Nutritional and Functional Roles of Phytase and Xylanase Enhancing the Intestinal Health and Growth of Nursery Pigs and Broiler Chickens

Development and application of a multi-step porcine in vitro system to evaluate feedstuffs and feed additives for their efficacy in nutrient digestion, digesta characteristics, and intestinal immune responses

In vitro model provides alternatives to the use of live animals in research. In pig nutrition, there has been a tremendous increase in in vivo research over the decades. Proper utilization of in vitro models could provide a screening tool to reduce the needs of in vivo studies, research duration, cost, and the use of animals and feeds. This study aimed to develop a multi-step porcine in vitro system to simulate nutrient digestion and intestinal epithelial immune responses affected by feedstuffs and feed additives. Seven feedstuffs (corn, corn distillers dried grains with solubles [corn DDGS], barley, wheat, soybean meal, soy protein concentrates, and Corynebacterium glutamicum cell mass [CGCM]), feed enzymes (xylanase and phytase), and supplemental amino acids (arginine, methionine, and tryptophan), were used in this in vitro evaluation for their efficacy on digestibility, digesta characteristics, and intestinal health compared with the results from previously published in vivo studies. All in vitro evaluations were triplicated. Data were analyzed using Mixed procedure of SAS9.4. Evaluations included (1) nutrient digestibility of feedstuffs, (2) the effects of feed enzymes, xylanase and phytase, on digestibility of feedstuffs and specific substrates, and (3) the effects of amino acids, arginine, tryptophan, and methionine, on anti-inflammatory, anti-oxidative, and anti-heat stress statuses showing their effects (P < 0.05) on the measured items. Differences in dry matter and crude protein digestibility among the feedstuffs as well as effects of xylanase and phytase were detected (P < 0.05), including xylo-oligosaccharide profiles and phosphorus release from phytate. Supplementation of arginine, tryptophan, and methionine modulated (P < 0.05) cellular inflammatory and oxidative stress responses. The use of this in vitro model allowed the use of 3 experimental replications providing sufficient statistical power at P < 0.05. This indicates in vitro models can have increased precision and consistency compared with in vivo animal studies.

Investigation of the nutritional and functional roles of a combinational use of xylanase and β-glucanase on intestinal health and growth of nursery pigs

BACKGROUND

Xylanase and β-glucanase combination (XG) hydrolyzes soluble non-starch polysaccharides that are anti-nutritional compounds. This study aimed to evaluate the effects of increasing levels of XG on intestinal health and growth performance of nursery pigs.

METHODS

Forty pigs (6.5 ± 0.4 kg) were assigned to 5 dietary treatments and fed for 35 d in 3 phases (11, 9, and 15 d, respectively). Basal diets mainly included corn, soybean meal, and corn distiller's dried grains with solubles, contained phytase (750 FTU/kg), and were supplemented with 5 levels of XG at (1) 0, (2) 280 TXU/kg xylanase and 125 TGU/kg β-glucanase, (3) 560 and 250, (4) 840 and 375, or (5) 1,120 and 500, respectively. Growth performance was measured. On d 35, all pigs were euthanized and jejunal mucosa, jejunal digesta, jejunal tissues, and ileal digesta were collected to determine the effects of increasing XG levels and XG intake on intestinal health.

RESULTS

Increasing XG intake tended to quadratically decrease (P = 0.059) viscosity of jejunal digesta (min: 1.74 mPa·s at 751/335 (TXU/TGU)/kg). Increasing levels of XG quadratically decreased (P < 0.05) Prevotellaceae (min: 0.6% at 630/281 (TXU/TGU)/kg) in the jejunal mucosa. Increasing XG intake quadratically increased (P < 0.05) Lactobacillaceae (max: 40.3% at 608/271 (TXU/TGU)/kg) in the jejunal mucosa. Increasing XG intake quadratically decreased (P < 0.05) Helicobacteraceae (min: 1.6% at 560/250 (TXU/TGU)/kg) in the jejunal mucosa. Increasing levels of XG tended to linearly decrease (P = 0.073) jejunal IgG and tended to quadratically increase (P = 0.085) jejunal villus height to crypt depth ratio (max: 2.62 at 560/250 (TXU/TGU)/kg). Increasing XG intake tended to linearly increase the apparent ileal digestibility of dry matter (P = 0.087) and ether extract (P = 0.065). Increasing XG intake linearly increased (P < 0.05) average daily gain.

CONCLUSIONS

A combinational use of xylanase and β-glucanase would hydrolyze the non-starch polysaccharides fractions, positively modulating the jejunal mucosa-associated microbiota. Increased intake of these enzyme combination possibly reduced digesta viscosity and humoral immune response in the jejunum resulting in improved intestinal structure, and ileal digestibility of nutrients, and finally improving growth of nursery pigs. The beneficial effects were maximized at a combination of 550 to 800 TXU/kg xylanase and 250 to 360 TGU/kg β-glucanase.

Recombinant production of SAG1 fused with xylanase in Pichia pastoris induced higher protective immunity against Eimeria tenella infection in chicken

Chicken coccidiosis is an intestinal disease caused by the parasite Eimeria, which severely damages the growth of chickens and causes significant economic losses in the poultry industry. Improvement of the immune protective effect of antigens to develop high efficiency subunit vaccines is one of the hotspots in coccidiosis research. Sporozoite-specific surface antigen 1 (SAG1) of Eimeria tenella (E. tenella) is a well-known protective antigen and is one of the main target antigens for the development of subunit, DNA and vector vaccines. However, the production and immunoprotective effects of SAG1 need to be further improved. Here, we report that both SAG1 from E. tenella and its fusion protein with the xylanase XynCDBFV-SAG1 are recombinant expressed and produced in Pichia pastoris (P. pastoris). The substantial expression quantity of fusion protein XynCDBFV-SAG1 is achieved through fermentation in a 15-L bioreactor, reaching up to about 2 g/L. Moreover, chickens immunized with the fusion protein induced higher protective immunity as evidenced by a significant reduction in the shedding of oocysts after E. tenella challenge infection compared with immunized with recombinant SAG1. Our results indicate that the xylanase enhances the immunogenicity of subunit antigens and has the potential for developing novel molecular adjuvants. The high expression level of fusion protein XynCDBFV-SAG1 in P. pastoris holds promise for the development of effective recombinant anti-coccidial subunit vaccine.

Komagataella phaffii as a Platform for Heterologous Expression of Enzymes Used for Industry

In the 1980s, Escherichia coli was the preferred host for heterologous protein expression owing to its capacity for rapid growth in complex media; well-studied genetics; rapid and direct transformation with foreign DNA; and easily scalable fermentation. Despite the relative ease of use of E. coli for achieving the high expression of many recombinant proteins, for some proteins, e.g., membrane proteins or proteins of eukaryotic origin, this approach can be rather ineffective. Another microorganism long-used and popular as an expression system is baker's yeast, Saccharomyces cerevisiae. In spite of a number of obvious advantages of these yeasts as host cells, there are some limitations on their use as expression systems, for example, inefficient secretion, misfolding, hyperglycosylation, and aberrant proteolytic processing of proteins. Over the past decade, nontraditional yeast species have been adapted to the role of alternative hosts for the production of recombinant proteins, e.g., Komagataella phaffii, Yarrowia lipolytica, and Schizosaccharomyces pombe. These yeast species' several physiological characteristics (that are different from those of S. cerevisiae), such as faster growth on cheap carbon sources and higher secretion capacity, make them practical alternative hosts for biotechnological purposes. Currently, the K. phaffii-based expression system is one of the most popular for the production of heterologous proteins. Along with the low secretion of endogenous proteins, K. phaffii efficiently produces and secretes heterologous proteins in high yields, thereby reducing the cost of purifying the latter. This review will discuss practical approaches and technological solutions for the efficient expression of recombinant proteins in K. phaffii, mainly based on the example of enzymes used for the feed industry.

Carbohydrases and Phytase in Poultry and Pig Nutrition: A Review beyond the Nutrients and Energy Matrix

This review aimed to clarify the mechanisms through which exogenous enzymes (carbohydrases and phytase) influence intestinal health, as well as their effects on the nutrients and energy matrix in diets fed to poultry and pigs reared under sanitary challenging conditions. Enzyme supplementation can positively affect intestinal microbiota, immune system, and enhance antioxidant status. Although enzymes have been shown to save energy and nutrients, their responses under sanitary challenging conditions are poorly documented. Immune system activation alters nutrient partitioning, which can affect the matrix values for exogenous enzymes on commercial farms. Notably, the carbohydrases and phytase supplementation under sanitary challenging conditions align with energy and nutritional valorization matrices. Studies conducted under commercial conditions have shown that matrices containing carbohydrases and phytase can maintain growth performance and health in poultry and pigs. However, these studies have predominantly focused on assessing a single level of reduction in energy and/or available phosphorus and total calcium, limiting our ability to quantify potential energy and nutrient savings in the diet. Future research should delve deeper into determining the extent of energy and nutrient savings and understanding the effects of alone or blended enzymes supplementation to achieve more specific insights.

Effects of β-mannanase supplementation on intestinal health and growth of nursery pigs

Two experiments were conducted using 120 pigs to test the hypothesis that supplementation of β-mannanase could reduce digesta viscosity, enhance nutrient digestion, and improve intestinal health and growth of nursery pigs. In experiment 1, 48 crossbred barrows were randomly allotted to four treatments with increasing levels of β-mannanase at 0, 200, 400, and 600 U/kg in feeds. All pigs were euthanized on day 12 to collect jejunal digesta to measure digesta viscosity and ileal digesta to measure apparent ileal digestibility (AID) of dry matter (DM), gross energy (GE), neutral detergent fiber (NDF), and acid detergent fiber (ADF). In experiment 2, 72 nursery pigs were randomly allotted to three treatments with increasing levels of β-mannanase at 0, 400, and 600 U/kg in feeds. Plasma collected on day 9 was used to measure tumor necrosis factor-α (TNF-α), immunoglobulin G (IgG), malondialdehyde (MDA), and protein carbonyl (PC). All pigs were euthanized on day 10 to collect duodenal and jejunal tissues to evaluate the production of TNF-α, IL-6, and MDA, morphology, crypt cell proliferation, and expression of tight junction proteins in the jejunum. Data were analyzed using the MIXED procedure for polynomial contrasts and the NLMIXED procedure for broken-line analysis of SAS. In experiment 1, β-mannanase supplementation tended to have quadratic effects on digesta viscosity (P = 0.085) and AID of GE (P = 0.093) in the pigs. In experiment 2, jejunal digesta viscosity of the pigs was reduced (P < 0.05) when β-mannanase was supplemented at 360 U/kg of feed. β-Mannanase supplementation linearly reduced (P < 0.05) TNF-α, IgG, MDA, and PC in the duodenum, and TNF-α, IgG, and MDA in the jejunum of the pigs. β-Mannanase supplementation linearly increased (P < 0.05) villus height to crypt depth ratio and crypt cell proliferation in the jejunum. β-Mannanase supplementation tended to linearly improve (P = 0.083) expression of zonula occludens-1 in the jejunum. In conclusion, supplementation of β-mannanase at 360 U/kg reduced the digesta viscosity and up to 600 U/kg positively affected intestinal health and growth of pigs by reducing inflammation and oxidative stress whilst enhancing structure and barrier function in the jejunum.

Individual or combinational use of phytase, protease, and xylanase for the impacts on total tract digestibility of corn, soybean meal, and distillers dried grains with soluble fed to pigs

OBJECTIVE

This study was to evaluate the effects of individual or combinational use of phytase, protease, and xylanase on total tract digestibility of corn, soybean meal, and distillers dried grains with soluble (DDGS) fed to pigs.

METHODS

Each experiment had four 4×4 Latin squares using 16 barrows. Each period had 5-d adaptation and 3-d collection. All experiments had: CON (no enzyme); Phy (CON+phytase); Xyl (CON+xylanase); Pro (CON+protease); Phy+Xyl; Phy+Pro, Xyl+Pro, Phy+Xyl+Pro. Each Latin square had 'CON, Phy, Xyl, and Phy+Xyl'; 'CON, Phy, Pro, and Phy+Pro'; 'CON, Pro, Xyl, and Xyl+Pro'; and 'Phy+Xyl, Phy+Pro, Xyl+Pro, Phy+Xyl+Pro'.

RESULTS

The digestible energy (DE), metabolizable energy (ME), and nitrogen retention (NR) of corn were not affected by enzymes but the apparent total tract digestibility (ATTD) of phosphorus (P) was improved (p<0.01) by Phy. The DE and ATTD dry matter (DM) in soybean meal were increased (p<0.05) by Phy+Pro and the ATTD P was improved (p<0.01) by Phy, Phy+Pro, and Phy+Xyl. The DE, ME, and ATTD DM in DDGS were improved (p<0.05) by Phy+Xyl and the ATTD P was improved (p<0.01) by Phy, Phy+Pro, and Phy+Xyl.

CONCLUSION

Phytase individually or in combination with xylanase and protease improved the Ca and P digestibility of corn, soybean meal, and DDGS, from the hydrolysis of phytic acid. The supplementation of protease was more effective when combined with phytase and xylanase in the soybean meal and DDGS possibly due to a higher protein content in these feedstuffs. Xylanase was more effective in DDGS diets due to the elevated levels of non-starch polysaccharides in these feedstuffs. However, when xylanase was combined with phytase, it demonstrated a higher efficacy improving the nutrient digestibility of pigs. Overall, combinational uses of feed enzymes can be more efficient for nutrient utilization in soybean meal and DDGS than single enzymes.

Effects of prebiotics and precision biotics on performance, animal welfare and environmental impact. A review

This review aims to analyze the recent studies about prebiotics and precision biotics, as alternatives to animal growth promoters. These substances improve intestinal health, growth performance and poultry environmental impact. Prebiotics are insoluble fibers, that have no nutritive value, but they promote the growth of positive bacteria, increase the nutrients absorption and modulate the immune response. Instead, precision biotics are carbohydrates with glycosidic linkages, which interact with gut bacteria metabolism, reducing the excretion of nitrogen and consequentially, the poultry environmental impact. In the last years, different studies were published in this field, and for this reason, it is necessary to organize the results found. It was shown that mannan-oligosaccharides and β-glucans increase ileal nutrient digestibility, nitrogen retention and antibodies titers. Inulin, arabinoxylans-derived oligosaccharides, and galacto-oligosaccharides improved intestinal morphology, arranging for a larger absorption surface area. It was reported that prebiotics enhance the colonization of positive bacteria and can reduce the count of Campylobacter colonies. Furthermore, xylo-oligosaccharides are often used in animal feed, due to their ability to form organic acids, which decompose noxious substances, improving litter quality, and consequentially, reducing the environmental impact. Litter quality is a relevant aspect for ammonia emissions and for animal welfare. Whether the litter quality is poor, footpad dermatitis increase, worsening animal welfare and increasing nitrogen emissions to air. Precision biotics select metabolic pathways to modulate amino acid degradation, reintegrating the nitrogen discarded, and reducing the ammonia level in litter. It was also reported an improvement of growth performance and a better animal welfare. In conclusion, prebiotics and precision biotics can have positive effects on animal performance and welfare, and they can be a new strategy to reduce the environmental impact of chickens' farms.

The Effects of 1-Deoxynojirimycin from Mulberry on Oxidative Stress and Inflammation in Laying Hens and the Direct Effects on Intestine Epithelium Cells In Vitro

The intestine is highly vulnerable to various factors and has been proposed as a promising determinant for poultry health. Phytogenic or plant-derived feed additives can be used to help improve intestinal health. In this study, we aimed to investigate the effects of DNJ on the antioxidative parameters, including malondialdehyde (MDA), total superoxide dismutase (T-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and inflammatory cytokines (IL-6, IL-1β, and TNF-α), in plasma and intestinal tissues using layers supplemented with or without the DNJ extract of mulberry leaves (DNJ-E) via the ELISA method. A total of 192 healthy Hy-Line Brown layers, aged 47 weeks old, were used to conduct a 56-day study. All hens were randomly separated into four groups as follows: a basal diet containing 0 mg/kg DNJ-E(CON), 50 mg/kg, 100 mg/kg, and 150 mg/kg DNJ-E. Furthermore, the potential mechanism by which DNJ influences intestinal function was also investigated in in vitro cultured intestinal epithelium cells (IEC) with quantification methods including the use of a cell counting kit-8 (CCK8), ELISA, qRT-PCR, and ROS detection. The results showed that CAT in plasma significantly increased following 50 mg/kg DNJ-E supplementation. Moreover, 50 mg/kg DNJ-E supplementation was associated with increases in T-SOD in the jejunum and ileum. However, there was no significant difference in inflammatory cytokines between groups in in vivo experiments. Subsequent in vitro IEC studies revealed that cell viability increased significantly following 5 µM and 10 µM DNJ treatments while decreasing significantly following 20 µM DNJ treatment. Antioxidative parameters improved at 5 µM and 10 µM DNJ concentrations. However, there were no ameliorative effects on antioxidant parameters observed under 20 µM DNJ treatment. The expression levels of Nrf2 mRNA increased significantly under DNJ treatment. DNJ treatment was associated with significant changes in the expression of genes of inflammatory cytokines. In conclusion, our study revealed that DNJ could improve oxidative stress and inflammation responses in the chicken intestine. These findings provide a theoretical reference for the development of functional feed additives that regulate intestinal health and lay the foundation for systematically revealing the mechanism of DNJ.

Effect of phytase and xylanase enzymes on growth performance and Mucin2 gene expression in broiler chickens

BACKGROUND

Development of exogenous enzymes is one of the most important discoveries in animal nutrition. The supplementation of exogenous enzymes in broiler diets allows for supplying nutrient deficiencies and to decrease endogenous losses.

OBJECTIVES

The effects of phytase (Hostazym and Phyzyme) and xylanase (Ronozyme) enzymes were investigated on growth performance and Mucin2 gene expression in broilers.

METHODS

A completely randomized design was applied, including 7 treatments, 4 replicates and 25 birds per replicates. A total of 700 male Ross (308) broiler chickens were fed with similar diets supplemented by Hostazym and Phyzyme (500 and 1000 FTU/kg) and Ronozyme (100 and 200 EXU/kg). Weight gain (WG), feed intake (FI) and feed conversion ratio (FCR) were determined for three phases and entire rearing period. On 42 days of age, four birds per replicate were slaughtered. Total RNA was extracted from jejunum samples, and Mucin2 gene expression was measured by real-time PCR.

RESULTS

Phytase and xylanase enzymes had a significant effect (p < 0.05) on traits (WG and FCR) in grower and finisher phases and whole rearing period, but FI was not affected by enzymes (p > 0.05). Carcass (74.13 g) and breast (27.76 g) weights by Hostazym (1000 FTU/kg) were higher than other treatments (p < 0.05). Weight of liver, bursa and spleen were significantly influenced by enzymes (p < 0.05). Likewise, bursa and spleen weights in Hostazym (1000 FTU/kg feed) and Ronozyme (200 EXU/kg feed) were significantly higher than other treatments (p < 0.05). Mucin2 gene expression was affected by enzymes in whole treatments. The lowest amount of Mucin2 gene expression belonged to Ronozyme (200 and 100 EXU/kg), and the highest was belonging to Hostazym (1000 FTU/kg).

CONCLUSIONS

Phytase enzymes have higher effect on broiler performance and Mucin2 gene expression compared to xylanase. High doses of Hostazym (1000 FTU/kg feed) could be supplemented in broiler chicken diets to improve optimum growth and feed efficiency.

Efficacy of a bacterial 6-phytase supplemented beyond traditional dose levels on jejunal mucosa-associated microbiota, ileal nutrient digestibility, bone parameters, and intestinal health, and growth performance of nursery pigs

This study aimed to determine the efficacy of a bacterial 6-phytase (Buttiauxella spp.) supplemented beyond traditional dose levels based on jejunal mucosa-associated microbiota, apparent ileal digestibility (AID), intestinal health and bone parameters, and growth performance of nursery pigs. Seventy-two weaned pigs (36 barrows and 36 gilts at 21 d of age with 5.8 ± 0.5 kg BW) were allotted to six treatments based on randomized complete block design with sex and initial BW as blocks and fed in three dietary phases (phase 1 for 14 d, phase 2 for 10 d, and phase 3 for 14 d). The treatments included a negative control (NC) diet without phytase formulated meeting nutrient requirements by NRC and the other five treatments were deficient in calcium (Ca) and phosphorus (P) by 0.12% with increasing levels of a bacterial 6-phytase (0, 500, 1,000, 2,000, and 5,000 FTU/kg feed). Titanium dioxide (0.4%) was added to phase 3 diets as an indigestible marker to measure AID of nutrients. On day 45, all pigs were euthanized to collect ileal digesta to measure AID, the third metacarpus to measure bone parameters, and jejunal mucosa to evaluate intestinal health and microbiota. Data were analyzed using the MIXED procedure for polynomial contrasts and the NLMIXED procedure for broken line analysis using the SAS 9.4. Broken line analysis demonstrated that 948 FTU/kg feed increased (P < 0.05) the ADG and the bone P content. Increasing phytase supplementation increased (linear, P < 0.05) AID of CP, bone P, and ash content. Increasing phytase supplementation reduced (P < 0.05) the fecal score during phases 2 and 3. Broken line analysis demonstrated that 1,889 FTU/kg feed increased (P < 0.05) bone breaking strength. Increasing phytase supplementation (PC vs. Phy) increased (P < 0.05) AID of ether extract (EE) and P. The supplementation of phytase at 2,000 FTU/kg feed tended (P = 0.087) to reduce the relative abundance of Prevotellaceae. In conclusion, the supplementation of a bacterial 6-phytase beyond traditional dose levels improved bone breaking strength, bone ash, and P content, AID of CP, EE, and P, and growth performance of nursery pigs with reduced relative abundance of Bacteroidetes specifically Prevotellaceae in the jejunal mucosa. Supplementation of a bacterial 6-phytase between 1,000 and 2,000 FTU/kg feed provided benefits associated with growth performance and bone parameters of nursery pigs.