Effect of supplementation of Bacillus spp. strains with high enzymatic activities on energy efficiency and growth performance in grow-finish pigs fed corn-soybean meal based diet

Abstract Text: The effect of 3 Bacillus spp. strains specifically selected based on their high enzyme producing ability on energy efficiency and growth performance was evaluated in grow-finish pigs fed corn-soybean meal based diets. Fifty-six pigs [(Yorkshire × Landrace) × Duroc] with initial BW 28.50 ± 1.50 kg were used in the 12 wk study period. Pigs were blocked by BW and sex and randomly assigned to two dietary treatments with 4 pigs/pen and 7 replicate pens/treatment. The diets were formulated to meet the nutritional requirements of the pigs and contained corn, SBM, corn DDGS (15-20%) and wheat middlings (1-7%). The ME and SID Lys in the basal starter, grower and finisher diets were 3241.0, 3234.0 and 3249.0 kcal/kg, and 0.91, 0.75 and 0.61%, respectively. The Bacillus product was added at 0 (Control) or 500 g/MT of feed in the tested diet (BAC, 3 × 10⁸ CFU per gram). All diets contained 500 FTU/kg of Buttiauxella spp. phytase expressed in Trichoderma reesei. Pigs were allowed to consume the assigned experimental diet for the entire study period. Pigs and feed were weighed, and ADG, ADFI and G:F were determined at the start and completion of each study phase. Data were analyzed using the Proc mixed procedure in SAS. Overall, ADG was not affected by BAC supplementation (1.04 vs 1.03 kg/d; P>0.05). However, compared to Control pigs, pigs fed the BAC diet consumed less feed (P<0.05; 2.92 vs 2.73 kg/d). Compared with Control, BAC pigs had improved (P < 0.05) G:F ratio during Phase 2, 3, and the overall period; the overall G:F ratios were 0.355 and 0.377 for Control and BAC pigs, respectively. Bacillus spp. supplementation improved (P<0.05) energy efficiency during phase 2, 3, and overall study period by 5.2, 8.3 and 6.0%, respectively. In conclusion, supplementation of a combination of the 3 Bacillus strains with high enzymatic activities allowed grow-finish pigs to efficiently utilize energy in feed containing cereal by-products and subsequently improve feed efficiency.  

Bacillus supplementation improves pig performance

Parameter	Control	BAC	SEM	P value
Overall ADFI, kg/d	2.92	2.73	0.050	0.02
Overall ADG, kg/d	1.036	1.027	0.016	0.73
Overall gain to feed	0.355	0.377	0.004	<0.01
Feed cost per kg gain, $/kg gain	0.810	0.766	0.006	<0.01
Income over feed cost, $	110.90	114.80	1.138	0.06
Average feed cost, $/MT	288.60	290.10	-	-
Energy efficiency (Mcal/kg gain)	9.14	8.59	0.070	<0.01

Keywords: Pigs, Bacillus, energy efficiency