PHOSPHORUS SUPPLEMENTS AND FLUOROSIS IN CATTLE - A NORTHERN AUSTRALIAN EXPERIENCE

Chronic fluoride toxicosis caused lameness, dental lesions and illthri ft in an extensive beef cattle herd In northern Australia. Up to 15% o f the herd was lame and the disease forced the culling of large number s of cows. The source of fluoride was fertiliser-grade monoammonium an d diammonium phosphate fed as part of a mineral supplement. Large quan tities of mineral supplement were provided to the cattle because lamen ess was attributed to phosphorus deficiency, which is endemic in the a rea. Most lameness developed in the late dry season In the post-lactat ion phase. Severe lameness was caused by fractured pedal bones.