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This study was conducted to evaluate the effects of dietary lycopene supplementation on growth performance, antioxidant status, and muscle nuclear transcription factor [Kelch like-ECH-associated protein 1 (Keap1) and (erythroid-derived 2)-like 2 (Nrf2)] expressions in broiler chickens exposed to heat stress (HS). A total of 180 one-day-old male broiler chicks (Ross 308) were assigned randomly to one of 2×3 factorially arranged treatments: two housing temperatures (22°C for 24 h/d; thermoneutral, TN or 34°C for 8 h/d HS) and three dietary lycopene levels (0, 200, or 400 mg/kg). Each treatment consisted of three replicates of 10 birds. Birds were reared to 42 d of age. Heat stress caused reductions in feed intake and weight gain by 12.2 and 20.7% and increased feed efficiency by 10.8% (P

This experiment was conducted to compare the effect of the supplemental chromium (Cr) form on performance, egg quality, and metabolic profile in laying hens exposed to heat stress (HS). Laying hens (n = 1800; 16-wk-old; Lohmann LSL-Lite) were kept in cages in temperature-controlled rooms at either 22 ± 2°C for 24 h/d (thermoneutral, TN) or 34 ± 2°C for 8 h/d, from 08:00 to 17:00 h, followed by 22°C for 16 h (HS) for 12 wks. Hens reared under both environmental conditions were fed 1 of 3 diets: a basal diet and the basal diet supplemented with either 1.600 mg of chromium-picolinate (CrPic, 12.43% Cr) or 0.788 mg of chromium-histidinate (CrHis, 25.22% Cr) per kg of diet, delivering 200 μg elemental Cr per kg diet. Data were analyzed by 2-way ANOVA. Exposure to HS caused decreases in feed intake (P < 0.0001), egg production (P < 0.0001), egg weight (P < 0.0001), eggshell weight (P < 0.0009), eggshell thickness (P < 0.0001), eggshell strength (P < 0.0001), and Haugh unit (P < 0.0001), deterioration in feed conversion ratio (P < 0.0001), increases in serum glucose and cholesterol concentrations (P < 0.0001 for both), decreases in serum and egg yolk Cr concentrations (P < 0.0001 for both), and decreases in serum Na (P < 0.002) and K (P < 0.01) concentrations. Both Cr sources were equally effective in alleviating performance variables under the HS condition. However, neither Cr sources alleviated deteriorations in egg quality parameters and serum electrolytes. Both Cr sources decreased serum glucose and cholesterol concentrations and increased serum and egg yolk Cr concentrations under the HS condition. In conclusion, HS adversely affected laying performance, egg quality, and metabolic profile. Both CrPic and CrHis partially alleviated the adverse effect of HS on these parameters. Inclusion of either Cr source could be a part of nutritional management strategies to overcome the adverse effects of HS performance and metabolic profile in laying hens.

This experiment was conducted to investigate effects of the organic complex form of supplemental chromium (Cr) on performance, oxidative stress markers, and serum profile in broilers exposed to heat stress (HS). A total of 1,200 10-day-old boilers (Ross-308) was divided into one of the 6 treatments (2 environmental temperatures x 3 diets with different Cr forms). The birds were kept in temperature-controlled rooms at either 22 ± 2°C 24 h/d (thermoneutral, TN group) or 34 ± 2°C for 8 h/d, 08:00 to 17:00 h, followed by 22°C for 16 h (HS group) and fed either a basal diet (C) or the basal diet supplemented with Cr (200 μg/kg) through 1.600 mg of CrPic (12.43% Cr) and 0.788 mg of CrHis (25.22% Cr). Feed intake and body weight were recorded weekly. After cervical dislocation, liver samples were harvested to analyze Cr concentration and glucose transporter-2,4 (GLUT-2,4) expression. The breast meat also was sampled for the concentration of Cr and expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB). Data were analyzed by 2-way ANOVA. Heat stress caused depressions in feed intake (12.1%) and weight gain (21.1%) as well as elevations in feed conversion (11.2%) and abdominal fat (32.8%). It was also associated with depletion of Cr reserves and increases in serum concentrations of glucose, cholesterol, creatine, and enzymes. Exposure to HS was accompanied by suppression of the expressions of Nrf2 and GLUT-2 in muscle and GLUT-4 in the liver and amplification of the expression of NF-κB in muscle. Both Cr sources partially alleviated detrimental effects of HS on performance and metabolic profile. The efficacy of Cr as CrHis was more notable than Cr as CrPic, which could be attributed to higher bioavailability. In conclusion, CrHis can be added into the diet of broilers during hot seasons to overcome deteriorations in performance and wellbeing related to oxidative stress.

Recent studies have suggested a protective role for lycopene, an antioxidant carotenoid, in the prevention of stress including environmental stress. Tomatoes and tomato products are the major dietary source of lycopene. The objective of the present study was to investigate the effect of dietary tomato powder supplementation on the performance and lipid peroxidation of meat in Japanese quail (Coturnix coturnix japonica) exposed to a high ambient temperature of 34 degrees C. A total of 180 ten-day-old male quails were randomly allocated into 6 groups consisting of 10 replicates of 3 birds. Birds were kept in wire cages in a temperature-controlled room at either 22 degrees C (thermoneutral) or 34 degrees C (heat stress) for 8 h/ d (0900 to 1700 h during the study). Birds were fed either a basal diet or the basal diet supplemented with 2.5 or 5.0% of tomato powder. Tomato powder supplementation linearly increased feed intake, live weight gain, and feed conversion (P = 0.01) under heat stress conditions but did not show the same effect at thermoneutral conditions (P > 0.05). Heat stress significantly increased malondialdehyde concentration and decreased vitamin concentrations in the serum, liver, and muscles of quail. Serum lycopene and vitamin C, E, and A (P = 0.01) concentrations increased linearly in birds at all groups. Malondialdehyde levels in serum, liver (P = 0.001), and muscles linearly decreased in all birds of both thermoneutral and heat stress groups as dietary tomato powder supplementation increased. The results of the study indicate that tomato powder modulates the oxidation-antioxidation system of the muscles in Japanese quail exposed to high ambient temperature.

Epigallocatechin-3-gallate (EGCG), a polyphenol derived from green tea, exerts antioxidant effects. Oxidative stress is one of the consequences of heat stress (HS), which also depresses performance in poultry. This experiment was conducted to elucidate the action mode of EGCG in alleviation of oxidative stress in heat-stressed quail (Coturnix coturnix japonica). A total of 180 five-week-old female Japanese quails were reared either at 22°C for 24 h/d (thermoneutral, TN) or 34°C for 8 h/d (HS) for 12 wk. Birds in both environments were randomly fed 1 of 3 diets: basal diet and basal diet added with 200 or 400 mg of EGCG/kg of diet. Each of the 2×3 factorially arranged groups was replicated in 10 cages, each containing 3 quails. Performance variables [feed intake (FI) and egg production (EP)], oxidative stress biomarkers [malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px)] and hepatic transcription factors [nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2)] were analyzed using 2-way ANOVA. Exposure to HS caused reductions in FI by 9.7% and EP by 14.4%, increased hepatic MDA level by 84.8%, and decreased hepatic SOD, CAT, and GSH-Px activities by 25.8, 52.3, and 45.5%, respectively (P

Resveratrol, a polyphenol derived from red grapes, berries, and peanuts, exerts antiinflammatory, antioxidant, and immunomodulatory effects. The objective of this study was to investigate the effects of dietary resveratrol supplementation on performance and serum and egg yolk antioxidant status in quail (Coturnix coturnix japonica). A total of 150 five-week-old quails were allocated randomly to 1 of 3 dietary treatments: basal diet and basal diet supplemented with 200 or 400 mg of resveratrol/kg of diet. Each diet was offered to 10 cages of 5 birds in each from 4 to 16 wk of age. Serum and egg samples were collected at the beginning and end the experimental period to be evaluated for malondialdehyde (MDA), vitamin A, and vitamin E. Data were subjected to analysis of covariance using the MIXED procedure. There was no treatment effect on feed intake, egg production, or egg quality parameters related to shell, yolk, and albumen. There were no effects of resveratrol supplementation on serum and egg yolk vitamin A concentrations. The quails supplemented with resveratrol had a lower serum MDA concentration (0.56 vs. 0.88 mg/L, P