Effects of a multi-strain Bacillus spp. direct-fed microbial and a protease enzyme on growth performance, nutrient digestibility, blood characteristics, fecal microbiota, and noxious gas emissions of grower pigs fed corn-soybean-meal-based diets—A meta-analysis1

Abstract

Three studies involving 352 grower pigs were conducted to determine the effects of dietary supplementation with multistrain spp. direct-fed microbial (DFM) and protease, alone or in combination, on growth performance, nutrient digestibility, blood characteristics, fecal microbiota, and noxious gas emissions, and to use a meta-analysis to increase the reliability of the findings. Treatments ( = 4) were set up as a 2 × 2 factorial design with 2 levels of protease (0 and 5.000/6.000 units/kilogram of feed [U/KG]) and 2 levels of DFM (0 and 1.5 × 10 colony forming units/gram of feed [CFU/G]), plus a protease + DFM combination. Pigs were housed in groups of 3 or 4/pen with 8 replicate pens/treatment. Experimental diets were fed for 42 d and feed intake and BW were measured weekly. Fecal samples were collected at d 42 and analyzed to determine apparent total tract digestibility (ATTD). Fecal counts of and coliforms, and noxious gas emissions were measured. Blood samples were taken by anterior vena cava puncture to measure blood urea nitrogen (BUN) and creatinine. Data from the 3 studies were pooled and analyzed as a 2 × 2 factorial using the Fit Model platform of JMP 11 (SAS Inst. Inc., Cary, NC). Means separation was determined using Tukey's honest significant difference test. The main effect of protease and DFM increased: BW at 42 d, overall ADG, and overall G:F compared to the control ( < 0.04). There were no interactions between protease and DFM ( > 0.05); however, the protease + DFM combination was the only treatment to improve ADG and G:F in all phases compared to the control. The main effect of protease increased ATTD of DM, nitrogen (N), and ADF ( < 0.04). The main effect of DFM increased ATTD of DM, N, GE, DE, ADF, and fat ( < 0.02). There was a trend for an interaction between protease and DFM for ATTD of GE and DE ( < 0.08) because the protease + DFM combination increased energy digestibility more than the additive effects of the protease and DFM alone. The main effects of protease and DFM decreased fecal ammonia emissions ( < 0.01), but the protease + DFM combination was the only treatment to decrease ammonia emissions compared to the control. In conclusion, the main effects of protease and DFM improved growth performance and nutrient digestibility compared to the control, but there was a greater additive effect of the protease + DFM combination on energy and N digestibility.

Effects of Bacillus subtilis PB6 and/or chromium propionate supplementation on clinical health, growth performance, and carcass traits of high-risk cattle during the feedlot receiving and finishing periods1

“…A similar study by Wilson et al (2019) did not observe CST improve BW, ADG, or DMI during either the receiving or finishing periods; however, CST-supplemented cattle tended to have improved feed efficiency over both feeding periods. Bacillus subtilis PB6 DFM alone and in combination with other Bacillus organism DFM have been reported to improve growth performance and gut integrity of nursery pigs ( Cai et al, 2015 ; Brooks and Kim, 2017 ; Payling et al, 2017 ) and have anticlostridial activity against the causative pathogen in necrotic enteritis of poultry ( Teo and Tan, 2005 ). Given the limited existing literature in beef cattle, further research in supplementing B. subtilis PB6 is warranted.…”

Effects of dietary mixture of protease and probiotics on growth performance, blood constituents, and carcass characteristics of growing-finishing pigs

“…The MULTI did not affect growth performance of growing-finishing pigs during the overall experimental period (Table 2). Most previous studies showed that pigs fed diets with dietary protease or probiotics had higher growth rate of pigs than those fed diets without dietary protease or probiotics [2,7,9,25–28]. However, some research reported that addition of dietary protease or probiotics in pig diets did not affect growth rate of pigs [29,30].…”

“…Addition of protease in pig diets is a way to improve protein utilization. The main mechanism of dietary protease is to increase the hydrolysis of proteins in the small intestine [1], resulting in liberating amino acids and peptides for utilization and absorption by pigs [2]. Previous studies showed that dietary protease in pig diets decreased the nitrogen (N) pollution by enhancing N digestibility of pigs and reducing N excretion of pigs [3–5].…”

“…Recently, the swine industry has been trying to make some dietary mixtures using enzymes and/or probiotics to have their beneficial effects all together. There are some studies to verify the effects of dietary mixtures of enzymes and probiotics [2,10,23,24], but the experimental evidence for their positive or negative effects in pig diets is limited. Therefore, the objective of this study was to investigate effects of dietary mixture of protease and probiotics on growth performance, blood constituents, and carcass characteristics of growing-finishing pigs.…”

Effects of different Bacillus licheniformis and Bacillus subtilis ratios on nutrient digestibility, fecal microflora, and gas emissions of growing pigs

“…Probiotic supplementation has been used to overcome the above-mentioned problems [ 12 - 14 ]. Probiotics can accelerate the breakdown of the carbohydrates which are resistant to digestion, thus it encourages the use of dietary fiber as a prebiotic substance, and promotes the substrate availability of colonic microbiota, and its population [ 15 ]. It has been extensively studied probiotics are able to support growth performance, gut micro-environment, feed utilization efficiency, immune system, and gastrointestinal tract (GIT) diseases for farm animals [ 16 , 17 ].…”