THE EFFECT OF FEEDING VARIOUS LEVELS OF BIFIDOBACTERIUM-GLOBOSUM-A ON THE PERFORMANCE, GASTROINTESTINAL MEASUREMENTS, AND IMMUNITY OF WEANLING PIGS AND ON THE PERFORMANCE AND CARCASS MEASUREMENTS OF GROWING-FINISHING PIGS

Four trials using 312 weanling pigs (average initial weight, 7.2 kg) were conducted to examine the effect of Bifidobacterium globosum A (BGA) on the growth performance, scour scores, humoral and cell-mediated immune response, and pH and chloride ion concentration (CIC) of feces and gastrointestinal tract contents of pigs. Dietary treatments were 0, 5.0 x 10(4), 6.7 x 10(6), and 7.5 x 10(8) colony forming units (cfu) of BGA/d in Trial 1 and 0, 6.0 x 10(4), 5.0 x 10(5), and 5.0 x 10(6) cfu/d in Trials 2 through 4. Pigs fed the low or medium levels of supplemental BGA had a greater ADG (P < .05) than control pigs throughout Trial 1, whereas ADG was quadratically increased (P < .05) for the low or medium levels only during wk 3 to 5 for the pooled data for Trials 2, 3, and 4. The primary effect of dietary BGA additions on ADFI was a quadratic increase during wk 3 to 5 for Trial 1 (P < .05) and for the pooled data of Trials 2 through 4 (P < .10). Gain:feed ratios were generally unaffected by addition of BGA. Both ADFI and ADG tended to be decreased (P < .10) at the highest level of BGA in all trials. Scouring was not severe in any of the trials and was not consistently affected by feeding BGA. The pH and CIC of gastrointestinal contents or feces were not influenced by the feeding of BGA. Feeding of BGA did not influence cell-mediated immunity as measured by an intradermal injection of phytohemagglutinin or humoral immune response to sheep red blood cells (SRBC), except for a positive linear (P < .10) secondary response to injected SRBC in Trial 2. The immune response was generally lowest for controls when ovalbumin was injected without adjuvant but was highest for controls when ovalbumin was injected with adjuvant. The feeding of BGA from weaning to market weight in Trial 3 (n = 80) did not influence performance, estimated backfat thickness, or longissimus muscle area of growing-finishing swine. In summary, the feeding of BGA at low and medium levels tended to improve weight gain and feed intake with no consistent effect on feed efficiency, scour scores, fecal or gastrointestinal pH and CIC, or humoral and cell-mediated immune response.