Salmonella in Swine Feed and Feed Ingredients: A Review
The presence of the salmonellae as contaminants of animal feeds and feed ingredients has been recognized for over 40 years. In his extensive review of Salmonella in poultry feeds, Williams (1981) traced the first reports of finding Salmonella in feed in the U.S. and Great Britain back to 1948. Attention was first focused on animal by-products used in feeds such as meat and bone meal, fishmeal, and meat scraps, when it was found that feed made from such products contaminated by Salmonella had the potential of introducing and spreading salmonellosis to domestic animals (Muller, 1952). As early as 1954, Denmark required that all imported meat and bone meal was to be resterilized before sale due to an association between the occurrence of Salmonella in poultry and the importation of large quantities of meat, bone, blood, and fish meal and bones (Muller, 1957). Vegetable products and finished feeds, both meal and pellets were soon found to harbor the bacteria as well (Grumbles and Flowers, 1961).