour in relation to skin lesion surface due to Psoroptes and Trychophyton in Belgian Blue Cattle.

Skin lesions due to infection with the parasitic Psoroptes mite is a common problem in Belgian Blue Beef and causes substantial growth reduction. Skin lesions due to fungi such as Trychophyton verrucosum are considered to have little economic implication s. We studied weekly growth over 11 weeks in 36 growing animals of both sexes. Twelve were infested with Psoroptes mites and developed lesions by week 11. 19 animals spontaneously obtained a Trychophyton infection. First skin lesions were observed in week four. Beha viour was scored daily from week 1 till week 6, and from week 10 till week 11. Animals without lesi ons, with lesions due to Psoroptes and with lesions due to Trychophyton did not show a significant difference in weight ga in. There was however an effect of surface of lesions (of any kind) on th e growth (p<0,02): larger lesions related to less growth. Lesion surface also related to reduced rumi nation quality. Animals with Psoroptes lesions showed more itching behaviours (licking, tail switc hing, scratching, rubbing) in relation to lesion surface from week 5 on. We confirm that are welfare implications and economic implications in animals with skin lesions due to Psoroptes or Trychophyton .