Effect of polyphenols extracted from Tamarind (Tamarindus indica L.) seed coat on physiological changes, heterophil/lymphocyte ratio, oxidative stress and body weight of broilers (Gallus domesticus) under chronic heat stress

Impacts of thyme and/or garlic oils on growth, immunity, antioxidant and net farm income in Damascus goats

This study aimed to evaluate the impact of thyme and/or garlic oil administration on growth performance, immunity, antioxidant, biochemical parameters, and net farm income of Damascus goats. Forty weaned Damascus goats were allocated into four groups. The first group was the control without oral administration, while the 2nd (Th), 3rd (Gr), and 4th (ThGr) groups were orally administrated by (2 ml/goat/day) of thyme oil, garlic oil and their mixture (1:1), respectively during the whole experiment period. The final body weight of goats orally administered oil mixture was the heaviest group, it was 10, 4.5 and 3.5% than the control, Th. and Gr. groups, respectively with better feed conversion ratio and high net farm income. Goats of ThGr. group revealed the best immunity, antioxidant and general health condition than the control group with 50% reduction of MDA. Liver (AST, 33% and ALT, 38%) and kidney (creatinine, 88%) functions improved by oils mixtures orally administration compared with the control group. LDL, triglyceride and cholesterol were reduced by 47, 33 and 21% compared with the control group, respectively. Thus, mixture oil administration (thyme and garlic at the ratio of 1:1, 2 ml/goat/day) improved growth (10%), antioxidant status (MDA 50%), liver (AST, 33% and ALT, 38%), kidney function (creatinine, 88%), the FCR (17.4%) and net farm income (21%), of Damascus goats.

Effects of Ban Lian Zi Jin San on intestinal inflammation and barrier function of heat-stressed broilers

Heat stress (HS) in broilers can be an environmental stressor that leads to intestinal inflammation and intestinal barrier damage. In order to examine the effect of Ban Lian Zi Jin San (BLZJS) on intestinal inflammation and barrier function in heat-stressed broilers, a model of chronic cyclic HS in broilers was established. A total of 300 twenty-one-day-old broilers were divided into 5 treatments at random. Broilers in 3 BLZJS dosage groups were kept in an ecologically controlled room at 37℃ ± 2℃ for 6 wk, and fed basal diets supplemented with 0.5, 1, and 2% BLZJS. Broilers in HS group were housed in the same room, but fed the basal diets. The findings indicated that supplementation of BLZJS significantly declined serum HS indexes levels (HSP70, HSP90), and increased serum antioxidant capacity (SOD and T-AOC) in broilers (P < 0.05). Besides, supplementation of BLZJS significantly inhibited the expression of HS indexes (HSP70 and HSP90), genes related to TLR4 inflammatory signal pathway (TLR4, MyD88, TRIF, IRAK-4, and NF-κB), inflammatory factors (IL-6 and TNF-α), and upregulated anti-inflammatory cytokines (IL-10) and intestinal tight junction-related genes (Occludin, Claudin-1, and ZO-1) in broiler jejunum (P < 0.05). On the other hand, supplementation of BLZJS could significantly reduce the protein expression of NF-κB and HSP70 in chick jejunum (P < 0.05). In conclusion, BLZJS inhibited the activation of TLR4 signal pathway and reduced the production of inflammatory factors, restoring the level of intestinal tight junction protein and protecting jejunal intestinal barrier function in heat-stressed broilers.

Dietary Supplementation of Tannins: Effect on Growth Performance, Serum Antioxidant Capacity, and Immunoglobins of Weaned Piglets-A Systematic Review with Meta-Analysis

In recent years, the swine industry has witnessed the withdrawal of antibiotics and continuous regulation of zinc and copper oxides in the early-life nutrition of piglets. Due to this development, alternative additives from plant sources have been extensively explored. Therefore, this study's objective was to evaluate the effect of dietary supplementation with tannins on weaned piglets' growth performance, serum antioxidant capacity, and serum immune status using a systematic review and meta-analysis approach. A total of 16 studies with parameters of interest were deemed eligible after a two-step screening process following a comprehensive literature search in the scientific databases of Web of Science, Scopus, ScienceDirect, PubMed, and Google Scholar. The inclusion criteria were mainly (1) studies involving basal diet supplemented with tannins and (2) studies with the quantification of tannin doses, while the exclusion criteria were (1) studies with pre- and post-weaning pigs and (2) challenged studies. Applying the random-effects models, Hedges' g effect size of supplementation with tannins was calculated using R software to determine the standardized mean difference (SMD) at a 95% confidence interval. Sub-group analysis and meta-regression further explored heterogeneity (PSMD < 0.05, I2 > 50%, n ≥ 10). Supplementation with tannins reduced the feed conversion ratio (p < 0.01) but increased the final body weight (p < 0.01) of weaned piglets. Chestnut and grape seed proanthocyanidin tannin sources yielded higher effects on growth performance. In addition, meta-regression models indicated that tannin dosage and supplementation duration were directly associated with tannins' effectiveness on productive performance. In the serum, the concentration of glutathione peroxidase, superoxide dismutase, and total antioxidant capacity were elevated (p < 0.01) in response to tannin supplementation, whereas malondialdehydes was reduced (p < 0.01). Likewise, increased immunoglobin M and G levels (p < 0.01) were detected. In conclusion, dietary supplementation with tannins, particularly with chestnut and grape seed proanthocyanidins, increases the productivity of weaned piglets. At the same time, it is a possible nutritional strategy to mitigate oxidative stress and stimulate gut health. Thus, supplementing chestnut and grape seed proanthocyanidin tannins in the early phase of swine production could be used to alleviate the incidence of diarrhea.

The effect of feeding with different protein levels on internal organ weight and gene expression of MEF2A and ATF3 in crossbred local chicken using RT-PCR

BACKGROUND

Myogenic enhancer transcription factor 2A (MEF2A) is a transcription factor known for its role in controlling skeletal muscle regeneration and metabolic processes, while activating transcription factor 3 (ATF3) is a stress-induced transcription factor that plays a role in modulating metabolic processes, immunity, and oncogenesis. Environmental factors, such as dietary protein, can influence gene expression levels. Insufficient protein intake can negatively affect the metabolic performance of internal organs, leading to the abnormal weight of internal organs. A total of 192 non-sexing crossbred local chickens day-old-chick (DOC) with a completely randomized design (CRD) method of 3 treatments and 8 replicates. Real-time polymerase chain reaction (RT-PCR) is used to measure the gene expression levels. This study aimed to determine the effect of feeding with various protein levels on internal organ weight and gene expression of MEF2A and ATF3 in crossbred local chickens.

RESULT

The analysis of treatment revealed that the results were not significantly different (P > 0.05) on gizzard weight and spleen weight. However, it shows a significantly different result (P < 0.05) on heart weight and a highly significantly different result (P < 0.01) on pancreas weight. These findings suggest that protein levels in the diet had a significant impact on heart and pancreas weights. In terms of gene expression, the increased utilization of protein did not result in an elevation of MEF2A gene expression in both muscle tissue and liver tissue. Specifically, in muscle tissue, MEF2A gene expression was highly expressed at 18% protein feed for the starter phase and 16% for the finisher phase. Conversely, in liver tissue, MEF2A gene expression was highly expressed at 22% protein feed for the starter phase and 20% for the finisher phase. Moreover, ATF3 gene expression in muscle tissue exhibited a negative correlation with increasing feed protein levels.

CONCLUSION

The results indicate that varying protein levels did not lead to abnormal weights in the liver, kidney, heart, and spleen organs. Additionally, the differential gene expression patterns of MEF2A and ATF3 in muscle tissue and liver tissue suggest that these genes respond differently to varying protein-feeding treatments. These findings provide insights into the complex regulatory mechanisms of MEF2A and ATF3 genes in relation to protein levels and organ-specific responses in crossbred local chickens.

Effect of HSPA8 gene on the proliferation, apoptosis and immune function of HD11 cells

HSPA8 (Heat shock 70 kDa protein 8) is a molecular chaperone involved in a variety of cellular processes. This gene may affect the proliferation, apoptosis and immune function of chicken macrophages, but the specific mechanism remains unclear. The purpose of this study was to explore the effect of the HSPA8 gene on the proliferation, apoptosis and immune function of chicken macrophages. In this study, a chicken HSPA8 overexpression plasmid, interference fragment and corresponding controls were transfected into HD11 cells, and then the expression of the HSPA8 gene, cell proliferation, cell cycle, apoptosis rate and immune function of each group were detected. The results showed that transfection of the HSPA8 overexpression plasmid significantly upregulated the level of HSPA8 expression in HD11 cells compared with the control; significantly promoted the proliferation of HD11 cells and the expression of PCNA, CCND1 and CCNB3; decreased the number of cells in the G1 phase and increased the number of cells in the S phase; decreased the rate of apoptosis and upregulated the expression of Bcl-2; and promoted the expression of the LPS-induced cytokines IL-1β, IL-6 and TNF-α. Transfection of the HSPA8 interference fragment significantly downregulated the level of HSPA8 expression in HD11 cells; significantly inhibited the proliferation of HD11 cells and the expression of PCNA, CCND1 and CDK1; increased the number of cells in the G1 phase and decreased the number of cells in the S phase; increased the rate of apoptosis, downregulated the expression of Bcl-2 and upregulated the expression levels of Fas and FasL; and inhibited the expression of the LPS-induced cytokines IL-1β and NF-κB. The results suggested that HSPA8 promotes the proliferation of and inhibits the apoptosis of HD11 cells and has a proinflammatory effect.

Global trends and research frontiers on heat stress in poultry from 2000 to 2021: A bibliometric analysis

Background: Heat stress remains a major environmental factor affecting poultry production. With growing concerns surrounding climate change and its antecedent of global warming, research on heat stress in poultry has gradually gained increased attention. Therefore, this study aimed to examine the current status, identify the research frontiers, and highlight the research trends on heat stress in poultry research using bibliometric analysis. Methods: The literature search was performed on the Web of Science Core Collection database for documents published from 2000 to 2021. The documents retrieved were analyzed for their publication counts, countries, institutions, keywords, sources, funding, and citation records using the bibliometric app on R software. Network analysis for co-authorship, co-occurrence, citation, co-citation, and bibliographic coupling was visualized using the VOSviewer software. Results: A total of 468 publications were retrieved, and over the past two decades, there was a gradual increase in the annual number of publications (average growth rate: 4.56%). China had the highest contribution with respect to the number of publications, top contributing authors, collaborations, funding agencies, and institutions. Nanjing Agricultural University, China was the most prolific institution. Kazim Sahin from Firat University, Turkey contributed the highest number of publications and citations to heat stress in poultry research, and Poultry Science was the most productive and the most cited journal. The top 10 globally cited documents mainly focused on the effects of heat stress, alleviation of heat stress, and the association between heat stress and oxidative stress in poultry. All keywords were grouped into six clusters which included studies on "growth performance", "intestinal morphology", "heat stress", "immune response", "meat quality", and "oxidative stress" as current research hotspots. In addition, topics such as; "antioxidants", "microflora", "intestinal barrier", "rna-seq", "animal welfare", "gene expression", "probiotics", "feed restriction", and "inflammatory pathways" were identified for future research attention. Conclusion: This bibliometric study provides a detailed and comprehensive analysis of the global research trends on heat stress in poultry over the last two decades, and it is expected to serve as a useful reference for potential research that will help address the impacts of heat stress on poultry production globally.

Performance, blood biochemistry, carcass fatty acids, antioxidant status, and HSP70 gene expressions in Japanese quails reared under high stocking density: the effects of grape seed powder and meal

Japanese quails reared under high stocking density (SD) were evaluated for the effects of grape seed powder (GSP) and meal (GSM) supplementation on performance, blood biochemistry, thigh and breast muscle fatty acids, antioxidant status, and HSP70 gene expression. We randomly assigned 288 (15-day-old) quail chicks to six treatment groups in a factorial design (2 × 3) with four replicates, involving two density levels [160 cm²/bird (LD) and 80 cm²/bird (HD)] and three feed forms (FFs) [no supplementation, grape seed powder (3% GSP), grape seed meal (3% GSM)]. SD had a significant effect on live weight, but not on weekly feed intake, daily weight gain, and feed conversion ratio. Serum creatinine and aspartate aminotransferase levels were significantly affected by FF and SD × FF (p < 0.05). A high SD reduced the n-3/n-6 ratio of breast muscle and a significant interaction was found between FF (p < 0.001). The SD × FF interaction reduced the Σn-6 ratio in HDM's thigh muscle, whereas in LDM, the ratio increased (p < 0.01). At high SD, neither GSP nor GSM reduced biological markers of oxidative stress (p > 0.05). Compared to GSP, GSM had higher efficacy at reducing HSP70 levels related to high SD levels. Despite this, at high SD, a diet containing 3% of GSP and GSM was not effective in overcoming oxidative stress. Therefore, more studies using different doses of GSM and GSP in quail diets would be beneficial.

Betaine: A Potential Nutritional Metabolite in the Poultry Industry

Poultry industry has been recognized as a fast-developing sector aiming to produce low-cost and high-nutrient foods for human consumption. This review article aimed to focus on the significant roles of dietary betaine supplementation in the poultry industry. In this respect, different effects of betaine on performance and carcass traits, as well as its osmoregulatory, anticoccidial, immune-modulatory, and heat-stress alleviation activities, were discussed. Different concentrations of betaine supplementation can improve the feed conversion ratio, final body weight, breast muscle yield, egg production ratio, and reduce body fat contents in broiler chicken, turkey, duck, geese, and quail diets. Betaine supplemented with methyl groups can eliminate the need to have some methyl-group donors, including choline and methionine, therefore having positive effects on feed conversion ratio in poultry diets. The osmolytic character of betaine can alleviate heat stress and have a positive impact on tonic immobility, which consequently reduces stress in poultry. By inhibiting distinct developmental stages of Eimeria species, betaine reduces the damaging effects of coccidiosis on broiler chickens and improves intestinal structure and function. The immunological, cardiovascular, neurological, renal, and hepatic metabolic systems benefit from betaine's osmo-protective properties. Therefore, betaine has the potential to be considered as an alternative to feed additives and enhances the health status and productive performance of poultry.

Potential impact of stocking density on growth, carcass traits, indicators of biochemical and oxidative stress and meat quality of different broiler breeds

The aim of the current study to investigate the potential impact of different stocking densities on growth performance, carcass traits, indicators of biochemical and oxidative stress and meat quality of Arbor Acres and Ross-308 broiler breeds to recommend the better stocking density with low production cost simultaneously with high quality. A total of 312 one-day old of each Arbor Acres broiler and Ross-308 were randomly classified into 3 experimental groups with different stocking density, each of 6 replicates. The first group (SD1) was 14 birds/m2 (28 kg/m2), while the second group (SD2) was 18 birds/m2 (36 kg/m2) and the third group (SD3) was 20 birds/m2 (40 kg/m2). The growth performance, carcass traits, meat quality hematological and biochemical parameters were measured. SD3 group possessed the lowest body weight. Alanine transaminase in Arbor Acres was 15 and 14% higher in SD3 when compared with SD1 and SD2, respectively. While, was 21 and 20% of Ross-308, respectively. SD3 revealed the highest values of cholesterol, TG, MDA, and LDL of both breeds when compared with SD1 and SD2, with the lowest levels of HDL, GPX, and IGG. Birds of SD3 was the nastiest carcass weight 873 (P = 0.000) and 1,411.60 g (P = 0.000); dressing percentage 63.07 (P = 0.000) and 75.83% (P = 0.000); breast weight 513.10 g (P = 0.000) and 885.50g (P = 0.000); thigh weight 359.90 g (P = 0.000) and 526.08 g (P = 0.000) when compared with SD1 and SD2 of Arbor Acres and Ross-308, respectively. The dressing % of SD1 and SD2 was approximately 19% better than that of SD3 of Arbor Acres, while it was 4% of Ross-308. The cooking loss and drip loss of breast and thigh muscles were higher in SD3 of both breeds. Moreover, SD3 possessed the highest bacterial count. In conclusion birds reared in medium stocking density revealed better performance and welfare than high density but similar to low density. Therefore, from the economic point, medium density was the best.

Thermal stress consequences on growth performance, immunological response, antioxidant status, and profitability of finishing broilers: transcriptomic profile change of stress-related genes

The current study was conducted to investigate the impact of thermal stress on growth performance, blood biomarkers, metabolic hormones, immunological response, antioxidant activity, and expression of stress-related genes in broilers. One hundred and fifty one-day-old chicks (Ross 308) were utilized in this work. On the 21st day of age, birds were subjected to three environmentally controlled treatments with five replicate pens of 10 birds per each, representing an initial density of 10 birds/m²-control: reared in a thermoneutral condition; THS₁ and THS_2: exposed to 4 and 6 h of daily thermal stress at 40 ± 1 °C, respectively, until the 42 days of age. The results demonstrated that thermal stress for 4 and 6 h significantly reduced (P < 0.001) daily weight gain, daily feed intake, blood leukocyte and lymphocyte counts, serum immunoglobulins (IgM, IgA, IgG), and insulin-like growth factor-1 (IGF-1), while serum levels of aspartate aminotransferase, alanine aminotransferase, glucose, cholesterol, low-density lipoprotein, and lactate dehydrogenase were elevated relative to the thermoneutral group. Additionally, the corticosterone level and the ratio of heterophil:lymphocyte increased significantly (P < 0.001) in thermal-stressed groups. The antioxidant enzymes were affected by thermal stress as represented by a significant decrease in the activity of serum catalase (CAT) and glutathione peroxidase (GSH-Px) along with an increase in malonaldehyde concentration. Thermal stress affected gene expression by upregulating heat shock protein 70, heat shock factors 1 and 3, nuclear factor kappa B, interleukin-4, and uncoupling protein, and downregulating GSH-Px, CAT, and IGF-1 transcript levels. However, no changes were observed in interleukin-2 expression levels. It can be concluded that thermal stress destructively influences productivity, physiological status, and gene expression by upregulating heat shock protein 70, heat shock factors 1 and 3, nuclear factor kappa B, interleukin-4, and uncoupling protein, and downregulating GSH-Px, CAT, and IGF-1 transcript levels of broiler chickens.

The role of polyphenols in poultry nutrition

In the last two decades, poultry and animal industries became increasingly interested in using plant-based feed supplements, herbs and their derivatives to retain or enhance their health and productivity. These health benefits for the host mainly attributed to the secondary plant metabolites, namely polyphenols. Polyphenols are renowned for their antioxidant, immunomodulatory, anti-mutagenic and anti-inflammatory properties. However, despite these advantages of polyphenols, they have been characterized by poor absorption in the gut and low concentration in target cells that compromise their role as effective antioxidants. The low bioavailability of polyphenols necessitates the need for further investigations to harness their full potential in poultry farms. This review is existing evidence about the bioavailability of polyphenols and their antioxidant, immunomodulatory, antimicrobial, detoxification properties and their impacts on poultry performance.

Effect of polyphenol extract on performance, serum biochemistry, skin pigmentation and carcass characteristics in broiler chickens fed with different cereal sources under hot-humid conditions

This study investigated the interaction between polyphenols with different cereal sources and their effects on performance, serum biochemistry, corticosterone levels and carcass characteristics in broiler chickens reared under hot-humid environment. Newly hatched coloured broiler chicks (n = 240) were randomly divided into six groups with five replicates of two different cereal sources, namely corn and broken rice-sorghum combined, and three levels of pomegranate peel polyphenol extracts (PPP) 0, 50 and 100 mg/kg in each cereal groups. Birds were maintained under standard management conditions for six weeks during hot-humid environment (Temperature: 29-36 °C; Relative Humidity: 69-80%). Fortnight body weight and feed consumption were recorded and serum biochemical constituents were estimated at 28 and 42 days of age. The body weight gain was significantly (p < 0.05) higher in broken rice-sorghum diet than in corn diet. The supplementation of polyphenols increased the skin and shank pigmentation. Serum protein, lipids and minerals showed significant difference due to cereals, polyphenols and their interactions. Corn-fed birds had significantly higher visceral organs weight than the alternate grain-fed broilers. The serum corticosterone levels were significantly reduced in the PPP supplemented groups than the control, it could be concluded that, supplementation of 50 mg/kg polyphenol extract from pomegranate peels improved production performance in broilers fed broken rice-sorghum as cereal source under hot-humid conditions.

Tamarind: A diet-based strategy against lifestyle maladies

The modern-day review article is an exquisite attempt to demonstrate the extreme therapeutic potential of tamarind fruit (Tamarindus indica), particularly its pulp, seed, and leaf extract, against lifestyle-related chronic disorders. The rapid transition in the diet patterns and also the varying lifestyle of the people has made its way forth, a momentous upsurge in a number of chronic as well as degenerative diseases. An excess of foods having functional and nutraceutical significance has come into view recently. These foods have emerged as effective therapeutical remedies against these disorders owing to their natural phytochemical constituents present in them, in abundance. Tamarindus indica serves as a proverbial herbal medicine in each and every part of the world that is known to mankind. Also, the tamarind kernel powder (TKP) is of immense commercial significance in some of the major, leading industries of the World. The derivation of an important gel-forming substance (polysaccharide), named as "jellose," from the decorticated seed kernels of tamarind fruit has led to the manufacture of pectin. It is used in industrial scale in the preparation of various products like jams, jellies, and most important in the preparation of cheese. It plays an evident role as a stabilizer of commercial significance, and it has also been greatly recommend by the scientists to be used as a potent ingredient in a range of pharmaceutical products. The leaves of tamarind plant are also used as part of the daily diet in several countries where they are readily consumed in fresh form and especially during drought season.

Thermotolerance of Broiler Chicks Ingesting Dietary Betaine and/or Creatine

The present study aimed to assess the effect of dietary betaine (B) and/or creatine (C) on performance and thermoregulatory responses of broiler chicks. Indian River broiler chicks, fitted with compact thermosensors, were reared to market age (five weeks). The chicks were randomly distributed into four treatment groups, in a 2 × 2 factorial arrangement of treatments-basal control diet (Control group: CONT; B-/C-); 1 g betaine/kg feed (Betaine group: BETA; B+/C-), 1.2 g creatine monohydrate/kg feed (Creatine group: CRET; B-/C+), and combination (Betaine and Creatine group: COMB; B+/C+) of both supplements. At 31 days of age, 20 chicks from each group were exposed to acute heat stress (A-HS) for 3 h (34.45 ± 0.20 °C), and hemogramic profiles were screened before and after. Performance parameters (feed intake, body weight gain, and feed conversion ratio) were reported on a weekly basis, and carcass meat quality was evaluated at the end of experiment. Redness of breast was higher due to B and C treatments separately than the CONT group (B by C interaction; p < 0.05). Compared to the CONT, dietary supplements alleviated hyperthermia responses, with B alone being more efficient than C or COMB treatments. The mitigation of hyperthermia is likely mediated by enhancement of water balance indicators. Although not efficient in improving growth performance, dietary B and/or C are efficient in improving thermophysiological performance and survival of finishing broiler chicks under A-HS.

Effect of stocking density and alpha-lipoic acid on the growth performance, physiological and oxidative stress and immune response of broilers

Objective

The study was conducted to evaluate the effect of stocking density and alpha-lipoic acid (ALA) on the growth performance, feed utilization, carcass traits, antioxidative ability and immune response of broilers.

Methods

A total of 1,530 22-day-old male broilers (Arbor Acres) with comparable body weights (731.92±5.26) were placed into 18 cages (2.46×2.02 m) in groups of 75 birds (15 birds/m², 37.5 kg/m²; low stocking density [LD]), 90 birds (18 birds/m², 45.0 kg/m²; high stocking density [HD]) and 90 birds with 300 mg/kg ALA added to the basal diet (18 birds/m², 45.0 kg/m²; HD+ALA, high stocking density+α-lipoic acid); each treatment was represented by 6 replicates. The experimental period was 3 weeks.

Results

The results showed that the high stocking density regimen resulted in a decreased growth, feed conversion ratio, carcass weight, thigh yield and bursa weight relative to body weight (p<0.05) on d 42. The abdominal fat yield in the HD+ALA group was lower (p = 0.031) than that of the LD group at 42 d. The superoxide dismutase and glutathione peroxidase activities in serum were increased, and malondialdehyde content decreased after adding ALA product (p<0.05) on d 42. Additionally, the serum concentrations of immunoglobulin A (IgA) and IgG were decreased (p<0.05) and the level of diamine oxidase was higher (p< 0.01) in the HD group on d 42.

Conclusion

The high stocking density significantly decreased broiler growth performance, feed utilization and carcass traits, increased physiological and oxidative stress and induced intestinal mucosal injury. The supplementation of ALA product in broiler diet at 300 mg/kg may reduce the adverse effects of high stocking density-mediated stress by maintaining the antioxidant system and humoral immune system.

The effect of polyphenols and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature

The aim of this study was to determine the effect of a polyphenol product (PP) (Proviox) and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature. The experimental materials comprised 120 ROSS 308 broilers (6 treatments, 10 replications, 2 birds per replication). Dietary supplementation with vitamin E and PP was applied in the following experimental design: group I (negative control) - without supplementation; group II (positive control) - without supplementation; group III - supplementation with 100 mg vitamin E/kg; group IV - 200 mg vitamin E/kg; group V - 100 mg vitamin E/kg and 100 mg PP/kg; group VI - 200 mg PP/kg. In groups II-VI, broiler chickens aged 21-35 d were exposed to increased temperature (34°C for 10 h daily). In chickens exposed to high temperature, dietary supplementation with antioxidants, mostly PP, improved growth performance parameters, including body weight, body weight gain and feed intake until 28 d of age. Vitamin E added to broiler chicken diets at 200 mg/kg and vitamin E combined with PP was most effective in improving the total antioxidant status of birds, enhancing blood antioxidant enzyme activities and increasing vitamin E concentrations in the liver and breast muscles. Broilers fed diets supplemented with 200 mg/kg of vitamin E alone and vitamin E in combination with PP were characterised by a higher percentage content of breast muscles in the carcass. Dietary supplementation with antioxidants improved the water-holding capacity of meat, reduced natural drip loss and increased the crude ash content of meat. The breast muscles of chickens fed diets supplemented with PP had a lower contribution of yellowness. The breast muscles of chickens receiving diets with 100 mg vitamin E/kg(group III) and diets supplemented with PP (groups V and VI) were characterised by the highest concentrations of polyunsaturated fatty acids. The PP can be a valuable component of diets for broiler chickens exposed to high temperature.

Flavangenol regulates gene expression of HSPs, anti-apoptotic and anti-oxidative factors to protect primary chick brain cells exposed to high temperature

Heat-stress exposure increased the expression of heat-shock proteins (HSPs), B-cell lymphoma 2 (BCL-2) and anti-oxidative enzymes to maintain normal cellular function by attenuating the oxidative reaction and apoptosis. Reducing the stress response or enhancing anti-stress capability is an important goal in animal production. Our previous study indicated a protective role of flavangenol, a pine bark extract, in chicks after three hours of high-temperature exposure. However, the cellular mechanism of flavangenol was not clarified ex vivo. In the current study, we investigated the effect of flavangenol on cellular apoptosis and oxidation in heat-stressed treated chick brain cells (mixed neurons and glia cells). The primary brain cells were isolated from the diencephalon of 14-day-old chicks and cultured at 41.5 °C (to mimic the body temperature of young chicks), and were treated with flavangenol from day 3 of isolation to day 8. Cells were kept bathed in the cell culture dish under a high temperature (HT: 45 °C, 20 or 60 min) on day 8 and were then collected for analysis of cell viability as well as for HSP and other related gene expression. Flavangenol treatment significantly increased cell viability and BCL-2 mRNA expression, and attenuated HSP-70 and BCL-2-associated X protein mRNA expression. Moreover, flavangenol treatment elevated the mRNA expression of glutathione peroxidase in the HT group, which indicates that cellular anti-oxidative ability was strengthened by flavangenol. In conclusion, flavangenol may play a protective role in cells damaged or killed by heat stress by increasing cellular anti-oxidative pathways.

Effect of chronic heat stress on some physiological and immunological parameters in different breed of broilers

The differences in physiological and immunological parameters and pathological damage to organ tissues exposed to chronic heat stress provide the basis for evaluating heat resistance of different chicken breeds (white recessive rock [WRR] and The Lingshan [LS]). Ninety broilers of each breed were divided equally into a chronic heat stress group and a no heat stress group. The effects of chronic heat stress on the physiological and immunological parameters of broilers were analyzed using flow cytometry, ELISA, RT-qPCR, etc. Under heat stress conditions: (1) H and H/L values were significantly increased (P < 0.01) in the 2 breeds, and were higher in the WRR broilers than in the LS broilers at a late stage (P < 0.05). Although the corticosterone levels were also significantly increased (P < 0.01) in both breeds, they were lower in the 49 d WRR broilers than in the LS broilers (P < 0.01). The number of leukocytes were significantly increased in the 49 d WRR broilers (P < 0.01), whereas the number of CD3+, CD8+ cells, and erythrocytes were significantly reduced (P < 0.05). A significantly (P < 0.01) lower number of CD3+, CD4+ T-lymphocytes, and CD4+/CD8+ were present in WRR compared to that in the LS broilers. (2) The HSP70 transcript was significantly increased in the WRR broilers (P < 0.01), and was higher than the level in the LS broilers. The expression level of HSP70 protein was significantly (P < 0.05) increased in WRR broilers. (3) The WRR broilers developed cardiac and leg muscle inflammatory cellular hyperplasia and local inflammatory lesions, as well as cerebral meningitis and inflammatory hyperplasia of the brain tissue. The LS broilers developed mild cerebral inflammatory hyperplasia and mild inflammatory cellular proliferation in the leg muscle. In conclusion, under heat stress conditions, the relative physiological and immunological parameters were worse in the WRR broilers than in the LS broilers. The WRR broilers showed poor heat tolerance as evidenced from the expression of HSP70 and the extent of histopathological damages.

Effects of chronic thermal stress on growth performance, carcass traits, antioxidant indices and the expression of HSP70, growth hormone and superoxide dismutase genes in two broiler strains

The objective was to investigate the effects of genetic type and the duration of chronic thermal stress (36 °C) on the growing efficiency, carcass traits, antioxidant status, and the expression of liver heat shock protein 70 (HSP70), growth hormone (GH) and superoxide dismutase (SOD) genes. Two hundred and seventy one-day-old chicks (135 male chicks of each breed; Ross 308 and Cobb 500) were used in this work. On the 21st day of age, birds were allocated randomly into 3 equal groups till the 42 days of age (CON:raised in a thermoneutral condition; HS₁ and HS₂ groups were subjected to 4 and 6 h of daily thermal stress, respectively). Regardless of genetic type, thermal stress decreased the dressing percentage in broilers when compared with the thermoneutral conditions (p = 0.039). In both broiler strains, thermal stress for 6 h (HS₂) increased the heterophil to lymphocyte ratio (p = 0.036) and the serum albumin, cholesterol and triglyceride levels (p = 0.023, 0.012 and 0.005, respectively) compared with the thermoneutral group. Under the thermonuteral and heat stress conditions, the Ross broiler chickens showed a significant lower serum triiodothyronine level compared with the Cobb boilers (p = 0.042). It is interesting to note that the expression of HSP70 in the liver of heat-stressed Ross broilers, either 4 or 6 h, was significantly (p = 0.002) higher than that reported in the heat-stressed Cobb broilers. In both broiler strains, the thermal stress for 6 h up-regulate the expression of SOD gene (p = 0.001), but down-regulate the expression of GH gene (p = 0.021) when compared with the CON group. In conclusion, chronic thermal stress down-regulate the mRNA expression of liver GH, concomitantly with an increase in the expression of HSP70 and SOD genes in both broiler strains. This could be useful in the identification of molecular genetic markers to assist in selecting broilers that are more tolerant to heat stress.

Association between heat stress and oxidative stress in poultry; mitochondrial dysfunction and dietary interventions with phytochemicals

Heat as a stressor of poultry has been studied extensively for many decades; it affects poultry production on a worldwide basis and has significant impact on well-being and production. More recently, the involvement of heat stress in inducing oxidative stress has received much interest. Oxidative stress is defined as the presence of reactive species in excess of the available antioxidant capacity of animal cells. Reactive species can modify several biologically cellular macromolecules and can interfere with cell signaling pathways. Furthermore, during the last decade, there has been an ever-increasing interest in the use of a wide array of natural feed-delivered phytochemicals that have potential antioxidant properties for poultry. In light of this, the current review aims to (1) summarize the mechanisms through which heat stress triggers excessive superoxide radical production in the mitochondrion and progresses into oxidative stress, (2) illustrate that this pathophysiology is dependent on the intensity and duration of heat stress, (3) present different nutritional strategies for mitigation of mitochondrial dysfunction, with particular focus on antioxidant phytochemicals. Oxidative stress that occurs with heat exposure can be manifest in all parts of the body; however, mitochondrial dysfunction underlies oxidative stress. In the initial phase of acute heat stress, mitochondrial substrate oxidation and electron transport chain activity are increased resulting in excessive superoxide production. During the later stage of acute heat stress, down-regulation of avian uncoupling protein worsens the oxidative stress situation causing mitochondrial dysfunction and tissue damage. Typically, antioxidant enzyme activities are upregulated. Chronic heat stress, however, leads to downsizing of mitochondrial metabolic oxidative capacity, up-regulation of avian uncoupling protein, a clear alteration in the pattern of antioxidant enzyme activities, and depletion of antioxidant reserves. Some phytochemicals, such as various types of flavonoids and related compounds, were shown to be beneficial in chronic heat-stressed poultry, but were less or not effective in non-heat-stressed counterparts. This supports the contention that antioxidant phytochemicals have potential under challenging conditions. Though substantial progress has been made in our understanding of the association between heat stress and oxidative stress, the means by which phytochemicals can alleviate oxidative stress have been sparsely explored.

Polyphenols from the extract and fraction of T. indica seeds protected HepG2 cells against oxidative stress

Background

Tamarindus indica L. (T. indica) or locally known as “asam jawa” belongs to the family Leguminosae. T. indica seeds as by-products from the fruits were previously reported to contain high polyphenolic content. However, identification of their bioactive polyphenols using recent technologies is less well researched but nonetheless important. Hence, it was the aim of this study to provide further information on the polyphenolic content and antioxidant activities as well as to identify and quantify its bioactive polyphenols.

Methods

T. indica seeds were extracted with methanol and were then fractionated with different compositions of hexane, ethyl acetate and methanol. Polyphenolic contents were measured using Folin-Ciocalteu assay while antioxidant activities were measured using DPPH radical scavenging and ferric reducing (FRAP) activities. The cytotoxic activities of the crude extract and the active fraction were evaluated in HepG2 cells using MTT assay. The cells were then pre-treated with the IC₂₀ concentrations and induced with H₂O₂ before measuring their cellular antioxidant activities including FRAP, DPPH, lipid peroxidation, ROS generation and antioxidant enzymes, SOD, GPx and CAT. Analyses of polyphenols in the crude extract and its active fraction were done using UHPLC and NMR.

Results

Amongst the 7 isolated fractions, fraction F3 showed the highest polyphenolic content and antioxidant activities. When HepG2 cells were treated with fraction F3 or the crude extract, the former demonstrated higher antioxidant activities. F3 also showed stronger inhibition of lipid peroxidation and ROS generation, and enhanced activities of SOD, GPx and CAT of HepG2 cells following H₂O₂-induced oxidative damage. UHPLC analyses revealed the presence of catechin, procyanidin B2, caffeic acid, ferulic acid, chloramphenicol, myricetin, morin, quercetin, apigenin and kaempferol, in the crude seed extract of T. indica. UHPLC and NMR analyses identified the presence of caffeic acid in fraction F3. Our studies were the first to report caffeic acid as the active polyphenol isolated from T. indica seeds which likely contributed to the potent antioxidant defense system of HepG2 cells.

Conclusion

Results from this study indicate that caffeic acid together with other polyphenols in T. indica seeds can enhance the antioxidant activities of treated HepG2 cells which can provide protection against oxidative damage.

Response of laying hens to feeding low-protein amino acid-supplemented diets under high ambient temperature: performance, egg quality, leukocyte profile, blood lipids, and excreta pH

An experiment was conducted to determine whether, by using a low-protein amino acid-supplemented diet, the health status, stress response, and excreta quality could be improved without affecting the productive performance of heat-stressed laying hens. The requirements for egg production, egg mass, and feed conversion ratio were also estimated using second-order equations and broken-line regression. A total of 150 Lohmann Selected Leghorn (LSL-Lite) hens were divided randomly into five groups of 30 with five replicates of six hens. The hens were raised for an 8-week period (52 to 60 weeks) in wire cages situated in high ambient temperature in an open-sided housing system. The five experimental diets (ME; 2,720 kcal/kg) varied according to five crude protein (CP) levels: normal-CP diet (control, 16.5 % CP) and low-CP diets containing 15.0, 13.5, 12.0, or 10.5 % CP. All experimental diets were supplemented with crystalline amino acids at the levels sufficient to meet their requirements. The results showed that under high temperature conditions, all productive performance and egg quality parameters in the birds fed with 15.0, 13.5, and 12.0 % CP diets were similar to those of birds fed with control diet (16.5 % CP), whereas feeding 10.5 % CP diet significantly decreased egg production and egg mass. Estimations of requirements were of 13.93 and 12.77 % CP for egg production, 14.62 and 13.22 % CP for egg mass, and 12.93 and 12.26 % CP for feed conversion ratio using quadratic and broken-line models, respectively. Egg yolk color index, blood triglyceride level, and excreta acidity were also significantly higher in birds fed with 12.0 and 10.5 % CP diets compared with those of control birds. The heterophil to lymphocyte ratio, as a stress indicator, was significantly decreased by 15.0, 13.5, and 12 % CP diets. On the basis of our findings, reducing dietary CP from 16.5 to 12.0 % and supplementing the diets with the essential amino acids showed merit for improving the stress response and excreta quality while maintaining acceptable production performance from laying hens under high ambient temperature conditions.

Ameliorative potential of Tamarindus indica on high fat diet induced nonalcoholic fatty liver disease in rats

Nonalcoholic fatty liver disease (NAFLD), the prevalence of which is rising globally with current upsurge in obesity, is one of the most frequent causes of chronic liver diseases. The present study evaluated the ameliorative effect of extract of Tamarindus indica seed coat (ETS) on high fat diet (HFD) induced NAFLD, after daily administration at 45, 90, and 180 mg/kg body weight dose levels for a period of 6 weeks, in albino Wistar rats. Treatment with ETS at all tested dose levels significantly attenuated the pathological alterations associated with HFD induced NAFLD viz. hepatomegaly, elevated hepatic lipid and lipid peroxides, serum alanine aminotransferase, and free fatty acid levels as well as micro-/macrohepatic steatosis. Moreover, extract treatment markedly reduced body weight and adiposity along with an improvement in insulin resistance index. The study findings, therefore suggested the therapeutic potential of ETS against NAFLD, acting in part through antiobesity, insulin sensitizing, and antioxidant mechanisms.

Effect of dietary vitamin E on broiler meat qualities, color, water-holding capacity and shear force value, under heat stress conditions

This study was conducted to evaluate the effect of dietary vitamin E (VE) on broiler meat quality, especially focused on PSE (pale color, soft and exudative), under chronic heat stress (HS) conditions. Twenty-eight-day-old female Ross broilers were kept in independent cages with a controlled temperature of 24°C (normal temperature: NT) or 30°C (high temperature: HT). The NT chickens were fed basal feed. The HT chickens were fed basal feed (HT) or VE (200 mg/kg) added feed (HT + E). Broilers were weighed and slaughtered at 38 days old. The breast muscle was removed immediately and then the samples were used for determination of meat color, pH, water holding capacity (WHC) and shear force value (SFV). Body weight gain and feed intake were significantly decreased in the HT and HT + E groups compared to the NT group. VE supplementation did not affect the growth performance. Chronic HS at 30°C for 10 days may cause deterioration of meat quality such as PSE. The effects of chronic HS on meat quality were most significant in the toughness of broiler breast meat. Supplementation of VE in broiler feed would be effective to prevent the extent of PSE on broiler meat by chronic HS.