The Role of ß-Mannanase (Hemicell) in Improving Poultry Productivity, Health and Environment

Dietary lysozyme and avilamycin modulate gut health, immunity, and growth rate in broilers

BACKGROUND

Attempts to use dietary lysozyme (LYZ) as an alternative to antibiotics in broilers have been successful, but further research is needed for effective use. Here, we compared the differences between LYZ and avilamycin (AVI) feed additives for growth performance, gut health and immunity of broilers. One-day old, one hundred and twenty broiler chicks (Ross 308) were randomly allocated into three groups consisting forty birds in each group. Standard diet without supplementation was applied as the control group (I), while the chicks of the other groups were supplemented with 100 mg of AVI per kg diet (AVI, group II), and 90 mg LYZ per kg diet (LYZ, group III) for five consecutive weeks.

RESULTS

Body weight, feed conversion ratio, body weight gain, and European production efficiency factor were markedly (p < 0.05) increased in both AVI and LYZ groups in relation to CON group, but the feed intake and protein efficiency ratio were not affected. Both AVI and LYZ significantly (p < 0.001) upregulated the mRNA expression of ileal interleukin-18 (IL-18), interferon-gamma (IFN-γ), and interleukin-10 (IL-10), interleukin-2 (IL-2), and glutathione peroxidase (GSH-PX) genes compared to CON group. However, IL-2, IL-10, IL-18, and GSH-PX genes were markedly (p < 0.01) upregulated in LYZ compared to the AVI group. LYZ treated group had a significant increase (p < 0.05) in the serological haemagglutination inhibition titers of H5N1 vaccination and a significant decrease (p < 0.0001) in coliform counts compared to control and AVI groups, but all growth parameters were nearly similar between AVI and LYZ groups. The VH and VH/CD were markedly higher in LYZ than AVI and control groups.

CONCLUSION

Exogenous dietary lysozyme supplementation by a dose of 90 mg/kg broilers' diet induced better effects on intestinal integrity, fecal bacterial counts, immune response, and growth performance which were comparable to avilamycin. Therefore, dietary lysozyme could safely replace avilamycin in the broiler chickens' diet. However, further experimental studies regarding the use of lysozyme in commercial broilers, both in vitro and in vivo, targeting more communities of intestinal microbiome and explaining more details about its beneficial effects need to be conducted.

Dietary supplementation with β-mannanase and probiotics as a strategy to improve laying hen performance and egg quality

The objective of this study was to assess the impact of β-mannanase and probiotic on the performance, serum biochemistry, gut morphometric traits, and fresh egg quality of laying hens. A total of 120 cages, housing light-weight laying hens (36 weeks old), were randomly assigned to four different treatments. These treatments included a control group fed non-supplemented diets; diets supplemented with 300 g/ton of beta-mannanase; diets supplemented with 50 g/ton of probiotic; or diets containing both 300 g/ton of β-mannanase and 50 g/ton of probiotics. The trial spanned a duration of 26 weeks and was divided into three productive phases, each lasting 28 days. The inclusion of β-mannanase resulted in a significant improvement in the laying rate by 11% (p < 0.05) compared to the control treatment. Similarly, the addition of probiotics also enhanced the laying rate by 7% (p < 0.05), as well as the supplementation with combined additives (11.5%). Combined additives showed an increase in egg masses, and additive association improved by 13.9% (p < 0.001) in contrast to the control treatment. Overall, β-mannanase and combined additives used during the supplementation period resulted in improvements in the weight of fresh eggs. These benefits were observed after a period of 14 weeks without supplementation (p < 0.05). Furthermore, significant differences were observed in the serum biochemistry and egg masses of birds that were fed diets containing both additives (β-mannanase + probiotics) compared to the control group. Parameters such as uric acid, total cholesterol, and triglycerides displayed notable variations. The villi height: crypt depth showed differences with combined additives (β-mannanase + probiotics). The β-mannanase improved specific gravity, yolk height, length, and pH, and yolk color traits compared to the control treatment. The use of probiotics helped to improve yolk height, pH, and color score. Besides, combined additives (β-mannanase + probiotics) improve yolk height, length, weight, pH, and better traits in yolk color. Hence, incorporating β-mannanase and probiotics into laying hen diets proves to be a highly effective strategy for enhancing laying rate and overall health status, while simultaneously elevating certain quality attributes of fresh eggs.

Diet medication and beta-glucanase affect ileal digesta soluble beta-glucan molecular weight, carbohydrate fermentation, and performance of coccidiosis vaccinated broiler chickens given wheat-based diets

Exogenous enzymes as alternatives to feed antibiotics in poultry has become an emerging research area with the emergence of antibiotic resistance. The objective was to evaluate the effects of diet medication (antibiotics) and β-glucanase (BGase) on digesta soluble β-glucan depolymerization, carbohydrate fermentation, and performance of coccidiosis-vaccinated broiler chickens fed wheat-based diets. A total of 1,782 broilers were raised on litter floor pens, and each treatment was assigned to 1 pen in each of the 9 rooms. The 3 dietary treatments were based on wheat as the sole grain (control, control + medication and control + 0.1% BGase), and the birds were fed the respective treatments ad libitum from 0 to 33 d. Treatments were arranged in a randomized complete block design and analyzed as a one-way ANOVA. Beta-glucanase reduced the peak molecular weight, weight average molecular weight (Mw) and maximum molecular weight for the smallest 10% β-glucan molecules (MW-10%) in ileal digesta at d 11 and 33, whereas diet medication reduced Mw and MW-10% at d 33 compared to the control (P < 0.01). Beta-glucanase and medication reduced the ileal viscosity at d 11 compared to the control (P = 0.010). Ileal propionic acid concentration at d 11 and caecal total SCFA, acetic, and butyric acid concentrations at d 33 were lower in the BGase-supplemented diet than in the control (P < 0.05). The BGase-added diet had higher duodenal pH compared to the control at d 33 (P = 0.026). The effect of medication on carbohydrate fermentation was minimal. Diet medication increased weight gain after d 11, whereas BGase increased the gain for the total trial period compared to the control (P < 0.001). Feed intake was not affected by the dietary treatment. Medication and BGase improved feed efficiency after d 11 compared to the control (P < 0.001). The response to diet medication was larger than BGase, considering weight gain and feed efficiency after d 11 (P < 0.001). In conclusion, diet medication and BGase depolymerized high molecular weight ileal soluble β-glucan and increased overall bird performance. Dietary BGase may benefit bird health in broilers fed wheat-based diets without medication.

Ameliorative avian gut environment and bird productivity through the application of safe antibiotics alternatives: a comprehensive review

The avian digestive tract is an important system for converting ingested food into the nutrients their bodies need for maintenance, growth, and reproduction (meat, table eggs, and fertile eggs). Therefore, preserving digestive system integrity is crucial to bird health and productivity. As an alternative to antibiotics, the world has recently turned to the use of natural products to enhance avian development, intestinal health, and production. Therefore, the primary goal of this review is to explain the various characteristics of the avian digestive tract and how to enhance its performance with natural, safe feed additives such as exogenous enzymes, organic acids, photogenic products, amino acids, prebiotics, probiotics, synbiotics, and herbal extracts. In conclusion, the composition of the gut microbiome can be influenced by a number of circumstances, and this has important consequences for the health and productivity of birds. To better understand the connection between pathogens, the variety of therapies available, and the microbiome of the gut, additional research needs to be carried out.

Guar gum as galactomannan source induces dysbiosis and reduces performance in broiler chickens and dietary β-mannanase restores the gut homeostasis

Galactomannans are abundant nonstarch polysaccharides in broiler feed ingredients. In broilers, diets with high levels of galactomannans have been associated with innate immune response stimulation, poor zootechnical performance, nutrient and lipid absorption, and excessive digesta viscosity. However, data about its effects on the gut microbiome are scarce. β-Mannanases are enzymes that can hydrolyze β-mannans, resulting in better nutrient utilization. In the current study, we have evaluated the effect of guar gum, a source of galactomannans, supplemented to broiler diets, either with or without β-mannanase supplementation, on the microbiota composition, in an attempt to describe the potential role of the intestinal microbiota in β-mannanase-induced gut health and performance improvements. One-day-old broiler chickens (n = 756) were randomly divided into 3 treatments: control diet, guar gum-supplemented diet (1.7%), or guar gum-supplemented diet + β-mannanase (Hemicell 330 g/ton). The zootechnical performance, gut morphometry, ileal and cecal microbiome, and short-chain fatty acid concentrations were evaluated at different time points. The guar gum supplementation decreased the zootechnical performance, and the β-mannanase supplementation restored performance to control levels. The mannan-rich diet-induced dysbiosis, with marked effects on the cecal microbiota composition. The guar gum-supplemented diet increased the cecal abundance of the genera Lactobacillus, Roseburia, Clostridium sensu stricto 1, and Escherichia-Shigella, and decreased Intestinimonas, Alistipes, Butyricicoccus, and Faecalibacterium. In general, dietary β-mannanase supplementation restored the main microbial shifts induced by guar gum to levels of the control group. In addition, the β-mannanase supplementation reduced cecal isobutyric, isovaleric, valeric acid, and branched-chain fatty acid concentrations as compared to the guar gum-supplemented diet group, suggesting improved protein digestion and reduced cecal protein fermentation. In conclusion, a galactomannan-rich diet impairs zootechnical performance in broilers and results in a diet-induced dysbiosis. β-Mannanase supplementation restored the gut microbiota composition and zootechnical performance to control levels.

Dietary supplementation with β-mannanase and probiotics as a strategy to improve laying hen's welfare

A trend toward animal welfare improvement is observed in animal production, in addition to restrictions imposed on the use of antimicrobials. This study's objective was to evaluate whether β-mannanase and probiotic supplementation can change hen's behavior. Light weight laying hens (36 weeks old) were housed in cages randomly allocated to one of four different treatments: control group, fed non-supplemented diets; diets supplemented with 300 g/ton of β-mannanase; diets supplemented with 50 g/ton of probiotic; or diets containing both 300 g/ton of β-mannanase and 50 g/ton of probiotic. The behavior of 24 birds was recorded for a week using video cameras. The frequency and time of main behaviors (eating, walking, standing, sitting, drinking, and exploring) were analyzed in three periods per day (from 09:00 to 09:15; from 01:00 to 01:15, and from 04:00 to 04:15), as well as the time of other behaviors (leg-stretching and wings, scratching, wing-flapping, aggressive and non-aggressive pecks). Frequency and lesion scores were also analyzed using a visual score of three body regions: neck, tail, and cloaca; as well as comb injuries. β-mannanase was able to increase the frequency of feeding behavior by 49% (P < 0.05) and hens also spend 20% (P < 0.05) more time in this behavior compared to the control treatment. The use of probiotics also enhanced by 39% (P < 0.05) the frequency and 19% the time (P < 0.05) and the supplementation with combined additives was able to increase by 29% (P < 0.05) the frequency and 25% (P < 0.05) the time in feeding behavior. β-mannanase and probiotics also increased the frequency and time spent exploring behavior (P < 0.05) and promoted a higher frequency in standing behavior (P < 0.05) and decreased the time spent on sitting behaviors (P < 0.05). The combined additives showed less frequency and time in sitting behaviors (P < 0.05), while increased wing-flapping behavior (P < 0.05). All the treatments were able to reduce pecking (P < 0.05). Therefore, the addition of β-mannanase and probiotics to laying hen diets is an effective strategy to improve bird welfare.

Does supplementing β-mannanase modulate the feed-induced immune response and gastrointestinal ecology in poultry and pigs? An appraisal

The provision of adequate and balanced nutrients is critical for efficient and profitable animal protein production. However, non-nutritive components in feedstuffs can elicit responses that can negatively impact nutrient utilization efficiency. For example, dietary β-mannans are recognizable by cell surface mannose receptors are pivotal for diverse cellular functions. This review will evaluate the physiological implications of dietary native β-mannans, the utility of supplemental feed β-mannanase in hydrolyzing β-mannans, and subsequent metabolic responses. Dietary native β-mannans have been implicated in inadvertent stimulation of immune response through a phenomenon called the feed-induced immune response (FIIR), that has been associated with intestinal inflammation and depression in animal performance. Supplemental β-mannanase blunted the FIIR by hydrolyzing native β-mannans to smaller fragments with a reduced ability to stimulate the innate immune system as indicated by the modulation of oxidative stress, mucosal permeability, and blood concentration of acute phase proteins and immunoglobulins in broilers and piglet models. Moreover, β-mannanase hydrolysis of native β-mannans to mannooligosaccharides (MOS) impacted gastrointestinal microbial ecology. Indeed, β-mannanase-derived MOS reduced the concentration of pathogenic bacteria such as Escherichia coli and Salmonella and increased the production of short-chain fatty acids in gastrointestinal tracts of various animal models. Consequently, by hydrolyzing native β-mannans, supplemental β-mannanase may have nutritional, metabolic, and microbial ecology benefits. In summary, integrating multi-functional feed additives such as β-mannanase into feeding programs for monogastric animals will be critical for efficient and sustainable animal protein production in the context of evolving challenges such as the mandated elimination of use of antibiotics for growth promotion.

Potential Feed Additives as Antibiotic Alternatives in Broiler Production

This article aimed to describe the current use scenario, alternative feed additives, modes of action and ameliorative effects in broiler production. Alternative feed additives have promising importance in broiler production due to the ban on the use of certain antibiotics. The most used antibiotic alternatives in broiler production are phytogenics, organic acids, prebiotics, probiotics, enzymes, and their derivatives. Antibiotic alternatives have been reported to increase feed intake, stimulate digestion, improve feed efficiency, increase growth performance, and reduce the incidence of diseases by modulating the intestinal microbiota and immune system, inhibiting pathogens, and improving intestinal integrity. Simply, the gut microbiota is the target to raise the health benefits and growth-promoting effects of feed additives on broilers. Therefore, naturally available feed additives are promising antibiotic alternatives for broilers. Then, summarizing the category, mode of action, and ameliorative effects of potential antibiotic alternatives on broiler production may provide more informed decisions for broiler nutritionists, researchers, feed manufacturers, and producers.

Effects of dietary Bacillus amyloliquefaciens CECT 5940 supplementation on growth performance, antioxidant status, immunity, and digestive enzyme activity of broilers fed corn-wheat-soybean meal diets

This experiment was conducted to investigate the effects of dietary supplementation with Bacillus amyloliquefaciens CECT 5940 (BA-5940) on growth performance, antioxidant capacity, immunity, and digestive enzyme activity of broiler chickens. A total of 720 one-day-old Arbor Acres male broiler chicks (average body weight, 45.87 ± 0.86 g) were randomly allocated to 5 treatments of 8 replicates with 18 chicks in each replicate. Broilers in the control group were fed a corn-wheat-soybean basal diet, the other 4 groups were fed the same basal diet supplemented with 500, 1,000, 1,500, or 2,000 mg/kg Ecobiol (1.27 × 109 CFU/g BA-5940) for 42 d, respectively. Broilers fed diets supplemented with BA-5940 showed a quadratic response (P < 0.05) of average daily gain (ADG) and feed to gain ratio (F:G) during d 22 to 42 and d 0 to 42. The glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities in serum and liver, and total antioxidant capacity (T-AOC) in liver of broilers on d 42 increased linearly (P < 0.05) with increasing levels of BA-5940, while malondialdehyde (MDA) level in serum decreased linearly (P < 0.05). Concentrations of serum immunoglobulin (Ig) A and IgM on d 21, and IgM on d 42 increased linearly (P < 0.05) as BA-5940 levels increased. Supplementation with increasing levels of BA-5940 linearly decreased serum tumor necrosis factor-α (TNF-α) levels on d 21 and 42, while increased interleukin (IL)-10 concentration (linear, P < 0.05) on d 21. Meanwhile, the levels of IL-1β, IL-6, and TNF-α in the mucosa of jejunum and ileum were decreased (linear, P < 0.05) on d 42 as dietary supplementation of BA-5940 increased. Additionally, supplementation with BA-5940 also increased the activities of amylase (linear, P < 0.01), lipase (linear, P < 0.05) and chymotrypsin (linear, P < 0.01) in jejunal digesta, and lipase (linear, P < 0.05) in ileal digesta of broilers on d 42. To summarize, inclusion of BA-5940 in corn-wheat-soybean meal-based diet improved growth performance of broilers through improving antioxidant capacity, immunity, and digestive enzyme activity. Based on the results of this study, 1.1-1.6 × 109 CFU/kg BA-5940 is recommended for supplementation in broiler diets.

Multi-Omics Characterization of Host-Derived Bacillus spp. Probiotics for Improved Growth Performance in Poultry

Microbial feed ingredients or probiotics have been used widely in the poultry industry to improve production efficiency. Spore-forming Bacillus spp. offer advantages over traditional probiotic strains as Bacillus spores are resilient to high temperature, acidic pH, and desiccation. This results in increased strain viability during manufacturing and feed-pelleting processes, extended product shelf-life, and increased stability within the animal’s gastrointestinal tract. Despite numerous reports on the use of Bacillus spores as feed additives, detailed characterizations of Bacillus probiotic strains are typically not published. Insufficient characterizations can lead to misidentification of probiotic strains in product labels, and the potential application of strains carrying virulence factors, toxins, antibiotic resistance, or toxic metabolites. Hence, it is critical to characterize in detail the genomic and phenotypic properties of these strains to screen out undesirable properties and to tie individual traits to clinical outcomes and possible mechanisms. Here, we report a screening workflow and comprehensive multi-omics characterization of Bacillus spp. for use in broiler chickens. Host-derived Bacillus strains were isolated and screened for desirable probiotic properties. The phenotypic, genomic and metabolomic analyses of three probiotic candidates, two Bacillus amyloliquefaciens (Ba ATCC PTA126784 and ATCC PTA126785), and a Bacillus subtilis (Bs ATCC PTA126786), showed that all three strains had promising probiotic traits and safety profiles. Inclusion of Ba ATCC PTA12684 (Ba-PTA84) in the feed of broiler chickens resulted in improved growth performance, as shown by a significantly improved feed conversion ratio (3.3%), increased of European Broiler Index (6.2%), and increased average daily gain (ADG) (3.5%). Comparison of the cecal microbiomes from Ba PTA84-treated and control animals suggested minimal differences in microbiome structure, indicating that the observed growth promotion presumably was not mediated by modulation of cecal microbiome.

Significance of single β-mannanase supplementation on performance and energy utilization in broiler chickens, laying hens, turkeys, sows, and nursery-finish pigs: a meta-analysis and systematic review

This review will give a brief description of β-mannans, abundance in feedstuffs, utility of supplemental feed β-mannanase, and subsequent animal responses. Soybean products and co-products of processing palm, coconut, and guar seeds are the major sources of β-mannans in poultry and livestock feed. β-Mannans are linear polymers of mannose residues linked by β-1,4 glycosidic bonds and their ingestion elicit undesirable and metabolically costly responses. Web of Science was searched to retrieve published studies for meta-analyses of the impact of supplemental β-mannanase on performance and digestibility in pigs and poultry. The mean difference (MD) between β-mannanase and control on average daily gain (g/d) was +0.23 (P = 0.013; 95% CI of 0.05; 0.41), +10.8 g/d (P = 0.0005; 95% CI of 6.6; 15.0 g/d), and +20.68 (P < 0.000; 95% CI of 17.15; 24.20 g/d) for broiler chickens, nursery pigs, and grow-finish pigs, respectively. The MD on β-mannanase improvement on feed conversion (FCR) was -0.02 (P < 0.0001) with 95% CI (-0.03; -0.02) suggesting a 2-to-3-point FCR improvement in broiler chickens. β-Mannanase improvement on gain to feed (G:F) was +13.8 g/kg (P = 0.027; 2.1; 25.4 g/kg) and +8.77 g/kg (6.32; 11.23 g/kg) in nursery and grow-finish pigs, respectively. β-Mannanase improved apparent metabolizable energy by 47 kcal/kg (P = 0.0004) with 95% CI (28.8; 65.7 kcal/kg) in broiler chickens. The improvement of gross energy digestibility in pigs was 1.08% unit with 95% CI (0.90; 1.26) translating to the release of between 30.6 and 42.8 kcal/kg of digestible energy. Although data were limited, β-mannanase improved egg production in laying hens linked to improved energy metabolism in laying hens linked to improved energy metabolism but had no impact on egg quality. Turkeys may be more adversely affected by β-mannans because of the high protein/amino acids requirements necessitating higher dietary inclusion of soybean meal. However, growth performance and feed efficiency responses of turkeys fed diets supplemented with β-mannanase were variable. In summary, β-mannanase supplementation improved performance linked to energy and nutrient utilization. However, the magnitude of response was variable within and between species indicating further application refinement is warranted to achieve consistent efficacy, and improved understanding of the functional contribution of β-mannans hydrolysis products.

Effects of potato peels inclusion with exogenous enzymes in broiler diet on growth performance, nutrients digestibility and carcass characteristics

The purpose of the research was to investigate the effects of including potato peels (PP) in broilers diet with exogenous enzymes supplementation on feed intake (FI), body weight gain (BWG), nutrient digestibility and carcass parameters. For this purpose, five iso-caloric and iso-nitrogenous rations were formulated with different levels of PP (0, 5, 10, 15 and 20%). Experimental diets were supplemented with a blend of exogenous enzymes (Xylanase, Mannanase, Protease, Cellulase). A total of four hundred male broiler chicks (day old) of 38 ± 3 gram were randomly distributed into 5 experimental groups in such a way that each group had 8 replicates and each replicate had 10 birds. Results revealed that the inclusion of PP @ 5% with exogenous enzymes had similar FI, BWG and nutrients digestibility with control. However, the inclusion of P @ of 10, 15, and 20% with exogenous enzymes in the broiler diet adversely affected the BWG, feed conversion ratio and nutrient digestibility (p < 0.05). Results of carcass parameters were not affected (p > 0.05) by dietary treatments. Based on findings, it is concluded that 5% addition of PP with exogenous enzymes could be practiced in broiler diet without any adverse effect on the performance of commercial broilers.

Effects of different feeding regimens with protease supplementation on growth, amino acid digestibility, economic efficiency, blood biochemical parameters, and intestinal histology in broiler chickens

Background

This study was conducted to estimate the impacts of using varied feeding regimens with or without protease supplementation on the growth performance, apparent amino acid ileal digestibility (AID%), economic efficiency, intestinal histology, and blood biochemical parameters of broiler chickens. Three hundred one-day-old chicks (Ross 308 broiler) were randomly allotted to a 3 × 2 factorial design. The experimental design consisted of three feeding regimens; FR1: a recommended protein SBM diet, FR2: a low-protein SBM diet, and FR3: a low-protein diet with the inclusion of 5% DDGS and 5% SFM, with or without protease supplementation (250 mg/kg).

Results

Increased feed intake and feed conversion ratio were observed in the FR3 treatment during the starter stage and decreased body weight and body weight gain during the grower stage. However, there was no significant effect of the different feeding regimens, protease supplementation, or interaction on the overall performance. The economic value of diets also remained unaffected by the different feeding regimens, protease supplementation, or interaction. Protease supplementation resulted in lowering the AID% of tryptophan and leucine. Reduced AID% of methionine was evident in the FR2 + VE and FR3 − VE treatments. Histological findings substantiated the FR3 treatment mediated a decrease in the duodenal and jejunal villous height (VH), jejunal villous width (VW), and ileal VW, whereas, increase in the ileal crypt depth (CD). The FR2 + VE treatment reduced the VH:CD ratio in the duodenum. The duodenal CD and the jejunal goblet cell count were reduced as a consequence of protease supplementation. The FR3 + VE treatment documented a rise in duodenal CD, while an increase in the jejunal goblet cell count was observed in the FR3 − VE treatment. The FR3 treatment enhanced the IgM serum levels compared to the FR1 and FR2 treatments. IgM serum levels were also elevated following protease supplementation. FR3 + VE treatment increased IgM serum levels. The highest serum ALP was found in the FR3 treatment, whereas the lowest level was obtained in the FR2 treatment.

Conclusion

Low-protein SBM-based diets could be used without affecting the birds’ growth. Altered morphometric measures of the intestine and increased IgM and ALP levels indicated the low-protein SBM/DDGS-SFM diet-induced damage of the intestinal histoarchitecture and immune system of birds. These different diets and protease supplementation failed to affect economic efficiency positively.

Effects of dietary protein, energy and β-mannanase on laying performance, egg quality, and ileal amino acid digestibility in laying hens

β-mannan is a nonstarch polysaccharide found in hulled and dehulled soybeans that can survive drying-toasting phase of processing soybeans and have antinutritive effects in poultry. β-mannanase is an active enzyme (endohydrolase) that can hydrolyze β-mannan to reduce its antinutritional effects. Two experiments were conducted to evaluate the effects of β-mannanase supplementation in low energy/protein diets on egg production, egg quality, and apparent ileal digestibility of the dry matter (DM), crude protein (CP), and amino acids in 21-week-old Single Comb White Leghorn hens (Hy-Line W-36). A total of 192 hens (8 replicates of 6 hens per treatment) for a production study (Exp. 1) and a total of 64 hens (8 replicates of 2 hens per treatment) for a digestibility study (Exp. 2) were randomly allocated to 4 experimental treatments in a 2 × 2 factorial arrangement. Four dietary treatments were control (CS) based on corn and 44% CP soybean meal (ME: 2,850 kcal/kg CP: 18.5%) and CS-low energy/protein (CSL) (ME: 2,750 kcal/kg CP: 17.5%), with or without 0.05% β-mannanase enzyme. Hens were fed the experimental diets for 14 d for the digestibility study and 8 wk for the production study. Hen-day egg production (HDEP), weekly feed intake, FCR, and biweekly egg quality parameters were measured. Significant interaction on feed intake (P < 0.01) was observed between energy/protein and enzyme. At 3, 6 and 8 wk, the feed intake and FCR of CSL with enzyme were significantly lower than those of CSL without enzymes. The main effects indicated that birds fed diets without inclusion of β-mannanase had higher feed intake than those fed diets with enzymes at 4, 7, and 8 wk. The inclusion of β-mannanase significantly increased (P < 0.05) HDEP at 2, 3, 5, and 7 wk. However, there was no significant effect of nutrient density or enzyme supplementation on egg quality parameters. The digestibility study showed that the inclusion of β-mannanase significantly improved (P < 0.01) apparent ileal digestibility of lysine, histidine and tryptophan in the diet. The results of these experiments indicate that supplementation of β-mannanase could reduce the feed intake and FCR and improve HDEP and apparent ileal digestibility of key amino acids in corn/soy diets fed to laying hens.

Effect of β-mannanase enzyme supplementation on the morphofunctional state of broiler chickens’ immunocompetent organs

Identifying and eliminating factors that interfere with the nutrient absorption from feed is essential for successful poultry rearing. The nutritional value of feed mixtures used in the poultry industry can be increased by the use of enzyme supplements, in particular β-mannanase (Hemicell), which breaks down the anti-nutrients β-mannans that are present in significant quantities in soy products. For the study, two groups of 50 broiler chickens were formed. In the control group a standard feed mixture from cereals was used, particularly soybeans, and in the experimental group 0.05% β-mannanase enzyme supplement (Hemicell) in addition to the compound feed was used. Production indicators were established (average daily gain, survival rate, feed costs). On the 15th, 25th and 42nd days of rearing, lymphatic organs (cloacal bursa and spleen) were collected from seven chickens of each group, followed by macro, microscopic and morphometric evaluation. It was found that the addition of an enzyme supplement promotes an increase in the production indicators of poultry rearing, reduces feed use, does not affect the macroscopic characteristics of the lymphatic organs. β-mannanase (Hemicell) contributes to the maintenance of an active morphofunctional state of the cloacal bursa and spleen during the entire period of poultry rearing. This was manifested by high indices of the absolute and relative organ masses, a moderate development degree of tissue components and cloacal bursa histological structures (number, shape and average length of lymphatic nodules, density of lymphocytes in the cortex and medulla) and spleen (number and diameter of lymphatic nodules and periarterioal lymphatic sheaths). In the control group, at all stages of rearing, the morphofunctional state of the bursa was found to be lower and signs of immunosuppression were revealed by the end of the rearing period (a sharp decline in the bursa absolute mass, organ mass index, a decrease in the average length of nodules, change in their shape, thinned cortical layer and delymphotisation). The morphofunctional state of the spleen of chickens from the control group remained high throughout the entire study period. So use of the β-mannanase enzyme supplement (Hemicell) while rearing broiler chickens not only increased the efficiency of their rearing but also contributed to maintaining a high morphological and functional state of the cloacal bursa.

Cultivation of Mushrooms and Their Lignocellulolytic Enzyme Production Through the Utilization of Agro-Industrial Waste

A large amount of agro-industrial waste is produced worldwide in various agricultural sectors and by different food industries. The disposal and burning of this waste have created major global environmental problems. Agro-industrial waste mainly consists of cellulose, hemicellulose and lignin, all of which are collectively defined as lignocellulosic materials. This waste can serve as a suitable substrate in the solid-state fermentation process involving mushrooms. Mushrooms degrade lignocellulosic substrates through lignocellulosic enzyme production and utilize the degraded products to produce their fruiting bodies. Therefore, mushroom cultivation can be considered a prominent biotechnological process for the reduction and valorization of agro-industrial waste. Such waste is generated as a result of the eco-friendly conversion of low-value by-products into new resources that can be used to produce value-added products. Here, we have produced a brief review of the current findings through an overview of recently published literature. This overview has focused on the use of agro-industrial waste as a growth substrate for mushroom cultivation and lignocellulolytic enzyme production.