INFLUENCE OF WHEY AND PROBIOTIC-SUPPLEMENTED WITHDRAWAL FEED ON THE RETENTION OF SALMONELLA INTUBATED INTO MARKET AGE BROILERS

Broilers (6 wk of age) were crop-intubated with a nalidixic acid-resistant strain of Salmonella typhimurium and given four withdrawal feeds: 1) control feed (corn and soybean meal base, 18% CP and 3,200 kcal ME/kg); 2) control plus 5% whey (61% lactose); 3) control plus probiotic (6.8 x 10(6) cfu of Bifidobacterium pseudolongum, Bifidobacterium thermophilium, and Lactobacillus acidophilus); and 4) control plus 5% whey plus probiotic. In Experiment 1, male broilers received 9.8 x 10(7) cfu of S. typhimurium per bird midway through a 20-h fast. The withdrawal feeds were continuously offered through a subsequent period of 6 to 7 days. Live performance of broilers during this time was similar among treatments. Ceca from birds consuming whey were significantly (P less than .05) increased in weight and distended with gas. Recovery of S. typhimurium from the ceca was low with all treatments, and the effects of whey or probiotic at reducing the organism could not be determined. In Experiment 2, female broilers received the same four experimental feeds for 48 h. Salmonella typhimurium was intubated 24 h after feed access (1.2 x 10(7) cfu per bird). Again, no differences (P greater than .05) in performance occurred, but the inclusion of whey led to increased cecal weight and size (P less than .05). Large numbers of S. typhimurium were recovered from the ceca 24 h after intubation, but the levels were similar among treatments. Whey and probiotic in the withdrawal feed did not appear to affect the Salmonella level in ceca when the organism was consumed prior to marketing.