PROBIOTIC-ANTIBIOTIC INTERACTIONS IN PERFORMANCE, INTESTINAL FERMENTATION AND MANURE PROPERTIES OF PIGLETS USING A BACILLUS (BACILLUS-LICHENIFORMIS BACILLUS-SUBTILIS) PREPARATION AND CARBADOX

64 weaned piglets housed in 16 cages of 2 females and 2 castrated male s each were subjected to 1 of 4 dietary treatments after 1 week of ada ptation: 1) no feed additive, 2) 50 ppm of Carbadox, 3) 400 ppm of Bio Plus 2B (Bacillus licheniformis and Bacillus subtilis), 4) both additi ves together. In the first 3 weeks, prestarter diets were fed, and, in the subsequent 3 weeks, starter diets were provided. Apart from weekl y data on performance, out of each cage fecal samples were drawn in we eks 1, 3 and 6 and complete excreta were collected in week 5 of the ex periment. From these samples, data on carbohydrate fermentation by gut bacteria, on fecal and manure nitrogen composition and on N and P bal ance were otained. With both additives alone, live-weight gain was non -significantly enhanced by on average 2.7 %. Performance was 6.5 % hig her as in the control group if the supplements were provided together (significant in weeks 3 and 4) which indicates an additive reaction. F eed conversion efficiency was only enhanced in the prestarter period b y both supplements together. With the additives, body protein retentio n was slightly and phosphorus retention was significantly increased as obtained in week 5. Overall phosphorus loss during rearing could be e stimated to be lower by 3 % to 8 % with each additive. The additives h ad no effect on the digestibility of crude fiber and N-free extract, h owever with both additives together significantly higher quantities of non-starch-non-sugar carbohydrates were fermented in the gut as compa red to the group receiving only the probiotic. The effects of the supp lements on fecal and manure nitrogen composition were small and the di fferences in P content of manure were not significant.