Comparative Effects of Two Bacillus-based Direct-fed Microbial Products on Nursery Pig Growth Performance

Direct-fed microbials (DFM) are commonly included in swine diets to support gut health, combat enteric pathogens, and promote growth. The effects of Bacillus-based direct-fed microbials have been documented many times. Among commercially available Bacillus-based DFMs, BioPlus® 2B (Novonesis) and Visano® Nursery (United Animal Health) are commonly used to improve nursery health and performance. This trial was conducted to further evaluate the impact of BioPlus® 2B and Visano® Nursery on nursery pig growth performance. Pigs (n = 741; PIC 800 × PIC 1050; 22 ± 1.91 d) were blocked by sex and wean weight (6.36 ± 1.15 kg) and individually assigned to pens of 17-18 pigs/pen with similar BW pigs housed together (14 replicate pens/treatment group). Pigs were assigned to 1) Negative control diet (no DFM; NC), 2) NC + 0.5 kg/MT Visano® Nursery (VN), or 3) NC + 0.5 kg/MT BioPlus® 2B (B2B). Test ingredients were added at the expense of corn. Diets were fed for the 42-d trial duration in three phases (phase 1 = 10 d; phase 2 = 11 d; phase 3 = 21 d). Pens were weighed and feed disappearance measured at days 10, 21, and 42. Data were analyzed using the Mixed (performance) and NPar1Way (morbidity/mortality) procedures of SAS, with treatment as main effect and replicate as random effect. At day 21, pigs fed VN had increased body weight (BW) compared to NC (0.43 kg; P = 0.003) with B2B BW intermediate to the other two treatments. During the first 21 days, both VN and B2B increased ADG (11.76 and 5.88%, respectively; P = 0.002), and ADFI (8.33 and 4.17%, respectively; P = 0.002), and numerically improved G:F (4.29 and 1.43%, respectively; P = 0.111) compared to NC. BW at day 42 was numerically increased for both VN and B2B (0.63 and 0.20 kg, respectively; P = 0.180) compared to NC, due to numerically improved cumulative ADG (5.41 and 2.70%, respectively, vs. NC; P = 0.142). A tendency for increased cumulative ADFI (5.56% vs. NC, P = 0.089) was observed for VN. Overall mortality was low (0.67%) with no differences observed between treatments. Feeding a Bacillus-based DFM product to nursery pigs can improve ADG and BW throughout the nursery period.