THE INFLUENCE OF COMPLEX CARBOHYDRATES ON SALMONELLA-TYPHIMURIUM COLONIZATION, PH, AND DENSITY OF BROILER CECA

Salmonella typhimurium colonization, pH, and density of ceca were meas ured in 3-, 5-, and 6-wk-old broilers fed either a control ration or r ations with added fructooligosaccharides (FOS) or lactose derivatives (LD). The purpose was to compare dietary crude FOS from Jerusalem arti chokes with refined FOS and two LD for ability to reduce Salmonella co lonization as determined by semi-quantitative procedures. Chicks were challenged commencing at 5 d, by exposure to chicks orally infected wi th S. typhimurium. With the exception of chicks fed elude FOS, the hig h prevalence of Salmonella infection at 3 wk declined as chicks aged. At 6 wk, broilers fed crude FOS had higher Salmonella counts than all other broiler groups, whereas broilers fed refined FOS had lower infec tions than control broilers. The decline of Salmonella infection of br oilers fed either refined FOS or LD ceased after dietary additives wer e discontinued at 5 wk of age. At 6 wk, infection rates of the latter groups were at least as high as those of control broilers. Both FOS an d LD reduced cecal pH and density. Broilers fed the control ration had higher pH at 5 and 6 wk and higher cecal densities at 3 and 5 wk than those of broilers fed rations containing 5% (wt/wt) carbohydrates. Tr eatment differences for cecal pH and density disappeared within 1 wk o f withdrawal of carbohydrates from 5-wk-old broilers. No consistent ef fect of cecal pH and density on Salmonella infection was observed. Den sity was dependent on cecal volume, and at 6 wk of age, on broiler siz e.