The effect of concentrate: silage ratio and of hoof trimming on lameness in dairy cattle

Abstract
During weeks 3 to 26 of lactation, two groups of 24 cows were offered either a 60:40 (high) or a 40:60 (low) ratio of concentrate dry matter:silage dry matter. The 40:60 diet was restricted to give the same daily metabolizable energy and crude protein intake. The hooves of half the cows on each diet were trimmed prior to the experiment, the other half remaining untrimmed. The high concentrate ratio significantly increased locomotion score (high scores indicating poorer locomotion), and the number and duration of clinical cases of lameness. Trimming of hooves significantly reduced the number and diiration of clinical cases. Hoof growth was significantly increased by trimming. Hoof hardness was significantly reduced by the high concentrate ratio. The low concentrate ratio had 8/24 cows lame for an average of 3·3 weeks compared with 11 cows for 3·9 weeks on the high ratio. There were 7/24 trimmed cows lame for 3·1 weeks compared with 12 untrimmed cows lame for 4·2 weeks. The main hoof lesions were solar ulcers and heel erosion. There was no significant effect on milk yield, but milk protein was signficantly increased by the high concentrate ratio. Condition score was significantly negatively correlated with locomotion score.