Abstract The objective of these two experiments was to examine two different proprietary probiotic blends in comparison to either no probiotic or another commercially available probiotic blend on growth performance and fecal consistency in nursery pigs raised under low sanitary conditions. In Exp. 1 and Exp. 2, a combined total of 2,304 maternal barrows (PIC Camborough®; initial BW 5.5 kg Exp. 1 and 5.7 kg Exp. 2) were used in a 40-d trial and placed in unwashed pens with 18 pigs/pen. Pens were blocked by initial BW and randomly allotted to 1 of 4 dietary treatments with 16 replicates per treatment. Treatments in both Exp. 1 T2: commercially available blend of Bacillus subtilis and Bacillus licheniformis; T3: proprietary Bacillus subtilis and Bacillus licheniformis blend (Devenish Nutrition, Fairmont, MN); and T4: proprietary Bacillus subtilis and Bacillus amyloliquefaciens blend (Devenish Nutrition, Fairmont, MN). All probiotic blends were fed at a total dietary concentration of 1.1 x 106 cfu/g over the entire 40-d test period. Zinc oxide was supplemented to provide a dietary zinc concentration of 3,000 ppm for the first week post-weaning and 2,000 ppm for the second two weeks post-weaning. In Exp.2, fecal scores were examined at 7 days post-weaning. Feces were assigned a categorical variable with fecal scores 1 and 2 considered as “no diarrhea”, while fecal scores 3 and 4 were considered as “diarrhea”. Growth performance data were analyzed as a randomized complete block design using PROC MIXED procedure of SAS. Injectable medications and mortality + morbidity data were analyzed using the PROC GLIMMIX procedure in SAS. In Exp. 1, T2, T3, and T4 had heavier final BW and improved cumulative ADG compared with T1 (P 0.01) and T4 had a heavier final BW and improved cumulative ADG compared with T2 (P 0.05). Cumulative GF was improved for T2, T3, and T4 compared to T1 (P 0.01), while T3 and T4 had improved cumulative GF compared with T2 (P 0.01). Probiotic supplementation resulted in an average ROI of 57:1 and T4 had a 2.7 times greater ROI than T2. In Exp. 2, no differences were observed in growth performance. T2 and T3 had a greater proportion of pigs with a fecal score 1 and 2 compared to T1 (P 0.1) with T4 being intermediary. In Exp. 1, Bacillus-based probiotic supplementation resulted in positive effects on growth performance and economic return, with notable improvements in final BW, ADG and GF. Pigs fed T4 had the most pronounced effects, outperforming T2 in Final BW, cumulative ADG and GF. In Exp. 2, improvement in the fecal consistency of pigs fed Bacillus-based probiotics was observed.
Lutz et al. (Wed,) studied this question.