Effect of lincomycin on prevalence, duration, and quantity of Salmonella typhimurium excreted by swine.

Thirty-one swine (7.5 kg live wt) were fed diets which contained 0 or 110 mg of lincomycin/kg. These pigs were then inoculated with a nalidixic acid-resistant strain of Salmonella typhimurium and monitored for 56 days thereafter to determine (1) the quantity of S typhimurium shed in the feces, (2) the length of time the organism was shed, and (3) the number of swine which shed the organism for the 56-day period after exposure. Addition of lincomycin to diets did not alter these 3 criteria from those obtained in S typhimurium-exposed nontreated swine when results for nontreated and treated swine were compared. In addition, the sensitivity of the S typhimurium strain to 8 antibiotics, 1 nitrofuran, and 1 sulfonamide was not affected by in vivo exposure to lincomycin for 39 days. Lincomycin did not produce adverse effects in either inoculated or noninoculated pigs.