The effect of feeding non-heat treated, non-pelleted feed compared to feeding pelleted, heat-treated feed on the Salmonella-prevalence of finishing pigs

Abstract

The effect of feeding different grinding levels and the effect of pelleted feed were tested on the salmonella-prevalence of finishing pigs. The feed was given to pigs in the weight interval from 27 to 99 kilos. The pigs were given dry feed ad libitum. The experiment comprised approximately 1,000 finishers divided into four groups. In the test both meal and pelleted feed were used. The conclusions are: I. Meal feed gave a significantly lower salmonella level than heat-treated, pelleted feed. 2. The number of salmonella positive pigs were lower when using coarse grinding, but the effect of grinding level was not significant (P=0.08). 3. Pelleted feed gave a significantly higher production economy compared to meal feed - mainly due to a better feed conversion. 4. The content of starch in manure was affected by both grinding level and the pelleting process. Analyses showed approximately 25 times more starch in manure when using coarse grinded meal feed compared to fine grinded pelleted feed. 5. Pelleted feed gave a significantly poorer gastric health than meal feed. 6. The gastric health was considerably better when using coarse grinded meal feed compared to the other groups tested. It has been concluded that use of coarse grinded meal feed gives a better protection against salmonella, but the poorest economy. The other way round very fine grinded pelleted meal feed gives the best production economy by an unacceptable high level of gastric changes and salmonella prevalence.