Copper Pine of Calves

Unthriftiness in grazing calves has been recognized by farmers in parts of Caithness during the last 10 years. A noticeable feature of the disorder is that Aberdeen-Angus and cross-bred West Highland calves are chiefly affected. Adult cattle of these breeds grazing the same pastures do not appear to be clinically affected. In Caithness, cattle are housed from November to April and managed so that calves are born in March and A4pril. Cows and calves are then turned out to pasture where they remain until October, when the calves are sold. ‘l’he geological formation of Caithness is Middle Old Red Sandstone extensively overlaid with peat, but around coastal areas sandy machairs are common. About 709/~ of the county is classed as moor and heathland. Of the remaining land about 15 % is arable and j y b permanent pasture, mostly reclaimed from peat, but a considerable proportion of this is still marginal. Although the disorder has been attributed to various factors, one of which was excess molybdenum in the pastures, no observations have been made to ascertain the true cause. In 1945, one of us (S. J.) made the empirical observation that the disorder could be cured by administration of small amounts of copper sulphate, but detailed investigations were not commenced until June 1948, when the present observations were made. Clinical description of the disease Initial symptoms may appear about a month after calves are put out on pasture. The first sign of the condition is a stilted gait, particularly of the hind limbs. This is followed by a slowly progressive loss of condition during the next 4 or 5 months, which in severe cases results in extreme emaciation and death. In black-coloured breeds the hair around the eyes becomes grey, giving the animal a ‘spectacled’ appearance. This depigmentation frequently extends down the forehead and lower jaw, and in severely affected animals a general greying of the hair takes place, usually along the back and forelegs. In brown-coloured breeds, the coat changes to a muddy yellow. PI. I , I shows the appearance of a typical ‘pining’ calf. Diarrhoea is not a common symptom but has been observed in a few instances. ?;o pica has been noted even in badly affected animals. ‘I‘he incidence of clinical cases is usually Z O Z ~ ~ / , of grazing calves, but the rate varies on different farms and may reach 100%. There is a year-to-year variation in