Combination of Multi-Strain Bacillus Spp. Direct-Fed Microbial and a Protease Enzyme Improved Wean-to-Finish Pig Performance - a Commercial Scale Evaluation

A trial was carried out to evaluate the effect of a multi-strain Bacillus spp. direct-feed microbial (DFM) in combination with a protease on growth performance and death loss of wean-finish pigs fed corn/soybean meal type diets under commercial conditions. Two treatments were tested (18 replicates per treatment and 31 pigs per replicate): 1) negative control (NC), and 2) NC + Bacillus-based DFM (Danisco Animal Nutrition, Marlborough, UK) and a Bacillus subtilis protease (Danisco Animal Nutrition, Marlborough, UK). A corn/SBM/DDGs based NC diet was formulated to meet the nutrient requirements (NRC, 2012) with the exception of net energy which was reduced by 80, 25 and 15 kcal/kg in nursery (d 0-48), grower (d 48-104) and finisher (d 104-132), respectively. The DFM supplied three strains of Bacillus in equal proportions to provide 1.5 x 10⁵ cfu/g. The protease preparation supplied 5000 U/kg. All pigs in the trial were fed the mash diet with ad lib. access from weaning (d 0 post-weaning, BW=6.00±0.33 kg) to finish (d 132). Both diets were supplemented with 750 FTU/kg Buttiauxella sp. phytase. Performance, including body weight and feed intake by pen, was measured on d 0 and every subsequent 28 days until the end of the trial. Over the entire growth period, liveability was 87.5% in pigs fed NC and 89.9% in pigs fed NC+DFM+protease. Overall FCR (d 0-132) of pigs fed DFM+protease diet was 6 percentage points lower (2.38 vs. 2.43 g/g, P<0.01), with numerically greater ADG (794 vs. 777 g/d, P>0.05) and ADFI (1909 vs. 1891 g/d, P>0.05) than those fed NC treatment. Responses of pigs to DFM+protease inclusion differed depending on growth phase. The ADG and ADFI were similar between pigs fed NC and NC+DFM+protease diets during nursery (average, 528 g/d) and grower (average, 979 g/d) phases (P>0.05). As a result, FCR was not affected by diet treatments, with an average of 1.54 and 2.39 g/g for nursery and grower, respectively (P>0.05). During finisher phase, even though there were only numerical improvements in ADG (874 vs. 821 g/d; P=0.07) and ADFI (2926 vs. 2793 g/d; P=0.07) due to DFM+protease inclusion, the resulting FCR was 15 percentage points lower as compared to those fed NC only diet (3.26 vs. 3.41 g/g, P<0.01). In conclusion, the combination of a multi-strain Bacillus spp. DFM and a protease improved FCR of pigs fed reduced energy diet, which was most effective during the finisher phase.