Nutrition and lameness in dairy cattle - a different perspective?

Abstract

Lameness due to foot problems in dairy cattle can be divided into two categories. The first of these categories is infectious lameness, which is primarily caused by digital dermatitis and foul-in-the foot. The second category is made up of the non-infectious diseases which affect the claw horn. In the UK these are primarily sole ulcer and white-line disease, with around 40% of reports of lameness by NADIS vets being associated with these diseases. While there may be some link between diet and infectious hoof horn disease (e.g. wetter diets - more slurry - more digital dermatitis), it is the claw horn diseases which are most often linked to nutrition; indeed they are often said to be caused by laminitis, a term which implies a nutritional aetiology. However, much recent research has questioned the laminitic aetiology of cla w horn disease and thus the importance of nutrition as the primary cause of white line disease and sole ulcers. LAMINITIS AND LAMENESS IN DAIRY CATTLE Acute laminitis as a result of inappropriate feeding, particularly starchy concentrates is a well recognised cause of acute lameness in cattle. However in dairy cattle such acute outbreaks of disease are sporadic and cannot be responsible for the large numbers of co ws which are lame due to white line disease or sole ulcer. Instead it has been hypothesised that claw horn diseases are due to ‘subclinical laminitis’, resulting from a subacute ruminal acidosis. The hypothesis is that this subacute acidosis leads to the release of vasoactive substances (particularly histamine and/or endotoxins) which cause vasoconstriction and dilation in the hoof blood v essels destroying the microvasculature of the corium. This produces ischaemia which results in haemorrhage and hoof horn damage, and ultimately claw horn disease. However this hypothesis is still unproven. Giving cows endotoxins or histamine does not produce claw horn disease; there is no evidence that hoof haemorrhages are associated with an acute phase