[Effect of footbaths on the control of foot lameness in dairy cattle]

ABSTRACT

To determine the effect of footbaths in control of foot lameness a follow-up study was carried out in 23 dairies in the vicinity of Tehran during a 4 years period early in 1989. These dairies had had a recognised foot lameness problem and most of them had not used a regular footbaths and had kept records of lameness cases for at least 6 months before the commencement of the study. In all dairies the days of spring and fall seasons were considered in each of the successive years as proper time for footbathing and a walk-through footbaths was sited near the exit to the milking parlour. Formalin and copper sulfate were used at 5 and 3 percent solution as disinfectant/astringent ingredients respectively. The cows were walked through the bath after each of three successive milking per day and the bath solution was refreshed every two to four days interval based on the population size of dairies under study. In 14 dairies which hoof ulcer was more prevalent, recommendation was made as follows formalin in 3 dairies, copper sulfate in 6 dairies and both ingredients with defined time interval in 5 dairies. In 9 dairies which lameness was confirmed to be associated with digital dermatitis [known as mortellaro disease], 4 dairies were advised to use formalin [test] and copper sulfate was recommended in 3 dairies [Positive control] and in two dairies cold water footbath was suggested as negative control. This procedure was repeated for the entire period of the study [March 1989 through March 1992]. Annual mean prevalence rate of lameness in each year was calculated and compared statistically with that in the year before on each of the group dairies which specific footbath material was advocated, using paired student " t " test. Results of tins field study suggested that spring and fall footbathing containing 5% formalin together with 3% copper sulfate could be beneficial in reducing the prevalence of lameness due to sub-clinical laminitis and related injuries such as white line, hoof ulcer and heel horn erosion. But formalin as well as copper sulfate cannot be expected to be wholly effective in control of digital dermatitis. In this regard the new cases and/or relapsing the case should be anticipated