Rice expressing lactoferrin and lysozyme has antibiotic-like properties when fed to chicks

Postbiotic, anti-inflammatory, and immunomodulatory effects of aqueous microbial lysozyme in broiler chickens

Lysozymes, efficient alternative supplements to antibiotics, have several benefits in poultry production. In the present study, 120, one-day-old, Ross 308 broiler chickens of mixed sex, were allocated into 2 equal groups, lysozyme treated group (LTG) and lysozyme free group (LFG), to evaluate the efficacy of lysozyme (Lysonir®) usage via both drinking water (thrice) and spray (once). LTG had better (p = 0.042) FCR, and higher European production efficiency factor compared to LFG (p = 0.042). The intestinal integrity score of LTG was decreased (p = 0.242) compared to that of LFG; 0.2 vs. 0.7. Higher (p ≤ 0.001) intestinal Lactobacillus counts were detected in chickens of LTG. Decreased (p ≤ 0.001) IL-1β and CXCL8 values were reported in LTG. The cellular immune modulation showed higher (p ≤ 0.001) opsonic activity (MΦ and phagocytic index) in LTG vs. LFG at 25 and 35 days. Also, higher (p ≤ 0.001) local, IgA, and humoral, HI titers, for both Newcastle, and avian influenza H5 viruses were found in LTG compared to LFG. In conclusion, microbial lysozyme could improve feed efficiency, intestinal integrity, Lactobacillus counts, anti-inflammatory, and immune responses in broiler chickens.

Chicken egg lysozyme enhanced the growth performance, feed utilization, upregulated immune-related genes, and mitigated the impacts of Aeromonas hydrophila infection in Nile tilapia (Oreochromisniloticus)

Functional supplements, including lysozyme, are highly approved as immunostimulant and antibacterial agents with a high potential for use in aquaculture. In this regard, Nile tilapia was treated with lysozyme at 0, 0.5, 1, 1.5, and 3 g/kg for 60 days, then challenged with Aeromonas hydrophila. Fish were stocked in 15 glass aquaria (70 L each) with an equal initial weight of 10.72 ± 0.71 g per fish and 15 fish per aquarium. The regression analysis revealed that dietary lysozyme supplementation at 1.83-2 g/kg enhanced the growth performance, protein efficiency ratio, and protein productive value while reducing the feed conversion ratio of tilapia. Markedly, tilapia treated with lysozyme had a low mortality rate (30-50 %) compared to the control, which recorded a 70 % mortality rate after 15 days of challenge with A. hydrophila. The regression analysis also revealed that the highest lysozyme activity of tilapia-fed lysozyme for 60 days is achieved by 2.05 g/kg lysozyme. The expression of Nf-κb, IL-1β, and IL-8 genes is upregulated in tilapia-fed lysozyme at 0.5, 1, 1.5, and 3 g/kg for 60 days before and after A. hydrophila infection. The expression of GPX and CAT genes was higher in tilapia-fed lysozyme at 0.5, 1, 1.5, and 3 g/kg for 60 days before and after A. hydrophila infection. Before infection, the relative transcription of the lysozyme and C3 was upregulated in tilapia-fed lysozyme at 0.5, 1, 1.5, and 3 g/kg. However, lysozyme gene expression in tilapia treated with 0.5 g/kg lysozyme had no significant differences from those fed 0 g/kg lysozyme. After infection, the relative transcription of the lysozyme gene was upregulated in tilapia fed 1 and 1.5 g/kg, while tilapia fed 1 g/kg lysozyme had the highest C3 gene transcription. After infection, the hepatocytes in the livers of fish fed 0 g/kg lysozyme exhibited a noticeable fatty alteration, along with congestion, a light infiltration of inflammatory cells, and the start of necrosed cell regeneration. However, the livers of fish that received lysozyme were normal except for infiltrations of perivascular and interstitial mononuclear cells, depending on the supplementation dose. In conclusion, dietary lysozyme is recommended at 1.83-2.05 g/kg to gain high growth performance, immune response, and high resistance to A. hydrophila in Nile tilapia.

Nutraceutical and Health-Promoting Potential of Lactoferrin, an Iron-Binding Protein in Human and Animal: Current Knowledge

Lactoferrin is a natural cationic iron-binding glycoprotein of the transferrin family found in bovine milk and other exocrine secretions, including lacrimal fluid, saliva, and bile. Lactoferrin has been investigated for its numerous powerful influences, including anticancer, anti-inflammatory, anti-oxidant, anti-osteoporotic, antifungal, antibacterial, antiviral, immunomodulatory, hepatoprotective, and other beneficial health effects. Lactoferrin demonstrated several nutraceutical and pharmaceutical potentials and have a significant impact on improving the health of humans and animals. Lactoferrin plays a critical role in keeping the normal physiological homeostasis associated with the development of pathological disorders. The current review highlights the medicinal value, nutraceutical role, therapeutic application, and outstanding favorable health sides of lactoferrin, which would benefit from more exploration of this glycoprotein for the design of effective medicines, drugs, and pharmaceuticals for safeguarding different health issues in animals and humans.

Effects of Dietary Microbial Muramidase on the Growth, Liver Histoarchitecture, Antioxidant Status, and Immunoexpression of Pro-Inflammatory Cytokines in Broiler Chickens

The impact of microbial muramidase (MMUR) addition to broiler chicken rations was evaluated through growth parameters, liver histoarchitecture, antioxidant status, biochemical analysis, and expression of pro-inflammatory cytokines for 35 days. Four hundred three-day-old chicks (97.68 ± 0.59 g) were distributed to four distinct groups with ten duplicates each (100 chicks/group) consisting of: group 1 (G1): a basal diet without MMUR (control group); G2: a basal diet + 200 mg MMUR kg-1 G3: a basal diet + 400 mg MMUR kg-1; and G4: a basal diet + 600 mg MMUR kg-1. The results showed that the final body weight and total weight gain were increased (p = 0.015) in birds fed with diets supplemented with MMUR at 600 mg kg-1. The feed conversion ratio (FCR) was improved in all treatment groups compared with the control group. Birds fed with a diet supplemented with 600 mg MMUR kg-1 showed the highest body weight gain and improved FCR. The values of thyroxin hormones and growth hormones were increased in all MMUR-supplemented groups. Dietary MMUR increased the activities of antioxidant enzymes (total antioxidant activity, catalase, and superoxide dismutase) and decreased the activity of malondialdehyde (p < 0.05). In addition, it increased the values of interleukin 1 beta and interferon-gamma compared with the control group. Furthermore, dietary MMUR increased the expression of transforming growth factor-beta immunostaining in the liver and spleen tissues. Our results show that supplementing broilers' diets with 600 mg MMUR kg-1 could enhance the chicken growth rate and improve their antioxidant, inflammatory, and anti-inflammatory responses.

Exploring the effects of lysozyme dietary supplementation on laying hens: performance, egg quality, and immune response

An experiment was conducted to evaluate the dietary supplementation with lysozyme's impacts on laying performance, egg quality, biochemical analysis, body immunity, and intestinal morphology. A total of 720 Jingfen No. 1 laying hens (53 weeks old) were randomly assigned into five groups, with six replicates in each group and 24 hens per replicate. The basal diet was administered to the laying hens in the control group, and it was supplemented with 100, 200, 300, or 400 mg/kg of lysozyme (purity of 10% and an enzyme activity of 3,110 U/mg) for other groups. The preliminary observation of the laying rate lasted for 4 weeks, and the experimental period lasted for 8 weeks. The findings demonstrated that lysozyme might enhance production performance by lowering the rate of sand-shelled eggs (P < 0.05), particularly 200 and 300 mg/kg compared with the control group. Lysozyme did not show any negative effect on egg quality or the health of laying hens (P > 0.05). Lysozyme administration in the diet could improve intestinal morphology, immune efficiency, and nutritional digestibility in laying hens when compared with the control group (P < 0.05). These observations showed that lysozyme is safe to use as a feed supplement for the production of laying hens. Dietary supplementation with 200 to 300 mg/kg lysozyme should be suggested to farmers as a proper level of feed additive in laying hens breeding.

New Insights into the Effects of Microbial Muramidase Addition in the Diets of Broiler Chickens

The study aimed to explore how broiler chickens' blood biochemistry, breast muscles' fatty acid profile, growth, intestinal morphology, and immune status would be influenced by adding microbial muramidase (MUR) to the diet. Four hundred 3-day-old male broiler chickens were allocated to a completely randomized design consisting of four nutritional treatments (n = 100 per treatment, 10 chicks/replicate), each containing MUR at levels of 0 (control group), 200, 400, and 600 mg Kg^-1 diet, with enzyme activity 0, 12,000, 24,000, and 36,000 LSU(F)/kg diet, respectively. The 35-day experiment was completed. The findings showed that adding MUR to broiler meals in amounts of 200, 400, or 600 mg/kg had no impact on growth performance (p > 0.05) during the periods of 4-10, 11-23, and 24-35 days of age. MUR supplementation quadratically impacted the feed conversion ratio of broiler chicks at 11 and 23 days of age (p = 0.02). MUR addition to the diet significantly and level-dependently enhanced the percentage of n-3 and n-6 polyunsaturated fatty acids (PUFA) in breast muscles (p ≤ 0.01), with no alterations to the sensory characteristics of the breast muscles. Dietary MUR increased most of the morphometric dimensions of the small intestine, with the best results recorded at the 200 and 400 mg Kg^-1 levels. MUR supplementation at 200, 400, and 600 mg kg^-1 linearly lowered the total cholesterol, triglycerides, and low-density lipoprotein cholesterol level (p < 0.01). Still, it significantly increased the high-density lipoprotein cholesterol and very-low-density lipoprotein cholesterol contents compared with the unsupplemented group. Compared to controls, there was a substantial rise in the blood concentration of total protein, albumin, globulin, IL10, complement 3, and lysozyme activity as MUR levels increased (p < 0.01). Moreover, MUR addition significantly increased the immunoexpression of lymphocyte subpopulation biomarkers. We could conclude that MUR can be added to broiler chicken diets up to 600 mg kg ^-1 to improve broiler chickens' fatty acid profile in breast muscles, immunity, and blood biochemistry. MUR addition had no positive influence on the bird's growth.

Current and future interventions for improving poultry health and poultry food safety and security: A comprehensive review

Poultry is thriving across the globe. Chicken meat is the most preferred poultry worldwide, and its popularity is increasing. However, poultry also threatens human hygiene, especially as a fomite of infectious diseases caused by the major foodborne pathogens (Campylobacter, Salmonella, and Listeria). Preventing pathogenic bacterial biofilm is crucial in the chicken industry due to increasing food safety hazards caused by recurring contamination and the rapid degradation of meat, as well as the increased resistance of bacteria to cleaning and disinfection procedures commonly used in chicken processing plants. To address this, various innovative and promising strategies to combat bacterial resistance and biofilm are emerging to improve food safety and quality and extend shelf-life. In particular, natural compounds are attractive because of their potential antimicrobial activities. Natural compounds can also boost the immune system and improve poultry health and performance. In addition to phytochemicals, bacteriophages, nanoparticles, coatings, enzymes, and probiotics represent unique and environmentally friendly strategies in the poultry processing industry to prevent foodborne pathogens from reaching the consumer. Lactoferrin, bacteriocin, antimicrobial peptides, cell-free supernatants, and biosurfactants are also of considerable interest for their prospective application as natural antimicrobials for improving the safety of raw poultry meat. This review aims to describe the feasibility of these proposed strategies and provide an overview of recent published evidences to control microorganisms in the poultry industry, considering the human health, food safety, and economic aspects of poultry production.

Supplementation of broiler chicken diets with bovine lactoferrin improves growth performance, histological parameters of jejunum and immune-related gene expression

The aim of this study was to investigate the influence of dietary supplementation of bovine lactoferrin (bLF) on growth performance, carcass traits, histomorphology of jejunum, immune function and hepatic and splenic gene expression of interferon-gamma (IFN-γ) and interleukine-2 (IL-2) in broiler chickens. A total of 240 one-day-old Ross 308 male broiler chickens were randomly allotted into six dietary treatments with four replicate pens (10 chicks per pen) and fed experimental diet in 3 feeding phases (starter: d 0-10, grower: d 11-24 and finisher: d 25-42). The experimental treatments were (1) corn-soya bean meal-based basal diet (control), (2-5) basal diet supplemented with 200, 400, 600, 800 mg/kg bLF, respectively, and (6) basal diet supplemented with 200 mg/kg oxytetracycline (OTC). The average body weight gain (ABWG) of broilers fed 800 mg/kg bLF was 8.48% higher than those fed a corn-soybean meal-based diet during the starter period (d 0-10) (linear effect, p = 0.002; quadratic effect, p = 0.24). Average daily feed intake (ADFI) and the feed conversion ratio (FCR) were not affected (p>0.05) by bLF supplementation. At 42 days of age, the breast meat percentage and carcass yield of broilers fed 800 mg/kg bLF compared with the control group significantly increased by 9.51% and 6.03% respectively (p < 0.05). Compared with the chicks fed the control diet, the chicks fed diets supplemented with bLF had higher villus height, muscle thickness and villus surface area (p > 0.05). Dietary bLF inclusion increased the total immunoglobulin (IgT) titre against sheep red blood cells (SRBCs) antigen (linear effect, p = 0.031; quadratic effect, p = 0.035) and improved the phytohaemagglutinin-P (PHA-P)-skin test of broilers. Compared with the control, bLF enhanced the gene expression of IFN-γ in spleen (p = 0.048, linear effect, p = 0.009; quadratic effect, p = 0.093) and liver (p = 0.012, linear effect, p = 0.008; quadratic effect, p = 0.01) and IL-2 expression in spleen (p = 0.021, linear effect, p = 0.026; quadratic effect, p = 0.103). The bLF supplementation had no effect on IL-2 gene expression in liver (p > 0.05, linear effect, p = 0.213; quadratic effect, p = 0.159). In conclusion, we found that supplementation of broiler diets with 800 mg/kg bLF can improve the growth performance, carcass yield, cell-mediated and antibody-mediated immune responses and enhance the IL-2 and IFN-γ gene expression of broilers.

Effects of Dietary Coated Lysozyme on the Growth Performance, Antioxidant Activity, Immunity and Gut Health of Weaned Piglets

The purpose of this study was to evaluate the effects of dietary coated lysozyme on growth performance, serum biochemical indexes, antioxidant activity, digestive enzyme activity, intestinal permeability, and the cecal microbiota in weaned piglets. In total, 144 weaned Large White × Landrace piglets were divided into six treatment groups, with 3 replicates and 8 piglets per replicate: CN, a basal diet; CL-L, CL-M, and CL-H, basal diet supplemented with 100, 150, 500 mg/kg coated lysozyme; UL, basal diet supplemented with 150 mg/kg lysozyme; and Abs, basal diet supplemented with 150 mg/kg guitaromycin for 6 weeks. Compared with the CN and UL diets, dietary CL-H inclusion increased the average daily gain (ADG) and decreased the feed/gain (F/G) ratio of piglets (p < 0.05). The addition of 500 mg/kg coated lysozyme to the diet significantly increased the total protein (TP) and globulin (Glob) plasma levels of weaned piglets (p < 0.05). Supplementation with 500 mg/kg coated lysozyme significantly increased the serum IgM concentration and increased lipase activity in the duodenum (p < 0.05). The addition of coated lysozyme and lysozyme significantly decreased the malondialdehyde (MDA) content, while the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) levels all increased (p < 0.05). High-throughput sequencing results showed that CL-H treatment effectively improved the intestinal microbiome. The relative abundance of Terrisporobacter in the CL-H and CL-M groups was significantly lower than that in the other groups (p < 0.05). LEfSe analysis results showed that the relative abundance of Coprococcus_3 was higher in the CL-M treatment group. The marker species added to the CL-H treatment group was Anaerofilum. In summary, as a potential substitute for feed antibiotics, lysozyme is directly used as a dietary additive, which is inefficient. Therefore, we used palm oil as the main coating material to coat lysozyme. Lysozyme after coating can more effectively improve the growth performance of piglets by improving the intestinal flora, improving the activity of digestive enzymes, reducing the damage to intestinal permeability and oxidative stress in piglets caused by weaning stress, and improving the immunity of piglets.

Promising prospective effects of Withania somnifera on broiler performance and carcass characteristics: A comprehensive review

Poultry production contributes markedly to bridging the global food gap. Many nations have limited the use of antibiotics as growth promoters due to increasing bacterial antibiotic tolerance/resistance, as well as the presence of antibiotic residues in edible tissues of the birds. Consequently, the world is turning to use natural alternatives to improve birds' productivity and immunity. Withania somnifera, commonly known as ashwagandha or winter cherry, is abundant in many countries of the world and is considered a potent medicinal herb because of its distinct chemical, medicinal, biological, and physiological properties. This plant exhibits antioxidant, cardioprotective, immunomodulatory, anti-aging, neuroprotective, antidiabetic, antimicrobial, antistress, antitumor, hepatoprotective, and growth-promoting activities. In poultry, dietary inclusion of W. somnifera revealed promising results in improving feed intake, body weight gain, feed efficiency, and feed conversion ratio, as well as reducing mortality, increasing livability, increasing disease resistance, reducing stress impacts, and maintaining health of the birds. This review sheds light on the distribution, chemical structure, and biological effects of W. somnifera and its impacts on poultry productivity, livability, carcass characteristics, meat quality, blood parameters, immune response, and economic efficiency.

Antioxidant Stress and Anti-Inflammatory Activities of Egg White Proteins and Their Derived Peptides: A Review

Oxidative stress and chronic inflammation are the common pathological bases of chronic diseases such as atherosclerosis, cancer, and cardiovascular diseases, but most of the treatment drugs for chronic diseases have side effects. There is an increasing interest to identify food-derived bioactive compounds that can mitigate the pathological pathways associated with oxidative stress and chronic inflammation. Egg white contain a variety of biologically active proteins, many of which have antioxidant and anti-inflammatory activities and usually show better activity after enzymatic hydrolysis. This review covers the antioxidative stress and anti-inflammatory activities of egg white proteins and their derived peptides and clarifies their mechanism of action in vivo and in vitro. In addition, the link between oxidative stress and inflammation as well as their markers are reviewed. It suggests the potential application of egg white proteins and their derived peptides and puts forward further research prospects.

Applications of Lysozyme, an Innate Immune Defense Factor, as an Alternative Antibiotic

Lysozyme is a ~14 kDa protein present in many mucosal secretions (tears, saliva, and mucus) and tissues of animals and plants, and plays an important role in the innate immunity, providing protection against bacteria, viruses, and fungi. Three main different types of lysozymes are known: the c-type (chicken or conventional type), the g-type (goose type), and the i-type (invertebrate type). It has long been the subject of several applications due to its antimicrobial properties. The problem of antibiotic resistance has stimulated the search for new molecules or new applications of known compounds. The use of lysozyme as an alternative antibiotic is the subject of this review, which covers the results published over the past two decades. This review is focused on the applications of lysozyme in medicine, (the treatment of infectious diseases, wound healing, and anti-biofilm), veterinary, feed, food preservation, and crop protection. It is available from a wide range of sources, in addition to the well-known chicken egg white, and its synergism with other compounds, endowed with antimicrobial activity, are also summarized. An overview of the modified lysozyme applications is provided in the form of tables.

Effects of the prebiotic lactoferrin on multidrug-resistant Escherichia coli infections in broiler chickens

Background and Aim

Increased multidrug resistance in Escherichia coli has created challenges for the poultry industry. Consequently, new antimicrobial agents should preferentially be utilized for the prevention and treatment of E. coli outbreaks. This study aimed to evaluate the effects of lactoferrin (LF) as a prebiotic on broiler chicks challenged with multidrug-resistant E. coli in comparison with antibiotics.

Materials and Methods

A total of 70 diseased flocks from Egypt were collected for E. coli isolation and identification, serotyping, and antimicrobial susceptibility pattern determination. E. coli was isolated and characterized phenotypically and one isolate that showed multidrug-resistance was selected. A challenge trial was performed to evaluate the effectiveness of LF as a prebiotic on the isolated multidrug-resistant E. coli. Liver samples were collected from the experimental chicks and subjected to E. coli enumeration to illustrate the effectiveness of LF on the liver cells and bacteria using an electron microscope. Serum samples were also collected to estimate lysozyme and nitric oxide (NO) concentrations.

Results

After isolation of E. coli with a percentage of 54.3% from the diseased broilers, the strain was serotyped (identified serotypes: O2, O18, O55, O78, O86a, O111, O125, O126, O127, O157, O159, and O166). Multi-antibiotic resistance was found to be harbored in a high percentage among 11 antibiotic discs. The LF in the prophylactic and treated groups was found to have a significant effect in comparison with the group treated with the drug of choice (ciprofloxacin). Furthermore, a significant difference in the NO (one of non-specific immune response) and a non-significant difference in lysozyme concentrations were reported in the group fed on rations with LF in comparison with the non-fed group.

Conclusion

LF was thus identified as an effective prebiotic that can improve chick performance, help them to overcome multidrug-resistant E. coli and stimulate immunity.

Responses of Vaginal Microbiota to Dietary Supplementation with Lysozyme and its Relationship with Rectal Microbiota and Sow Performance from Late Gestation to Early Lactation

Simple Summary

The vaginal microbiota has a crucial role for the health of the sow and the newborn piglet. The purpose of this study was to investigate the effect of dietary supplementation with lysozyme in the vaginal microbiota and evaluate its relationship with the fecal microbiota of the rectum and the reproductive performance of the sow. The results suggest that, lysozyme supplementation changed vaginal microbiota composition at different taxonomic levels, the changed vaginal microbiota was associated with variations in fecal microbiota, and these changes correlated with some reproductive performance of the sow.

Abstract

This study was conducted to evaluate the effects of dietary lysozyme (LZM) supplementation on the vaginal microbiota, as well as the relationship between vaginal microbiota and the fecal microbiota of rectum and the reproductive performance of the sow. A total of 60 Yorkshire × Landrace sows (3–6 of parity) were arranged from day 85 of gestation to the end of lactation in a completely randomized design with three treatments (control diet, control diet + lysozyme 150 mg/kg, control diet + lysozyme 300 mg/kg). The results showed that sows fed with lysozyme increased serum interleukin-10 (IL-10, p < 0.05) on day 7 of lactation. The vaginal microbiota varied at different taxonomic levels with LZM supplementation by 16S rRNA gene sequencing. The most representative changes included a decrease in Tenericutes, Streptococcus, Bacillus and increase in Bacteroidetes, Actinobacteria, Enterococcus, and Lactobacillus (p < 0.05). There were 777 OTUs existing in both, vaginal and fecal microbiota. The addition of LZM also decreased the abundance of Tenericutes (p < 0.05) in the vagina and feces. The changes in the microbiota were correlated in some cases positively with the performance of the sow, for example, Bacillus in feces was positively correlated with the neonatal weight (p < 0.05). These results indicate that the addition of lysozyme to the diet of sow during perinatal period promote the change of vaginal bacterial community after farrowing. The variations in vaginal microbiota are also associated with the changes in the fecal microbiology of the rectum and the reproductive performance of the sow. Therefore, it is concluded that dietary supplementation with lysozyme in sows in late gestation stage until early lactation, is beneficial to establish vaginal microbiota that seems to promote maternal health and reproductive performance.

Plant Platforms for Efficient Heterologous Protein Production

Production of recombinant proteins is primarily established in cultures of mammalian, insect and bacterial cells. Concurrently, concept of using plants to produce high-value pharmaceuticals such as vaccines, antibodies, and dietary proteins have received worldwide attention. Newer technologies for plant transformation such as plastid engineering, agroinfiltration, magnifection, and deconstructed viral vectors have been used to enhance the protein production in plants along with the inherent advantage of speed, scale, and cost of production in plant systems. Production of therapeutic proteins in plants has now a more pragmatic approach when several plant-produced vaccines and antibodies successfully completed Phase I clinical trials in humans and were further scheduled for regulatory approvals to manufacture clinical grade products on a large scale which are safe, efficacious, and meet the quality standards. The main thrust of this review is to summarize the data accumulated over the last two decades and recent development and achievements of the plant derived therapeutics. It also attempts to discuss different strategies employed to increase the production so as to make plants more competitive with the established production systems in this industry.

Dietary microbial muramidase improves feed efficiency, energy and nutrient availability and welfare of broilers fed commercial type diets containing exogenous enzymes

1. The aim of this study was to evaluate the effect of graded levels of the microbially derived feed lysozyme, muramidase (MUR) on feed intake (FI), weight gain (WG), feed conversion ratio (FCR), European Performance Index (EPI), dietary N-corrected apparent metabolisable energy (AMEn), footpad dermatitis score (FPD) and other welfare variables, when fed to broilers from 0 to 42d age. 2. A four-phase dietary programme and four experimental pelleted diets were used; a control diet (following breeder recommendations without MUR supplementation), and three diets based on the control diet supplemented with 25,000, 35,000 and 45,000 LSU (F)/kg of MUR, respectively. In addition, all experimental diets contained exogenous xylanase, phytase and a coccidiostat. Each diet was fed to birds in 24 pens (20 male Ross 308 chicks in each pen) following randomisation. Dietary AMEn was determined at 21 d of age, and FPD was evaluated at the end of the study. Data were analysed by ANOVA, using orthogonal polynomials for assessing linear and quadratic responses to MUR activity. 3. The inclusion of MUR did not change FI (P > 0.05), but increased WG in a linear manner (P < 0.05) and reduced FCR in a quadratic manner, with optimum WG and FCR observed in birds fed approximately 35 000 LSU (F)/kg. In accordance with the improvement in FCR, 35 000 LSU (F)/kg MUR supplementation produced the highest EPI (P < 0.05). FPD score was linearly decreased with increased addition of MUR (P < 0.05). Dietary AMEn responded in a quadratic fashion to the MUR inclusion, as the highest values were obtained with the highest inclusion rate (P < 0.05). 4. In conclusion, the results showed that inclusion of MUR improved feed efficiency and the foot health of birds.

Evaluation of dietary supplementation of a novel microbial muramidase on gastrointestinal functionality and growth performance in broiler chickens

This study was conducted to assess the effect of dietary supplementation of Muramidase 007 to broiler chickens on gastrointestinal functionality, evaluating growth performance, apparent ileal digestibility, intestinal histomorphology, vitamin A in plasma and cecal microbiota. A total of 480 one-day male chicks (Ross 308) were distributed in 16 pens allocated in 2 experimental diets: the control diet (CTR) without feed enzymes, coccidiostat or growth promoters, and the experimental diet (MUR): CTR supplemented with 35,000 units (LSU(F))/kg of the Muramidase 007. Digesta and tissue samples were obtained on days 9 and 36 of the study. A lower feed conversion ratio was observed in the MUR treatment. Apparent ileal digestibility of DM, organic matter and energy were improved by Muramidase 007. It was also observed that MUR improved digestibility of total fatty acids, mono-unsaturated fatty acids and poly-unsaturated fatty acids, and content of vitamin A in plasma at day 9 (P < 0.05). Histomorphological analysis of jejunum samples revealed no differences in the villus height or crypt depth; but a higher number of goblet cells and intraepithelial lymphocytes at day 36 with MUR. No differences were observed in plate counts of enterobacteria or Lactobacillus along the gastrointestinal tract, neither on the cecal short-chain fatty acids. An statistical trend was observed for reduction of cecal clostridia at day 9 for MUR. Analysis of cecal microbiota structure by 16S rRNA gene sequencing revealed relevant changes correlated to age. At day 9, broilers receiving MUR showed decreased alpha diversity compared to CTR that was not detected at day 36. Changes in specific taxonomic groups with an increase in Lactobacillus genus were identified. In conclusion, evaluation of the variables in this study indicates that dietary Muramidase 007 contributes to improve feed conversation ratio and gastrointestinal function in broiler chickens. Effects could have been mediated by slight shifts observed in the intestinal microbiota. More studies are guaranteed to fully understand the mechanisms involved.

Growth performance, immune response, and digestive enzyme activity in Pacific white shrimp, Penaeus vannamei Boone, 1931, fed dietary microbial lysozyme

The present study investigates the effects of the dietary microbial lysozyme (ML) as an immunostimulant, on the growth performance, some immune parameters and digestive enzyme of Pacific white shrimp, Penaeus vannamei. Six hundred shrimps were obtained and randomly allocated into four groups as follows with three replicates. The shrimps were fed diets supplemented with 0 (control), 0.5, 1, and 2 g kg^-1 ML for 4 months. The results indicated that dietary supplementation of ML significantly improved final weight, weight gain, average daily weight gain rate (ADG), feed conversion rate (FCR), and feed efficiency rate (FER) compared to the control (P ˂ 0.05). However, weight gain specific growth rate (SGR) and survival rate were not significantly affected by dietary ML (P ˃ 0.05). Dietary ML had a progressive effects on some immune parameters status including total antioxidant capacity (TAOC), superoxide dismutase (SOD), glutathione peroxidase (GPX), lysozyme (LYZ), alkaline phosphatase (ALP), phenoloxidase (PO) and acid phosphatase (ACP) activity as well as differential haemocyte count (DHC) and total haemocyte count (THC), in shrimps treated with the lysozyme than untreated shrimps (P ˂ 0.05). However, feeding with ML had no significant effect on plasma malondialdehyde (MDA) level (P ˃ 0.05). Furthermore, intestinal digestive enzymes (lipase, protease, and amylase) in shrimp fed with dietary ML were significantly (P ˂ 0.05) higher than those fed with non-supplemented control basal diet. Thus, the results indicate that oral administration of ML can be recommended for shrimp feed to improve immune response as well digestive enzymes activity modulation.

Evaluation of a microbial muramidase supplementation on growth performance, apparent ileal digestibility, and intestinal histology of broiler chickens

The current study evaluated the effects of different inclusion levels of microbial muramidase (Muramidase 007, DSM Nutritional Products) on gastrointestinal functionality by determination of apparent ileal digestibility (AID) of nutrients, investigation of intestinal histomorphology, and quantification of resulting growth performance. Four maize-wheat-soybean experimental diets were produced without (C) and with different dosages of muramidase: low (L, 25,000 LSU(F)/kg), medium (M, 35,000 LSU(F)/kg), and high (H, 45,000 LSU(F)/kg); diets were fed to broilers for 35 d. At the end of the experiment, AID of ether extract (EE), crude protein (CP), Ca, and P were determined and samples of the mid-jejunum and -ileum were collected for histomorphological observations. Data were subjected to ANOVA analysis using the GLM procedure. Orthogonal polynomial contrasts were used to assess linear and quadratic effects of different levels of the muramidase. At the end of the trial, Muramidase 007 supplementation linearly increased body weight gain and decreased feed conversion ratio (FCR) (P ≤ 0.05). Adding the muramidase to broiler diets also linearly increased the European poultry efficiency factor (P ≤ 0.05). Inclusion of the muramidase in broiler diets linearly increased AID of CP, EE, and P (P ≤ 0.05), and the H group had a higher AID of EE and CP compared to C group (P ≤ 0.05). Microbial muramidase supplementation linearly increased ileal villus length to crypt depth ratio and decreased the number of ileal CD45 cells (P ≤ 0.05). Broilers fed M and H diets had fewer number of CD45 cells in the ileum compared to those in C group (P ≤ 0.05). In conclusion, the results of the present study demonstrated that inclusion of the microbial muramidase in broiler diets could increase AID of key nutrients and improve growth performance in broilers. Adding microbial muramidase to broiler diets can therefore be considered as an interesting prospect to improve gastrointestinal functionality. Biological mechanisms causing these improvements need to be studied further.

Amino Acids as Additives against Amorphous Aggregation: In Vitro and In Silico Study on Human Lysozyme

The effect of 16 amino acids (AA) with various physicochemical properties was investigated on human lysozyme (HL) heat-induced amorphous aggregation. UV-Visible spectrophotometry was used to monitor the kinetics of aggregation in the absence and presence of AA, and transmission electron microscopy (TEM) images were taken from the aggregates. To conduct in silico experiments, Autodock vina was used for docking of AA into protein (via YASARA interface), and FTmap information was checked for an insight onto putative binding sites. Prediction of aggregation-prone regions of lysozyme was made by AGGRESCAN and Tango. Among all tested AA, phenylalanine had the best anti-aggregation effect, followed by lysine. In addition, based on in silico tests, Trp 109 and Val 110 of lysozyme are suggested to be of importance in the aggregation process of the enzyme. In conclusion, phenylalanine, arginine, and lysine were found to affect the nucleation phase of lysozyme aggregation and could be considered as suitable stabilizing structures for this enzyme.

Effects of dietary lysozyme levels on growth performance, intestinal morphology, immunity response and microbiota community of growing pigs

BACKGROUND

Lysozyme has been studied as a potential alternative to antibiotics for animals in recent years. The aim of this study was to evaluate the effect of dietary lysozyme on growth performance, serum biochemical parameters, immune response and gut health of growing pigs.

RESULTS

A total of 216 growing pigs (19.81 ± 0.47 kg) were fed the diets supplemented with colistin sulfate at 20 mg kg^-1 (control), or lysozyme at 50 (L50) or 100 mg kg^-1 (L100) diet for 30 days. The results showed that pigs fed with L100 or control had greater average daily gain and gain-to-feed ratio than pigs in the L50 group. Pigs fed with L100 or colistin had greater villus height to crypt depth ratio in jejunum compared with pigs in the L50 group. Pigs fed with L100 had greater serum immunoglobulin A and jejunal secretory immunoglobulin A than control and L50, but lower serum total protein and globulin than control. No differences were observed in the messenger RNA expression of genes related to mucosal cytokines, antioxidant capacity, enzyme activity, and barrier functions among three treatments. The caecal microflora evenness was lower in the L100 group than in the control or L50 group by 16S ribosomal DNA sequencing. Phylogenetic investigation of communities by reconstruction of unobserved states analysis predicted that lysozyme may modify nutrient metabolism by changing intestinal microbial function of pigs.

CONCLUSIONS

Pigs supplemented with 100 mg kg^-1 lysozyme had similar growth performance and intestinal morphology as pigs fed with colistin. This was likely due to the improved systemic and gut immune responses and the reduced microbiota diversity by feeding 100 mg kg^-1 lysozyme. © 2018 Society of Chemical Industry.

Enrichment of rainbow trout (Oncorhynchus mykiss) fingerlings diet with microbial lysozyme: Effects on growth performance, serum and skin mucus immune parameters

A two-month study was conducted to determine the influence of different levels of microbial lysozyme (LZ) contents (0, 0.5, 1.0, and 1.5 g kg^-1 of diet) on growth performance, serum and skin mucus immune parameters as well as intestinal immune-related genes expression in rainbow trout Oncorhynchus mykiss fingerlings (5.5 ± 0.1 g). Growth performance and feed utilization were not affected significantly by dietary LZ. Fish fed LZ-supplemented diets had higher serum total immunoglobulins concentration than the control group. In addition, fish fed 1.5 g LZ kg^-1 diet had the highest skin mucosal total protein and immunoglobulin contents compared to other experimental groups. Furthermore, skin mucosal lysozyme and alkaline phosphatase activities as well as intestinal tumor necrosis factor-α and interlukine-1β relative genes expression were higher in fish fed 1.0 and 1.5 g LZ kg^-1 diets than the other groups. Overall, the present results clearly showed that LZ powder can be considered as a potential immunostimulant in O. mykiss fingerlings, but in the long term period it may result in negative effects on intestinal health as a consequence of inducing pro-inflammatory cytokines gene expression in the intestine.

Effects of dietary supplementation with lysozyme during late gestation and lactation stage on the performance of sows and their offspring

This study investigated the effects of supplementing sow diets with lysozyme during the late gestation to lactation stage on the performance of sows and their offspring. Sixty sows (Yorkshire × Landrace, 3 to 6 of parity) at day 85 of gestation were allocated to the following 3 dietary treatments: 1) sows fed a basal diet from late gestation to lactation (control, n = 20), 2) sows fed a basal diet with lysozyme 150 g/t (LZM 150, n = 20), and 3) sows fed a basal diet with lysozyme 300 g/t (LZM 300, n = 20). During the lactation period, sows fed diets containing lysozyme had increased average daily feed intake (ADFI) (P < 0.01) and decreased weaning-to-estrus interval (WEI, P < 0.05), but there were no significant effects on backfat during the trial among treatments. Sows fed lysozyme diets had increased (P < 0.05) serum concentration of total protein (TP) compared with those fed the control diets. Serum immunoglobulin M (IgM) of the sows increased (P < 0.05) on day 1 of lactation, immunoglobulin A (IgA) and interleukin-10 (IL-10) increased (P < 0.05) on day 7 of lactation, and immunoglobulin G (IgG) had a tendency to increase (P = 0.05) during the lactation. Milk concentration of IgA increased (P < 0.05) on day 1 and 7 of lactation and tended to be greater (P = 0.06) on day 21 of lactation. No significant differences among the dietary treatments were observed in placental tissue mRNA expression of interleukin-6 (IL-6), IL-10, tumor necrosis factor-α (TNF-α), polymeric immunoglobulin receptor (pIgR), or the concentrations of IL-6, IL-10, TNF-α, or secretory immunoglobulin A (sIgA). Moreover, there was a decrease (P < 0.05) in stillborn in sows fed lysozyme diets. The diarrhea rate decreased (P < 0.05) and serum concentrations of IgA, IgG, IgM, and IL-10 increased (P < 0.05) in piglets from sows fed the diets containing lysozyme compared with piglets from sows fed the control diet. The serum concentrations of TP increased (P < 0.05), and albumin (ALB) and globulin (GLB) had a tendency to increase (P = 0.08, P = 0.06) in piglets from sows fed the diets containing lysozyme compared with piglets from sows fed the control diet. In conclusion, this study indicates that feeding sows diets supplemented with lysozyme from the late gestation through lactation stage increased sow ADFI during the lactation, shortened the WEI, and improved the maternal and offspring health status as indicated by immunological characteristics and a reduced incidence of diarrhea in piglets.

Nutraceutical and Functional Foods in Treatment of Anemia

WHO database mentions that the global anemia-affected population is 24.8%. To name a few conditions in which compromisation of the red blood corpuscles and hemoglobin occurs are iron deficiency anemia, gestational anemia, anemia due to malaria and parasitism, hemolytic anemia, sickle cell anemia. The line of treatment in case of anemia involves administration of iron supplements, plasmapheresis, steroids, blood transfusion at regular intervals, and lifestyle changes. The systematic approach applied for the pharmaceutical molecules should be equally inculcated in the case of nutraceuticals. The traditional system when woven carefully with the novel drug delivery system will give effective nutrient delivery. Functional foods have inherent nutritional value. Nutraceuticals and functional food cannot cure the anemic condition, but help the patient lead life almost like a normal individual.

Expression of recombinant human lysozyme in bacterial artificial chromosome transgenic mice promotes the growth of Bifidobacterium and inhibits the growth of Salmonella in the intestine

Targeted gene modification is a novel intervention strategy to increase disease resistance more quickly than traditional animal breeding. Human lysozyme, a natural, non-specific immune factor, participates in innate immunity, exerts a wide range of antimicrobial activities against pathogens, and has immuneregulatory effects. Therefore, it is a candidate gene for improved disease resistance in animals. In this study, we successfully generated a transgenic mouse model by microinjecting a modified bacterial artificial chromosome containing a recombinant human lysozyme (rhLZ) gene into the pronuclei of fertilized mouse embryos. rhLZ was expressed in serum, liver, spleen, lung, kidney, stomach, small intestine, and large intestine but not in milk. rhLZ protein concentrations in the serum of transgenic mice ranged from 2.09 to 2.60 mg/l. To examine the effect of rhLZ on intestinal microbiota, total aerobes, total anaerobes, Clostridium, Enterococcus, Streptococcus, Salmonella, Escherichia coli, Staphylococcus, Bifidobacterium, and Lactobacillus were measured in the intestines of transgenic and wild type mice. Results showed that Bifidobacteria were significantly increased (p < 0.001), whereas Salmonella were significantly decreased (p < 0.001) in transgenic mice compared to wild type mice. Our study suggests that rhLZ expression is a potential strategy to increase animal disease resistance.

Exogenous dietary lysozyme improves the growth performance and gut microbiota in broiler chickens targeting the antioxidant and non-specific immunity mRNA expression

Supplementation of exogenous enzymes in chickens has been widely practiced, yet mechanisms responsible are not fully delineated. To investigate the effects of the dietary lysozyme on the growth performance and immunity of broiler chickens, a total of 120 one-day-old Ross 308 chicks were randomly allocated into four groups, each having three replicates (30 birds/group). The chicks were fed the starter (1–21 d) and grower (22–35 d) diets supplemented with 0 (control), 70 (LYZ70), 90 (LYZ90) and 120 (LYZ120) g of lysozyme 10%^® per ton of basal diet for five weeks. The results revealed significant improvement in the growth performance and gut environment. There were significant decreases (P < 0.05 or 0.01) in the harmful fecal Coliform and Clostridia and an increase (P ˂ 0.05) in the beneficial Lactobacillus in the lysozyme-supplemented groups, especially in LYZ90. Moreover, the mRNA expressions of Cu, Zn-superoxide dismutase (SOD1), glutathione peroxidase (GSH-Px), interferon-gamma (IFN-γ), interleukin-10 (IL-10), and interleukin-18 (IL-18) were upregulated in response to lysozyme supplementation. In comparison to control, LYZ90 fed birds had a significant increase (P < 0.01) in the GSH-Px gene expression that enhances the antioxidant status of the gut. Expression of the biomarkers involved in the gut non-specific immunity indicated significant increases in the mRNA expression of INF-γ (P < 0.001), IL-10 (P < 0.001), and IL-18 (P < 0.05) in LYZ90 group. Also, serum globulin levels were significantly elevated (P ˂ 0.05) in lysozyme-supplemented groups. Histologically, the intestinal villi length and crypts depth were also enhanced (P ˂ 0.05) by dietary lysozyme supplementation. In conclusion, supplementation of broiler chickens with exogenous lysozyme, especially at 90 g of lysozyme per ton of basal diet dose rate, improved the growth performance, gut antioxidant status, and nonspecific immunity of broiler chickens.

Preventive Effects of Heat-Killed Enterococcus faecalis Strain EC-12 on Mouse Intestinal Tumor Development

Establishing effective methods for preventing colorectal cancer by so-called “functional foods” is important because the global burden of colorectal cancer is increasing. Enterococcus faecalis strain EC-12 (EC-12), which belongs to the family of lactic acid bacteria, has been shown to exert pleiotropic effects, such as anti-allergy and anti-infectious effects, on mammalian cells. In the present study, we aimed to evaluate the preventive effects of heat-killed EC-12 on intestinal carcinogenesis. We fed 5-week-old male and female Apc mutant Min mice diets containing 50 or 100 ppm heat-killed EC-12 for 8 weeks. In the 50 ppm treated group, there was 4.3% decrease in the number of polyps in males vs. 30.9% in females, and significant reduction was only achieved in the proximal small intestine of female mice. A similar reduction was observed in the 100 ppm treated group. Moreover, heat-killed EC-12 tended to reduce the levels of c-Myc and cyclin D1 mRNA expression in intestinal polyps. Next, we confirmed that heat-killed EC-12 suppressed the transcriptional activity of the T-cell factor/lymphoid enhancer factor, a transcriptional factor involved in cyclin D1 mRNA expression in intestinal polyps. Our results suggest that heat-killed EC-12 very weakly suppresses intestinal polyp development in Min mice, in part by attenuating β-catenin signaling, and this implies that heat-killed EC-12 could be used as a “functional food”.

Milk with and without lactoferrin can influence intestinal damage in a pig model of malnutrition

Malnutrition remains a leading contributor to the morbidity and mortality of children under the age of five worldwide. However, the underlying mechanisms are not well understood necessitating an appropriate animal model to answer fundamental questions and conduct translational research into optimal interventions. One potential intervention is milk from livestock that more closely mimics human milk by increased levels of bioactive components that can promote a healthy intestinal epithelium. We tested the ability of cow milk and milk from transgenic cows expressing human lactoferrin at levels found in human milk (hLF milk) to mitigate the effects of malnutrition at the level of the intestine in a pig model of malnutrition. Weaned pigs (3 weeks old) were fed a protein and calorie restricted diet for five weeks, receiving cow, hLF or no milk supplementation daily from weeks 3-5. After three weeks, the restricted diet induced changes in growth, blood chemistry and intestinal structure including villous atrophy, increased ex vivo permeability and decreased expression of tight junction proteins. Addition of both cow and hLF milk to the diet increased growth rate and calcium and glucose levels while promoting growth of the intestinal epithelium. In the jejunum hLF milk restored intestinal morphology, reduced permeability and increased expression of anti-inflammatory IL-10. Overall, this pig model of malnutrition mimics salient aspects of the human condition and demonstrates that cow milk can stimulate the repair of damage to the intestinal epithelium caused by protein and calorie restriction with hLF milk improving this recovery to a greater extent.

In ovo trace element supplementation enhances expression of growth genes in embryo and immune genes in post-hatch broiler chickens

BACKGROUND

Differential expression of growth- and immunity-related genes and post-hatch performances were evaluated in in ovo zinc (Zn), iodine (I) or selenium (Se) supplemented chicken embryos.

RESULT

There was about 9-18% reduction in hatchability of Zn, I or Se supplemented eggs. In ovo trace element supplementation did not improve post-hatch growth. Two-way analysis of data revealed significant effect (P > 0.01) of period, trace elements and their interactions. Expression of hepatic somatotropin, insulin-like growth factor-II and mucin gene was highest at 20(th) embryonic day but decreased during post-hatch periods. In ovo Zn or I supplemented embryos had higher expression of growth-related genes compared to the Se or un-injected control group. Expression of interleukin-6 was higher (P < 0.01) in in ovo I supplemented chicks (2.5-fold) but lower in the Zn and Se groups than in the un-injected control group. However, Zn and Se supplemented chicks had higher cellular immune gene expression. In vivo response to mitogen phytohaemaglutinin was also higher (P < 0.01) in Zn or Se supplemented chicks

CONCLUSION

In ovo supplementation of Zn, I and Se did not improve the post-hatch growth, but increased growth-related gene expression. Iodine improved humoral immune gene expression whereas Zn and Se enhanced cell-mediated immune gene expression in broiler chickens. © 2015 Society of Chemical Industry.

Lactoferrin supplementation of the neonatal calf has no impact on immunoglobulin G absorption and intestinal development in the first days of life

The objectives of this study were to determine if newborn calves receiving supplemental lactoferrin (LF) had improved IgG uptake and if supplemental LF enhanced intestinal development through estimation of xylose uptake. Twenty-four newborn Holstein bull calves were randomly assigned to 1 of 2 treatments: 0 or 1 g/d of supplemental LF. Calves were fed pooled maternal colostrum from 9 cows in 2 feedings: at birth and 12 h later. Calves consumed in excess of 200 g of IgG. Blood samples were taken before colostrum feeding (0 h) and at 12, 18, and 24 h after birth. Blood samples were analyzed for IgG concentration. On d 2 of life, calves were fed milk replacer with the added LF and 0.5 g/kg of BW xylose to determine if supplemental LF affected intestinal development. Blood was sampled at 0, 0.5, 1, 2, 3, 4, 6, 8, and 12 h after the xylose dose. All calves attained passive transfer and supplemental LF did not affect IgG uptake ( ≥ 0.36) or apparent efficiency of absorption of IgG ( = 0.49). Lactoferrin did not enhance rate of absorption at any time point ( ≥ 0.36). There were no differences in xylose ( = 0.28) or glucose ( = 0.27) area under the curve values in calves supplemented with either 0 or 1 g/d LF. Lactoferrin did not enhance IgG uptake during the first 24 h or intestinal development in calves on the second day of life.

Purification and Characterization of Recombinant Human Lysozyme from Eggs of Transgenic Chickens

Transgenic chickens as bioreactors have several advantages, such as the simple establishment procedure, correct glycosylation profile of expressed proteins, etc. Lysozyme is widely used in food industry, livestock farming, and medical field as a replacement of antibiotics because of its antibacterial and complement system-modulating activity. In this study, we used RT-PCR, Western blot, and immunofluorescence to detect the expression of recombinant human lysozyme (rhLY) in the transgenic chicken. We demonstrated that the transgene of rhLY was genetically stable across different generations. We next optimized the purification procedure of rhLY from the transgenic eggs by utilizing two steps of cation-exchange chromatography and one gel-filtration chromatography. About 6 mg rhLY with the purity exceeding 90% was obtained from ten eggs, and the purification efficiency was about 75%. The purified rhLY had similar physicochemical and biological properties in molecular mass and antibacterial activity compared to the commercial human lysozyme. Additionally, both of them exhibited thermal stability at 60°C and tolerated an extensive pH range of 2 to 11. In conclusion, our study proved that the transgenic chickens we have previously generated were genetically stable and suitable for the production of active rhLY. We also provided a pipeline for purifying the recombinant proteins from transgenic eggs, which could be useful for other studies.

Effects of dietary lysozyme levels on growth performance, intestinal morphology, non-specific immunity and mRNA expression in weanling piglets

The aim of the present study was to determine the effect of dietary lysozyme levels on growth performance, gut health and non-specific immunity of weanling piglets. A total of 150 weanling piglets were allocated to six treatments. The piglets were fed the same basel diet supplemented with 0, 30, 60, 90 and 120 mg/kg lysozyme as well as antibiotics for 28 days. From day 14 to day 28 of dietary treatment, piglets fed 90 mg/kg lysozyme had greater average daily gain than piglets fed control diet. During the whole experimental period, piglets fed 120 mg/kg lysozyme tended to have greater average daily gain than piglets fed control diet. Compared with piglets fed control diet, piglets fed diets containing antibiotics and 90 mg/kg lysozyme had greater villus height to crypt depth ratio in duodenum and jejunum. Additionally, dietary supplementation of 60 and 90 mg/kg lysozyme as well as antibiotics enhanced the phagocytic activity of peritoneal macrophages in piglets. In conclusion, dietary lysozyme can accelerate the growth of weanling piglets by improving gut health and non-specific immunity and supplementing 90 mg/kg lysozyme is as effective as antibiotics (20 mg/kg colistin sulphate + 50 mg/kg kitasamycin) in improving the growth performance of weanling piglets.

Lysozyme as an alternative to growth promoting antibiotics in swine production

Lysozyme is a naturally occurring enzyme found in bodily secretions such as tears, saliva, and milk. It functions as an antimicrobial agent by cleaving the peptidoglycan component of bacterial cell walls, which leads to cell death. Antibiotics are also antimicrobials and have been fed at subtherapeutic levels to swine as growth promoters. These compounds benefit swine producers by minimizing production losses by increasing feed efficiency and decreasing susceptibility to bacterial infection and disease. This manuscript reviews the knowledge of the effects of lysozyme, as compared to traditional subtherapeutic antibiotics in swine feed, on pig performance and health. It is clear from decades of studies that antibiotic use in feeds increases pig performance, particularly in the nursery. Similarly, lysozyme, as a feed additive, increases growth and feed efficiency. While the mechanism by which antibiotics and lysozyme improve performance is not clearly understood, both of these feed additives improve gastrointestinal health, improve the metabolic profile, and alter the gastrointestinal bacteria ecology of swine. Therefore, lysozyme is a suitable alternative to growth-promoting subtherapeutic antibiotic use in swine feed.

Characterization of bioactive recombinant antimicrobial peptide parasin I fused with human lysozyme expressed in the yeast Pichia pastoris system

Parasin I (PI) is a 19 amino acid peptide with potent antimicrobial activities against a broad spectrum of microorganisms and is a good candidate for development as a novel antimicrobial agent. The objective of this study was to express and characterize a codon optimized parasin I peptide fused with human lysozyme (hLY). A 513 bp cDNA fragment encoding the mature hLY protein and parasin I peptide was designed and synthesized according to the codon bias of Pichia pastoris. A 4×Gly flexible amino acid linker with an enterokinase cleavage (DDDDK) was designed to link the PI to the C-terminal of hLY. The codon optimized recombinant hLY-PI was cloned into the pPICZαA vector and expressed in P. pastoris. The over-expressed extracellular rehLY-PI was purified using Ni sepharose affinity column and exhibited a molecular mass of approximately 18 kDa. After digested with enterokinase the rehLY-PI protein release its corresponding rehLY and rePI, with molecular mass of 16 kDa and 2 kDa, respectively, on Tricine-SDS-PAGE. The released rehLY exhibited similar lytical activity against Micrococcus lysodeikticus to its commercial hLY. The digested rehLY-PI product exhibited antimicrobial activities against Bacillus subtilis, Staphylococcus aureus and Escherichia coli, and synergism has been found between the released rePI and rehLY. In conclusion, we successfully optimized a rehLY-PI fusion protein encoding gene and over-expressed the rehLY-PI in P. pastoris. The recombination protein digested with enterokinase released functional hLY and antimicrobial parasin I, which demonstrates a potential for future use as an animal feed additive to partly replace antibiotic.

Production of transgenic-cloned pigs expressing large quantities of recombinant human lysozyme in milk

Human lysozyme is a natural non-specific immune factor in human milk that plays an important role in the defense of breastfed infants against pathogen infection. Although lysozyme is abundant in human milk, there is only trace quantities in pig milk. Here, we successfully generated transgenic cloned pigs with the expression vector pBAC-hLF-hLZ-Neo and their first generation hybrids (F1). The highest concentration of recombinant human lysozyme (rhLZ) with in vitro bioactivity was 2759.6 ± 265.0 mg/L in the milk of F0 sows. Compared with wild-type milk, rhLZ milk inhibited growth of Escherichia coli K88 during the exponential growth phase. Moreover, rhLZ in milk from transgenic sows was directly absorbed by the intestine of piglets with no observable anaphylactic reaction. Our strategy may provide a powerful tool for large-scale production of this important human protein in pigs to improve resistance to pathogen infection.

Nutritional effects of egg shell membrane supplements on chicken performance and immunity

Eggshell membranes (ESM) contain a variety of proteins and peptides which help in the development of embryo and provide protection to it. Many of the peptides and proteins associated with ESM have antimicrobial, immune-modulatory, and adjuvant properties. We hypothesized that the membrane byproducts from egg, provided as posthatch nutritional supplements to chickens, may improve their performance and immunity. To explore its effect, we fed 3 groups of broiler chicks with feed containing 0, 0.2, and 0.4% ESM from d 1 posthatch through 14 d and regular feed thereafter. The birds were individually weighed at the onset of the study and at weekly intervals until the termination at third wk when they were bled and euthanized. The relative weights of liver, spleen, bursa, and heart, hematology profiles, and clinical chemistry variables including serum IgM, IgG, and corticosterone concentrations were measured. The chickens in the ESM treated groups showed a statistically significant increase in BW with no impact on relative organ weights. Compared with controls, the WBC and lymphocyte percentage increased in chickens fed 0.4% ESM whereas the monocyte percentage decreased at both levels of ESM. Except for the serum protein which increased in ESM fed birds no other metabolic clinical chemistry variables showed any significant change. Both IgM and IgG(Y) levels were elevated and corticosterone levels reduced in chickens fed ESM supplemented diets. Our results suggest that ESM supplements during the early phases of growth may improve immunity and stress variables, and enhance their growth performance without any detrimental effect on other physiological parameters.

Generation of bi-transgenic pigs overexpressing human lactoferrin and lysozyme in milk

Intensive swine production industry uses antibiotics to treat diseases and improve pig growth. This can not only cause antibiotic resistance, but can also pollute the environment or eventually affect human public health. To date, human lactoferrin (hLF) and human lysozyme (hLZ) have been known as non-adaptive but interactive antimicrobial members and could act in concert against bacteria, which contribute to host defense. Therefore, their expression in pigs might be an alternative strategy for replacing antibiotics in the pig production industry. In our study, we produced hLF and hLZ bi-transgenic pigs and assessed the milk's antibacterial ability. Integration of both transgenes was confirmed by PCR and southern blot. Both the hLF and hLZ were expressed in the mammary gland of bi-transgenic pigs, as detected by western blotting. The expression amounts were 6.5 g/L for hLF and 1.1 mg/L for hLZ using ELISA. Interestingly, pig milk containing hLF and hLZ had synergistic antimicrobial activity. Our results suggest an alternative approach for avoiding the use of antibiotics in the pig industry, which would be of great benefit to the commercial swine production.