ChangQing compound relieves Eimeria tenella infection symptoms by modulating intestinal probiotic and pathogenic bacteria balance

Cecal coccidiosis is a severe and lethal parasitic disease affecting chickens, making the search for effective preventive agents free of contamination and drug resistance crucial for controlling this condition in poultry. Previous studies have demonstrated that the ChangQing compound has significant therapeutic effects against cecal coccidiosis; however, its potential as a preventive measure has yet to be evaluated. In this study, we established an experimental model for the prevention of cecal coccidiosis in chickens using the ChangQing compound for the first time. A comprehensive evaluation was performed on survival rates, relative weight gain, oocyst production, the anticoccidial index (ACI), immune parameters, parasitic tissue pathology, and microbial diversity in cecal contents. Results indicated that the ChangQing compound at a concentration of 5.0 g/L achieved an ACI of 178.10 in the Pre-Exposure Prophylaxis (PrEP) group and 173.12 in the Post-Exposure Prophylaxis (PEP) group. Compared to the positive control group, cecal lesions were reduced, and indices for the spleen, liver, and bursa of Fabricius increased in both experimental groups following ChangQing administration. Furthermore, levels of immune factors, IgA, IgG, and IgM significantly elevated. The abundance of beneficial bacteria, including Lactobacillus, Bacteroides, and Alistipes, increased in the 5.0 g/L ChangQing compound group, while potential pathogens like Escherichia-Shigella, Enterococcus, and norank_f_Oscillospiraceae were reduced. These findings offer critical data for coccidiosis prevention in chickens and lay a theoretical foundation for future research on the antiparasitic mechanisms of traditional Chinese medicine.

Effects of Amino Acid Supplementation on the Growth Performance of Broiler Chicks Challenged With Coccidiosis: A Meta-Analysis

This meta-analysis aimed to evaluate the effects of amino acid supplementation on the growth performance of broiler chicks challenged with coccidiosis. Data were collected on authorship, publication year, study sample characteristics and outcomes of interest related to growth performance. Effect sizes were calculated for both overall effects and the individual effects of each amino acid. The effects of moderator factors, such as supplementation levels and duration, were also assessed, and bias was calculated. Works were obtained from PubMed, Elsevier, ScienceDirect, Wiley, Springer Link and Scopus databases, with the help of search engines like Google Scholar and ResearchGate, covering the period from 2013 to 2023. A random-effects model was used. Thirteen works were included in the current analysis, examining the effects of arginine (n = 4), methionine (n = 6), threonine (n = 3) and glutamine (n = 3). Amino acid supplementation [0.326, CI 95% (0.297-0.355); p = 0.000], arginine [0.430, CI 95% (0.293-0.568); p = 0.000] and threonine [0.793, CI 95% (0.193-1.38); p = 0.009] significantly increased body weight. Amino acid supplementation [0.052, CI 95% (0.022-0.081); p = 0.000] and arginine [0.317, CI 95% (0.049-0.585); p = 0.000] also significantly increased feed intake. Higher levels of amino acids (≥1.50%) and longer supplementation periods (≥15 days) significantly increased body weight and feed intake, while reducing the feed conversion ratio. Funnel plots, fail-safe N and Egger tests showed no evidence of bias. In conclusion, arginine supplementation has the potential to increase body weight and feed intake in poultry challenged with coccidiosis. Higher doses of amino acids and longer supplementation periods are recommended in such cases.

A Comprehensive Evaluation of Nutritional Quality and Antioxidant Capacity of Different Chinese Eggplant Varieties Based on Multivariate Statistical Analysis

Free amino acids, polyphenols, and anthocyanins were quantified in 30 Chinese eggplant varieties. Moreover, antioxidant capacity characterizations including 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric-reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were performed. The total amino acid content of the 30 eggplant varieties ranged from 15,267.19 to 26,827.4 mg kg-1 DW. The most abundant amino acids were glutamic acid, arginine, and aspartic acid. The coefficients of variation (CV) for the 20 amino acids ranged from 5.85 to 106.14%, of which 18 free amino acids had CVs > 20%. Total polyphenol and anthocyanin contents ranged from 17,097.41 to 39,474.98 µg g-1 DW and 5.28 to 978.32 µg g-1 DW, respectively. The variability of both polyphenol and anthocyanin components was >20%, with a range of 21.25-102.89%. Chlorogenic acid was the most abundant polyphenol. The total anthocyanin content of purple eggplant varieties was significantly higher than green varieties. Of the purple eggplant varieties, V28 ('E150725'), V30 ('1952'), and V16 ('Weichangqie101') had significantly higher total anthocyanins than the other eggplant varieties. DPPH, ABTS, and FRAP assays showed peaks at V3 ('Zhengqie924'). Pearson's correlation analysis revealed that polyphenols and anthocyanins were the main contributors to the antioxidant capacity of eggplants. A classification model with principal component analysis classified 30 Chinese eggplant varieties into two categories: high and low antioxidant capacities. The top five Chinese eggplant varieties ranked for amino acids, antioxidants, and antioxidant capacity were V29 ('Zhengqie903'), V24 ('Zhengqie78'), V1 ('1871'), V3 ('Zhengqie924'), and V28 ('E150725'). These findings provide theoretical basis for high-quality breeding and producer/consumer selection of eggplants.

Transcriptomic analysis of ileal adaptations and growth responses in growing hens supplemented with alanyl-glutamine dipeptide

The growing phase of laying hens is crucial for growth and development due to its direct impact on their productivity during laying phase. During initial growth phase, intestinal tract undergoes rapid development which requires plenty of nutrients to help laying hens grow and mature. This study investigated the effect of Alanyl-Glutamine (Aln-Gln) levels on growth performance, ileal morphology and transcriptomic analysis of growing Hy-line brown hens. A total of 480 day old Hy-line brown chicks having similar body weight (BW) were randomly divided to be fed diets having 0%, 0.1%, 0.2% and 0.3% Aln-Gln for 6-wks (8 replicates/group, 15 birds/replicate). One bird from every pen was slaughtered and morphological parameters of ileum were evaluated. Results taken on day 42 revealed an improved average daily gain (ADG), final body weight (FBW) and feed-to-gain ratio (F/G) in the birds that consumed 0.2% and 0.3% Aln-Gln supplemented diet (P < 0.05). Ileal morphological assays showed that villus height, villus width and villus to crypts ratio (V/C) were significantly increased at 42 days of age in birds fed diets with 0.2% Aln-Gln (P<0.05). The RNA sequencing (RNA-Seq) was executed to identify differentially expressed genes (DEGs) among groups that found 2265 DEGs (1256 up-regulated; 1009 down-regulated) in ileum tissue. According to the Kyoto Encyclopedia of Genes (KEGG) and Genomic Pathway Enrichment Analysis, majority of DEGs indicated change in metabolic pathways. Genes related to growth factors, intestinal morphology and protein metabolism were up-regulated in test groups as compared to control group. In conclusion, addition of Aln-Gln to the diet improved growth performance and ileum development in growing hens; transcriptomic analysis revealed up-regulation of genes related to growth and intestinal morphology.

Growth performance and immune response of broilers during active Eimeria infection are modified by dietary inclusion of canola meal or corn-DDGS in reduced-protein corn-soybean meal diets

The objective of this experiment was to study the effects of partial replacement of soybean meal (SBM) with canola meal (CM) or corn-distillers' dried grains with solubles (cDDGS) in reduced-protein (RP) diets for Eimeria-infected broilers. A total of 1120 broiler chicks were distributed in a 4 × 2 (4 diets × with or without infection) factorial arrangement with 7 replicates per treatment and 20 birds per replicate. The 4 diets, fed between d 7 and 42, were (i) a standard diet with crude protein at 200 g/kg (SP); (ii) a RP (crude protein at 160 g/kg) corn-SBM diet (RP-SBM); (iii) a RP diet in which 80 g/kg CM replaced 60 g/kg SBM (RP-CM); and (iv) a RP diet in which 100 g/kg cDDGS replaced 50 g/kg SBM (RP-cDDGS). On d 15, birds were infected with mixed Eimeria (+E) oocysts. Birds and feed were weighed at intervals for growth performance, and samples for immunology responses were collected on d 21. The results showed as follows: 1) during the acute infection phase, diet × Eimeria infection was shown by the diets having no effect in the uninfected group. In contrast, the RP-SBM diet tended to produce higher (P < 0.10) weight gain among the infected birds. The d 42 body weight was greater (P = 0.001) for the uninfected birds. 2) There was a significant diet × Eimeria infection on bile anti-Eimeria immunoglobulin A (IgA) concentrations (P = 0.015), splenocyte proliferation, macrophage nitric oxide (NO) production (P < 0.001), and cecal tonsil interleukin (IL)-17 mRNA amounts (P < 0.001). Most of these responses were not influenced by the diets in the uninfected birds. However, among the infected birds, birds fed RP-SBM had higher (P < 0.05) bile IgA than those fed SP or RP-cDDGS. For the spleen, the interaction was that birds fed RP-SBM or RP-cDDGS diets had the highest or lowest NO production, respectively, and birds that received RP-SBM had greater (P < 0.05) splenic CD8+:CD4+ cell ratio than other diets. In conclusion, partial replacement of SBM with CM or cDDGS had only a marginal effect on d 42 body weight and FCR of the broiler chickens receiving the RP diets. In contrast, these had a negative impact on the immune responses of the broiler chickens.

A Comprehensive Study on the Amino Acids and Tryptophan-Derived Molecules in Iberian Wine Vinegar

Wine vinegar, valued for its ancient origins and culinary versatility, has garnered scientific interest due to its complex composition and potential health benefits. This study aims to explore the nutritional and bioactive properties of different wine vinegars, focusing on their amino acid content, particularly tryptophan-derived molecules such as serotonin and melatonin. White wine vinegar, red wine vinegar, port wine vinegar, and balsamic vinegar from the Douro and Rioja regions were analyzed using high-performance liquid chromatography and solid-phase extraction (HPLC-SPE). The study examined the amino acid profiles and the presence of serotonin and melatonin across the samples. The analysis revealed the presence of significant bioactive amino acids, including arginine (found in sample 059 at 61.21 mmol/L), alanine (in a concentration of 30.33 mmol/L in sample 209), and threonine (sample 336 presented the highest concentration-71.47 mmol/L), which have been linked to cardiovascular health, immune system support, and mucosal regulation. The amino acid content varied among the vinegar types, with slower acetification and prolonged aging reducing their concentrations. Tryptophan was mainly found in sample 059 (30.54 mmol/L). These findings, with their potential to influence the scientific community's understanding of the health-promoting properties of wine vinegar, particularly its amino acid content and the potential influence of production processes on bioactive molecules, are of great interest.

Effect of arginine, glycine + serine concentrations, and guanidinoacetic acid supplementation in vegetable-based diets for chickens

The study investigated guanidinoacetic acid (GAA) supplementation with varying dietary digestible arginine (Arg) and glycine+serine (Gly+Ser) concentrations in the starter phase, exploring respective carry-over effects on growth performance, blood chemistry, incidence of pectoral myopathies and proximate composition in broilers. A total of 2,800 one-day-old male broiler chicks were distributed in a central composite design with 2 factors and double experimental mesh, represented by supplementation or omission of 0.6 g per kg of GAA, with a central point represented by 107% of Arg and 147% of Gly+Ser, 4 factorial points (combinations of Arg/Gly+Ser concentrations: 96.4/132.5%; 117.6/132.5%; 96.4/161.5%, and 117.6/132.5%), and 4 axial points (combinations of axial points estimated for Arg and Gly+Ser, with the central points of 92/147%; 122/147%; 107/126.5, and 107/167.5%), totaling 18 treatments, 4 repetitions to factorial and axial points, 24 replicates to the central point, and 25 birds per pen. Feed conversion ratio (FCR) from d 1 to 10 had a linear response (P = 0.009) for the decreasing Arg content and a quadratic response (P = 0.047) for Gly+Ser concentrations. Broilers supplemented GAA had lower FCR compared with nonsupplemented groups from d 1 to 10 (P = 0.048) and d 1 to 42 (P = 0.026). Aspartate aminotransferase (AST) exhibited increasing and decreasing linear effects as a function of Arg (P = 0.008) and Gly+Ser (P = 0.020) concentrations, respectively. Guanidinoacetic acid decreased serum AST (P = 0.028). Guanidinoacetic acid reduced moderate + severe (P = 0.039) and mild (P = 0.015) Wooden Breast scores. The occurrence of normal White Striping increased (P = 0.002), while severe score was reduced (P = 0.029) with GAA supplementation. In conclusion, increased digestible Arg:Lys and 14% and 6% above the recommendations (107% and 147%), respectively, provided improved FCR during the starter phase. Dietary GAA supplementation (0.6 g per kg) improved FCR, reduced severity of breast myopathies and appears to have reduced muscle damage in broilers fed plant-based diets.

The potential of glutamine supplementation in reduced-crude protein diets for chicken-meat production

This review explores the potential of including glutamine, a so-called non-essential amino acid, in the formulation of reduced-crude protein (CP) diets for broiler chickens. There is a precedent for benefits when including glycine and serine in reduced-CP diets. Fundamentally this is due to decreases in non-essential amino acid concentrations in reduced-CP diets - an unavoidable consequence of reducing CP without amino acid supplementation. The situation for glutamine is complicated because analysed dietary concentrations are very rarely provided as standard assays do not differentiate between glutamine and glutamate and are reported on a combined basis as glutamic acid. The dietary requirement for glutamic acid is approximately 36.3 g/kg but it is increasingly unlikely that this requirement will be met as dietary CP levels are progressively reduced. Glutamine is an abundant and versatile amino acid and constitutes 50.5 mg/g of whole-body chicken protein and is the dominant free amino acid in systemic plasma where it has been shown to provide 22.6% (139.9 of 620.3 μg/mL) of the total in birds offered 215 g/kg CP, wheat-based diets. In addition to dietary intakes, glutamine biosynthesis is derived mainly from the condensation of glutamate and ammonia (NH3) catalysed by glutamine synthetase, a reaction that is pivotal to NH3 detoxification. Glutamate and NH3 are converted to glutamine by phosphate-dependent glutaminase in the reciprocal reaction; thus, glutamine and glutamate are interchangeable amino acids. However, the rate of glutamine biosynthesis may not be adequate in rapidly growing broiler chickens and exogenous and endogenous glutamine levels are probably insufficient in birds offered reduced-CP diets. The many functional roles of glutamine, including NH3 detoxification and maintenance of acid-base homeostasis, then become relevant. Twenty feeding studies were identified where dietary glutamine supplementation, usually 10 g/kg, was evaluated in birds kept under thermoneutral conditions. On balance, the outcomes were positive, but the average dietary CP was 213 g/kg across the twenty feeding studies, which indicates that CP and, in turn, glutamine concentrations would have been adequate. This suggests that glutamine inclusions in reduced-CP diets hold potential and consideration is given to how this may be best confirmed.

Modulation of gut-microbiota through probiotics and dietary interventions to improve host health

Dietary patterns play an important role in regards to the modulation and control of the gut microbiome composition and function. The interaction between diet and microbiota plays an important role in order to maintain intestinal homeostasis, which ultimately affect the host's health. Diet directly impacts the microbes that inhabit the gastrointestinal tract (GIT), which then contributes to the production of secondary metabolites, such as short-chain fatty acids, neurotransmitters, and antimicrobial peptides. Dietary consumption with genetically modified probiotics can be the best vaccine delivery vector and protect cells from various illnesses. A holistic approach to disease prevention, treatment, and management takes these intrinsically linked diet-microbes, microbe-microbe interactions, and microbe-host interactions into account. Dietary components, such as fiber can modulate beneficial gut microbiota, and they have resulting ameliorative effects against metabolic disorders. Medical interventions, such as antibiotic drugs can conversely have detrimental effects on gut microbiota by disputing the balance between Bacteroides and firmicute, which contribute to continuing disease states. We summarize the known effects of various dietary components, such as fibers, carbohydrates, fatty acids, vitamins, minerals, proteins, phenolic acids, and antibiotics on the composition of the gut microbiota in this article in addition to the beneficial effect of genetically modified probiotics and consequentially their role in regards to shaping human health. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Supplementing low protein diets with methionine or threonine during mixed Eimeria challenge

We investigated the effects of supplementing low protein diets with methionine (Met) or threonine (Thr) during a mixed Eimeria (consisting of E. acervulina, E. maxima and E. tenella) challenge in broilers. All birds were fed the same starter diet (d1-9) and finisher diet (d28-35) which met Cobb 500 nutrient specifications. Birds were allocated to 1 of 4 dietary treatments from d9 to 28: a standard protein diet (19% CP); a low protein diet (16% CP); or the low protein diet supplemented with Met or Thr at 50% above recommendations. On d14, half of the birds were challenged, and half of the birds were unchallenged. From d14 to 28, feed intake was recorded daily and BW every 3 or 4 d. Oocyst excretion was measured daily from d18 to 27. On d21 and 28, 3 birds per pen were euthanized to assess nutrient digestibility, cytokine expression and intestinal histology. During the acute stage of the challenge, challenged birds reduced ADFI and ADG (P < 0.05). In the pre-patent and recovery stages, birds given the 16% CP diets increased ADFI (P < 0.05), meanwhile there were no differences in ADG in these stages (P > 0.05). Nutrient digestibility was reduced in challenged birds in the acute stage (P < 0.05) but tended to be greater than in unchallenged birds during the recovery stage. There was no significant effect of diet on oocyst excretion or intestinal histology (P > 0.05). Interactions were observed between diet and challenge on IL-10 and IL-21 expression in the cecal tonsils during the acute stage of the challenge (P < 0.05), due to reduced IL-10 expression in challenged Thr birds and greater IL-21 expression in challenged Met birds. Supplementation with Thr or Met had limited effects on the outcomes of a mixed Eimeria challenge but provides benefits to the host by enhancing their immune response.

Enhancing Growth and Gut Health in Squabs: The Impact of Fermented Mixed Feed

The purpose of this study was to evaluate the effect of fermented mixed feed (FMF) (soybean meal-rapeseed meal-corn bran (6:3:1, m/m/m)) on the growth performance, intestinal microbial communities, and metabolomes of squabs. One hundred and eighty 1-day-old squabs were randomly allocated to two groups, each containing six replicates of fifteen squabs cared for by 60 pairs of breeding pigeons secreting crop milk. Each pair of breeding pigeons cared for three squabs. The control group was fed a basal diet, while the experimental group was fed the basal diet containing 5% FMF. The results showed that daily weight gain, carcass weight, villus height, and the mRNA level of ZO-1 in the ileum were increased in the birds fed FMF compared to the control squabs (p < 0.05). Greater abundances of beneficial bacteria such as Lactobacillus, Bifidobacteria, and Bacillus as well as fewer harmful bacteria (i.e., Enterococcus, Veillonella, and Corynebacterium) in the ilea of squabs fed FMF. Six differential metabolites were identified in the FMF-treated squabs; one metabolite was increased (ω-salicoyisalicin) and five were decreased (3-benzoyloxy-6-oxo-12-ursen-28-oic acid, estradiol-17-phenylpropionate, aminotriazole, phosphatidyl ethanolamine (22:6/0:0), and 1-arachidonoylglycerophosphoinositol). Positive correlations were observed between the abundance of Lactobacillus and villus height. Overall, FMF treatment improved both growth and intestinal health in pigeons, suggesting potential benefits for pigeon production.

The Impact of Essential Amino Acids on the Gut Microbiota of Broiler Chickens

The research involving the beneficial aspects of amino acids being added to poultry feed pertaining to performance, growth, feed intake, and feed conversion ratio is extensive. Yet currently the effects of amino acids on the gut microbiota aren't fully understood nor have there been many studies executed in poultry to explain the relationship between amino acids and the gut microbiota. The overall outcome of health has been linked to bird gut health due to the functionality of gastrointestinal tract (GIT) for digestion/absorption of nutrients as well as immune response. These essential functions of the GI are greatly driven by the resident microbiota which produce metabolites such as butyrate, propionate, and acetate, providing the microbiota a suitable and thrive driven environment. Feed, age, the use of feed additives and pathogenic infections are the main factors that have an effect on the microbial community within the GIT. Changes in these factors may have potential effects on the gut microbiota in the chicken intestine which in turn may have an influence on health essentially affecting growth, feed intake, and feed conversion ratio. This review will highlight limited research studies that investigated the possible role of amino acids in the gut microbiota composition of poultry.

Coccidiosis in Egg-Laying Hens and Potential Nutritional Strategies to Modulate Performance, Gut Health, and Immune Response

Avian coccidiosis, despite advancements in management, nutrition, genetics, and immunology, still remains the most impactful disease, imposing substantial economic losses to the poultry industry. Coccidiosis may strike any avian species, and it may be mild to severe, depending on the pathogenicity of Eimeria spp. and the number of oocysts ingested by the bird. Unlike broilers, low emphasis has been given to laying hens. Coccidiosis in laying hens damages the gastrointestinal tract and causes physiological changes, including oxidative stress, immunosuppression, and inflammatory changes, leading to reduced feed intake and a drastic drop in egg production. Several countries around the world have large numbers of hens raised in cage-free/free-range facilities, and coccidiosis has already become one of the many problems that producers have to face in the future. However, limited research has been conducted on egg-laying hens, and our understanding of the physiological changes following coccidiosis in hens relies heavily on studies conducted on broilers. The aim of this review is to summarize the effect of coccidiosis in laying hens to an extent and correlate it with the physiological changes that occur in broilers following coccidiosis. Additionally, this review tries to explore the nutritional strategies successfully used in broilers to mitigate the negative effects of coccidiosis in improving the gut health and performance of broilers and if they can be used in laying hens.

Effect of diet supplemented with functional amino acids and polyphenols on gut health in broilers subjected to a corticosterone-induced stress

To address the overuse of antimicrobials in poultry production, new functional feed ingredients, i.e. ingredients with benefits beyond meeting basic nutritional requirements, can play a crucial role thanks to their prophylactic effects. This study evaluated the effects of the supplementation of arginine, threonine and glutamine together with grape polyphenols on the gut integrity and functionality of broilers facing a stress condition. 108 straight-run newly hatched Ross PM3 chicks were kept until 35 days and were allocated to 3 treatments. Broilers in the control group were raised in standard conditions. In experimental groups, birds were administered with corticosterone in drinking water (CORT groups) to impair the global health of the animal and were fed a well-balanced diet supplemented or not with a mix of functional amino acids together with grape extracts (1 g/kg of diet-CORT + MIX group). Gut permeability was significantly increased by corticosterone in non-supplemented birds. This corticosterone-induced stress effect was alleviated in the CORT + MIX group. MIX supplementation attenuated the reduction of crypt depth induced by corticosterone. Mucin 2 and TNF-α gene expression was up-regulated in the CORT + MIX group compared to the CORT group. Caecal microbiota remained similar between the groups. These findings indicate that a balanced diet supplemented with functional AA and polyphenols can help to restore broiler intestinal barrier after a stress exposure.

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.

Metabolic and microbiota response to arginine supplementation and cyclic heat stress in broiler chickens

Little attention has been paid to the biological role of arginine and its dietary supplementation in broilers under heat stress (HS) conditions. Therefore, the main aim of this study was to assess the response of broilers to arginine supplementation and cyclic HS, with a focus on liver, pectoral muscle, and blood metabolic profiles and the cecal microbiota. Day-old male Ross 308 broilers (n = 240) were placed in 2 rooms with 12 pens each for a 44-day trial. Pens were assigned to one of two groups (6 pens/group/room): the control group (CON) was given a basal diet in mash form and the treated group (ARG) was fed CON diet supplemented with crystalline L-arginine. The total arginine:lysine ratio of CON diet ranged between 1.02 and 1.07, while that of ARG diet was 1.20. One room was constantly kept at thermoneutral (TN) conditions, while the birds in the other room were kept at TN conditions until D34 and subjected to cyclic HS from D35 onwards (∼34°C; 9:00 A.M.–6:00 P.M.). Blood, liver, Pectoralis major muscle, and cecal content were taken from 2 birds per pen (12 birds/group/room) for metabolomics and microbiota analysis. Growth performance data were also collected on a pen basis. Arginine supplementation failed to reduce the adverse effects of HS on growth performance. Supplemented birds showed increased levels of arginine and creatine in plasma, liver, and P. major and methionine in liver, and reduced levels of glutamine in plasma, liver, and P. major. HS altered bioenergetic processes (increased levels of AMP and reduced levels of fumarate, succinate, and UDP), protein metabolism (increased protein breakdown to supply the liver with amino acids for energy production), and promoted the accumulation of antioxidant and protective molecules (histidine-containing dipeptides, beta-alanine, and choline), especially in P. major. Arginine supplementation may have partially counterbalanced the effects of HS on energy homeostasis by increasing creatine levels and attenuating the increase in AMP levels, particularly in P. major. It also significantly reduced cecal observed diversity, while HS increased alpha diversity indices and affected beta diversity. Results of taxonomic analysis at the phylum and family level are also provided.

Feeding broiler chickens with arginine above recommended levels: effects on growth performance, metabolism, and intestinal microbiota

BACKGROUND

Arginine is an essential amino acid for chickens and feeding diets with arginine beyond the recommended levels has been shown to influence the growth performance of broiler chickens in a positive way. Nonetheless, further research is required to understand how arginine supplementation above the widely adopted dosages affects metabolism and intestinal health of broilers. Therefore, this study was designed to assess the effects of arginine supplementation (i.e., total arginine to total lysine ratio of 1.20 instead of 1.06-1.08 recommended by the breeding company) on growth performance of broiler chickens and to explore its impacts on the hepatic and blood metabolic profiles, as well as on the intestinal microbiota. For this purpose, 630 one-day-old male Ross 308 broiler chicks were assigned to 2 treatments (7 replicates each) fed a control diet or a crystalline L-arginine-supplemented diet for 49 d.

RESULTS

Compared to control birds, those supplemented with arginine performed significantly better exhibiting greater final body weight at D49 (3778 vs. 3937 g; P < 0.001), higher growth rate (76.15 vs. 79.46 g of body weight gained daily; P < 0.001), and lower cumulative feed conversion ratio (1.808 vs. 1.732; P < 0.05). Plasma concentrations of arginine, betaine, histidine, and creatine were greater in supplemented birds than in their control counterparts, as were those of creatine, leucine and other essential amino acids at the hepatic level. In contrast, leucine concentration was lower in the caecal content of supplemented birds. Reduced alpha diversity and relative abundance of Firmicutes and Proteobacteria (specifically Escherichia coli), as well as increased abundance of Bacteroidetes and Lactobacillus salivarius were found in the caecal content of supplemented birds.

CONCLUSIONS

The improvement in growth performance corroborates the advantages of supplementing arginine in broiler nutrition. It can be hypothesized that the performance enhancement found in this study is associated with the increased availability of arginine, betaine, histidine, and creatine in plasma and the liver, as well as to the ability of extra dietary arginine to potentially ameliorate intestinal conditions and microbiota of supplemented birds. However, the latter promising property, along with other research questions raised by this study, deserve further investigations.

Nutritional supplements for the control of avian coccidiosis

Coccidiosis is acclaimed as the most prevalent enteric parasitic ailment of poultry. It is caused by an apicomplexan protozoon of the genus Eimeria, which resides in chicken intestinal epithelium leading to intestinal damage. As a result, bloody droppings are there, feed efficiency is reduced, the growth rate is impaired, and egg production is temporarily decreased. Treatment and prevention of coccidiosis are primarily accomplished by inoculating live vaccines and administering anticoccidial drugs. Due to anticoccidials’ continuous and excessive use, the mounting issue is drug resistant Eimeria strains. The poultry industry has managed resistance-related issues by suggesting shuttle and rotation schemes. Furthermore, new drugs have also been developed and introduced, but it takes a long time and causes cost inflation in the poultry industry. Moreover, government disallows growth promoters and drugs at sub-therapeutic doses in poultry due to increased concerns about the drug residues in poultry products. These constraints have motivated scientists to work on alternative ways to control coccidiosis effectively, safely, and sustainably. Using nutritional supplements is a novel way to solve the constraints mentioned above. The intriguing aspects of using dietary supplements against coccidiosis are that they reduce the risk of drug-resistant pathogen strains, ensure healthy, nutritious poultry products, have less reliance on synthetic drugs, and are typically considered environmentally safe. Furthermore, they improve productivity, enhance nonspecific immunity, preventing oxidation of fats (acting as antioxidants) and inflammation (acting as an anti-inflammatory). The present manuscript focuses on the efficacy, possible mechanism of action, applications, and different facets of nutrition supplements (such as organic acids, minerals, vitamins, probiotics, essential oils, amino acids, dietary nucleotides, feed enzymes, and yeast derivatives) as feed additive for treating poultry coccidiosis.

Inulin and Chinese Gallotannin Affect Meat Quality and Lipid Metabolism on Hu Sheep

The aim of this study was to investigate the impacts of inulin and Chinese gallotannin on the meat fatty acids and urinary metabolites in sheep. Twenty-four healthy (25.80 ± 3.85 kg) weaned Hu lambs of approximately 4.5 months old were equally divided into four groups: control group (basal diet), treatment group I (basal diet + 0.1% inulin), treatment group II (basal diet + 0.1% inulin + 2% Chinese gallotannin), and treatment group III (basal diet + 0.1% inulin + 2% Chinese gallotannin + 4% PEG). The contents of myristic acid (C14:0) and palmitic acid (C16:0) were found to be lower in treatment group II than in the control group (p < 0.05). Moreover, the palmitoleic acid (C16:1) content in treatment group II was notably higher than that in the control group (p < 0.05), while the elaidic acid (C18:1n9t) content in treatment group II was higher than that in other groups (p < 0.05). Besides, the linoleic acid (C18:2n6c) content was higher in the treatment II and control groups than in the treatment I and III groups. Furthermore, compared with the control group, both 4-pyridoxic acid and creatinine in treatment groups I and II were upregulated (p < 0.05), while other metabolites, such as nicotinuric acid, l-threonine, palmitic acid, and oleic acid, were drastically downregulated (p < 0.05). These differential metabolites were found to be mainly involved in nicotinate and nicotinamide metabolism (ko00760), vitamin B6 metabolism (ko00750), and the fatty acid biosynthesis pathway (ko00061). It is concluded that the combination of inulin and Chinese gallotannin in the diet could improve the energy and lipid metabolism of sheep, which may improve both mutton quality and production performance.

Cannabidiol and Nano-Selenium Increase Microvascularization and Reduce Degenerative Changes in Superficial Breast Muscle in C. perfringens-Infected Chickens

Here, we demonstrated the potential of Cannabis-derived cannabidiol (CBD) and nanosized selenium (nano-Se) for the modulation of microvascularization and muscle fiber lesions in superficial breast muscle in C. perfringens-challenged chickens. The administration of CBD resulted in a decreased number of atrophic fibers (3.13 vs. 1.13/1.5 mm²) compared with the control, whereas nano-Se or both substances resulted in a decreased split fiber number (4.13 vs. 1.55/1.5 mm²) and in a lower number of necrotic myofibers (2.38 vs. 0.69/1.5 mm²) in breast muscle than the positive control. There was a significantly higher number of capillary vessels in chickens in the CBD+Nano-Se group than in the control and positive control groups (1.31 vs. 0.97 and 0.98, respectively). Feeding birds experimental diets lowered the activity of DNA damage repair enzymes, including 3,N4-ethenodeoxycytosine (by 39.6%), 1,N6-ethenodeoxyadenosine (by 37.5%), 8-oxo-guanine (by 36.2%), formamidopyrimidine (fapy)-DNA glycosylase (by 56.2%) and human alkyl adenine DNA glycosylase (by 40.2%) in the ileal mucosa, but it did not compromise the blood mitochondrial oxygen consumption rate (-2.67 OD/min on average). These findings indicate a potential link between gut mucosa condition and histopathological changes in superficial pectoral muscle under induced inflammation and show the ameliorative effect of CBD and nano-Se in this cross-talk due to their protection from mucosal DNA damage.

Rosehip (Rosa canina L.) Meal as a Natural Antioxidant on Lipid and Protein Quality and Shelf-Life of Polyunsaturated Fatty Acids Enriched Eggs

Eggs are a common food of animal origin, inexpensive, and rich in bioactive substances with high biological value. Eggs enriched in polyunsaturated fatty acids (PUFA) are extremely desired by the progressive consumer. However, during storage, eggs undergo some physiochemical changes, which decrease their value. In this regard, the effect of dietary rosehip meal and flaxseed meal on hens’ egg quality characteristics, amino acids, fatty acids, health-related indices, antioxidant capacity, total polyphenols content, and shelf life was examined. For this study 120 Tetra SL laying hens, 29 weeks of age, were fed, for 4 weeks, three diets that included control (basal diet—RF0), basal diet + 1.5% rosehip and 7% flaxseed meal (RF1), and basal diet + 3% rosehip and 7% flaxseed meal (RF2). Productive performance of hens were recorded. The content of essential amino acids (EAA), antioxidant amino acids (AAA), and sulfur amino acids (SAA) was higher in RF1 and RF2, compared with RF0. Eggs belonging to the RF1 and RF2 groups had significantly (p < 0.05) higher content of n-3 PUFAs, especially linolenic and docosahexaenoic acids. Total antioxidant capacity and polyphenol content increased in both rosehip supplemented groups, but especially in RF2. Moreover, eggs from RF1 and RF2 groups maintained significantly higher egg quality parameters after storage for 14 and 28 days in the refrigerator (5 °C) and ambient temperature (21 °C), compared with those from the RF0 group. In the Haugh unit, yolk and albumen pH presented better values in RF1 and RF2 eggs compared to the RF0 eggs.

The Sarcoplasmic Protein Profile of Breast Muscle in Turkeys in Response to Different Dietary Ratios of Limiting Amino Acids and Clostridium perfringens-Induced Inflammation

In this study, the effects of the Arginine/Lysine (Arg/Lys) ratio in low- and high-methionine (Met) diets on the sarcoplasmic protein profile of breast muscles from turkeys reared under optimal or challenge (Clostridium perfringens infection) conditions were determined. One-day-old Hybrid Converter female turkey poults (216 in total) obtained from a commercial hatchery on hatching day, and on the basis of their average initial body weight were randomly allocated to 12 pens (4 m² each; 2.0 m × 2.0 m) containing litter bedding and were reared over a 42-day experimental period. Diets with high levels of Lys contained approximately 1.80% and 1.65% Lys and were offered in two successive feeding periods (days 1–28 and days 29–42). The supplemental levels of Lys were consistent with the nutritional specifications for birds at their respective ages as established in the Management Guidelines for Raising Commercial Turkeys. The experiment was based on a completely randomized 3 × 2 × 2 factorial design with three levels of Arg (90%, 100% and 110%) relative to the content of dietary Met (30 or 45%) and without (−) or with (+) C. perfringens challenge at 34, 36, or 37 d of age. Meat samples were investigated in terms of pH, color, and sarcoplasmic protein profile. The experimental factors did not influence meat quality but the dietary Arg content affected meat color. The sarcoplasmic protein profile was influenced by all studied factors, and glycolytic enzymes were the most abundant. This study evidenced strong association between the challenge conditions and the involvement of glycolytic enzymes in cell metabolism, particularly in inflammatory processes, and DNA replication and maintenance in turkeys. The results showed an effect of C. perfringens infection and feeding with different doses of Arg and Met may lead to significant consequences in cell metabolism.

The effect of gradually decreasing the dietary energy content, at constant or increased lysine:energy ratio on broiler performance, carcass yield, and body composition

Formulating diets with high AME, especially in the grower and finisher phases, hinders the inclusion of alternative ingredients that are usually cheaper and have lower AME. Moreover, as the chicken grows the feed intake capacity is greater and may be able to maintain BW over a wide range of AME. The objective of this study was to evaluate the performance of chickens fed diets with progressive AME reductions, at constant or increased standardized ileal digestible (SID) lysine:AME ratio (Lys:AME). Treatment 1 (control) was formulated following the SID lysine and AME recommendations for a 4-phase feeding program. Treatment 5 was formulated with -4, -8, and -12% AME in the grower-1, grower-2, and finisher phases, respectively, and with the same Lys:AME compared with the control. Treatment 9 had the same AME as treatment 5 but higher SID lysine, increasing the Lys:AME by 1.5, 3.5, and 5.0% compared with treatment 5. In the grower-1, grower-2, and finisher phases, the final 9 dietary treatments were prepared by mixing the control diet with either treatment 5 or 9 at different proportions (75:25, 50:50, or 25:75). All birds were fed the same starter control diet. Treatments were replicated in 10 pens with 31 male chickens each, and the growth performance of birds was monitored for 42 d. Final BW linearly decreased (P < 0.05) when lowering dietary AME, but it followed a positive quadratic response with higher Lys:AME (P < 0.05). Feed intake increased (P < 0.05) with low AME, independently of the Lys:AME; but the linear regression in the feed conversion ratio (FCR) had a lower slope when the Lys:AME increased. At the end of the study, there were no differences in carcass or breast meat yield (P > 0.10). Progressively reducing AME in the last feeding phases may be a viable nutritional strategy to increase the inclusion of alternative ingredients and potentially reduce feeding costs, despite increments in feed intake and FCR. Adjusting the Lys:AME in low AME diets may help maintain the final BW of birds.

Increased arginine, lysine, and methionine levels can improve the performance, gut integrity and immune status of turkeys but the effect is interactive and depends on challenge conditions

Arginine (Arg), lysine (Lys), and methionine (Met) can be used to support the health status of turkeys. The present study investigated selected performance, gut integrity, and immunological parameters in turkeys reared in optimal or challenge conditions. The experiment lasted for 28 days, and it had a completely randomized 2 × 3 factorial design with two levels of dietary Arg, Lys and Met (high or low) and challenge with Clostridium perfringens (C. perfringens), Escherichia coli lipopolysaccharide (LPS) or no challenge (placebo). Increased dietary levels of Arg, Lys and Met had a beneficial effect on turkey performance and immunological parameters, and it improved selected indicators responsible for maintaining gut integrity in different challenge conditions. Under optimal conditions (with no challenge), high ArgLysMet diets did not compromise bird performance and they improved selected performance parameters in challenged birds. The immune system of turkeys was not excessively stimulated by high ArgLysMet diets, which did not disrupt the redox balance and had no negative effect on gut integrity. High ArgLysMet diets increased the expression levels of selected genes encoding nutrient transporters and tight junction proteins. However, the influence exerted by different dietary inclusion levels of Arg, Lys and Met on gut integrity was largely determined by the stressor (C. perfringens vs. LPS). Further studies are required to investigate the role of Arg, Lys and Met levels in the diet on the immune response, gut function and performance of turkeys in different challenge conditions.

Infection with Ascaridia galli Does Not Significantly Alter Intestinal Microbiota and Is Cleared After Changes in the Expression of Cytokines

Because of the trend of cage-free egg production, infections with the nematode Ascaridia galli are receiving increased attention. The aim of this study was to establish a timeline for the influence of A. galli on the expression of key cytokines related to a parasitic immune response, and on the composition of the jejunal microbiota. Twenty-eight male layer-type birds were challenged at 24, 25, and 26 days of age. An additional 28 birds were kept as uninfected controls. Starting on Day 31, three birds of each group were euthanized every week until 8 wk postinfection (PI). The number of larvae isolated from the intestinal wall decreased over time, until no larvae were seen at 7 and 8 wk PI. At 5 wk PI, there was a numerical upregulation of all cytokines (TGF-β, IFN-γ, IL-4, IL-8, IL-10, IL-13) in the infected group, but this change was only statistically significant for IL-13. At this time point, larvae were expected to have developed into adults that would have shed eggs in the feces. However, no adult worms were seen and there was no egg shedding. For the microbiota analysis, there were significant differences in the alpha diversity (Faith's phylogenetic diversity) between challenge and control groups, and the beta diversity analysis showed slight differences between samples, suggesting that the age of the birds was the main reason for the separation of groups. These findings suggest that the upregulation of all cytokines evaluated in Week 5 might be the reason for resolution of the infection. Possible explanations are that a high infection dose and the fact that birds were fed with a more nutritionally dense feed might have contributed to the birds' immune system clearing the infection before the worms were able to reach maturity.

The influence of nutrition on intestinal disease with emphasis on coccidiosis

Ever since the poultry industry began to intensify early last century, coccidiosis has been a significant problem with which it has had to contend. Losses due to mortality and morbidity can be significant and before the advent of control agents there were several practices, some of which were nutritional, which were implemented to limit these losses. The development of coccidiostats reduced these problems considerably and as a result some of the more extreme intervention measures were no longer necessary. Modern day interpretation of what may have been happening with some of these early interventions provide interesting insights into what may be possible today should cocciodiostats be removed. More recent research has also indicated that the diet has a significant influence on the ability of poultry to resist and resolve an infection through direct and indirect effects on the pathogen, the immune system and on the litter. This paper reviews the role of dietary ingredients and nutrients on the pathogen to establish and the host to resist such an infection. There is clearly no panacea, but the combination of a few practices may reduce the overall challenge experienced by the poultry producer.

Dietary Fructooligosaccharides Effectively Facilitate the Production of High-Quality Eggs via Improving the Physiological Status of Laying Hens

The focus of this study was to investigate the influence of prebiotics, such as fructooligosaccharides (FOS), on laying performance, egg quality, apparent fecal amino acid digestibility, jejunal morphology, hematological indices, immunological response, and antioxidant capacity in laying hens. A total of 216 healthy Hy-Line Brown laying hens aged 30 weeks were randomly assigned to one of three dietary treatments: basal diet, basal diet supplemented with 0.3 percent FOS, or 0.6 percent FOS. For 84 days, each treatment was fed the corresponding experimental diet. According to the findings, dietary supplementation with FOS enhanced laying performance and egg mass while lowering mortality rate. Albumen height, thick albumen content, Haugh unit, and eggshell thickness were also improved by the prebiotics. Prebiotics also boosted antioxidant status by increasing the activity of antioxidant enzymes, improved morphological development of the jejunum as demonstrated by significant increases in villi height, villi width, ratio of villi height to crypt depth, and reduced crypt depth. The prebiotics group showed a considerable increase in immunoglobulin M, G, and A (IgM, IgG, and IgA) levels, as well as a similar effect on complement proteins (C3). Furthermore, the apparent fecal amino acid digestibility of most essential amino acids was significantly enhanced. Conclusively, fructooligosaccharides at inclusion level of 0.6% efficiently enhanced laying performance and production of high-quality eggs while positively modulating amino acid digestibility, jejunal morphology, antioxidant status, and immune functions of the laying hens.

Starving for nutrients: anorexia during infection with parasites in broilers is affected by diet composition

In 2 experiments, we investigated whether diet composition plays a role in pathogen-induced anorexia, the voluntary reduction in ADFI during infection in broilers. We hypothesized that either energy or CP dietary content could influence the extent of anorexia in Ross 308 broilers and infection outcomes with Eimeria maxima. From d 13 of age, half of the birds were infected, and half were uninfected. ADFI was measured daily, and BW every 3 d until d 29. Oocyst excretion was measured daily from d 17 to 23. The impact of parasitism on the small intestine was assessed on d 19 and 25. In Experiment 1, 336 birds were offered diets progressively diluted with lignocellulose, starting from a diet with 3,105 (kcal ME/kg) and 20% CP. There was a significant interaction between infection and diet on ADFI during the acute stage of infection (d 17 to 21): for control birds diet dilution decreased ADFI and consequently reduced energy and CP intake. For infected birds, diet dilution increased ADFI, leading to the same energy and CP intake across diets. Oocyst excretion and villi length to crypt depth ratio (VCR) were constant across infected treatments. In Experiment 2, 432 birds were offered diets with constant ME (3,105 kcal/kg), but different CP contents (24, 20, 26, and 12%). Infection significantly reduced ADFI. Although there was no interaction between infection and diet on ADFI, there was an interaction on CP intake during the acute stage of infection. Infected birds on the 20% CP diet achieved the same CP intake as uninfected birds. There were no differences in the VCR and ADG of the infected birds on 24, 20 and 16% CP treatments, but birds on 12% had the lowest ADG and excreted more oocysts. We suggest that during infection, birds target a nutrient resource intake, which appears to be beneficial for infection outcomes, while at the same time they avoid excess protein intake. We conclude that different mechanisms regulate ADFI in infected and uninfected birds.

Nutrients Interaction with the Immune System

This study described the interactions of different nutritional components with the immune system. A detailed search was carried out on Google Scholar and PubMed databases to find out the relevant research studies using different keywords, such as "Nutrients", "Micronutrients", and "Immune system and micronutrients". Only those papers that discussed the interactions between nutrients and the components of the immune system were included in the study. This research outlined the impact of different vitamins, trace elements or metals, amino acids, and fatty acids on different immune system components. It was found that vitamins, such as vitamin A, D, and C, tend to help immune cell differentiation and enhance the expression of different cytokines. Vitamins also contribute to the proliferation of T and B cells and impact the production of white blood cells. Similarly, trace elements or metals act as enzyme cofactors and control different immune response cycles by controlling the expression of cytokines, chemokines, and other signaling molecules. Moreover, different essential and non-essential amino acids play important roles in immune system development as they are primarily involved in protein synthesis. Amino acids, such as arginine, glutamine, and alanine, modulate the expression of cytokines and also control the migration and transmigration capabilities of macrophages. They also enhance the phagocytic properties of macrophages and neutrophils. In a similar way, fatty acids act as anti-inflammatory agents since they can decrease the expression of major histocompatibility complex class I (MHC-I) and MHC-II. Furthermore, they inhibit the secretion of different inflammatory cytokines. In conclusion, all the components of our daily diet are associated with the development of the immune system, and understanding their interactions is important for future immune therapies and drug development.

Effects of low-crude protein diets supplemented with arginine, glutamine, threonine, and methionine on regulating nutrient absorption, intestinal health, and growth performance of Eimeria-infected chickens

The study was conducted to evaluate the effects of low crude protein diets supplemented with arginine, glutamine, methionine, and/or threonine on apparent ileal digestibility of amino acids, intestinal morphology, intestinal permeability, gene expression of nutrient transporters, and tight junction proteins of broiler chickens challenged with mixed Eimeria spp. A total of five hundred seventy-six, 12-day-old male broiler chickens were allocated into 8 treatments, and 6 replicate cages of 12 chickens per cage. This experiment included a nonchallenged control (NC) fed regular corn-soybean meal-based diet (Regular diet, 19% crude protein), an Eimeria-challenged control (CC) fed Regular diet, an Eimeria challenge group fed low-crude protein diet (LCP, 16% crude protein), 4 Eimeria challenge groups fed low-crude protein diet supplemented with 0.75% arginine, glutamine, methionine, and threonine, respectively (ARG, GLN, MET, and THR), and an Eimeria challenge group fed low-crude protein diet with 0.75% supplemented arginine, glutamine, methionine, and threonine collectively as a combination group (COMB). On d 14, birds in the challenge groups were gavaged with a mixed Eimeria spp. solution containing 12,500 oocysts of E. maxima, 12,500 oocysts of E. tenella, and 62,500 oocysts of E. acervulina. The results showed that the Eimeria challenge reduced overall growth performance, but the LCP had no adverse impacts on intestinal health and growth of Eimeria-infected birds compared to the CC. Additionally, supplementation of crystalline arginine, glutamine, methionine, and threonine improved the apparent ileal digestibility of these specific amino acids on 6 dpi. Moreover, the THR treatment increased villus height in the duodenum. The ARG treatment decreased intestinal permeability and gene expression of amino acid transporters, whereas the GLN and THR treatments both reversed adverse effects of coccidiosis on gene expression of tight junction protein (claudin 1). However, the MET and COMB treatments exacerbated infection severity of coccidiosis. In summary, adding 0.75% of arginine, glutamine, or threonine in a low crude protein diet can improve the intestinal health of birds challenged with a mild coccidia infection.

Potential Implications of Citrulline and Quercetin on Gut Functioning of Monogastric Animals and Humans: A Comprehensive Review

The importance of gut health in animal welfare and wellbeing is undisputable. The intestinal microbiota plays an essential role in the metabolic, nutritional, physiological, and immunological processes of animals. Therefore, the rapid development of dietary supplements to improve gut functions and homeostasis is imminent. Recent studies have uncovered the beneficial effects of dietary supplements on the immune response, microbiota, gut homeostasis, and intestinal health. The application of citrulline (a functional gut biomarker) and quercetin (a known potent flavonoid) to promote gut functions has gained considerable interest as both bioactive substances possess anti-inflammatory, anti-oxidative, and immunomodulatory properties. Research has demonstrated that both citrulline and quercetin can mediate gut activities by combating disruptions to the intestinal integrity and alterations to the gut microbiota. In addition, citrulline and quercetin play crucial roles in maintaining intestinal immune tolerance and gut health. However, the synergistic benefits which these dietary supplements (citrulline and quercetin) may afford to simultaneously promote gut functions remain to be explored. Therefore, this review summarizes the modulatory effects of citrulline and quercetin on the intestinal integrity and gut microbiota, and further expounds on their potential synergistic roles to attenuate intestinal inflammation and promote gut health.

Effect of supplemental glycerol monolaurate and oregano essential oil blend on the growth performance, intestinal morphology, and amino acid digestibility of broiler chickens

Background

This experiment tested the impact of the combined supplementation of glycerol monolaurate (GLM) and oregano essential oil (EO) to broiler diets. Growth performance, metabolic response, immune status, apparent ileal digestibility coefficient (AID%), and intestinal histomorphology were assessed. Three-day-old Ross-308 broilers (76.62 g ± 0.50, n = 240) were randomly allocated into 4 experimental groups (6 replicates/group and 10 chicks/replicate). Birds were fed corn-soybean meal basal diets supplemented with four levels of GLM and oregano EO blend: 0, 0.15, 0.45, and 0.75% for 35 days.

Results

During the starter period, dietary GLM and oregano EO did not show significant (P > 0.05) changes in growth performance. During the grower period, GLM and oregano EO supplemented groups showed a linear and quadratic decline in FCR. During the finisher and overall performance, a linear increase in the body weight (BW), body weight gain (BWG), the protein efficiency ratio (PER), and relative growth rate (RGR), and a linear decrease in the FCR at 0.75% dietary level of GLM and oregano EO compared to the control. The broken-line regression model showed that the optimum dietary level of GLM and oregano EO blend was 0.58% based on final BW and FCR. The 0.45% or 0.15% dietary level of supplemented additives lowered (P < 0.05) the AID% of threonine and arginine, respectively, with no change in the AID% of other assessed amino acids at all dietary levels. Muscle thickness in jejunum and ileum in all dietary supplemented groups was increased (P < 0.05); however, such increase (P < 0.05) in the duodenum was shown at 0.45 and 0.75% dietary levels. All GLM and oregano EO supplemented groups showed increased (P < 0.05) duodenal, jejunal, and ileal villus height. The 0.15 and/or 0.75% dietary levels of supplemented additives increased (P < 0.05) the ileal and duodenal crypt depth, respectively, with a decreased (P < 0.05) duodenal crypt depth at 0.15% dietary level. The goblet cell count in ileum decreased (P < 0.05) in all GLM and oregano EO supplemented groups, but this decreased count (P < 0.05) was detected in jejunum at 0.45 and 0.75% dietary levels. The GLM and oregano EO supplemented groups did not show significant (P > 0.05) changes in the assessed metabolic and immune status parameters. Economically, the total return and performance index was increased at 0.75% dietary level.

Conclusion

Better growth performance was achieved at a 0.75 % dietary level of GLM and oregano EO by improving most intestinal morphometric measures. The optimum dietary level detected was 0.58%. The lack of influence of supplemented additives on chickens' immune and metabolic responses could indicate a lack of synergy between GLM and oregano EO.

Intestinal Barrier Function and Performance of Broiler Chickens Fed Additional Arginine, Combination of Arginine and Glutamine or an Amino Acid-Based Solution

Two experiments were conducted to investigate the effect of arginine (Arg); the combination of Arg and glutamine (Gln); as well as an amino acid-based solution (MIX) containing Arg, Gln, threonine (Thr), and grape extract, on performance, intestinal permeability, and expression of selected mechanistic genes. Using 240 male Ross 308 off-sex broiler chickens, four experimental treatments were replicated six times with 10 birds per replicate. The experimental treatments included 5 g/kg Arg, 2.5 g/kg Arg and 2.5 g/kg Gln, and 1 g/kg MIX added to a basal diet as control. In the second study, the four dietary treatments were then given to 24 birds with or without a synthetic glucocorticoid, dexamethasone (DEX), as a gut dysfunction model. Feed conversion ratio was improved by all the supplemented treatments from day 7 to 35 of age (p < 0.001). DEX injections increased (p < 0.001) the intestinal permeability in all treatments, which tended to be reversed by Arg or MIX. Additional Arg, Arg-Gln, and MIX suppressed (p < 0.05) the overexpression of IL-1β generated by DEX. Feeding birds with MIX treatment increased (p < 0.05) expression of SGLT-1 and glutathione synthetase. In conclusion, tested amino acid supplements were effective in improving feed efficiency and restraining intestinal inflammation caused by DEX through IL-1β pathway.

Effects of sodium humate and glutamine combined supplementation on growth performance, diarrhea incidence, blood parameters, and intestinal microflora of weaned calves

This experiment was conducted to investigate the effects of sodium humate (HNa) and glutamine (Gln) alone or combined supplementation on growth performance, diarrhea incidence, blood parameters, and intestinal microflora of weaned Holstein calves. In a 14-day experiment, 40 calves at 51 ± 3 days of age were randomly allocated to four treatment groups: (1) NC (basal diet), (2) NC + 5% HNa, (3) NC + 1% Gln, and (4) NC + 5% HNa + 1% Gln. Calves combined supplementation with HNa and Gln had a higher (P < .05) ADG, serum concentration of glucose (GLU), IgA, and IgG but lower fecal scores, diarrhea incidence, serum concentration of TNF-α, and IL-10 compared with NC group (P < .05). Compared with NC group, HNa + Gln group showed higher (P < .05) serum GSH and T-AOC activities but lower (P < .05) concentration of MDA and D-lac. Furthermore, the abundances of Prevotella ruminicola, Bifidobacterium, and Lactobacillus in rectal digesta were increased (P < .05), but the Escherichia coli was significantly decreased. In conclusion, combined supplementation with HNa and Gln can effectively improve the immune status, antioxidant capacity, and intestinal microflora of the weaned calves while reducing diarrhea incidence.

Review: Physiological growth trend of current meat broilers and dietary protein and energy management approaches for sustainable broiler production

The food production system needs to be sustainable including poultry sector to feed the increasing global population. An accepted economical and environmental approach of broiler production is to produce larger broilers faster while using less feed. Broiler production is aimed at producing consumable meat and meat products. The global broiler meat market has evolved over the years with increasing selection pressure shifted toward attaining yield characteristics for increased cut-up parts such as breast and thighs. There is a shift toward a big bird market in the U.S. with approximately 70% of the broiler meat produced from large birds (>2.72 kg). Genetic selection of broilers for quantitative traits such as growth rate and lean muscle mass without increasing the fat mass has altered broiler physiological homeostasis to adapt toward the larger rates of muscle protein turnover. Physiological stresses created due to selection pressures in broilers have produced several muscle myopathies including an emerging one called woody breast myopathy. The sustainable broiler production practice may require humane consideration of raising broilers in less stressful grow-out regimes that will have minimal impact on broiler metabolic health. Another sustainability approach of broiler production toward feed efficiency lies on understanding dietary formulation approach of amino acids and energy that promote optimal nutrient utilization and minimal nutrient output to environment while also fulfilling the growth demands and body composition changes associated with increased protein gain in current meat broilers brought by the genetic progress.

Functional Amino Acids in Pigs and Chickens: Implication for Gut Health

In pigs and broiler chickens, the gastrointestinal tract or gut is subjected to many challenges which alter performance, animal health, welfare and livability. Preventive strategies are needed to mitigate the impacts of these challenges on gut health while reducing the need to use antimicrobials. In the first part of the review, we propose a common definition of gut health for pig and chickens relying on four pillars, which correspond to the main functions of the digestive tract: (i) epithelial barrier and digestion, (ii) immune fitness, (iii) microbiota balance and (iv) oxidative stress homeostasis. For each pillar, we describe the most commonly associated indicators. In the second part of the review, we present the potential of functional amino acid supplementation to preserve and improve gut health in piglets and chickens. We highlight that amino acid supplementation strategies, based on their roles as precursors of energy and functional molecules, as signaling molecules and as microbiota modulators can positively contribute to gut health by supporting or restoring its four intertwined pillars. Additional work is still needed in order to determine the effective dose of supplementation and mode of administration that ensure the full benefits of amino acids. For this purpose, synergy between amino acids, effects of amino acid-derived metabolites and differences in the metabolic fate between free and protein-bound amino acids are research topics that need to be furtherly investigated.

Progress of amino acid nutrition for diet protein reduction in poultry

There is growing interest among nutritionists in feeding reduced protein diets to broiler chickens. Although nearly a century of research has been conducted providing biochemical insights on the impact of reduced protein diets for broilers, practical limitation still exists. The present review was written to provide insights on further reducing dietary protein in broilers. To construct this review, eighty-nine peer reviewed manuscripts in the area of amino acid nutrition in poultry were critiqued. Hence, nutritional research areas of low protein diets, threonine, glycine, valine, isoleucine, leucine, phenylalanine, histidine, and glutamine have been assessed and combined in this text, thus providing concepts into reduced protein diets for broilers. In addition, linkages between the cited work and least cost formation ingredient and nutrient matrix considerations are provided. In conclusion, practical applications in feeding reduced protein diets to broilers are advancing, but more work is warranted.

Nutritional manipulation to combat heat stress in poultry - A comprehensive review

Global warming and climate change adversely affect livestock and poultry production sectors under tropical and subtropical conditions. Heat stress is amongst the most significant stressors influencing poultry productivity in hot climate regions, causing substantial economic losses in poultry industry. These economic losses are speculated to increase in the coming years with the rise of global temperature. Moreover, modern poultry strains are more susceptible to high ambient temperature. Heat stress has negative effects on physiological response, growth performance and laying performance, which appeared in the form of reducing feed consumption, body weight gain, egg production, feed efficiency, meat quality, egg quality and immune response. Numerous practical procedures were used to ameliorate the negative impacts of increased temperature; among them the dietary manipulation, which gains a great concern in different regions around the world. These nutritional manipulations are feed additives (natural antioxidants, minerals, electrolytes, phytobiotics, probiotics, fat, and protein), feed restriction, feed form, drinking cold water and others. However, in the large scale of poultry industry, only a few of these strategies are commonly used. The current review article deliberates the different practical applications of useful nutritional manipulations to mitigate the heat load in poultry. The documented information will be useful to poultry producers to improve the general health status and productivity of heat-stressed birds via enhancing stress tolerance, oxidative status and immune response, and thereby provide recommendations to minimize production losses due to heat stress in particular under the growing global warming crisis.

Interorgan Metabolism, Nutritional Impacts, and Safety of Dietary L-Glutamate and L-Glutamine in Poultry

L-glutamine (Gln) is the most abundant amino acid (AA) in the plasma and skeletal muscle of poultry, and L-glutamate (Glu) is among the most abundant AAs in the whole bodies of all avian tissues. During the first-pass through the small intestine into the portal circulation, dietary Glu is extensively oxidized to CO₂, but dietary Gln undergoes limited catabolism in birds. Their extra-intestinal tissues (e.g., skeletal muscle, kidneys, and lymphoid organs) have a high capacity to degrade Gln. To maintain Glu and Gln homeostasis in the body, they are actively synthesized from branched-chain AAs (abundant AAs in both plant and animal proteins) and glucose via interorgan metabolism involving primarily the skeletal muscle, heart, adipose tissue, and brain. In addition, ammonia (produced from the general catabolism of AAs) and α-ketoglutarate (α-KG, derived primarily from glucose) serve as substrates for the synthesis of Glu and Gln in avian tissues, particularly the liver. Over the past 20 years, there has been growing interest in Glu and Gln metabolism in the chicken, which is an agriculturally important species and also a useful model for studying some aspects of human physiology and diseases. Increasing evidence shows that the adequate supply of dietary Glu and Gln is crucial for the optimum growth, anti-oxidative responses, productivity, and health of chickens, ducklings, turkeys, and laying fowl, particularly under stress conditions. Like mammals, poultry have dietary requirements for both Glu and Gln. Based on feed intake, tissue integrity, growth performance, and health status, birds can tolerate up to 12% Glu and 3.5% Gln in diets (on the dry matter basis). Glu and Gln are quantitatively major nutrients for chickens and other avian species to support their maximum growth, production, and feed efficiency, as well as their optimum health and well-being.

Nutritional significance of amino acids, vitamins and minerals as nutraceuticals in poultry production and health - a comprehensive review

Nutraceuticals have gained immense importance in poultry science recently considering the nutritional and beneficial health effects of their constituents. Besides providing nutritional requirements to birds, nutraceuticals have beneficial pharmacological effects, for example, they help in establishing normal physiological health status, prevent diseases and thereby improve production performance. Nutraceuticals include amino acids, vitamins, minerals, enzymes, etc. which are important for preventing oxidative stress, regulating the immune response and maintaining normal physiological, biochemical and homeostatic mechanisms. Nutraceuticals help in supplying nutrients in balanced amounts for supporting the optimal growth performance in modern poultry flocks, and as a dietary supplement can reduce the use of antibiotics. The application of antibiotic growth enhancers in poultry leads to the propagation of antibiotic-resistant microbes and drug residues; therefore, they have been restricted in many countries. Thus, there is a demand for natural feed additives that lead to the same growth enhancement without affecting the health. Nutraceuticals substances have an essential role in the development of the animals' normal physiological functions and in protecting them against infectious diseases. In this review, the uses of amino acids, vitamins and minerals as well as their mode of action in growth promotion and elevation of immune system are discussed.

What are the limits to feed intake of broilers on bulky feeds?

The view that genetic selection for carcass yield has limited the size of the gastrointestinal tract (GIT) of modern broilers has sparked concerns that their capacity to cope with energy dilution or bulk is also limited. We investigated the capacity of male Ross 308 broilers to deal with increasing levels of bulk and aimed to identify a feed bulk dimension responsible for limiting feed intake (FI). About 528 day-old broilers were allocated to 48 pens and offered a common starter feed until day 8, and 1 of 7 feeds from day 8 to 36 of age: a basal control (B), which was diluted to 3 levels (15, 30, or 45%) with either oat hulls (OH) or sugar beet pulp (SBP). Feed intake was measured daily and birds were dissected for GIT measurements at day 15, 22, and 36. Feed intake increased in birds offered OH15 (135 g/d), OH30 (140 g/d), and SBP15 (138 g/d) compared with birds offered the B feed (106 g/d; SEM 2.4). By increasing FI, birds were able to compensate for the lower energy content of their feeds. The greatest increase in FI was seen on OH30: its energy content (2,273 kcal/kg) was 26% lower than the B feed (3,081 kcal/kg). There was evidence of adaptation on the bulky feeds, as during the last week only birds on SBP45 were limited in FI and performance. The relative weights of the GIT were greater in the SBP than OH series, suggesting that the former needed to accommodate a higher bulk intake. For the OH series the increase in the relative GIT weights was confined to the gizzard and small intestine; whereas for the SBP series, the increase was extended to proventriculus and large intestine. Because only SBP45 was limiting FI, we were unable to identify a bulk dimension to be used to predict FI. Our data reject the suggestion that modern broilers have a reduced ability to cope with reductions in feed energy content.

Expression of selected genes encoding mechanistic pathways, nutrient and amino acid transporters in jejunum and ileum of broiler chickens fed a reduced protein diet supplemented with arginine, glutamine and glycine under stress stimulated by dexamethasone

Reducing crude protein and supplementation with synthetic amino acids in poultry nutrition is a recent trend to avoid wastage of protein and ammonia in production systems. Stress has been shown to impair intestinal barrier and increase inflammatory response. This study was performed on intestinal tissues of broiler chickens to understand the mechanism of stress induced by a synthetic glucocorticoid, dexamethasone (DEX) and the effect of supplementation of arginine, glutamine and glycine in reduced protein diets. Intestinal tissue samples from a previous study were utilized. Male Ross 308 chickens received a basal diet for the first seven days and then fed with crude protein that was reduced to 194 g/kg in grower experimental diets supplemented with glutamine, glycine and additional arginine at 10, 10 and 5 g/kg respectively. Half of the 96 individual birds were injected with DEX (0.5 mg/kg body weight) or saline on days 14, 16, 18 and 20 of age. mRNA expression for jejunum and ileum for amino acid transporters (y+LAT-1, B^o,+ AT, EAAT-3 and CAT-1), mechanistic genes (SGLT-1, mTOR, IAP and FABP-2) and pro-inflammatory genes (MUC-2, NF-κB, iNOS, IL-8 and IL-1β) were analysed using real-time PCR. The results showed that DEX decreased y+ LAT1 in jejunum, B^{o ,+} AT and EAAT-3 in ileum. Arginine increased CAT-1 in the jejunum and ileum under DEX treatment. Through an interaction, DEX reduced IAP in jejunum of glycine and arginine supplemented group and reduced mTOR in jejunum independently. DEX reduced MUC-2 and iNOS in jejunum and increased iNOS and IL8 in the ileum. Amino acid supplementation did not appear to ameliorate these effects; however, there were some positive effects of glycine on NF-κB and arginine through increased CAT-1. Mechanistic understanding of amino acid supplementation in broiler diets warrants further research particularly when dietary protein is reduced below the level tested in the present study.

Performance, intestinal permeability, and gene expression of selected tight junction proteins in broiler chickens fed reduced protein diets supplemented with arginine, glutamine, and glycine subjected to a leaky gut model

Changing dietary protein and amino acids may impact intestinal barrier function. Experiments were conducted in broiler chickens to evaluate supplementation of L-glutamine, glycine, and L-arginine in a reduced protein (RP) diet. Experiment 1 examined the growth performance of broilers fed 5 dietary treatments: 1) a standard diet; 2) an RP diet (193.9 g/kg CP in grower and 176.9 g/kg CP in finisher); 3) RP diet supplemented with 10 g/kg L-Gln; 4) RP diet supplemented with 10 g/kg Gly; 5) RP diet supplemented with 5 g/kg L-Arg. Each experimental diet was replicated 6 times with 10 birds per replicate. In a subset of 96 birds, experiment 2 tested the 4 RP diets with and without dexamethasone (DEX) to induce leaky gut. Each diet was replicated 24 times. Fluorescein isothiocyanate dextran (FITC-d) was used to test intestinal permeability (IP). Gene expression of selected tight junction proteins in ileal and jejunal tissues was assayed by quantitative PCR. From day 7 to 35, the RP diet increased feed intake (FI) (P < 0.05) and body weight gain (BWG) compared with the standard diet while Gln reduced FI and BWG (P < 0.05) compared with RP. Gly had no effect on BWG or FCR. Supplementation of Arg improved FCR from day 21 to 35 and day 7 to 35. In experiment 2, Arg tended to lower FITC-d (P = 0.086). DEX increased passage of FITC-d into the serum (P < 0.001). The villi surface area was increased in birds fed higher Arg (P < 0.05). DEX and diet interacted (P < 0.01) for jejunal claudin-3 mRNA level where DEX upregulated claudin-3 for all diets except the Arg diet. In summary, with a moderate reduction of protein, satisfactory performance can be obtained. Although Gln and Gly had no demonstrable positive effect on IP and performance of broilers, increasing the dietary Arg by approximately 140% improved FCR and showed indications of improved intestinal barrier function of birds fed an RP diet under a stress model.