The effect of disinfectants on the density of coliforms in sawdust bedding [Contamination of teat ends of cows]

Sawdust bedding in pens housing 6 cows was treated twice at an interval of 7 days with orthophenylphenol (1 gal/600 ft2 of a 1:128 dilution on day 1 and 3 gal/600 ft2 of a 1:3 dilution on day 8), slaked lime (8 lb/100 ft2), or paraformaldehyde (14.5 g/yd2 as a 5% suspension). Bedding samples were examined on days 1, 2, 5, 8, 9, 12 and 15 for total bacterial counts (TBC) and coliform counts. Teat swabs collected on the same days were examined for coliforms. TBC, coliform counts and moisture content were all reduced in bedding treated with slaked lime or paraformaldehyde. All three treatments increased the pH of the bedding. Coliform contamination of teat ends was reduced by slaked lime and paraformaldehyde treatments. Slaked lime is preferred because of ease of application and it is less likely to injure cattle or workers.