Effect of chronic oxidative/corticosterone-induced stress on ascorbic acid metabolism and total antioxidant capacity in chickens (Gallus gallus domesticus)

Effect of probiotic supplementation on performance, morphology and gene expression associated with immune responses in early age of broiler chickens exposed to stress induced by corticosterone injection

Context Broiler chickens are exposed to various stressors, which can affect production performance. The use of dietary probiotics is one of the feasible methods to maintain performance, intestinal health, humeral immunity, and ameliorating physiological stress in the broiler. Aims In all, 288 1-day-old male broiler chicks were used to evaluate the effect of probiotic supplementation on performance, morphology, and gene expression associated with immune responses in the starter phase of broiler chickens exposed to stress. Methods In total, 288 1-day-old male broiler chicks (Ross 308) were assigned to evaluate the effects of Bacillus subtilis spore (BSS; Gallipro®200) supplementation at three levels (0, 0.8 × 105 colony-forming units (CFU) and 1.6 × 105 CFU/g feed) with corticosterone (CORT; 4 mg/kg BW at 7–9 days of age) or without CORT (oil) subcutaneous injection. The experiment was conducted in a completely randomised 2 × 3 factorial design. Key results CORT injection and probiotic supplementation led to an increase and decrease respectively, in food conversion ratio compared with the control group (P < 0.05). CORT injections reduced the expression of TLR4, HSP70 and IgA in all parts of the intestine. However, the TLR4 gene expression increased in jejunum by CORT injections. BSS supplementation induced the expression of TLR4 in all sections of the intestine, both in stress and non-stress conditions. In stress-exposed chickens, IgA expression in the jejunum was affected by BSS supplementation. Interaction effects between CORT injections and BSS supplementation on the gene expression were significant in different parts of the intestine. Conclusions Chicks exposed to stress conditions induced by CORT injection showed that the ileum was more susceptible than were the other parts, especially for TLR4 and HSP70 gene expression. BSS-supplemented birds showed more capability to face the stress condition, probably due to intestinal health and immunity-modulated effect of BSS. Implication Formulating a ration with a probiotic can be more effective in stress conditions, through modulating immune-responsive genes in the intestine.

Prenatal yolk corticosterone exposure promotes skeletal growth and induces oxidative imbalance in yellow-legged gull embryos

Maternally derived hormones induce variation in offspring phenotype, with consequences that can carry over into post-natal life and even into adulthood. In birds, maternal egg corticosterone (CORT) is known to exert contrasting effects on offspring morphology, physiology and behaviour after hatching. However, information on the effects of CORT exposure on pre-hatching embryonic development is limited. We experimentally increased yolk CORT levels in yellow-legged gull (Larus michahellis) eggs, and assessed the effects on embryo pre-hatching development and oxidative status of brain and liver. CORT-supplemented embryos reached a larger skeletal size and liver mass compared with controls. Embryos from CORT-injected last-laid eggs showed decreased activity of the hepatic antioxidant enzymes superoxide dismutase and catalase, while intermediate-laid eggs showed increased levels of lipid peroxidation. However, elevated yolk CORT did not affect oxidative stress endpoints in the brain. Our results indicate that elevated yolk CORT levels affect prenatal embryo development by promoting skeletal growth, and induce laying sequence- and organ-specific oxidative imbalance, with potential adverse consequences during postnatal life, especially for late-hatched offspring.

Impact of zinc and arginine on antioxidant status of weanling piglets raised under commercial conditions

The effects of dietary zinc and L-arginine supplements on the weight gain, feed efficiency, antioxidant capacity and oxidative status of weanling piglets raised under commercial conditions were examined. A total of 288 piglets aged 21 d were fed for 15 d a diet supplemented or not with 2,500 mg/kg of zinc (provided as zinc oxide) and 1% L-arginine·HCl. The 4 treatments were distributed in a randomized complete block design with 6 initial body weight categories (12 animals per pen). Access to feed and water was ad libitum. Data were analyzed as a 2 × 2 factorial experiment using the SAS MIXED procedure, with zinc and arginine as the main independent variables. Blood collection day (d 8 and 15, samples were collected from the same 2 piglets in each pen before the morning feeding) was included as a third factor. The zinc supplement increased the average daily gain (ADG) from d 0 to 7, d 8 to 15 and d 0 to 15 (0.289 vs. 0.217 kg/d), average daily feed intake (ADFI) from d 8 to 15 and d 0 to 15 (0.338 vs. 0.279 kg/d) and the gain to feed (G:F) ratio from d 0 to 7 and d 0 to 15 (0.86 vs. 0.77) (P < 0.001). Both supplements significantly decreased the malondialdehyde concentration (zinc: 4.37 vs. 3.91 μmol/L, P = 0.005; arginine: 4.38 vs. 3.89 μmol/L, P = 0.002). Total antioxidant capacity and reduced glutathione (GSH) increased from d 8 to 15 (0.953 vs. 1.391 μmol/L, 2.22 vs. 3.37 μmol/L, P < 0.05) regardless of dietary treatment. Total and oxidized GSH concentrations on d 8 were higher in response to the combined supplements (zinc × arginine interaction, P < 0.05). Piglets fed either Zn-supplemented diet had a lower haptoglobin serum concentration (509 vs. 1,417 mg/L; P < 0.001). In conclusion, the zinc supplement improved piglet growth performance (ADG and ADFI) and oxidative status (based on malondialdehyde concentration). The arginine supplement had a limited effect on growth performance and oxidative status under these conditions.

Effect of thermal manipulation of broilers embryos on the response to heat-induced oxidative stress

Effects of embryonic thermal manipulation (TM) on mRNA expressional levels and total antioxidant capacity of genes associated with heat-induced oxidative stress (NOX4, GpX2, SOD2, catalase, and AvUCP) in 2 breeds of broiler chicken were investigated. Fertile Cobb and Hubbard eggs (n = 1,200) were divided into 4 treatment groups: Cobb control, Cobb TM, Hubbard control, and Hubbard TM. Control groups were maintained under standard conditions (37.8°C; 56% relative humidity), whereas TM groups were incubated at 39°C and 65% relative humidity for 18 h a day from embryonic days (ED) 10 to 18. On post-hatch day 28, the broilers were subject to acute heat stress (AHS) at 40°C for 7 h. At certain intervals (0, 1, 3, 5, and 7 h), 12 chickens from each of the 4 groups were humanely euthanized, and liver samples were immediately isolated. During AHS, in both breeds, the mRNA expression levels of NOX4, GPx2, SOD2, and catalase in TM chickens were significantly lower than in controls, but AvUCP mRNA expression in the TM group was higher. The total antioxidant capacity and activity of superoxidase dismutase and catalase were significantly lower in the TM than in the control group in both breeds. The results of this study suggest that TM has a long-lasting effect on the acquisition of thermotolerance in 2 broiler chicken breeds as indicated by the reduction of system genes associated with heat-induced oxidative stress.

Feed supplementation with arginine and zinc on antioxidant status and inflammatory response in challenged weanling piglets

Although supplementing the diet with zinc oxide and arginine is known to improve growth in weanling piglets, the mechanism of action is not well understood. We measured the antioxidant status and inflammatory response in 48 weanling castrated male piglets fed diets supplemented with or without zinc oxide (2,500 mg Zn oxide per kg) and arginine (1%) starting at the age of 20 days. The animals were injected with lipopolysaccharide (100 μg/kg) on day 5. Half of them received another injection on day 12. Blood samples were taken just before and 6, 24 and 48 h after injection and the mucosa lining the ileum was recovered following euthanizing on days 7 and 14. Zinc supplementation increased reduced and total glutathione (GSH) (reduced and total) during days 5 to 7 and arginine decreased oxidized GSH measured on days 5 and 12 and the ratio of total antioxidant capacity to total oxidative status during days 12 to 14. Zinc decreased plasma malondialdehyde measured on days 5 and 12 and serum haptoglobin measured on day 12 and increased both metallothionein-1 expression and total antioxidant capacity measured in the ileal mucosa on day 14. Tumour necrosis factor α concentration decreased from days 5 to 12 (all effects were significant at P < 0.05). This study shows that the zinc supplement reduced lipid oxidation and lipopolysaccharide-induced inflammation during the post-weaning period, while the arginine supplementation had only a limited effect.

Dietary α-ketoglutarate supplementation improves hepatic and intestinal energy status and anti-oxidative capacity of Cherry Valley ducks

α-Ketoglutarate (AKG) is an extensively used dietary supplement in human and animal nutrition. The aim of the present study was to investigate effects of dietary AKG supplementation on the energy status and anti-oxidative capacity in liver and intestinal mucosa of Cherry Valley ducks. A total of 80 1-day-old ducks were randomly assigned into four groups, in which ducks were fed basal diets supplemented with 0% (control), 0.5%, 1.0% and 1.5% AKG, respectively. Graded doses of AKG supplementation linearly decreased the ratio of adenosine monophosphate (AMP) to adenosine triphosphate (ATP) in the liver, but increased ATP content and adenylate energy charge (AEC) in a quadratic and linear manner, respectively (P < 0.05). Increasing dietary AKG supplemental levels produced linear positive responses in ATP content and AEC, and negative responses in AMP concentration, the ratio of AMP to ATP and total adenine nucleotide in the ileal mucosa (P < 0.05). All levels of dietary AKG reduced the production of jejunal hydrogen peroxide and hepatic malondialdehyde (P < 0.05). Hepatic and ileal messenger RNA expression of AMP kinase α-1 and hypoxia-inducible factor-1α were linearly up-regulated as dietary AKG supplemental levels increased (P < 0.05). In conclusion, dietary AKG supplementation linearly or quadratically enhanced hepatic and intestinal energy storage and anti-oxidative capacity of Cherry Valley ducks.

The potential effects of antioxidant feed additives in mitigating the adverse effects of corn naturally contaminated with Fusarium mycotoxins on antioxidant systems in the intestinal mucosa, plasma, and liver in weaned pigs

Seventy-two piglets (6.0 kg BW) were randomly distributed within six different dietary treatments to evaluate the effect of deoxynivalenol (DON) and the potential of four antioxidant feed additives in mitigating the adverse effects of DON on growth performances and oxidative status. Dietary treatments were as follows: control diet 0.8 mg/kg DON; contaminated diet (DON-contaminated diet) 3.1 mg/kg DON; and four contaminated diets, each supplemented with a different antioxidant feed additive, DON + vitamins, DON + organic selenium (Se)/glutathione (GSH), DON + quercetin, and DON + COMB (vitamins + Se/GSH + quercetin from the other treatments). Although DON was the main mycotoxin in the contaminated diet, this diet also contained 1.8 mg/kg of zearalenone (ZEN). The "mycotoxin" effects therefore included the combined effect of these two mycotoxins, DON, and ZEN. The DON-ZEN ingestion did not affect growth performances, average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F ratio), but partially induced oxidative stress in weaned pigs as shown by increased malondialdehyde (MDA) content in the plasma and superoxide dismutase (SOD) activity in liver (P < 0.05). However, no change in the activity of other antioxidant enzymes or GSH concentrations was observed in plasma and liver of piglets fed the DON-contaminated diet (P > 0.05). Supplementation with individual antioxidant feed additive had a limited effect in weaned pigs fed DON-ZEN-contaminated diets. Combination of antioxidants (vitamins A, C, and E, quercetin, and organic Se/GSH) reduced plasma and liver MDA content and SOD activity in liver (P < 0.05) of piglets fed DON-ZEN-contaminated diets. Furthermore, this combination also reduced MDA content in the ileum (P < 0.05), although activity of glutathione peroxidases (GPx), SOD or catalase (CAT) in the ileum was not affected by DON-ZEN contamination or antioxidant supplements. In conclusion, DON-ZEN contamination induced oxidative stress in weaned pigs and combination of antioxidant feed additives restored partially the oxidative status. Further studies will be necessary to assess whether the effects of antioxidant feed additives on oxidative status are specific when feed is contaminated with DON-ZEN.

Short Communication: Antioxidant capacity in the intestinal mucosa of weanling piglets fed diets containing Fusarium mycotoxins and the efficacy of commercial supplements sold as detoxifiers

Le Thanh, B. V., Lessard, M., Chorfi, Y. and Guay, F. 2015. Short Communication: Antioxidant capacity in the intestinal mucosa of weanling piglets fed diets containing Fusarium mycotoxins and the efficacy of commercial supplements sold as detoxifiers. Can. J. Anim. Sci. 95: 569–575. The ability of commercial feed additives to prevent oxidative damage due to deoxynivalenol (DON) in piglets was studied. Sixty piglets (6.0±0.5 kg) were assigned randomly to six wheat–corn–soybean diets: control (<0.5 mg kg−1 DON), DON-rich diet (4 mg kg−1 DON), and four DON-rich diets supplemented with either glucomannan (DON+GLUC), yeast, live bacteria, enzymes and plant extract (DON+YBP), aluminosilicate (DON+ALS), or a mixture of preservatives (DON+PV). Malondialdehyde concentration (MDA), glutathione peroxidase activity (GPx), catalase activity (CAT) and superoxide dismutase activity (SOD) in the small intestine were measured after 14 d. The DON-rich diet increased MDA in the jejunum while decreasing CAT in the jejunum and SOD in the ileum and increasing GPx in the ileum (P<0.05). The DON+GLUC diet decreased GPx and SOD (P<0.05) and tended to decrease MDA in the jejunum (P<0.10). The DON+YBP, DON+PV and DON+ALS diets all decreased CAT in the jejunum, while DON+YBP and DON+PV also did so in the ileum (P<0.05). DON+GLUC decreased SOD in the jejunum, while DON+YBP increased it (P<0.05). In the ileum, DON+PV decreased SOD, while DON+ALS increased GPx (P<0.05). No significant differences in total antioxidant capacity (TAC) in intestinal tissues were found. This study demonstrates that the mycotoxin DON and anti-mycotoxin additives modify oxidative status, including the antioxidant enzyme activities (CAT, SOD or GPx) in the intestinal mucosa of piglets. However, it was not possible to identify a specific antioxidant enzyme involved in counteracting the effect of DON.

Effects of corticosterone and dietary energy on immune function of broiler chickens

An experiment was conducted to investigate the effects of dietary energy level on the performance and immune function of stressed broiler chickens (Gallus gallus domesticus). A total of 96 three-day-old male broiler chickens (Ross × Ross) were divided into two groups. One group received a high energy (HE) diet and the other group received a low energy (LE) diet for 7 days. At 5 days of age, the chickens from each group were further divided into two sub-groups and received one of the following two treatments for 3 days: (1) subcutaneous injection of corticosterone, twice per day (CORT group; 2 mg of CORT/kg BW in corn oil) and (2) subcutaneous injection of corn oil, twice per day (Control/Sham treatment group). At 10 days of age, samples of blood, duodenum, jejunum, and ileum were obtained. Compared with the other three groups, the LE group treated with CORT had the lowest average daily gain (ADG) and the poorest feed conversion ratio (FCR, P < 0.05). Furthermore, CORT treatment decreased the relative weight (RW) of the bursa independent of the dietary energy level, but it decreased the RW of the thymus only in the chickens fed the LE diet. By contrast, CORT administration decreased the RW of the spleen only in the chickens fed the HE diet (P < 0.05). The plasma total protein, albumin, tumor necrosis factor alpha, interleukin 2 and immunoglobulin G (IgG) levels were affected by the CORT treatment (P < 0.05); however, these factors were not significantly affected by the dietary energy level. Toll-like receptor-5 mRNA level was down-regulated by CORT injection in the duodenum and ileum (P < 0.05) and showed a trend of down-regulation in the jejunum (P=0.0846). The present study showed that CORT treatment induced immunosuppressive effects on the innate immune system of broiler chickens, which were ameliorated by consumption of higher dietary energy.

Micro-encapsulated sodium butyrate attenuates oxidative stress induced by corticosterone exposure and modulates apoptosis in intestinal mucosa of broiler chickens

The aim of the present study was to investigate the effects of micro-encapsulated sodium butyrate (MSB) on oxidative stress and apoptosis induced by dietary corticosterone (CORT) in the intestinal mucosa of broiler chickens. In total, 120 1-day-old male broilers (Arbor Acres) were randomly allocated to two treatment groups and were fed on a control diet (without MSB) or 0.4 g MSB/kg diet. Each treatment had six replicates with five chickens each. From 7 days of age onward, 50% of the chickens in each dietary treatment were subjected to CORT treatment (30 mg/kg of diet). The experimental period was 21 days. The results showed that CORT administration decreased (P < 0.001) feed intake and bodyweight gain and increased (P < 0.001) feed to gain ratio (F : G) of broiler chickens. The dietary MSB supplementation decreased (P < 0.01) F : G and there was an interaction between MSB and CORT on F : G (P < 0.05). Moreover, the activities of superoxide dismutase, glutathione peroxidase and catalase in intestinal mucosa were decreased (P < 0.01 or P < 0.001), and the concentrations of malondialdehyde in the intestinal mucosa were elevated (P < 0.01) by CORT administration. In contrast, treatment of MSB increased (P < 0.01) the catalase activities in duodenal and jejunal mucosa and decreased (P < 0.01) the malondialdehyde concentrations in duodenal mucosa. Higher apoptosis index and lower mRNA expressions of bcl-2 in intestinal epithelial cells were induced (P < 0.05) by CORT treatment. However, MSB decreased (P < 0.05) the apoptosis index and increased the bcl-2 expression. These results suggest that dietary MSB can partially attenuate oxidative stress induced by CORT treatment and inhibit apoptosis of intestinal epithelial cells in broiler chickens.

Antioxidant status and inflammatory response in weanling piglets fed diets supplemented with arginine and zinc

Bergeron, N., Robert, C. and Guay, F. 2014. Antioxidant status and inflammatory response in weanling piglets fed diets supplemented with arginine and zinc. Can. J. Anim. Sci. 94: 87–97. Dietary supplementation with zinc oxide (Zn oxide) and arginine (Arg) is known to improve growth in weanling piglets. The mechanism of action is not yet well understood, although antioxidant effects and inflammatory responses may be involved. This experiment was conducted to evaluate the effects of Zn and Arg supplementation on the antioxidant status and inflammatory response of piglets. Thirty-two 20-d-old weanling piglets were placed for 12 d on diets supplemented or not with Zn (2500 mg Zn oxide kg−1) and Arg (1%), designated ZN0ARG0, ZN2500ARG0, ZN0ARG1 and ZN2500ARG1. On day 12, blood samples were taken before and 3 h after intra-peritoneal injection of lipopolysaccharide (LPS; 10 µg kg−1). The piglets were euthanized just after the second blood sample, and samples of mucosae were taken from the jejunum and ileum for determination of mRNA expression and morphological observation. Zn supplementation decreased plasma malondialdehyde measured before LPS injection (P<0.05). Arg supplementation increased the ferric-reducing ability of plasma (indicator of antioxidant status) measured after LPS injection (P<0.05). Piglets fed Zn-supplemented diets had lower total plasma superoxide-dismutase (SOD) activity (P<0.05) but higher plasma tumour necrosis factor-α (P<0.05) after LPS injection. Zinc-supplemented diets increased metallothionein-1 expression and total antioxidant capacity in the ileum and jejunum (P<0.05) and decreased interleukin-10 expression (P<0.05) in the ileum. In the jejunum, the combination of Zn and Arg supplementation increased villus height (Arg×Zn, P<0.05). These results indicate that Zn may reduce systemic oxidation and improve the antioxidant status in the jejunal and ileal mucosae. However, Zn and Arg supplementation did not appear to act synergistically to enhance antioxidant status or reduce inflammation in weanling piglets.

Age and breeding effort as sources of individual variability in oxidative stress markers in a bird species

Oxidative stress is the imbalance between the production of pro-oxidant substances and the level of antioxidant defenses, which leads to oxidative damage. It has been proposed that senescence is the result of accumulated oxidative damage throughout life. In birds, the sources of individual variability in oxidative stress are still poorly understood. Among these sources, age, as related to senescence, should be particularly relevant. Furthermore, recent findings suggest that breeding effort may also deeply influence susceptibility to oxidative stress. However, there is still no evidence of a link between breeding effort and oxidative damage in any vertebrate. Here we analyzed 288 captive red-legged partridges (Alectoris rufa) across a wide age range (i.e., 1-8 yr old), thus including potentially senescent birds. In spite of limitations due to the cross-sectional approach, results revealed that old birds produced less offspring and endured higher levels of oxidized glutathione and peroxidized lipids in erythrocytes than did middle-aged individuals. Old birds also showed higher plasma total antioxidant status and uric acid levels than did younger birds, but lower amounts of circulating carotenoids. Furthermore, hatching success was negatively correlated to lipid peroxidation in females but not in males, supporting the hypothesis that breeding effort promotes oxidative damage.