Effects of plant-derived isoquinoline alkaloids on growth performance and intestinal function of broiler chickens under heat stress

Effects of a dietary isoquinoline alkaloids blend on gut antioxidant capacity and gut barrier of young broilers

Extensive mechanistic evidence to support the beneficial function of dietary phytobiotic applications for broiler performance, gut function and health is highly warranted. In particular, for isoquinoline alkaloids (IQ) the underlying mechanisms related to critical gut homeostasis components such as cytoprotection and gut barrier are scarce, especially for young broilers at the starter growth stage (d1-10). The aim of this study was to investigate the effect of a standardized blend of IQs on the relative gene expression of critical biomarkers relevant for antioxidant response and barrier function along the intestine of young broilers at the end of starter growth phase. For this purpose, 182 one-day-old Ross 308 broilers were allocated in 2 treatments with 7 replicates of 13 broilers each: control diet-no other additions (NC), and control diet containing a standardized blend of IQs at 200 mg/kg of diet (M) for the starter growth period (1-10d). The results revealed that the IQs blend significantly upregulated (P < 0.05) the expression of genes related to antioxidant response in all intestinal segments. Moreover, the IQs blend enhanced (P < 0.05) gut barrier components primarily at duodenal level. In conclusion, the blend of IQs beneficially affected critical pathway components relevant for the gut antioxidant capacity and barrier along the intestine of young broilers.

Effect of a microencapsulated phyto/phycogenic blend supplementation on growth performance, processing parameters, meat quality, and sensory profile in male broilers

Powered by consumer taste, value, and preferences, natural products including phytogenics and algae are increasingly and separately used in the food systems where they have been reported to improve growth performance in poultry and livestock. The present study aimed to determine the effects of a new feed additive, microencapsulated NUQO© NEX, which contains a combination of phytogenic and phycogenic, on broiler growth performance, blood chemistry, bone health, meat quality and sensory profile. Male Cobb500 chicks (n = 1,197) were fed a 3-phase feeding intervals; 1-14d starter, 15-28d grower, and 29-40d finisher. The dietary treatments included a corn-soy basal Control (CON), basal diet supplemented with NUQO© NEX at 100 g/ton from 1 to 28d then 75 g/ton from d 28 to 40 (NEX75), and basal diet supplemented with NUQO© NEX at 100 g/ton from 1 to 40d (NEX100). The NEX100 supplemented birds had 62 g more BWG increase and 2.1-point improvement in FCR compared with CON in the finisher and overall growth phase (p < 0.05), respectively. Day 40 processing body weights and carcass weights were heavier for the NEX100 supplemented birds (p < 0.05). The incidences of muscle myopathies were also higher in NEX treatments, which could be associated with the heavier weights, but the differences were not detected to be significant. The NEX75 breast filets had more yellowness than other dietary treatments (p = 0.003) and the NEX 100 treatment reduced the levels of breast filet TBARS at 7 days-post harvest (p = 0.053). Finally, both NEX treatments reduced the incidence of severe bone (tibia and femur) lesions. In conclusion, the supplementation of the phytogenic NUQO© NEX improved finisher performance parameters, whole phase FCR, processing carcass weights, and breast filet yellowness, at varying inclusion levels.

Prebiotic effects of Talinum triangulare and Mangifera indica on slow growing broiler chickens (SASSO)

1

The study aim was to evaluate the prebiotic effects of Talinum triangulare and Mangifera indica used on slow growing broiler chickens.

2

Three hundred and sixty (360) slow-growing chicks of four weeks of age and similar weight were selected and divided into four (04) treatments (Positive Control, Negative Control, 2 % T. triangulare and 2 % M. indica) of 6 replicates with, fifteen (15) chicks per replicate, which made ninety (90) chicks per treatment.

3

At 12 week age, blood sample and cecal content were taken from 6 chickens per treatment to determine heamatological profile and fermentation parameters (Short Chain Fatty Acid). The data obtained were submitted to one-way analysis of variance (ANOVA) using the software R version 3.6.2 (R Core Team, 2019).

4

Results showed that growth performance, haematological parameters, acetic, butyric, valeric and caproic acids were similar between broilers fed with the leave powders and the positive control treatment. However, broilers fed with Talinum triangulare and Mangifera indica powders showed a lower mortality rate, compared to the negative and positive control treatments. Moreover, broilers fed with the leave powders showed significantly higher (p < 0.05) formic acid concentration than the other treatments.

5

Talinum triangulare and Mangifera indica leaves could have prebiotic properties because they stimulated the production of short-chain fatty acids that keep animals healthy.

Genistein alleviates chronic heat stress-induced lipid metabolism disorder and mitochondrial energetic dysfunction by activating the GPR30-AMPK-PGC-1α signaling pathways in the livers of broiler chickens

The objective of this study was to investigate the preventive effects and mechanisms of genistein (GEN) on production performance and metabolic disorders in broilers under chronic heat stress (HS). A total of 120 male 3-wk-old Ross broilers were randomly assigned to 5 groups: a thermoneutral zone (TN) group maintained at normal temperature (21°C ± 1°C daily), an HS group subjected to cyclic high temperature (32°C ± 1°C for 8 h daily), and 3 groups exposed to HS with varying doses of GEN (50, 100, or 150 mg/kg diet). The experimental period lasted for 3 wk. Here, HS led to a decline in growth performance parameters and hormone secretion disorders (P < 0.05), which were improved by 100 and 150 mg/kg GEN treatment (P < 0.05). Moreover, the HS-induced increases in the liver index (P < 0.01) and abdominal fat rate (P < 0.05) were attenuated by 150 mg/kg GEN (P < 0.05). The HS-induced excessive lipid accumulation in the liver and serum (P < 0.01) was ameliorated after 100 and 150 mg/kg GEN treatment (P < 0.05). Furthermore, the HS-induced decreases in lipolysis-related mRNA levels and increases in lipid synthesis-related mRNA levels in the liver (P < 0.01) were effectively blunted after 100 and 150 mg/kg GEN treatment (P < 0.05). Importantly, the HS-stimulated hepatic mitochondrial energetic dysfunction and decreases in the mRNA or protein levels of peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α), nuclear respiratory factor 1, and mitochondrial transcription factor A in the liver were ameliorated by 150 mg/kg GEN (P < 0.05). Moreover, 50 to 150 mg/kg GEN treatment resulted in a significant increase in the mRNA or protein levels of G protein-coupled estrogen receptor (GPR30), AMP-activated protein kinase (AMPK) α1, phosphorylated AMPKα, and phosphorylated acetyl-CoA carboxylase α. Collectively, GEN alleviated metabolic disorders and hepatic mitochondrial energetic dysfunction under HS, possibly through the activation of GPR30-AMPM-PGC-1α pathways. These data provide a sufficient basis for GEN as an additive to alleviate HS in broilers.

Comparative effects of medium-chain fatty acids or phytobiotics-based feed additives on performance, caecum microbiota, volatile fatty acid production and intestinal morphology of broilers

Antibiotic growth promoters have been utilized in broiler nutrition to alleviate the negative effects of the pathogenic microbes to promote performance. However, after the prohibition of antibiotics because of the increasing disclosure related to public health issues, various products have been developed as alternatives. This study was carried out to determine the effects of medium-chain fatty acids (MCFAs) or phytobiotics (essential oils [EOs] and alkaloids [ALKs]), blended feed additives on the growth performance, jejunum histomorphology, and cecal microbiota of broiler chickens. A total of 765 male Ross 308 chicks were randomly distributed into 5 experimental groups, each having 9 replicates with 17 chicks. The experimental procedures were as follows: a control group without supplementation (T1); control group+ MCFAs and EOs blend (T2); control group+ different EOs blend (T3); control group+ ALK sanguinarine (T4); and control group+ EOs and ALK piperine mixture (T5). The results showed that, broilers fed with MCFAs blended with EOs had significantly greater body weight gain during overall period in comparision to the control and T3 groups. Further, only MCFAs blended with EOs group significantly improved jejnum morphology in comparison with the control group (p ≤ 0.05). Besides, the MCFAs blended with EOs group significantly elevated propionate, acetate and butyrate concentration, and decreased the concentration of branch chain fatty acids in caecum (p ≤ 0.05). The results indicated that, the combination of MCFAs and EOs seems to have improvement effects and could be preferred as an efficient feed additive in broiler production.

Dietary Macleaya cordata extract supplementation improves the growth performance and gut health of broiler chickens with necrotic enteritis

BACKGROUND

The poultry industry needs effective antibiotic alternatives to control outbreaks of necrotic enteritis (NE) caused by Clostridium perfringens.

METHODS

The aim of this study was to investigate the effects of dietary supplementation with Macleaya cordata extract (MCE) on the immune function and gut microbiota of broilers with NE. A total of 288 1-day-old broiler chicks were randomly assigned to a 2 × 2 factorial arrangement with two concentrations of dietary MCE supplementation (0 or 350 mg/kg of diet) and two disease challenge statuses (control or NE).

RESULTS

The results revealed that NE significantly increased the feed conversion rate (FCR), mortality, intestinal lesion score, the levels of IL-1β, IL-17 and IFN-γ/IL-4 in serum and IL-17/IL-10 in the jejunal mucosa, mRNA levels of TLR2, IFN-γ and pIgR in the jejunum, and Clostridium perfringens concentrations in the cecum. NE significantly decreased the body weight (BW), body weight gain (BWG), jejunal villus height, V/C, mRNA level of AMPK-α1 in jejunum, IL-4 level in the jejunal mucosa and lactic acid bacteria abundance in the cecum. MCE significantly increased BW, BWG, jejunal villus height, V/C, mRNA levels of occludin, ZO-1 and AMPK-α1 in the jejunum, the levels of IgA and IgG in serum and IL-10 in the jejunal mucosa and mRNA levels of NF-κB, IL-10 and MHC-II in the jejunum. Additionally, MCE significantly decreased the FCR, mortality, intestinal lesion score, jejunal crypt depth, the levels of IFN-γ and IL-17 in serum and IL-17/IL-10 in the jejunal mucosa, Clostridium perfringens concentrations in the cecum, and mRNA levels of IL-17/IL-10 in the jejunum. Moreover, NE significantly increased the abundance of bacteria that are associated with inflammation, obesity and depression (Alistipes, Barnesiella, Intestinimonas, RF39 and UCG-005) and significantly decreased the abundance of short-chain fatty acid (SCFA)-producing bacteria (Anaerotruncus, Butyricicoccus and Bacteroides) in the cecum. MCE significantly increased the abundance of SCFA-producing bacteria (Streptococcus, Ruminococcus_torques_group and Lachnospiraceae_NK4A136_group) and significantly reduced the abundance of bacteria that are associated with inflammation and obesity (Alistipes, Barnesiella and UCG-010) in the cecum. In the cecum of broilers with NE, the relative abundance of Barnesiella and Alistipes was higher and that of Lachnoclostridium and Shuttleworthia was lower. Interestingly, these trends were reversed by the addition of MCE to the diet. Spearman correlation analysis showed that Barnesiella and Alistipes were associated with enhanced intestinal inflammation and inhibited growth performance, whereas Lachnoclostridium and Shuttleworthia were associated with anti-inflammatory effects.

CONCLUSIONS

MCE ameliorated the loss of growth performance in broiler chickens with NE, probably by regulating the intestinal barrier, immune function, and gut microbiota.

Mechanisms underlying the Effects of Heat Stress on Intestinal Integrity, Inflammation, and Microbiota in Chickens

Poultry meat and egg production benefits from a smaller carbon footprint, as well as feed and water consumption, per unit of product, than other protein sources. Therefore, maintaining a sustainable production of poultry meat is important to meet the increasing global demand for this staple. Heat stress experienced during the summer season or in tropical/subtropical areas negatively affects the productivity and health of chickens. Crucially, its impact is predicted to grow with the acceleration of global warming. Heat stress affects the physiology, metabolism, and immune response of chickens, causing electrolyte imbalance, oxidative stress, endocrine disorders, inflammation, and immunosuppression. These changes do not occur independently, pointing to a systemic mechanism. Recently, intestinal homeostasis has been identified as an important contributor to nutrient absorption and the progression of systemic inflammation. Its mechanism of action is thought to involve neuroendocrine signaling, antioxidant response, the presence of oxidants in the diet, and microbiota composition. The present review focuses on the effect of heat stress on intestinal dysfunction in chickens and the underlying causative factors. Understanding these mechanisms will direct the design of strategies to mitigate the negative effect of heat stress, while benefiting both animal health and sustainable poultry production.

Effects of dietary polyherbal mixtures on growth performance, antioxidant capacity, immune function and jejunal health of yellow-feathered broilers

This study aimed to investigate the effects of polyherbal mixtures (PHM) on growth performance, antioxidant capacities, immune function, and intestinal health in yellow-feathered broilers. PHM is composed of five traditional Chinese medicine herbs (Portulaca oleracea L., Radix Sophora flavescens, Thalictrum glandulosissimum, Terra flava usta, and Pogostemon cablin). A total of 270 one-day-old yellow-feathered broilers were randomly allotted into 3 treatments for a 42-d feeding trial, each with 6 replicates of 15 birds. The dietary treatments consisted of a basal diet (CON), a basal diet supplemented with 50 mg/kg chlortetracycline (CTC), and a basal diet supplemented with 1000 mg/kg PHM. The results showed that dietary PHM supplementation increased body weight, ADG, and decreased F/G compared to the CON. PHM also increased spleen index and mRNA expression of IL-4 (d 21), and thymus index, serum IgA (d 42) and IgG, IL-4 and sIgA in jejunal mucosa (d 21 and 42), but decreased serum IFN-γ and mRNA expression of IFN-γ (d 21 and 42). In addition, PHM increased serum SOD, GSH-Px (d 21 and 42) and T-AOC (d 42), but decreased the content of serum MDA (d 21), the up-regulated mRNA expression of GSH-Px, CAT (d 21), SOD and CAT (d 42). Furthermore, PHM also improved the intestinal epithelial barrier indicators by the up-regulated mRNA expression of CLDN-1, OCLN (d 21 and 42) and ZO-1 (d 21), and the increased of villus height and villus height to crypt depth in jejunum (d 42). The high-throughput sequencing results showed that dietary PHM supplementation increased the alpha diversity and relative abundance of Oscillospira and Ruminococcus (d 21) and Lactobacillus (d 42), whereas decreasing that of Enterococcus (d 21) compared with CON. PICRUSt analysis revealed that metabolic pathways of carbohydrate, energy, lipid, cofactors, and vitamins were significantly enriched in the PHM group. Spearman's correlation analysis revealed that the genera Lactobacillus, Enterococcus, Ruminococcus, Oscillospira, and Faecalibacterium were related to growth performance, intestinal integrity, immune-related factors, antioxidant indices, and tight junction proteins. In conclusion, the results indicated that dietary PHM supplementation improved growth performance and immune status of yellow-feathered broilers by enhancing antioxidant capacities, barrier function, and modulated jejunal microbial communities. PHM used in our study has the potential to replace prophylactic antibiotic use in poultry production systems.

Effect of Glutamine on the Growth Performance, Oxidative Stress, and Nrf2/p38 MAPK Expression in the Livers of Heat-Stressed Broilers

The purpose of this work was to study the effects of glutamine (Gln) on the growth performance, oxidative stress, Nrf2, and p38 MAPK pathway in the livers of heat-stressed broilers. In total, 300 broilers were divided into five groups, including a normal temperature (NT, without dietary Gln) group and four cyclic high temperature groups (HT, GHT1, GHT2, and GHT3) fed with 0%, 0.5%, 1.0%, and 1.5% Gln, respectively. High temperature conditions increased (p < 0.05) liver malonaldehyde (MDA) concentration, but decreased (p < 0.05), body weight gain (BWG), feed intake (FI), liver superoxide dismutase (SOD), total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST), and glutathione (GSH) levels in broilers. Nrf2 and p38 MAPK protein and mRNA expression levels were lower (p < 0.05) in the NT group than that in the HT group. However, dietary 1.5% Gln decreased (p < 0.05) liver MDA concentration, but increased (p < 0.05) BWG, FI, liver SOD, T-AOC, GSH-Px, GST, and GSH levels in heat-stressed broilers. Nrf2 and p38 MAPK protein and mRNA expression levels were higher (p < 0.05) in the GHT3 group than that in the HT group. In summary, Gln improved oxidative damage through the activation of Nrf2 and p38 MAPK expression in the livers of heat-stressed broilers.

Adverse effects of heat stress during summer on broiler chickens production and antioxidant mitigating effects

Broiler chicken meat is a good source of protein consumed universally, and is one of the most commonly farmed species in world. In addition to providing food, poultry non-edible byproducts also have value. A major advantage of broiler chicken production is their short production cycle, which results in a greater rate of production in comparison to other species. However, as with any production system, there are constraints in broiler production with one of the most pressing being energy requirements to keep the birds warm as chicks and cool later in the growth cycle, as a result of the cost needing mechanical heating and cooling. While this is feasible in more advanced economies, this is not readily affordable in developing economies. As a result, farmers rely on natural ventilation to cool the rearing houses, which generally becoming excessively warm with the resultant heat stress on the birds. Since little can be done without resorting to mechanical ventilation and cooling, exploring the use of other means to reduce heat stress is needed. For this review, we cover the various factors that induce heat stress, the physiological and behavioral responses of broiler chickens to heat stress. We also look at mitigating the adverse effect of heat stress through the use of antioxidants which possess either an anti-stress and/or antioxidant effects.

Effects of brown seaweed products on growth performance, plasma biochemistry, immune response, and antioxidant capacity of broiler chickens challenged with heat stress

Brown seaweed (Ascophyllum nodosum) is an exceptional bioactive substance known for its excellent antioxidant ability. Given the potential benefits of brown seaweed, the current study was conducted to determine its efficacy on growth performance, blood biochemistry, immunoglobulins (IgG and IgM), and the antioxidant capacity of broiler chickens challenged with heat stress (HS). A total of 336 mixed-sex Ross 308 broiler chicks (one-day-old) were randomly assigned into two groups; The thermoneutral group (TN, broilers were raised at 24 ± 1°C); and the heat stress group (HS; broilers were exposed to 32°C to 34°C, 8 h/d from day 21 to 27; the temperature in the remaining time was same as TN group). All birds in each group were randomly allotted to 4 dietary treatments—Negative control (NC) (without seaweed), NC + 1 mL seaweed extract (SWE) in drinking water, NC + 2 mL SWE in drinking water, and NC + 2% seaweed meal (SWM) in feed. Each treatment was assigned to six replicates with 7 broilers/replicate. Average body weight gain (ABWG), average feed intake (AFI), average water intake (AWI), feed conversion ratio (FCR), and mortality were determined weekly. On day 28, two male birds/cage were euthanized to collect blood and immune organs for subsequent biochemical, antioxidant, and immune status analysis. Data were analyzed as a 4 × 2  factorial analysis of variance using the GLM procedure of Minitab software. Overall, 2% SWM inclusion significantly increased (P < 0.05) the AFI, ABWG, and AWI of broiler chickens irrespective of HS. HS significantly reduced (P < 0.05) AFI and increased (P < 0.05) the bird's rectal temperature, plasma concentrations of sodium, chloride, glucose, amylase, and uric acid compared to TN birds. HS increased (P < 0.05) serum IgM and IgG and decreased plasma glutathione reductase and glutathione peroxidase compared to TN birds, while the activity of superoxide dismutase was not affected by HS and dietary treatments. 1 mL SWE in water and 2% SWM in feed significantly reduced (P < 0.05) the plasma activity of alanine aminotransferase and gamma-glutamyl transferase of heat-stressed broilers, respectively compared to other treatments. Conclusively, dietary supplementation of brown seaweed improved the growth performance of birds irrespective of HS and may help to reduce the negative effects of HS by improving the plasma enzyme activities of heat-stressed birds.

Heat stress in broilers of liver injury Effects of heat stress on oxidative stress and autophagy in liver of broilers

This study aimed to investigate the effect of chronic heat stress on oxidative stress in liver of broilers. In our study, chickens were randomly allocated to control 1 group (control 7 d), heat stress 1 group (HS1, 7 d), control 2 group (control 14 d) and heat stress 2 group (HS2, 14 d), with 30 replicates in each group. Broilers in heat stress groups exposed 8 h/day heat stress (35 ± 2°C) for 7 or 14 consecutive days, and the rest of time per day were kept at 23 ± 2℃ the same as control group broilers. Growth performance and the liver tissues were collected for histological observation and detection of organ index and liver redox status. The serum indicators (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) related to liver injury were determined. Moreover, Nrf2-related genes and protein expression levels in liver were measured. The results showed that in heat stress group broilers the body weight gain, feed conversion ratio, liver weight, and liver index were decreased, inflammatory cells infiltration in liver, and serum AST level was enhanced, compared with control group broilers. Moreover, the hepatic malondialdehyde (MDA) and superoxide dismutase (SOD) level were increased after 1 wk of heat stress. Nrf2, Sqstm1/p62, HO-1, and NQO1 mRNA expressions in the liver of broilers were decreased by heat stress. P62 and p-p62 protein expressions were significantly up-regulated, but Nrf2 and keap1 protein level was decreased in heat stress group broilers as compared to control group. The mRNA expression levels of Beclin1, LC3-I, LC3-II were down-regulated significantly with heat stress for 1 wk. The mRNA expression level of mTOR up-regulated after 2 wk of heat stress. In conclusion, heat stress induced liver injury of broilers by down-regulating Nrf2-keap1 signaling pathway and autophagy.

Non-Targeted Metabolomic Analysis of Chicken Kidneys in Response to Coronavirus IBV Infection Under Stress Induced by Dexamethasone

Stress in poultry can lead to changes in body metabolism and immunity, which can increase susceptibility to infectious diseases. However, knowledge regarding chicken responses to viral infection under stress is limited. Dexamethasone (Dex) is a synthetic glucocorticoid similar to that secreted by animals under stress conditions, and has been widely used to induce stress in chickens. Herein, we established a stress model in 7-day-old chickens injected with Dex to elucidate the effects of stress on IBV replication in the kidneys. The metabolic changes, immune status and growth of the chickens under stress conditions were comprehensively evaluated. Furthermore, the metabolic profile, weight gain, viral load, serum cholesterol levels, cytokines and peripheral blood lymphocyte ratio were compared in chickens treated with Dex and infected with IBV. An LC-MS/MS-based metabolomics method was used to examine differentially enriched metabolites in the kidneys. A total of 113 metabolites whose abundance was altered after Dex treatment were identified, most of which were lipids and lipid-like molecules. The principal metabolic alterations in chicken kidneys caused by IBV infection included fatty acid, valine, leucine and isoleucine metabolism. Dex treatment before and after IBV infection mainly affected the host’s tryptophan, phenylalanine, amino sugar and nucleotide sugar metabolism. In addition, Dex led to up-regulation of serum cholesterol levels and renal viral load in chickens, and to the inhibition of weight gain, peripheral blood lymphocytes and IL-6 production. We also confirmed that the exogenous cholesterol in DF-1 cells promoted the replication of IBV. However, whether the increase in viral load in kidney tissue is associated with the up-regulation of cholesterol levels induced by Dex must be demonstrated in future experiments. In conclusion, chick growth and immune function were significantly inhibited by Dex. Host cholesterol metabolism and the response to IBV infection are regulated by Dex. This study provides valuable insights into the molecular regulatory mechanisms in poultry stress, and should support further research on the intrinsic link between cholesterol metabolism and IBV replication under stress conditions.

Noninvasive fecal metabolic profiling for the evaluation of characteristics of thermostable lactic acid bacteria, Weizmannia coagulans SANK70258, for broiler chickens

Weizmannia coagulans SANK70258 is a spore-forming thermostable lactic acid bacterium and an effective probiotic for the growth of livestock animals, but its growth-promoting mechanism remains unclear. Here, the composition of fecal metabolites in broilers continuously administered with W. coagulans SANK70258 was assessed under a regular program with antibiotics, which was transiently given for 6 days after birth. Oral administration of W. coagulans to broiler chicks tended to increase the average daily gain of body weights thereafter. The composition of fecal metabolites in the early chick stage (Day 10 after birth) was dramatically altered by the continuous exposure. The levels of short-chain fatty acids (SCFAs) propionate and butyrate markedly increased, while those of acetate, one of the SCFAs, and lactate were reduced. Simultaneously, arabitol, fructose, mannitol, and erythritol, which are carbohydrates as substrates for gut microbes to produce SCFAs, also increased along with altered correlation. Correlation network analyses classified the modularity clusters (|r| > 0.7) among carbohydrates, SCFAs, lactate, amino acids, and the other metabolites under the two conditions. The characteristic diversities by the exposure were visualized beyond the perspective associated with differences in metabolite concentrations. Further, enrichment pathway analyses showed that metabolic composition related to biosynthesis and/or metabolism for SCFAs, amino acids, and energy were activated. Thus, these observations suggest that W. coagulans SANK70258 dramatically modulates the gut metabolism of the broiler chicks, and the metabolomics profiles during the early chick stages may be associated with growth promotion.

Ellagic Acid Improves Antioxidant Capacity and Intestinal Barrier Function of Heat-Stressed Broilers via Regulating Gut Microbiota

Heat stress (HS) has been revealed to damage the antioxidant system and intestinal barrier function, which greatly threatens poultry production. The present study investigated the effects of dietary ellagic acid (EA) on the antioxidant system, gut barrier function, and gut microbiota of heat-stressed broilers. Arbor Acres 14-day-old broilers numbering 360 were randomly divided into six groups, including one negative control group (NC) and five experimental groups. The broilers in the NC group were supplemented with a basal diet at a normal temperature (23 ± 2 °C). The broilers in the experimental groups were supplemented with basal diets containing EA at different doses (0, 75, 150, 300, and 600 mg/kg) at HS temperature (35 ± 2 °C). The experiment lasted for 4 weeks. Results showed that dietary EA reduced the corticosterone (CORT), LPS, and diamine oxidase (DAO) levels in the serum of heat-stressed broilers. Additionally, dietary EA improved the antioxidant enzyme activity and mRNA levels of Nrf2/HO-1 in the ileum of heat-stressed broilers. The relative abundances of Streptococcus, Ruminococcus_torques, Rothia, Neisseria, Actinomyces, and Lautropia in the cecum were significantly reduced by the EA supplementation in a dose-dependent manner. Notably, the LPS, DAO, and MDA in the serum were revealed to be positively correlated with the relative abundances of Rothia, Neisseria, Actinomyces, and Lautropia, while the GSH-px, SOD, and CAT levels in the serum were negatively correlated with the relative abundances of Ruminococcus_torques, Rothia, Neisseria, Actinomyces, Streptococcus, and Lautropia. Taken together, dietary EA improved the antioxidant capacity, intestinal barrier function, and alleviated heat-stressed injuries probably via regulating gut microbiota.

Meta-Analysis and Systematic Review of the Thermal Stress Response: Gallus gallus domesticus Show Low Immune Responses During Heat Stress

Heat stress, which affects broiler growth performance and immunity, is a major concern in the poultry industry. This meta-analysis aimed to demonstrate the significant effect of heat stress on broiler mass gain and immunoglobulin levels, which regulates the mortality rate of broilers. A total of 2,585 studies were downloaded from PubMed, Web of Science, and Google Scholar from January 1, 2015, to September 1, 2021. Eventually, 28 studies were selected based on specific criteria. The results for body mass gain, total mass of immune organs (thymus, spleen, and bursa of Fabricius), immunoglobulin (IgA, IgG, and IgM) levels, and mortality rate were analyzed using odds ratio or the random-effects model (REM) at a confidence interval (CI) of 95%. Compared to the control, heat stress significantly decreased body mass gain (10 trials: REM = 1.35, 95% CI: 1.21, 1.50). Compared to that in the control, heat stress significantly increased immunoglobulin levels: IgA (7 trials: REM = 1.69, 95% CI: 0.90, 3.16), IgG (6 trials: REM = 1.24, 95% CI: 0.85, 1.81), IgM (8 trials: REM = 0.69, 95% CI: 0.44, 1.08), and heat stress also increased the broiler mortality rate (6 trials: REM = 0.06, 95% CI: 0.01, 0.27). However, there were no significant changes in the immune organs between the control and heat-stressed groups. In conclusion, heat stress remarkably alters the mass gain and immunoglobulin levels of broilers, which may be a cause of the high mortality rate.

Dietary Lasia spinosa Thw. Improves Growth Performance in Broilers

This study aimed to evaluate the effects of dietary Lasia spinosa Thw. (LST) powder supplementation on growth performance, blood metabolites, antioxidant status, intestinal morphology, and cecal microbiome in broiler chickens. A total of 400 1-day-old male Guangxi partridge broilers (initial body weight: 42.52 ± 0.06 g) were randomly allotted to 4 dietary treatments: LST0 group (a basal diet), LST1 group (a basal diet with 1% LST powder), LST2 group (a basal diet with 2% LST powder), LST4 group (a basal diet with 4% LST powder), 10 replicates for each treatment, and 10 broilers in each treatment group. Results indicated that the average daily feed intake of broilers during 22-42 days and the average daily gain of chickens during 1-42 days significantly increased by dietary supplementation of LST powder (p < 0.01), while the feed conversion ratio during the overall periods was decreased by dietary supplementation of LST powder (p < 0.01). Except for the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in liver (p > 0.05), the levels of SOD, catalase (CAT) and GSH-Px in serum, liver, and breast muscle were significantly increased in the LST supplemented groups (p < 0.05), while the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in serum, liver, and breast muscle were significantly decreased in the LST supplemented groups (p < 0.05). Furthermore, the levels of triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) were significantly decreased by the addition of dietary LST powder (p < 0.01), while the levels of HDL-C, Ca, Fe, Mg, and P were linearly increased by the addition of dietary LST powder (p < 0.01). With respect to the gut morphometric, crypt depth was significantly decreased by LST supplementation (p < 0.05), while villus height and the ratio of villus height to crypt depth were notably increased by LST supplementation (p < 0.05). Sequencing of 16S ribosomal RNA (16S rRNA) from the cecal contents of broilers revealed that the composition of the chicken gut microbiota was altered by LST supplementation. The α-diversity of microbiota in broilers was increased (p < 0.05) in the LST1 group, but was decreased (p < 0.05) in the LST2 and LST4 groups compared with the LST0 group. The differential genera enriched in the LST1 group, such as Bacillus, Odoribacter, Sutterella, Anaerofilum, Peptococcus, were closely related to the increased growth performance, antioxidant status, intestinal morphology, Ca, Mg, and reduced blood lipid in the treated broilers.

Isoquinoline alkaloids induce partial protection of laying hens from the impact of Campylobacter hepaticus (spotty liver disease) challenge

Spotty liver disease (SLD) is a serious condition affecting extensively housed laying hens. The causative bacterium was described in 2015 and characterized in 2016 and named Campylobacter hepaticus. Antibiotics are the only tool currently available to combat SLD. However, antimicrobial resistance has already been detected, so finding therapeutic alternatives is imperative. Isoquinoline alkaloids (IQA), such as sanguinarine and chelerythrine, have been shown to have immunomodulatory effects. It has been hypothesized that IQA could ameliorate some of the deleterious effects of SLD. This study aimed to address that hypothesis in an experimental disease induction model. Birds were fed with diets containing 2 different doses of an IQA containing product, 100 mg of product/kg of feed (0.5 ppm of sanguinarine) and 200 mg of product/kg of feed (1.0 ppm of sanguinarine). Two additional groups remained untreated (a challenged positive control and an unchallenged negative control). After 4 wk of treatment, birds from all groups except the negative control group were exposed to C. hepaticus strain HV10. The IQA treated groups showed a reduction in the number of miliary lesions on the liver surface and reduced lesion scores compared with untreated hens. A significant reduction of egg mass was detected 6 d after exposure to C. hepaticus in the untreated group (P = 0.02). However, there was not a significant drop in egg-mass in the IQA groups, especially those fed with a high dose of IQA (P = 0.93). IQA supplementation did not produce significant changes in intestinal villus height and crypt depth but did result in a significant reduction in the proinflammatory cytokine, interleukin-8, in the blood (P < 0.01). Microbiota analysis showed that IQA treatment did not alter the alpha diversity of the cecal microbiota but did produce changes in the phylogenetic structure, with the higher dose of IQA increasing the Firmicutes/Bacteroidetes ratio.

Other minor changes in production indicators included an increase in feed consumption (P < 0.01) and an increase in body weight of the treated hens (P < 0.0001). The present study has demonstrated that IQA confers some protection of chickens from the impact of SLD.

Current experimental models, assessment and dietary modulations of intestinal permeability in broiler chickens

Maintaining and optimising the intestinal barrier (IB) function in poultry has important implications for the health and performance of the birds. As a key aspect of the IB, intestinal permeability (IP) is mainly controlled by complex junctional proteins called tight junction proteins (TJ) that link enterocytes together. The disruption of TJ is associated with increased gut leakage with possible subsequent implications for bacterial translocation, intestinal inflammation, compromised health and performance of the birds. Despite considerable data being available for other species, research on IP in broiler chickens and in general avian species is still an understudied topic. This paper reviews the available literature with a specific focus on IP in broiler chickens with consideration given to practical factors affecting the IP, current assessment methods, markers and nutritional modulation of IP. Several experimental models to induce gut leakage are discussed including pathogens, rye-based diets, feed deprivation and stress-inducing agents such as exogenous glucocorticoids and heat stress. Although various markers including fluorescein isothiocyanate dextran, expression of TJ and bacterial translocation have been widely utilized to study IP, recent studies have identified a number of excreta biomarkers to evaluate intestinal integrity, in particular non-invasive IP. Although the research on various nutrients and feed additives to potentially modulate IP is still at an early stage, the most promising outcomes are anticipated for probiotics, prebiotics, amino acids and those feed ingredients, nutrients and additives with anti-inflammatory properties. Considerable research gaps are identified for the mechanistic mode of action of various nutrients to influence IP under different experimental models. The modulation of IP through various strategies (i.e. nutritional manipulation of diet) may be regarded as a new frontier for disease prevention and improving the health and performance of poultry particularly in an antibiotic-free production system.

Cloacal temperature responses of broiler chickens administered with fisetin and probiotic (Saccharomyces cerevisiae) and exposed to heat stress

There is dearth information on the role of fisetin as an antistress agent in ameliorating heat stress in broiler chickens. Here, we experimentally compared probiotic, an antioxidant and antistress agent, with fisetin, an antioxidant agent with little or no report on its antistress effect. Sixty-day-old broiler chickens (Arbo Acre breed) were allotted into 4 groups of 15 birds each as follows; control, fisetin, probiotic, and fisetin + probiotic groups, respectively. All administrations were performed orally through gavage for the treatment groups. The environmental and cloacal temperature (CT) parameters were measured bi-hourly at Days 21, 28, and 35 from 7:00 to 7:00 hr, during the period of study. The environmental parameters exceeded the thermoneutral zone for broiler chickens. The probiotic-supplemented group had the least overall mean CT values all through the experimental period. Based on our findings, fisetin was not a potent antistress agent in mitigating heat stress in birds.

Effects of Dietary Supplementation of Algae-Derived Polysaccharides on Morphology, Tight Junctions, Antioxidant Capacity and Immune Response of Duodenum in Broilers under Heat Stress

Simple Summary

Heat stress (HS) has become a great challenge for poultry production in tropical and subtropical regions. HS results in the intestinal dysfunction of broilers, which seriously affects their productivity. Our previous study suggested that dietary supplementation of algae-derived polysaccharides (ADP) could promote the intestinal barrier function in broilers, but the effect of dietary ADP supplementation on the intestinal health of broilers under HS remains unclear. The present study showed that dietary ADP supplementation improved the duodenal tight junction expression of broilers under HS, and found that dietary ADP mitigated HS-induced oxidative stress and inflammation response by regulating Nrf2 and NF-κB signaling pathways. These findings reveal the potential application of ADP as an HS-alleviating agent to maintain gut health in broilers.

Abstract

To evaluate the ameliorative effect of algae-derived polysaccharide (ADP) supplementation on duodenal injury caused by heat stress (HS) in broilers, a total of 144 male yellow-feathered broilers (56-day-old) were randomly allocated into three groups: The TN group (thermoneutral zone, broilers were raised at 23.6 ± 1.8 °C); HS group (heat stress, broilers were exposed to 33.2 ± 1.5 °C 10 h/day, 8:00 a.m.–18:00 p.m., the temperature in the remaining period was consistent with the TN group); HSA group (heat-stressed broilers were fed with ADP supplemented diet at 1000 mg/kg). There were six replications in each treatment, and eight broilers in each replication. The feeding trial lasted four weeks. The results showed that dietary ADP supplementation tended to increase the villus height (p = 0.077) and villus width (p = 0.062), and decrease the apoptosis rate (p = 0.081) in the duodenum of broilers under HS. Furthermore, dietary ADP increased the relative mRNA and protein (based on immunofluorescence) expression levels of occludin and zonula occludens-1 (ZO-1) in the duodenum of broilers under HS (p < 0.05). In addition, dietary ADP enhanced the total antioxidation capacity (T-AOC) and activity of glutathione-S transferase (GST), while reducing the malondialdehyde (MDA) concentration of the duodenum in broilers under HS (p < 0.05). Moreover, dietary ADP supplementation upregulated the duodenal nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), glutathione peroxidase 1 (GPx1) and glutathione S-transferase theta 1 (GSTT1) mRNA expression levels in heat-stressed broilers (p < 0.05). Furthermore, compared with the HS group, broilers fed with an ADP supplemented diet had a higher relative mRNA expression of inhibitor kappa B alpha (IκBα) (p < 0.05) and a lower relative mRNA expression of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the duodenum (p < 0.05). In summary, dietary ADP supplementation had an ameliorative effect on HS-induced impairment of tight junctions, antioxidant capacity and the immune response of the duodenum in broilers. These beneficial effects might be related to the modulation of Nrf2 and NF-κB signaling pathways.

Isoquinoline Alkaloids in Sows' Diet Reduce Body Weight Loss during Lactation and Increase IgG in Colostrum

Simple Summary

Plant extracts containing isoquinoline alkaloids (IQ) have been demonstrated to have anti-inflammatory properties. In pigs, IQ supplementation has been shown to downregulate the stress response and improve the digestibility of nutrients. The present experiment was conducted to test the hypothesis that supplementing sows’ diets with IQ during gestation would decrease stress at farrowing and improve colostrum quality, positively affecting the piglets’ health and performance.

Abstract

Isoquinoline alkaloids (IQ) exert beneficial antimicrobial and anti-inflammatory effects in livestock. Therefore, we hypothesized that supplementing sows’ diets with IQ during gestation would decrease farrowing stress, affecting the piglets’ development and performance. Sows were divided into: IQ1, supplemented with IQ from gestation day 80 (G80) to weaning; IQ2, supplemented from gestation day 110 (G110) to weaning, and a non-supplemented (NC) group. Sow body weight (BW), feed intake, back-fat thickness and back-muscle thickness were monitored. Cortisol, glucose and insulin were measured in sows’ blood collected 5 d before, during, and after 7 d farrowing. Protein, fat, IgA and IgG were analyzed in the colostrum and milk. Piglets were monitored for weight and diarrhea score, and for ileum histology and gene expression 5 d post-weaning. IQ-supplemented sows lost less BW during lactation. Glucose and insulin levels were lower in the IQ groups compared to NC-sows 5 d before farrowing and had higher levels of protein and IgG in their colostrum. No other differences were observed in sows, nor in the measured parameters in piglets. In conclusion, IQ supplementation affected sows’ metabolism, reducing body weight loss during lactation. Providing IQ to sows from their entrance into the maternity barn might be sufficient to induce these effects. IQ improved colostrum quality, increasing the protein and IgG content, improving passive immunity for piglets.

Phytobiotics to improve health and production of broiler chickens: functions beyond the antioxidant activity

Phytobiotics, also known as phytochemicals or phytogenics, have a wide variety of biological activities and have recently emerged as alternatives to synthetic antibiotic growth promoters. Numerous studies have reported the growth-promoting effects of phytobiotics in chickens, but their precise mechanism of action is yet to be elucidated. Phytobiotics are traditionally known for their antioxidant activity. However, extensive investigations have shown that these compounds also have anti-inflammatory, antimicrobial, and transcription-modulating effects. Phytobiotics are non-nutritive constituents, and their bioavailability is low. Nonetheless, their beneficial effects have been observed in several tissues or organs. The health benefits of the ingestion of phytobiotics are attributed to their antioxidant activity. However, several studies have revealed that not all these benefits could be explained by the antioxidant effects alone. In this review, I focused on the bioavailability of phytobiotics and the possible mechanisms underlying their overall effects on intestinal barrier functions, inflammatory status, gut microbiota, systemic inflammation, and metabolism, rather than the specific effects of each compound. I also discuss the possible mechanisms by which phytobiotics contribute to growth promotion in chickens.