The influence of concentrate amount on locomotion and clinical lameness in dairy cattle

Abstract
An experiment with two groups of 24 cows during weeks 3 to 22 of lactation examined the influence of 7 (L) or 11 (H) kg concentrates per day on the prevalence of lameness. Grass silage was offered ad libitum. The cows were scored on a 1 to 5 scale for their locomotion on a weekly basis (1 = normal locomotion; 5 = severely lame). Cows scoring 3 or more were considered to be clinically lame. This allowed the prevalence of lameness, its severity and duration to be measured and statistically analysed. There were significantly more observations of lameness in the H cows than the L cows (0·077 and 0·021 observations per cow week) and the severity and duration of lameness incidents were significantly greater. The major causes of lameness were solar problems in the hind feet. The prevalence declined in both treatments as lactation progressed. The predisposing causes of the higher incidence in treatment H could have been the higher concentrate: forage ratio, the greater daily metabolizable energy intake or the greater daily crude protein intake. For treatments L and H, mean milk yields were 20·5, 23·7 kg/day; milk fat 41·7, 39·0 g/kg; milk protein 31·4, 32·0 g/kg; live-weight change -0·12, +0·11 kg/day; and condition score 2·04, 2·18.