EFFECT OF LYOPHILIZATION IN SUCROSE PLUS DEXTRAN AND REHYDRATION IN THIOGLYCOLATE BROTH ON PERFORMANCE OF COMPETITIVE-EXCLUSION CULTURES INBROILER CHICKS

Cecal bacteria grown under continuous-flow anaerobic conditions were l yophilized in skim milk (SM), Reagent 20 (R-20; sucrose and bovine ser um albumin fraction V), or sucrose plus dextran (SDx), rehydrated in d rinking water or thioglycollate-beef broth (TGB), and compared with fr esh broth culture for control of Salmonella typhimurium enteric coloni zation in broiler chicks. All groups were challenged on Day 3 with 10( 4) cfu of S. typhimurium per chick. Mean Salmonella colony-forming uni ts in cecal contents of groups provided lyophilized cultures rehydrate d in TGB were not different from those in groups provided fresh broth culture and were reduced (P <.05) compared with controls at 10 d of ag e. Likewise, groups treated with the cultures lyophilized in R-20 and SDx and rehydrated in TGB had fewer Salmonella than similar groups tre ated with culture rehydrated in water. The results of this study indic ated that the culture was as effective when lyophilized in SDx as it w as when lyophilized in SM or R-20; culture lyophilized in SDx, SM, or R-20 and rehydrated in TGB was more effective than when it was rehydra ted in water for the reduction of Salmonella colonization in broiler c hicks.