Effects of a Bacillus -based probiotic and dietary energy content on the performance and nutrient digestibility of wean to finish pigs

Effect of Bacillus amyloliquefaciens supplementation on intramuscular fat accumulation and meat quality in finishing pigs

OBJECTIVE

This study evaluated the potential of Bacillus amyloliquefaciens to improve growth performance and meat quality in finishing pigs.

METHODS

Thirty-two female Landrace×Duroc pigs, 21 weeks old with initial body weight 77.45±3.29 kg, were divided into two groups: a control group (basal diet) and a probiotic group (basal diet with Bacillus amyloliquefaciens at 1×109 CFU/kg). Body weight and average daily gain (ADG) were recorded at the start and at fortnight intervals for a 56-d feeding trial. At the end of the experiment, carcass traits, meat quality and intramuscular fat related gene expression of longissimus dorsi muscle were analyzed.

RESULTS

The probiotic group showed significantly higher final body weight and D0-D56 ADG (p<0.05). Additionally, the probiotic group had greater carcass weight, back fat thickness and marbling score (p<0.05), while the lean meat percentage remained unchanged. Meat quality analysis revealed that the probiotic group had a higher b* value (5.47) (p<0.05), and a lower shear value (p<0.001), but there was no effect on the a* value and water holding capacity. Moreover, probiotic treatment increased the gene expression of fatty acid uptake and regulators, such as lipoprotein lipase (LPL), cluster of differentiation 36 (CD36), and solute carrier family 27 member 1 (SLC27A1) (p<0.05).

CONCLUSION

Our findings suggest that the supplementation of Bacillus amyloliquefaciens not only enhanced growth performance and carcass weight in finishing pigs, but also improved marbling and tenderness in the longissimus dorsi muscle through the upregulation of lipogenic-genes related to fat accumulation. This indicates its potential as feed additive to enhance pork quality.

Live Multi-Strain Probiotics Enhance Growth Performance by Regulating Intestinal Morphology and Microbiome Population in Weaning Piglets

The effects of different forms of multi-strain probiotics on weaning piglets are limitedly addressed. Thus, this study investigated the effects of live or inanimate multi-strain probiotics comprising Lactobacillus plantarum, Streptococcus thermophilus, and Bacillus subtilis on growth performance, intestinal morphology, fecal microbiota, short-chain fatty acids, and intestinal gene expression of weaning piglets. A total of 160 weaning piglets (4 weeks old) were randomly allocated into four treatments (CON: basal diet; AB: basal diet with 110 ppm and 66 ppm colistin in the weaning and nursery phases, respectively; LP: basal diet with 2.0 × 109 CFU/kg live probiotics; and IP: basal diet with 2.0 × 109 CFU/kg inanimate probiotics). Piglets fed with LP had significantly lower FCR compared to those of the CON and IP groups in week 4 to week 8 (p < 0.05). Moreover, the LP group had significantly higher villus height (VH) compared with AB at week 6, lower crypt depth (CD) compared with IP, and higher VH/CD ratio compared to other treatments at week 10 (p < 0.05), which indicate healthier intestinal morphology. Probiotic treatments (LP and IP) increased Bifidobacterium population compared to CON at week 6 and lowered Enterobacteriaceae at week 6 and week 10 (p < 0.05). Regarding gene expressions of intestinal integrity, LP showed significantly higher TFF3 expression compared with CON and AB at week 6 and compared with other treatments in jejunum at week 10 (p < 0.05). IP treatment had significantly higher MUC2 expression compared to other treatments at week 6 and week 10 (p < 0.05). Overall, live multi-strain probiotics improved growth efficiency by enhancing gut integrity and microbiome balance, making them a potential antibiotic alternative to ameliorate weaning stress and promote productive performance in weaning piglets.

Differential growth enhancement followed by notable microbiota modulation in growing-finishing pigs by Bacillus subtilis strains ps4060, ps4100, and a 50:50 strain mixture

A 50:50 blend of two Bacillus subtilis strains positively impacted the productivity of finishing pigs. Given this observed effect, we hypothesized that each strain has distinct effects on weight gain and their influence on gut microbiota. In a 16-week test, 160 pigs were divided into four groups: basal diet, B. subtilis ps4100, B. subtilis ps4060, and 50:50 mixture supplemented. Subsequently, we compared body weight and fecal microbiota. Among the supplements, ps4100, ps4060, and the 50:50 mix yielded respective average daily weight gains (ADG) of 3.6%, 4.6%, and 3.9% by the 6th week. The weight difference was maintained through the 16th week. At the 11th week, the difference in α-diversity among the fecal microbiota was marginal, and 17 of 229 genera showed differential abundance between the control and either of the treatment groups. A total of 12 of the 17 genera, including Lactobacillus, showed differential abundance between the ps4100 and ps4060-fed groups, and only Eubacterium consistently decreased in abundance in both the ps4100 and ps4060 groups. In comparison, microbial diversity was significantly different at the 16th week (p < 0.05), with 96 out of 229 genera exhibiting differential abundance. A total of 42 of the 96 genera exhibited similar patterns in both the ps4100 and ps4060 groups compared to the control group. Additionally, 236 of 687 microbial enzymes with differential abundance deduced from 16S rRNA reads showed similar differential abundance in both groups compared to the control group. We concluded that the overall microbial balance, rather than the dominance or significant decrease of a few specific genera, likely caused the enhanced ADG until the 11th week. Substantial changes in microbiota manifested at the 16th week did not cause dramatically increased ADG but were a consequence of weight gain and could positively affect animal physiology and health afterward.

Effects of single and complex probiotics in growing-finishing pigs and swine compost

This study was conducted to supplement single and complex probiotics to investigate the effect on growing-finishing pigs and compost. In experiment 1, the 64 crossbred ([Landrace × Yorkshire] × Duroc) pigs with an initial body weight of 18.75 ± 0.33 kg and a birth of 63 days were assigned to a completely randomized four treatment groups based on the initial body weight (4 pigs in a pen with 4 replicate pens for each treatment). For 13 weeks, the dietary treatments were provided: 1) Control (CON; basal diet), 2) T1 (CON + 0.2% Bacillus subtilis), 3) T2 (CON + 0.2% Saccharomyces cerevisiae), 4) T3 (CON + 0.2% Bacillus subtilis + 0.2% Saccharomyces cerevisiae). In experiment 2, the pig manure was obtained from Chungbuk National University (Cheongju, Korea) swine farm. For 12 weeks, the supplementary treatments were provided: 1) CON, non-additive compost; 2) T1, spray Bacillus subtilis 10 g per 3.306 m2; 3) T2, spray Bacillus subtilis 40 g per 3.306 m2; 4) T3, spray Saccharomyces cerevisiae 10 g per 3.306 m2; 5) T4: spray Saccharomyces cerevisiae 40 g per 3.306 m2; 6) T5, spray Bacillus subtilis 5 g + Saccharomyces cerevisiae 5 g per 3.306 m2; 7) T6, spray Saccharomyces subtilis 20 g + S. cerevisiae 20 g per 3.306 m2 and there were 6 replicates each treatment. In experiment 1, During the overall experimental period, T3 showed significantly improved (p < 0.05) feed conversion ratio and average daily gain compared to other groups. In average maturity score, T3 showed significantly higher (p < 0.05) than other groups. Supplementing complex probiotics group improved (p < 0.05) H2S emissions and fecal microflora compared to the non-supplementing group. In experiment 2, additive probiotics groups had no effect (p > 0.05) on moisture content than the non-additive group at 9 and 12 weeks. T6 showed a significantly improved (p < 0.05) average maturity score at all periods and ammonia emissions at 1 week and 4 weeks compared to other groups. In summary, supplementation complex probiotics induced positive effects on both pigs and compost.

Effects of single and complex probiotics in growing-finishing pigs and swine compost

This study was conducted to supplement single and complex probiotics to investigate the effect on growing-finishing pigs and compost. In experiment 1, the 64 crossbred ([Landrace × Yorkshire] × Duroc) pigs with an initial body weight of 18.75 ± 0.33 kg and a birth of 63 days were assigned to a completely randomized four treatment groups based on the initial body weight (4 pigs in a pen with 4 replicate pens for each treatment). For 13 weeks, the dietary treatments were provided: 1) Control (CON; basal diet), 2) T1 (CON + 0.2% Bacillus subtilis), 3) T2 (CON + 0.2% Saccharomyces cerevisiae), 4) T3 (CON + 0.2% Bacillus subtilis + 0.2% Saccharomyces cerevisiae). In experiment 2, the pig manure was obtained from Chungbuk National University (Cheongju, Korea) swine farm. For 12 weeks, the supplementary treatments were provided: 1) CON, non-additive compost; 2) T1, spray Bacillus subtilis 10 g per 3.306 m2; 3) T2, spray Bacillus subtilis 40 g per 3.306 m2; 4) T3, spray Saccharomyces cerevisiae 10 g per 3.306 m2; 5) T4: spray Saccharomyces cerevisiae 40 g per 3.306 m2; 6) T5, spray Bacillus subtilis 5 g + Saccharomyces cerevisiae 5 g per 3.306 m2; 7) T6, spray Saccharomyces subtilis 20 g + S. cerevisiae 20 g per 3.306 m2 and there were 6 replicates each treatment. In experiment 1, During the overall experimental period, T3 showed significantly improved (p < 0.05) feed conversion ratio and average daily gain compared to other groups. In average maturity score, T3 showed significantly higher (p < 0.05) than other groups. Supplementing complex probiotics group improved (p < 0.05) H2S emissions and fecal microflora compared to the non-supplementing group. In experiment 2, additive probiotics groups had no effect (p > 0.05) on moisture content than the non-additive group at 9 and 12 weeks. T6 showed a significantly improved (p < 0.05) average maturity score at all periods and ammonia emissions at 1 week and 4 weeks compared to other groups. In summary, supplementation complex probiotics induced positive effects on both pigs and compost.

Effect of a Multi-Species Direct-Fed Microbial on Growth Performance, Nutrient Digestibility, Intestinal Morphology and Colonic Volatile Fatty Acids in Weanling Pigs

The potentials of ABO replacer of ENZ and DFM on growth performance, AID, colonic VFAs, gut morphology, fecal score and diarrhea incidence were evaluated. We randomly assigned 120 piglets to four experimental diets that included: (1) control diet (CON), fed the basal ration; (2) ABO was added at 250 ppm of in-feed ABO; (3) ENZ was added at a rate of 3 kg/ton feed; (4) DFM was added with 50 × 106 cfu/g of Bacillus subtilis and 2 × 106 cfu/g of Lactobacillus spp. at a rate of 1.2 kg/ton feed. A complete randomized design used six pens per treatment with five pigs per pen. Pigs had ad libitum access to feed and water throughout the 6-week trial. Feed intake and BW were recorded on weeks 0, 2, 4 and 6, as well as fecal scores and diarrhea incidences (visually recorded and calculated). At weeks 2 and 4, a sub-sample of pigs (n = 6) was sacrificed for intestinal morphology, enzyme activity and VFAs. The results of the study demonstrated that DFM piglets showed increased final BW (3 kg) (p < 0.001) vs. CON. Likewise, ADG was positively affected by the incorporation of ABO, ENZ and DFM in the diets, with an average increase of 8 to 17% on ADG compared with CON (p < 0.001). The AID of gross energy, organic matter, CP and EAAs in piglets fed ENZ and DFM were significantly higher (p < 0.05) than those of CON and ABO at weeks 2 and 4. Inclusion of DFM increased intestinal morphology, enzymatic activities and propionic and butyric acid more than in pigs fed CON, ABO and ENZ (p < 0.05). The fecal score and diarrhea incidence generally decreased over time in pigs fed DFM (p < 0.05). These findings indicate that dietary supplementation with DFM has better effects at any period on growth performance, CP and AA digestibility and beneficially altered the intestinal health in weanling piglets.

The Effects of Microbial Additive Supplementation on Growth Performance, Blood Metabolites, Fecal Microflora, and Carcass Characteristics of Growing-Finishing Pigs

This study aimed to assess the effects of microbial additives that produce antimicrobial and digestive enzymes on the growth performance, blood metabolites, fecal microflora, and carcass characteristics of growing-finishing pigs. A total of 180 growing-finishing pigs (Landrace × Yorkshire × Duroc; mixed sex; 14 weeks of age; 58.0 ± 1.00 kg) were then assigned to one of three groups with three repetitions (20 pigs) per treatment for 60 days of adaptation and 7 days of collection. Dietary treatments included 0, 0.5, and 1.0% microbial additives in the basal diet. For growth performance, no significant differences in the initial and final weights were observed among the dietary microbial additive treatments, except for the average daily feed intake, average daily gain, and feed efficiency. In terms of blood metabolites and fecal microflora, immunoglobulin G (IgG), blood urea nitrogen, blood glucose, and fecal lactic acid bacteria count increased linearly, and fecal E. coli counts decreased linearly with increasing levels of microbial additives but not growth hormones and Salmonella. Carcass quality grade was improved by the microbial additive. In addition, carcass characteristics were not influenced by dietary microbial additives. In conclusion, dietary supplementation with 1.0% microbial additive improved average daily gain, feed efficiency, IgG content, and fecal microflora in growing-finishing pigs.

Bacillus genus industrial applications and innovation: First steps towards a circular bioeconomy

In recent decades, environmental concerns have directed several policies, investments, and production processes. The search for sustainable and eco-friendly strategies is constantly increasing to reduce petrochemical product utilization, fossil fuel pollution, waste generation, and other major ecological impacts. The concepts of circular economy, bioeconomy, and biorefinery are increasingly being applied to solve or reduce those problems, directing us towards a greener future. Within the biotechnology field, the Bacillus genus of bacteria presents extremely versatile microorganisms capable of producing a great variety of products with little to no dependency on petrochemicals. They are able to grow in different agro-industrial wastes and extreme conditions, resulting in healthy and environmentally friendly products, such as foods, feeds, probiotics, plant growth promoters, biocides, enzymes, and bioactive compounds. The objective of this review was to compile the variety of products that can be produced with Bacillus cells, using the concepts of biorefinery and circular economy as the scope to search for greener alternatives to each production method and providing market and bioeconomy ideas of global production. Although the genus is extensively used in industry, little information is available on its large-scale production, and there is little current data regarding bioeconomy and circular economy parameters for the bacteria. Therefore, as this work gathers several products' economic, production, and environmentally friendly use information, it can be addressed as one of the first steps towards those sustainable strategies. Additionally, an extensive patent search was conducted, focusing on products that contain or are produced by the Bacillus genus, providing an indication of global technology development and direction of the bacteria products. The Bacillus global market represented at least $18 billion in 2020, taking into account only the products addressed in this article, and at least 650 patent documents submitted per year since 2017, indicating this market's extreme importance. The data we provide in this article can be used as a base for further studies in bioeconomy and circular economy and show the genus is a promising candidate for a greener and more sustainable future.

Assessing the Probiotic Effects of Pediococcus pentosaceus CACC616 in Weaned Piglets

During weaning, piglets experience various stressor events that disrupt their gut microbiota and immune balance, decrease growth parameters, and increase mortality rates. In this study, we assessed the efficacy of Pediococcus pentosaceus CACC616 as a probiotic supplement. We characterized this strain and evaluated its effect on improving growth performance, modulating gut microbiota composition, and reducing noxious odor components in weaned piglets compared to a non-supplementary diet (control). During the 26-day period, 40 crossbred weaned piglets were randomly assigned to pens with 20 animals each in two groups: control and treatment groups with CACC616. On day 26, the treatment group exhibited a lower feed conversion ratio (FCR) and a significant alteration in gut microbial composition, correlating with improved growth parameters and gut health (p < 0.05). The treatment group also exhibited significantly reduced digestibility- and intestinal-environment-related noxious odor components (p < 0.05). The CACC616 strain effectively reduced pathogenic genera numbers, including Campylobacter, Mogibacterium, Escherichia-Shigella, and Desulfovibrio spp., with the treatment group exhibiting lower fecal calprotectin levels than the control group (p < 0.05). Overall, this study revealed that the functional probiotic CACC616 contributes to enhanced FCR and effectively modulates weaned piglets' inflammation and intestinal microbiota.

The Effect of a Bacillus-Based Probiotic on Sow and Piglet Performance in Two Production Cycles

The aim of this study was to assess the impact of Bacillus-based probiotic diets on reproduction performance, fecal scores, microflora, and economic factors in lactating sows and suckling piglets across two productive cycles. A total of 96 sows, reared in a continuous farrowing system for two full cycles, were divided into two groups: a control group and an experimental group. Sows were fed a basal diet without the probiotic or a diet supplemented with viable bacterial spores. At seven days of age, control group piglets were offered standard creep feed, whereas piglets in the experimental (probiotic) group received a diet containing the probiotic fed to their dams. Sows receiving probiotic-supplemented diets were characterized by significantly higher (p ≤ 0.05) average daily feed intake in lactation, lower (p ≤ 0.01) body weight (BW) loss during lactation, and reduced loss of backfat thickness as well as higher body condition score after lactation. Dietary probiotic supplementation increased (p ≤ 0.01) birth weight, total creep feed consumption, litter weight gain, and piglet weaning weight. The probiotic also improved (p ≤ 0.01) overall fecal scores, decreased total E. coli count on day seven and Clostridium perfringens count (trend) in sucking piglets. The total feed cost per weaned piglet was lower in the experimental (probiotic) group. Supplementing the diet with a probiotic containing Bacillus strains improved the reproductive performance of sows and the performance and health of piglets.

Effect of a Bacillus-Based Probiotic on Performance and Nutrient Digestibility When Substituting Soybean Meal with Rapeseed Meal in Grower-Finisher Diets

The objective of the present study was to test the hypothesis of B. subtilis and B. licheniformis supplementation to a negative control diet in comparison to a standard control diet, had the potential to improve the performance and nutrient digestibility of growing-finishing pigs. For this purpose, 384 fattening pigs of 85 d of age were allotted to three treatments: a standard diet, a negative control (NC) diet (5% soybean meal replaced by 5% rapeseed meal), or a NC diet + probiotic. After reaching a body weight of approximately 110 kg, all animals going to the slaughterhouse (87% of total pigs) were selected to measure carcass quality. Moreover, the apparent total tract digestibility of protein was evaluated at the end of the grower period. The results of this study indicate that supplementation of the tested Bacillus-based probiotic significantly improved average daily gain (ADG, +14.6%) and Feed:gain ratio (F:G, -9.9%) during the grower phase compared to the NC diet. The improvement observed during the grower phase was maintained for the whole fattening period (ADG, +3.9%). Probiotic supplementation significantly improved the total apparent faecal digestibility of dry matter and crude protein in pigs at the end of the grower period. The improvements observed with the additive tested could indicate that supplementation of the Bacillus-based probiotic was able to counteract the lower level of crude protein and standardised ileal digestible amino acids in the NC diet by means of improved protein digestibility.

Effects of Compound Probiotics on Cecal Microbiota and Metabolome of Swine

Complex probiotics are made from various single probiotics mixed in scientific formula. The long-term intake of different probiotics is beneficial to maintain the intestinal microecological balance, inhibiting harmful pathogenic flora and facilitating organism health. Based on the limited research on intestinal flora and related metabolites after the long-term intake of the probiotic complex, in this study, 16S rRNA gene sequencing and untargeted metabolomics were used to further investigate the effects of the probiotic complex on the intestinal flora and metabolome of pigs. The results demonstrated that the content of flora in the intestinal tract or metabolites of pigs varied greatly and was related to cellular metabolic pathways after the long-term feeding of complex probiotics. This study provides a valuable theoretical basis for farmers to raise pigs scientifically and healthily.

Evaluation on the Growth Performance, Nutrient Digestibility, Faecal Microbiota, Noxious Gas Emission, and Faecal Score on Weaning Pigs Supplement with and without Probiotics Complex Supplementation in Different Level of Zinc Oxide

A total of 200 26-day-old crossbred weaning piglets ((Yorkshire × Landrace) × Duroc; 6.55 ± 0.62 kg) were used in a 6-week experiment to evaluate the effects of adding probiotics complex supplementation (Syner-ZymeF10) with high and low ZnO diets on the performance of weaning pigs in 42 days. Pigs were randomly allotted to a 2 × 2 factorial arrangement and they were supplemented with two concentration level of ZnO with 3000 ppm and 300 ppm and probiotics complex supplementation with 0 and 0.1%. There were ten replicate pens per treatment with five pigs per pen (two gilts and three barrows). Pigs fed diets with 3000 ppm ZnO had a higher BW during the overall period and ADG during d 8-21, d 22-42, and overall period than pigs receiving 300 ppm ZnO diets (p < 0.05), as well as a G: F which tended to increase on d 8-21 and overall period (p < 0.1) and decreased tendency on faecal gas emission of methyl mercaptans and acetic acid concentration (p < 0.1). Dietary probiotics complex supplementation had decreased the E. coli count (p < 0.05) and tended to increase the Lactobacillus count (p < 0.1). Dietary probiotics complex supplementation and different level of ZnO supplementation had no significant effect on the nutrition digestibility and faecal score (p > 0.05). In conclusion, probiotic supplementation reduced the fecal E. coli counts and tended to improve Lactobacillus counts. There were no interactive effects between ZnO and probiotic complex supplementation on all the measured parameters.

Dietary medium-chain fatty acid and Bacillus in combination alleviate weaning stress of piglets by regulating intestinal microbiota and barrier function

The present study evaluated the effects of dietary medium-chain fatty acid (MCFA) and Bacillus on growth performance, nutrient digestibility, antioxidant capacity, colonic fermentation, and microbiota of weaning piglets. A total of 400 weaned piglets were randomly divided into 4 treatments, with 10 replicates per treatment and 10 pigs per replicate. The treatment included: basal diet (control, CON), basal diet with 0.588 g/kg MCFA (MCF), basal diet with 1.3 × 109 CFU/kg Bacillus (BAC), and basal diet with 0.588 g/kg MCFA and 1.3 × 109 CFU/kg Bacillus (SYN). Compared with CON group, the average daily gain of MCF and SYN in the early (1 to 9 d) and whole stage (1 to 36 d) of trail were improved (P < 0.05), the feed to gain ratio of MCF in later (10 to 36 d) and whole stage of trial were decreased (P < 0.05), and the diarrhea rate of SYN in the early stage (1 to 9 d) of trial decreased (P < 0.05). The digestibility of dry matter, ether extract, acid detergent fiber digestibility of MCF were decreased (P < 0.05) compared with CON. The serum d-lactic acid in MCF, BAC, and SYN were lower (P < 0.05) compared with CON group. Compared with CON group, the contents of total antioxidant capacity, superoxide dismutase, and glutathione peroxidase were greater (P < 0.05), whereas the content of malondialdehyde and the contents of colonic isobutyrate and isovalerate were lower (P < 0.05) in MCF. The microbial Shannon and Simpson diversity was lower in MCF (P < 0.05) than that in BAC and SYN. The relative abundance of Prevotella was greater (P < 0.05), whereas the Treponema and Oscillibacter were lower (P < 0.05) in MCF than that in BAC and SYN. In addition, the metabolic pathways of bacteria such as pentose phosphate pathway, adenosine nucleotides degradation II were enhanced (P < 0.05), whereas the pathways such as incomplete reductive TCA cycle, and TCA cycle IV (2-oxoglutarate decarboxylase) were decreased (P < 0.05) in MCF compared with BAC. The results indicated that dietary MCFA and Bacillus in combination improved the intestinal barrier function of piglets by changing the intestinal microbiota and its metabolic function, and finally alleviated the diarrhea rate in early weaning stage and improved growth performance in whole trial period. In addition, MCFA was effective in improving feed efficiency and antioxidant capacity of piglets.

Protective effects of Bacillus licheniformis on growth performance, gut barrier functions, immunity and serum metabolome in lipopolysaccharide-challenged weaned piglets

Bacillus licheniformis (B. licheniformis) is a well-accepted probiotic that has many benefits on both humans and animals. This study explored the effects of B. licheniformis on growth performance, intestinal mucosal barrier functions, immunity as well as serum metabolome in the weaned piglets exposed to lipopolysaccharide (LPS). One hundred and twenty piglets weaned at four weeks of age were separated into two groups that received a basal diet (the control group, CON), and a basal diet complemented with B. licheniformis (500 mg/kg, the BL group, BL). Twenty-four piglets were chosen from the above two groups and 12 piglets were injected with LPS intraperitoneally at a concentration of 100 μg/kg and the others were injected with sterile saline solution of the same volume. All the piglets were sacrificed 4 h after LPS challenge. Results showed that B. licheniformis enhanced the ADG and final body weight and lowered the F/G and diarrhea rate. Pre-treatment with B. licheniformis markedly attenuated intestinal mucosal damage induced by LPS challenge. Supplementation with B. licheniformis strengthened immune function and suppressed inflammatory response by elevating the concentrations of serum immunoglobulin (Ig) A and jejunum mucosal IgA and IgG and decreasing serum IL-6 and jejunum mucosal IL-1β. In addition, B. licheniformis pretreatment prevented LPS-induced intestinal injury by regulating the NLRP3 inflammasome. Furthermore, pretreatment with B. licheniformis tended to reverse the reduction of acetate and propionic acids in the colonic contents that occurred due to LPS stress. B. licheniformis markedly modulated the metabolites of saccharopine and allantoin from lysine and purine metabolic pathways, respectively. Overall, these data emphasize the potentiality of B. licheniformis as a dietary supplement to overcome the challenge of bacterial LPS in the animal and to enhance the food safety.

Use of Microorganisms as Nutritional and Functional Feedstuffs for Nursery Pigs and Broilers

The objectives of this review paper are to introduce the structures and composition of various microorganisms, to show some applications of single cells as alternative protein supplements or energy feeds in swine and poultry diets, and to discuss the functional effects of microorganisms as feed additives on the growth performance and intestinal health of nursery pigs and broilers. Microorganisms, including bacteria, yeasts, and microalgae, have been commonly supplemented in animal diets because they are cost-effective, stable, and have quantitative production that provides nutritional and functional benefits to pigs and broilers. Microorganisms could be alternative antibiotics to enhance intestinal health due to bioactive components from cell wall components, which interact with receptors on epithelial and immune cells. In addition, bioactive components could be digested by intestinal microbiota to produce short-chain fatty acids and enhance energy utilization. Otherwise, microorganisms such as single-cell protein (SCP) and single-cell oils (SCOs) are sustainable and economic choices to replace conventional protein supplements and energy feeds. Supplementing microorganisms as feedstuffs and feed additives improved the average daily gain by 1.83%, the daily feed intake by 0.24%, and the feed efficiency by 1.46% in pigs and broilers. Based on the properties of each microorganism, traditional protein supplements, energy feeds, and functional feed additives could be replaced by microorganisms, which have shown benefits to animal's growth and health. Therefore, specific microorganisms could be promising alternatives as nutritional and functional feedstuffs in animal diets.

In vitro and in vivo evaluation of probiotic potential and safety assessment of Bacillus coagulans SKB LAB-19 (MCC 0554) in humans and animal healthcare

Bacillus coagulans is Gram positive, spore forming and high lactic acid producing bacteria; however, probiotic and safety assessment of the isolated strain need to be investigated for commercial applications. Current study aimed to screen SKB LAB-19 for potential probiotic characteristics viz. enzyme production, antimicrobial properties, pH/bile salt tolerance, temperature stability, antidiarrheal activity in Swiss albino mice and Wistar rats; and acute oral toxicity in mice. The results showed that, SKB LAB-19 produces eight potential enzymes, effective against E. coli and C. perfringensis, tolerant to bile salt (0.3%)/gastric pH (2.5), stable at 40-90 °C and nontoxic to cells. SKB LAB-19 was found to be safe and displayed promising results to reverse E. coli and castor oil induced diarrhoea. Histopathological studies showed repair to damaged mucosal epithelium cells and improves integrity of the goblet cells of colon. SKB LAB-19 showed immunomodulatory effects with increased immunoglobulins in blood and augmented weight of spleen and thymus. In addition, SKB LAB-19 showed significant in-vitro antioxidant activity (82.93%), reducing capacity and ascorbate auto-oxidation inhibition effect (94.62%). These preliminary results suggested that, SKB LAB-19 was found to be safe and has the potential to be used as effective probiotic and anti-diarrhoeal agent in humans and animal healthcare.

Bacillus spp. Probiotic Strains as a Potential Tool for Limiting the Use of Antibiotics, and Improving the Growth and Health of Pigs and Chickens

The pressure to increasingly optimize the breeding of livestock monogastric animals resulted in antimicrobials often being misused in an attempt to improve growth performance and counteract diseases in these animals, leading to an increase in the problem of antibiotic resistance. To tackle this problem, the use of probiotics, also known as direct in-feed microbials (DFM), seems to be one of the most promising strategies. Among probiotics, the interest in Bacillus strains has been intensively increased in recent decades in pigs and poultry. The aim of the present review was to evaluate the effectiveness of Bacillus strains as probiotics and as a potential strategy for reducing the misuse of antibiotics in monogastric animals. Thus, the potential modes of action, and the effects on the performance and health of pigs (weaning pigs, lactation and gestation sows) and broilers are discussed. These searches yielded 131 articles (published before January 2021). The present review showed that Bacillus strains could favor growth in terms of the average daily gain (ADG) of post-weaning piglets and broilers, and reduce the incidence of post-weaning diarrhea in pigs by 30% and mortality in broilers by 6-8%. The benefits of Bacillus strains on these parameters showed results comparable to the benefit obtained by the use of antibiotics. Furthermore, the use of Bacillus strains gives promising results in enhancing the local adaptative immune response and in reducing the oxidative stress of broilers. Fewer data were available regarding the effect on sows. Discordant effects have been reported regarding the effect on body weight (BW) and feed intake while a number of studies have supported the hypothesis that feeding probiotics to sows could benefit their reproductive performance, namely the BW and ADG of the litters. Taken all the above-mentioned facts together, this review confirmed the effectiveness of Bacillus strains as probiotics in young pigs and broilers, favoring their health and contributing to a reduction in the misuse of direct in-feed antibiotics. The continuous development and research regarding probiotics will support a decrease in the misuse of antibiotics in livestock production in order to endorse a more sustainable rearing system in the near future.

Effects of Bacillus-based probiotics on growth performance, nutrient digestibility, and intestinal health of weaned pigs

Bacillus is characterized by the formation of spores in harsh environments, which makes it suitable for use as a probiotic for feed because of thermostability and high survival rate, even under long-term storage. This study was conducted to investigate the effects of Bacillus-based probiotics on growth performance, nutrient digestibility, intestinal morphology, immune response, and intestinal microbiota of weaned pigs. A total of 40 weaned pigs (7.01 ± 0.86 kg body weight [BW]; 28 d old) were randomly assigned to two treatments (4 pigs/pen; 5 replicates/treatment) in a randomized complete block design (block = BW and sex). The dietary treatment was either a typical nursery diet based on corn and soybean meal (CON) or CON supplemented with 0.01% probiotics containing a mixture of Bacillus subtilis and Bacillus licheniformis (PRO). Fecal samples were collected daily by rectal palpation for the last 3 days after a 4-day adaptation. Blood, ileal digesta, and intestinal tissue samples were collected from one pig in each pen at the respective time points. The PRO group did not affect the feed efficiency, but the average daily gain was significantly improved (p < 0.05). The PRO group showed a trend of improved crude protein digestibility (p < 0.10). The serum transforming growth factor-β1 level tended to be higher (p < 0.10) in the PRO group on days 7 and 14. There was no difference in phylum level of the intestinal microbiota, but there were differences in genus composition and proportions. However, β-diversity analysis showed no statistical differences between the CON and the PRO groups. Taken together, Bacillus-based probiotics had beneficial effects on the growth performance, immune system, and intestinal microbiota of weaned pigs, suggesting that Bacillus can be utilized as a functional probiotic for weaned pigs.

Effects of in feed removal of antimicrobials in comparison to other prophylactic alternatives in growing and finishing pigs

ABSTRACT The utilization of antimicrobials in animal production, causes selection of resistant bacteria. The objective of this study was to compare the utilization of alternatives in association with preventive antibiotic therapy in swine feed during the growing and finishing phases. 1,045 animals were used from 60 to 190 days of age and were subjected to six treatments with 16 repetitions as follows: 1) antibiotic free; 2) antibiotics; 3) prebiotic; 4) probiotic; 5) essential oils; and 6) organic acid. Animals were weighted, and clinical history was recorded including mortality and diarrhea. At the abattoir, pneumonia index and gastric ulcers were investigated. The cost for each treatment was discussed. No difference between treatments were observed (P>0.05) regarding feed conversion rate (2.64±0.03), overall average weight gain (107.06±0.9kg), average daily weight gain (856.49±7.7g) and carcass weight (92.4±0.7kg). The application injectable drugs in animals presenting clinical symptoms, represented US$ 0.56/intervention, without difference between the treatments (P>0.05). Furthermore, independently of the treatment, high frequency of pneumonia was observed (>0.90). No difference for the degree of gastric ulcer nor feces consistency were observed (P>0.05). The utilization of antibiotic therapy and alternatives to antibiotics in feed did not produce benefits to the production indices and sanitary performances of the animals.

Immunomodulatory effect of the combined use of Vetosporin Zh probiotic and Gumi-malysh biologically active additive

Background and Aim:

Various means and methods, including probiotics and biologically active additives, have been developed and proposed for production to increase the immunobiological reactivity of the body, regardless of the etiology of its decrease. This study aimed to find out the immune status of calves during the preweaning period in association with Vetosporin Zh, Normosil, and Gumi-malysh.

Materials and Methods:

The research object was 30-day-old calves of black-and-white Holstein breed. The calves were divided into four groups of 20 heads each. The calves of the first, second, and third experimental groups were treated with Normosil probiotic, Vetosporin Zh probiotic, and Vetosporin Zh probiotic in combination with Gumi-malysh, respectively. The calves in the first, second, and third experimental groups were treated with Normosil probiotic, Vetosporin Zh probiotic, and Vetosporin Zh probiotic in combination with Gumi-malysh, respectively.

Results:

On days 10 and 21 of the experiment, animal blood was collected to determine the content of total protein, protein fractions, immunoglobulins, T and B lymphocytes, phagocytic activity and a phagocytic number of neutrophils, and circulating immune complexes (CIC). The combined use of Vetosporin Zh probiotic (dose, 20 mL) with Gumi-malysh (dose, 30 mL) per animal for 30 days in 1-month-old calves contributes to the increase in the number of T lymphocytes, B lymphocytes, and immunoglobulin A (IgA) and immunoglobulin G (IgG) levels by 2.9%, 3.8%, and 0.96 and 2 g/L, respectively, while reducing the immunoglobulin M (IgM) level; an increase in the phagocytic activity of blood neutrophils and the phagocytic number by 7% and 1.8%, respectively, as well as a decrease in the CIC level with similar indicators in calves that were not treated with the agents.

Conclusion:

The method used in the current study helps increase the number of T and B lymphocytes, increase IgA and IgG levels while reducing IgM levels, and increase the phagocytic activity and a phagocytic number of blood neutrophils, as well as decrease the CIC level.

Effect of low-nutrient-density diet with probiotic mixture (Bacillus subtilis ms1, B. licheniformis SF5-1, and Saccharomyces cerevisiae) supplementation on performance of weaner pigs

A total of one hundred and forty, 28 day-old weaner pigs [Duroc × (Yorkshire × Landrace)] with an initial body weight (BW) of 6.56 ± 1.25 kg were used in a six-week treatment (7 replicate pens per treatment; barrows, and 2 gilts/pen) to evaluate the effect of low-nutrient-density diet supplement with probiotic mixture supplementation on the growth performance, nutrient digestibility, faecal microbial and gas emission of weaner pigs. Pigs fed low-density diet with probiotic mixture supplementation had linearly increased (p = 0.028, 0.014) the body weight (BW) at weeks 3, and 6. Moreover, average daily gain (ADG) was linearly improved (p = 0.018, 0.014, 0.014) at weeks 3, 6 and the overall experiment. However, there were no interactive effects found on the nutrient digestibility of dry matter (DM), nitrogen (N) and energy (E) throughout the experiment. Dietary inclusion of a low-density diet with probiotic mixture supplementation has improved the faecal lactobacillus counts linearly, but E. coli was unaffected during the trial. On day 42, Ammonium gas emission was significantly decreased in pigs fed a low-density diet with probiotic mixture supplementation. However, H₂ S, acetic acid and CO₂ were not significantly affected by the probiotic mixture supplementation diet. Low-density diet with probiotic mixture supplementation had positively affected the growth performance, faecal microbial and faecal gas emission on weaner pigs.

Effect of dietary supplementation with essential oils and a Bacillus probiotic on growth performance, diarrhoea and blood metabolites in weaned pigs

Context Dietary supplementation of essential oils or in combination with a Bacillus probiotic was investigated as an antibiotic growth promoter for weaned pigs. Aims To evaluate the effect of essential oils (i.e. thymol and carvacrol mixture) or in combination with a probiotic strain (i.e. Bacillus subtilis PB6) on the growth performance, diarrhoea incidence, ammonia emission and serological profiles of weaned pigs. Methods A total of 96 crossbred ([Yorkshire × Landrace] × Duroc) weaned pigs were randomly allotted to one of six treatments based on sex and initial bodyweight. Each group was distributed into four replicates with four pigs each according to a randomised complete block design. The treatments were: (i) positive control, basal diet supplemented with colistin 150 g/tonne and amoxicillin 200 g/tonne; (ii) negative control, basal diet without supplementation; (iii) T3, basal diet supplemented with essential oils 300 g/tonne; (iv) T4, basal diet supplemented with essential oils 600 g/tonne; (v) T5, basal diet supplemented with essential oils 1000 g/tonne; and (vi) T6, basal diet supplemented with essential oils 300 g/tonne diet and Bacillus probiotics 1000 g/tonne. Key results The piglets fed with supplements had a significantly higher average daily gain and lower incidence of diarrhoea than the piglets in the negative control (P = 0.001). Feeding the essential oils alone or in combination with probiotics significantly reduced faecal ammonia emission (P = 0.027) and blood urea nitrogen (P = 0.039), while markedly increasing the serum immunoglobulin G concentration of weaned pigs compared with the negative control treatment (P = 0.014). The difference in time of blood collection had significant effects on blood urea nitrogen and immunoglobulins (P = 0.001). However, no significant differences emerged in average daily feed intake, gain: feed ratio, feed efficiency and antibody against swine fever among the treatments. Conclusions Diet supplementation with essential oils or in combination with probiotics improved growth performance and immunity, and lowered ammonia emissions and diarrhoea incidence of weaned pigs. Implications These findings provide a basis for the application of phytogenic compounds and probiotics as antibiotic growth promoter alternatives in post-weaning diets for pigs.

Effects of Bacillus subtilis on growth performance, serum parameters, digestive enzyme, intestinal morphology, and colonic microbiota in piglets

The present study was conducted to investigate effects of Bacillus subtilis on growth performance, serum parameters, digestive enzymes, intestinal morphology, and colonic microbiota in piglets. A total of 72 piglets were weighed and randomly allotted into three treatments (four replication pens per treatment with six piglets/pen) for a 28-day experiment. The dietary treatments were as follows: basal diet (control group, CTR), basal diet supplementation with antibiotic (antibiotic group, ABT), and basal diet supplementation with 0.1% Bacillus subtilis (probiotic group, PBT). The average daily gain of body weight increased in both the ABT and PBT groups, and dietary antibiotics decreased the feed:gain ratio (F:G), as compared to the CTR group (P < 0.05). Both ABT and PBT piglets had increased serum triglycerides and lipase, amylase, maltase activities and villus height:crypt depth ratio (V/C) in ileum (P < 0.05). The PBT group also showed an increase in serum glucose and villus height in the ileum (P < 0.05). Dietary antibiotics increased Lactobacillus johnsonii, as compared to the CTR group, but decreased bacterial diversity and increased Escherichia coli, as compared to the PBT group (P < 0.05). Piglets dietary with B. subtilis modulated the microbiota by increasing the abundance of Firmicutes (L. johnsonii, L. reuteri) and decreasing the abundance of E. coli, as compared to the control group (P < 0.05). These results indicate that dietary of B. subtilis improves growth performance and intestinal health and can be a promising alternative to antibiotics in piglets diet.

Effect of carbohydrases on growth performance, nutrient digestibility, blood profiles, and fecal microbiota in weanling pigs fed reduced energy diet

This study was conducted to evaluate the effect of carbohydrases on growth performance, nutrient digestibility, blood profiles, and fecal microbiota in weanling pigs fed reduced energy diet. A total of 160 crossbred [(Yorkshire × Landrace) × Duroc)] weanling pigs with an initial body weight (BW) of 7.23 ± 1.08 kg were used in this 42 d trial. Pigs were randomly allocated in one of the following four dietary treatments: (1) CON, basal diet [net energy (NE) 2545 kcal kg−1]; (2) LE, low-energy diet (NE 2470 kcal kg−1); (3) LEC1, LE + 0.1% carbohydrase; and (4) LEC2, LE + 0.2% carbohydrase based on the sex and BW. There were eight replications (pens) per treatment with five pigs (two male and three female) per pen. During day 0–7, pigs fed with LE diet had lower (P < 0.05) average daily gain (ADG) and average daily feed intake than those fed with CON and LEC2 diets. LE group reduced (P < 0.05) ADG throughout the experiment compared with CON and LEC2 groups. LE group reduced (P < 0.05) the digestibility of dry matter, nitrogen, and gross energy compared with LEC2 diet. Taken together, LE diet caused detrimental effects on growth performance and nutrient digestibility in weanlings, whereas the addition of carbohydrases (0.2%) partially counteracted these negative effects.

Effects of probiotics and nutrients addition on the microbial community and fermentation quality of peanut hull

The objective of this study was to develop a new type of feedstuff by utilizing probiotics to transform agricultural byproducts to meet the livestock feed shortage. In this study, peanut hull powder (PHP) was used as the fermentation substrate, which was inoculated with 18 kinds of feed probiotics combined with two kinds of nutritional additives. The desired value formula was used to select the strains suitable for fermentation of PHP, and the strains were combined as multi-culture starters. We compared the changes of the chemical composition and bacterial flora before and after the fermentation, which provided a theoretical basis for the establishment and quality evaluation of the system of PHP fermentation. The result shows that inoculation with CM6 together with nutrients co-fermenting clearly raised the content of organic acid, CP and WSC in the PHP and effectively inhibited the growth of harmful microorganisms such as Enterobacter and Fusarium.

Effects of Bacillus amyloliquefaciens and Bacillus subtilis on ileal digestibility of AA and total tract digestibility of CP and gross energy in diets fed to growing pigs

The objective of this experiment was to test the hypothesis that the apparent ileal digestibility (AID) of AA, CP, and GE, the apparent total tract digestibility (ATTD) of CP and GE, and the apparent hindgut digestibility of CP and GE by growing pigs may be improved by supplementing diets with two direct-fed microbials (DFM) containing different Bacillus strains. Twenty-four growing barrows (initial BW: 22.69 ± 1.48 kg) that had a T-cannula installed in the distal ileum were individually housed and randomly allotted to a three diet, three period design with 24 pigs and three 21-d periods. There were eight pigs per diet in each period for a total of 24 observations per diet. Three diets that were based on corn, soybean meal, and distillers dried grains with solubles were formulated. The control diet contained no DFM, but two additional diets contained two different Bacillus strains (Bacillus amyloliquefaciens or Bacillus subtilis). Feed was provided in mash form in two daily meals at 0800 and 1600 hours. The initial 12 d of each period was the adaptation period to the diet. Fecal and urine samples were collected from days 13 to 18, and ileal digesta were collected for 8 h on days 20 and 21. Results indicated that there were no differences among diets in ATTD of CP, but the AID of CP was reduced (P < 0.05) for the B. subtilis diet compared with control and B. amyloliquefaciens diets. Therefore, the apparent hindgut digestibility of CP was greater (P < 0.005) in pigs fed the B. subtilis diet compared with the other diets. The AID of total indispensable, total dispensable, and total AA was greater (P < 0.05) in the B. amyloliquefaciens diet compared with the control diet. There were no differences among diets in ATTD of GE, but the AID of GE was greater for the B. amyloliquefaciens diet than for the control and the B. subtilis diets (P < 0.001). Therefore, the apparent hindgut digestibility of GE was less (P < 0.05) in the B. amyloliquefaciens diet compared with the other diets. The DE (DM basis) for the B. subtilis diet was greater (P < 0.05) compared with the control and the B. amyloliquefaciens diets. In conclusion, supplementation of Bacillus spp. to diets fed to growing pigs may increase the AID of AA and GE, but there appears to be differences among strains of Bacillus spp. in their impact on AA and energy digestibility.

Effects of dietary energy and lipase levels on nutrient digestibility, digestive physiology and noxious gas emission in weaning pigs

Objective

This study was conducted to evaluate the effect of dietary energy and lipase supplementation on growth performance, nutrient digestibility, serum profiles, intestinal morphology, small intestinal digestive enzyme activities, biochemical index of intestinal development and noxious gas emission in weaning pigs.

Methods

A total of 240 weaning pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 7.3±0.12 kg were used in this 28-d experiment. Weaning pigs were randomly allocated to 4 dietary treatments in a 2×2 factorial arrangement with 2 levels of energy (net energy = 2,470 kcal/kg for low energy diet and 2,545 kcal/kg for basal diet) and 2 levels of lipase (0 and 1.5 U/g of lipase) according to BW and sex. There were 6 replications (pens) per treatment and 10 pigs per pen (5 barrows and 5 gilts).

Results

Weaning pigs fed the low energy diet had lower (p<0.05) gain-to-feed ratio (G:F) throughout the experiment, apparent digestibility of dry matter, nitrogen, ether extract, and gross energy during d 0 to 14, average daily gain during d 15 to 28, lipase activity in duodenum and ileum and protein/DNA in jejunum (p<0.05), respectively. Lipase supplementation had no effect on growth performance but affected apparent nutrient digestibility (p<0.05) on d 14 and enhanced lipase activity in the duodenum and ileum and protease activity in duodenum and jejunum of pigs (p<0.05) fed the low energy diet. Lipase reduced serum low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG), NH₃ production (p<0.05) from the feces.

Conclusion

The low energy diet decreased G:F throughout the experiment and nutrient digestibility during d 0 to 14 as well as lipase activity in duodenum and ileum. Lipase supplementation increased nutrient digestibility during d 0 to 14 and exerted beneficial effects on lipase activity in duodenum and ileum as well as protease activity in duodenum and jejunum, while reduced serum LDL-C, TG and fecal NH₃.

Application of Complex Probiotics in Swine Nutrition – A Review

The use of probiotics as alternatives to antibiotics for farm animals is gaining more and more interest during recent years. Probiotics are living microorganisms that provide a wide variety of health benefits to the host when ingested in adequate amounts. The bacterial strains most frequently used as probiotic agents are Bacillus, lactic acid bacteria, Enterococcus and Saccharomyces cerevisiae. It has been suggested that multi-strain probiotics might be more effective than mono-strain probiotics due to the additive and synergistic effects, and many previous studies demonstrated that dietary complex probiotics supplementation had growth promoting effects on pigs. However, the effect of complex probiotics in practice is not always consistent, the effect of probiotic could be affected by strain composition, dosage, feed formula, and the age of animals. In this review, we will give an overview on the current use of complex probiotics for weaning, growing and finishing pigs and sows.

Effect of Postpartum Endocrine Function, Metabolism, and Mastitis on Fertility in High-Yielding Cows – A Review

Decreasing fertility in dairy cows, especially in the highest yielders, may be due to excessive metabolic burdens placed on their bodies. Many authors attribute decreasing reproductive efficiency in high-yielding cows to energy deficiencies in early lactation and to associated metabolic and hormonal disorders. The complexity of the issues involved in the efficient reproductive management of cows and the scientifically and practically important understanding of factors affecting fertility in high-producing cows mandate continuous updating of existing knowledge. The aim of this study was to present the effect of postpartum endocrine function, metabolism, and mastitis on fertility in high-yielding cows. Gaining insight into these mechanisms and their relationships with factors such as nutrition and milk yield appears to be crucial for improving dairy cow fertility.

Bacillus probiotics: an alternative to antibiotics for livestock production

The use of probiotics as feed supplements in animal production has increased considerably over the last decade, particularly since the ban on antibiotic growth promoters in the livestock sector. Several Bacillus sp. are attractive for use as probiotic supplements in animal feed due to their ability to produce spores. Their heat stability and ability to survive the low pH of the gastric barrier represent an advantage over other probiotic micro-organisms. This review discusses important characteristics required for selection of Bacillus probiotic strains and summarizes the beneficial effect of Bacillus-based feed additives on animal production. Although the mechanism of action of Bacillus probiotics has not been fully elucidated, they are effective in improving the growth, survival and health status of terrestrial and aquatic livestock. Bacillus strains also have utility in bioremediation and can reduce nitrogenous waste, thereby improving environmental conditions and water quality. Finally, recent innovative approaches for using Bacillus spores in various applications are discussed.

Probiotic supplementation protects weaned pigs against enterotoxigenic Escherichia coli K88 challenge and improves performance similar to antibiotics

These studies evaluated the effects of probiotics (PB) as a potential substitute for antibiotics (AB) on diarrhea in relation to immune responses and intestinal health in weaned pigs challenged with enterotoxigenic (ETEC) K88 (Exp. 1) and the effects of PB on performance and nutrient digestibility in weaned pigs (Exp. 2). In Exp. 1, 24 weaned barrows (4.9 ± 0.4 kg initial BW) were randomly assigned to 1 of 4 treatments. The treatments consisted of pigs fed an unsupplemented corn-soybean meal basal diet and not challenged (NON-C) or challenged with ETEC K88 (CHA-C) on d 9 and pigs fed the same basal diet supplemented with AB (100 mg/kg zinc bacitracin, 50 mg/kg colistin sulfate, and 100 mg/kg olaquindox; CHA-AB) or 500 mg/kg PB ( and ; CHA-PB) and challenged with ETEC K88 on d 9. In Exp. 2, 108 weaned pigs (7.5 ± 0.9 kg initial BW) not challenged with ETEC K88 were randomly assigned to 1 of 3 treatments, including an AB-free basal diet (CON) and the basal diet with AB (ABD) or 500 mg/kg PB supplementation (PBD). In Exp. 1, after challenge, CHA-C decreased ( < 0.05) ADG and ADFI, whereas CHA-AB and CHA-PB revealed no significant change compared with NON-C. Compared with CHA-C, CHA-AB and CHA-PB improved ( < 0.05) ADG and ADFI and decreased ( < 0.05) the diarrhea incidence in pigs. Mucosal secretory Ig A contents in the jejunum and ileum were greater in CHA-C than in NON-C ( < 0.05) and lower than in CHA-PB ( < 0.05). The diet containing PB alleviated the increase in the endotoxin and diamine oxidase concentration and cecal count ( < 0.05) and the decrease in intestinal villus height, cecal count, and jejunal mucosal occludin protein abundance ( < 0.05). In Exp. 2, dietary supplementation with AB and PB had positive effects on ADG and feed efficiency ( < 0.05). Compared with CON, apparent digestibility of nutrients in PBD was improved ( < 0.05). Collectively, PB supplementation protected the pigs against ETEC K88 infection by enhancing immune responses and attenuating intestinal damage and improved the performance and nutrient digestibility of weaned pigs. Therefore, PB could be a potential effective alternative to AB for ameliorating diarrhea and improving performance in weaned pigs.

Effect of Bacillus subtilis and Bacillus licheniformis supplementation in diets with low- and high-protein content on ileal crude protein and amino acid digestibility and intestinal microbiota composition of growing pigs

Background

Bacillus spp. seem to be an alternative to antimicrobial growth promoters for improving animals’ health and performance. However, there is little information on the effect of Bacillus spp. in combination with different dietary crude protein (CP) levels on the ileal digestibility and microbiota composition. Therefore, the objective of this study was to determine the effect of Bacillus spp. supplementation to low- (LP) and high-protein diets (HP) on ileal CP and amino acid (AA) digestibility and intestinal microbiota composition.

Methods

Eight ileally cannulated pigs with an initial body weight of 28.5 kg were randomly allocated to a row-column design with 8 pigs and 3 periods of 16 d each. The assay diets were based on wheat-barley-soybean meal with two protein levels: LP (14% CP, as-fed) and HP diet (18% CP, as-fed). The LP and HP diets were supplemented with or without Bacillus spp. at a level of 0.04% (as-fed). The apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA was determined. Bacterial community composition from ileal digesta was analyzed by Illumina amplicon sequencing and quantitative real-time PCR. Data were analyzed as a 2 × 2 factorial design using the GLIMMIX procedures of SAS.

Results

The supplementation with Bacillus spp. did not affect both AID and SID of CP and AA in growing pigs. Moreover, there was no difference in AID of CP and AA between HP and LP diets, but SID of cystine, glutamic acid, glycine, and proline was lower (P < 0.05) in pigs fed the HP diets. The HP diets increased abundance of Bifidobacterium spp. and Lactobacillus spp., (P < 0.05) and by amplicon sequencing the latter was identified as predominant genus in microbiota from HP with Bacillus spp., whereas dietary supplementation of Bacillus spp. increased (P < 0.05) abundance of Roseburia spp..

Conclusions

The HP diet increased abundance of Lactobacillus spp. and Bifidobacterium spp.. The supplementation of Bacillus spp. resulted in a higher abundance of healthy gut associated bacteria without affecting ileal CP and AA digestibility, whereas LP diet may reduce the flow of undigested protein to the large intestine of pigs.