Effects of Dietary Selenium and Vitamin E on Growth Performance, Meat Yield, and Selenium Content and Lipid Oxidation of Breast Meat of Broilers Reared Under Heat Stress

Interactive effects of high n-3 PUFA intake and cyclic heat stress under two dietary antioxidant levels in broiler chickens

The study examined the combined effects of a diet high in n-3 PUFAs and cyclic heat stress (HS) considering two levels of dietary antioxidants. A total of 192 one-day-old male Ross 308 broilers were divided into eight groups in a 2 × 2 × 2 factorial design: thermoneutral (TN) or heat-stressed (34°C ± 1°C for 7 h/day from day 22) × fed a diet low in antioxidants (NRC group) or high in antioxidants (HAOX group; supplemented with a mixture of 200 IU/kg vitamin E, 250 mg/kg vitamin C and 0.15 mg/kg selenium) and supplemented or not with 5% linseed oil, forming the NRC N-3 and HAOX N-3 groups. High intake of n-3 PUFAs increased plasma F2-isoprostane and malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity. Cyclic HS decreased final body weight (BW) and average daily feed intake (ADFI) and increased DNA damage and serum corticosterone (CORT) levels. In addition, the changes in blood biochemistry indicated that the broilers were undergoing respiratory alkalosis. Interactions between n-3 PUFAs and HS were observed in liver MDA levels, plasma γ-tocopherol levels and serum alkaline phosphatase (AP) activity. Antioxidants increased blood levels of α-tocopherol, vitamin C, lipid- and water-soluble antioxidants and glutathione peroxidase (GPx) activity, while decreasing MDA, F2-isoprostane, CORT and AP levels. High intake of n-3 PUFA in combination with cyclic HS had negative effects on the health status of the broilers, which were alleviated by additional antioxidant supplementation.

Impact of vitamin E and selenium supplementation on growth, reproductive performance, and oxidative stress in dexamethasone-stressed Japanese quail cocks: Vitamin E & selenium in stressed quail cocks

This study investigated the effects of dietary vitamin E (VE) and selenium (Se) supplementation on body weight changes, blood profile, and semen quality in Dexamethasone (DEX)-stressed Japanese quails. One hundred and five 10-week-old quail cocks were acclimated and divided into five treatment groups: negative control - G1, DEX-treated (20 mgL-1 of drinking water) - G2, DEX + VE (180 mg kg diet-1) - G3; DEX + Se (0.3 mg kg diet-1) - G4; and DEX + VE (180 mg kg diet-1) + Se (0.3 mg kg diet-1) - G5. The birds received their respective treatments over 21 days, and various performance, hematological, and semen quality parameters were measured. Results indicated that DEX treatment significantly reduced weight gain (WG) and feed intake (P < 0.05). Supplementation with VE and Se, individually and combined, ameliorated these effects, with groups G3, G4, and G5 showing similar WG to the control. Hematological analysis revealed significant increases (P < 0.05) in packed cell volume, hemoglobin, and white blood cell count in DEX-treated groups compared to G1. Treatment did not affect blood glucose and cholesterol levels (P ≥ 0.05). Plasma antioxidant assays showed elevated superoxide dismutase and catalase functions and reduced malondialdehyde levels in G3, G4, and G5 compared to G2, indicating reduced oxidative stress. No marked differences were seen in the plasma glutathione peroxidase activities across groups. Sperm motility was impaired in the DEX-only group but improved (P < 0.05) with antioxidant supplementation. In conclusion, dietary VE and Se effectively mitigated the negative impacts of DEX-induced stress on growth, antioxidant status, and spermatozoa motility in Japanese quail cocks. VE and Se supplementation could be beneficial in enhancing the welfare and productivity of poultry under stress.

Jumbo quail responses to diets containing incremental levels of apple (Malus domestica Borkh) pomace

The utilization of nutraceutical sources such as apple (Malus domestica Borkh) pomace powder (APP) could be a strategy to reduce the excessive disposal of this agro-waste in landfills and promote sustainable Jumbo quail (Coturnix sp.) production. However, the amount of the APP that can be included in Jumbo quail diets to achieve optimum production is unknown. This study evaluated the impact of including incremental levels of APP on performance metrics, haemato-biochemical parameters, and meat quality responses in Jumbo quail. A total of 350 Jumbo quail (7-day-old; 28.0 ± 0.817 g live weight) were weighed and randomly allotted to five dietary treatments, where each treatment had seven replicates with 10 birds each. The diets were formulated to contain 0, 25, 50, 75, and 100 g/kg APP. Dietary APP induced negative quadratic effects (p < 0.05) on feed intake in weeks 2 and 3. Body weight gain and gain-to-feed ratio decreased linearly in weeks 2, 3, and 4, but quadratically responded to APP levels in week 5. Platelets, heterophils, lymphocytes, and serum phosphorus and calcium showed linear or quadratic responses (p < 0.05) as APP levels increased. Increasing levels of APP linearly (p < 0.05) reduced carcass performance and 24-hour breast meat redness and chroma values but increased 1-hour yellowness and 24-hour lightness. The inclusion of APP compromised growth and carcass performance in young growing Jumbo quail. However, feed efficiency and final body weight were maximized between 50 and 75 g APP levels/kg diet in five-week-old Jumbo quail without compromising blood and meat quality parameters.

Comparison of High n-3 PUFA Levels and Cyclic Heat Stress Effects on Carcass Characteristics, Meat Quality, and Oxidative Stability of Breast Meat of Broilers Fed Low- and High-Antioxidant Diets

This study investigated the individual and combined effects of a high dietary n-3 PUFA intake and cyclic heat stress (HS) on the carcass characteristics, meat quality, and oxidative stability of broiler breast meat and the potential of antioxidant supplementation (vitamins E, C, and selenium) to mitigate these effects. A total of 192 one-day-old male Ross 308 broilers were randomly assigned to 24 pens within two controlled environment chambers and fed with the following diets: a basal diet low in antioxidants according to NRC recommendations (NRC group), a basal diet according to Aviagen recommendations additionally supplemented with 200 IU/kg vitamin E, 250 mg/kg vitamin C, and 0.15 mg/kg selenium (HAOX group), and these two diets further supplemented with 5% linseed oil (NRC N-3 and HAOX N-3 groups). On day 22, the broilers were exposed to the following two environmental conditions: thermoneutral (TN, 21 °C) or cyclic HS (HS, 34 ± 1 °C, 7 h/d) in a 2 × 2 × 2 factorial design. A high intake of n-3 PUFAs significantly decreased growth performance, dressing percentage, and breast yield, while the incidence of pale, soft, and exudative (PSE) meat characteristics and malondialdehyde (MDA) levels increased. Cyclic HS reduced body weight (BW) and average daily feed intake (ADFI), but had limited effects on meat quality. No interactions between n-3 PUFAs and HS were observed for any measurements. High antioxidant supplementation increased breast yield, improved meat quality, and reduced oxidative stress, as evidenced by an enhanced antioxidant activity and lower MDA levels. In conclusion, n-3 PUFAs had a negative effect on both the carcass characteristics and meat quality of broilers, while HS primarily affected only carcass characteristics, with neither stressor having severe adverse effects. High levels of antioxidants could mitigate the negative effects of dietary- and heat-induced oxidative stress by enhancing the oxidative stability of broiler meat.

Functional oil in the feeding of heat-stressed Japanese quail

The objective of the present study was to evaluate a blend of functional oils (FO) composed of copaiba and garlic essential oils, pepper oleoresin and cashew nut liquid to mitigate the effects of heat stress on productivity, egg quality, organ morphology of the gastrointestinal tract, serum biochemical profile, nutrient metabolism and body temperature of Japanese quail. A completely randomized design was used in a 3 × 2 factorial scheme (without additive; 300 and 500 mg FO/kg of feed x birds raised in a thermal comfort (TC) and heat stress (HS) environment), with 6 replicates of 8 birds per plot. The birds under HS had lower feed intake (P = 0.0000), egg mass (P = 0.0000), laying rate (P = 0.0000) and higher percentage of infertile non-commercial eggs (P = 0.0004), lower head temperature amplitude (P = 0.0000) and higher average of body temperature (P = 0.0312). HS worsened the external and internal quality of the eggs. Birds kept in HS showed higher values of cholesterol (P = 0.0000) and glutamic-pyruvic transaminase (P = 0.0272). The use of 300 and 500 g FO/ton of feed improved the feed conversion (P = 0.0000) and egg mass (P = 0.0000) of the quail bred under HS, respectively, by 8.4 and 7.2% and increased the relative weight of liver (P = 0.0064) and pancreas (P = 0.0492). The use of such additives also provided a higher % of yolk (P = 0.0018) and reduced the percentage of albumen (P = 0.0029) of the eggs produced in TC, in addition to reducing the amplitude of head temperature (P = 0.0484) of birds bred under HS. The breeding of Japanese quail under HS results in negative impacts on the production, physiological and qualitative aspects of the eggs. The use of 300 g/ton of FO in the diet of Japanese quail leads to improvements in feed conversion, increased liver capacity in nutritional metabolism and results in eggs with a higher proportion of yolks, being, therefore, an alternative for feeding quail in a hot climate.

In-depth transcriptome profiling of Cherry Valley duck lungs exposed to chronic heat stress

Amidst rising global temperatures, chronic heat stress (CHS) is increasingly problematic for the poultry industry. While mammalian CHS responses are well-studied, avian-specific research is lacking. This study uses in-depth transcriptome sequencing to evaluate the pulmonary response of Cherry Valley ducks to CHS at ambient temperatures of 20°C and a heat-stressed 29°C. We detailed the CHS-induced gene expression changes, encompassing mRNAs, lncRNAs, and miRNAs. Through protein-protein interaction network analysis, we identified central genes involved in the heat stress response-TLR7, IGF1, MAP3K1, CIITA, LCP2, PRKCB, and PLCB2. Subsequent functional enrichment analysis of the differentially expressed genes and RNA targets revealed significant engagement in immune responses and regulatory processes. KEGG pathway analysis underscored crucial immune pathways, specifically those related to intestinal IgA production and Toll-like receptor signaling, as well as Salmonella infection and calcium signaling pathways. Importantly, we determined six miRNAs-miR-146, miR-217, miR-29a-3p, miR-10926, miR-146b-5p, and miR-17-1-3p-as potential key regulators within the ceRNA network. These findings enhance our comprehension of the physiological adaptation of ducks to CHS and may provide a foundation for developing strategies to improve duck production under thermal stress.

Dietary supplementation with Chlorella vulgaris in broiler chickens submitted to heat-stress: effects on growth performance and meat quality

Heat stress can greatly challenge growth and meat quality of broiler chickens where research is looking for sustainable ingredients, such as microalgae, that could also alleviate its negative impacts. Thus, in the present study, 576 1-D-old chicks (Ross 308) were housed until commercial slaughtering (42 D) in 36 pens in 2 rooms of a poultry house, according to a full factorial design encompassing 2 room temperatures (standard vs. high), 2 sexes (females vs. males), and 3 dietary treatments, that is, diet C0 (control diet), diet C3, and diet C6 containing 0, 3, and 6%, respectively, of C. vulgaris meal replacing the same quantities of soybean meal. The highest inclusion level of C. vulgaris decreased feed intake (P < 0.001) and body weight (P < 0.0001) compared to the control diet; it increased yellow and red indexes (P < 0.0001) of the breast muscle, besides the proportion of n3 polyunsaturated fatty acids (PUFA) (P = 0.028). Heat stress decreased feed intake (P = 0.001), breast (P = 0.001) and p. major yields (P = 0.036), and increased meat pH (P= 0.008) and cooking losses (P < 0.001), umami (P = 0.021) and brothy flavor (P < 0.001), and the proportion of n3 PUFA rates (P = 0.027), while reducing the contents of several amino acids in the breast meat (P ≤ 0.05). Compared to females, males displayed higher feed intake and growth, and more favorable feed conversion (P < 0.001). Carcass and p. major yields were greater in females (P < 0.001) which also showed a higher occurrence of spaghetti meat compared to males (P < 0.001). In conclusion, C. vulgaris can be used to replace until 3% of soybean meal in diets for broiler chickens without negative implications, while positively affecting breast meat color according to consumers' preferences. However, the microalgae inclusion did not mitigate the negative effects of a chronic heat stress on growth performance nor reduced the occurrence of any myopathies.

Role of vitamin E on bovine skeletal-muscle-derived cells from Korean native cattle under heat treatment

Our study aimed to evaluate the dualistic effect of heat stress on muscle differentiation at different temperatures, and whether vitamin E, a powerful antioxidant, could offset any negative effects, using bovine skeletal-muscle-derived cells (BSMCs) with myogenic properties. The BSMCs were extracted from the skeletal muscle of 30-mo-old Korean native cattle and subjected to myogenic differentiation under 3 heat exposure conditions: 37 °C (control; CON), 39 °C (mild heat stress; MHS), and 41 °C (severe heat stress; SHS) for 24 h with or without vitamin E treatment (NE or VE). After 24 h treatments, the cells were returned to 37 °C incubators and differentiated until day 6. On day 1, because of the heat exposure, the gene expression of MYOG was the highest in MHS (P = 0.047), suggesting a promotive effect of mild heat stress on myogenic differentiation, while on day 6, compared with CON and MHS, MYOD (P = 0.013) and MYOG (P = 0.029) were the lowest in SHS. Vitamin E treatment also lowered MYOG (P = 0.097), regardless of heat exposure. On day 1, HSPB1 (P = 0.001) and HSP70 (P < 0.001) were the highest in SHS, and an interaction between heat exposure and vitamin E treatment was found on day 6 (P < 0.027). BCL-2 was also the highest on day 1 in SHS (P = 0.05), and an interaction of heat exposure and vitamin E treatment was found on day 1 on BAX expression (P = 0.038). For antioxidant genes, SOD1 (P = 0.002) and GPX1 (P < 0.001) were affected by heat exposure, with the highest levels being observed in SHS, and on day 6, GPX1 was still the highest in SHS (P = 0.027). The fusion index was also affected by heat exposure, showing a decrease in SHS and an increase in MHS compared with CON (P < 0.001). Significant effects were noted from heat exposure (P < 0.001), vitamin E treatment (P < 0.001), and the interaction of heat exposure and vitamin E treatment (P = 0.002) on the protein content. Taken together, our findings provide evidence that vitamin E could ameliorate the harmful effects of heat exposure by modulating heat shock proteins and apoptosis regulators, improving the protein synthesis of BSMCs during myogenic differentiation. These results suggest that vitamin E supplementation could potentially protect muscle development in beef cattle under summer heat stress.

Early-age thermal manipulation and supplemental antioxidants on physiological, biochemical and productive performance of broiler chickens in hot-tropical environments

Heat stress has been ranked as a critical environmental issue confronting chicken farmers worldwide because of its detrimental effect on the growth, performance and health of the birds. This study evaluated the effects of early-age thermal manipulation (EATC) and supplemental antioxidants on the physiological responses of broilers in a hot tropical environment. A total of 300 day-old Ross broiler chicks were allocated to five thermal and dietary treatments, having 5 replicates of twelve birds each. The treatments were: chicks reared using the conventional method (CC), chicks exposed to early thermal manipulation with a temperature of 38 °C at day 5 with no antioxidant supplementation (TC), TC plus vitamin E at 250 mg/kg of feed (TV), TC plus selenium at 0.5 mg/kg of feed (TS) and the combination of TS and TV(TVS). The experiment was laid out in a Completely Randomized Design and data collected were analyzed using SAS (2008). The results showed that TVS broilers had significantly higher (P < 0.05) body weights at the finisher phase than the other treatment groups. The feed conversion ratio of TVS broilers was comparable to the TV group but lower (P < 0.05) than the other treatments. Reduced levels (P < 0.05) of heterophil, lymphocytes and hetrophil and lymphocyte ratio were recorded in the TVS compared to TV, TS and TC broilers. On day 42, the rectal temperature was significantly higher in CC than those in other treatment groups, which were comparable. TVS birds had higher (P < 0.05) weights of spleen, liver and lower abdominal fat than other treatments. The lowest concentration of plasma malondialdehyde and the highest activity of superoxide dismutase and glutathione peroxidase were recorded in TV and TVS birds. The study concluded that the growth performance and oxidative status in broilers were improved by the combination of EATC with supplemental Se and vitamin E (TVS).

Effects of dietary supplementation of cumin (Cuminum cyminum L.) essential oil on expression of genes related to antioxidant, apoptosis, detoxification, and heat shock mechanism in heat-stressed broiler chickens

This study was carried out to evaluate the impact of cumin essential oil (CEO) supplementation on levels of certain gene expression related to antioxidant, apoptotic, detoxific, and heat shock mechanisms in the breast meat and ileum of heat-stressed broilers. The study was conducted on a 2 × 6 factorial design (heat stress + feed additive) on 600 day-old male broiler chicks for a period of 42 days. From day 7 to 42, although broilers in heat stress groups (HT) were exposed to constant chronic heat stress (36 °C), others were housed at thermoneutral ambient temperature (TN). The chicks in both conditions were fed with 6 experimental diets: C0 (basal diet with no additive), ANTIB (basal diet + 100 mg/kg chloramphenicol), VITE (basal diet + 50 IU α-tocopherol), C2 (basal diet + 200 mg/kg CEO), C4 (basal diet + 400 mg/kg CEO), C6 (basal diet+ 600 mg/kg CEO). The results showed that heat stress upregulated (except for Bcl-2) the genes related to antioxidant, apoptosis, detoxification, and heat shock mechanism. However, cumin essential oil increased the dose-dependently positive effect on certain genes in tissues of the heat-stressed broilers and downregulated (except for Bcl-2) these genes.

Effects of feeding diets with zinc-l-selenomethionine on growth performance of broilers subjected to cyclic heat stress

Limited information exists on the use of zinc-l-selenomethionine (Zn-L-SeMet) in broiler diets and its effects on the growth performance, body temperature, mortality rates, blood profile, and gene expression, especially when animals are reared under cyclic heat stress conditions. This study aimed to investigate the impact of Zn-L-SeMet in broiler diets from 1 to 42 days of age reared under cyclic heat stress and its effects on growth performance, cloacal temperatures, mortality rate, blood parameters, and insulin-like growth factor 1 (IGF-1) and growth hormone receptor (GHR) gene expression in the breast muscle. A total of 1000 male Cobb 500® broiler chicks were randomly assigned to five treatments: 0, 0.15, 0.23, 0.47, and 1.30 mg/kg of Zn-L-SeMet. Each treatment consisted of 10 replicates with 20 birds each. No statistically significant differences in growth performance were observed from 1 to 21 days of age (P > 0.05). However, from 1 to 42 days, feed intake (FI) and feed conversion ratio (FCR) decreased linearly (P < 0.05). Cloacal temperatures showed no significant effects (P > 0.05), while overall mortality rate exhibited a quadratic response (P < 0.05), with the optimal inclusion level predicted to reduce broiler mortality at 0.71 mg/kg. Triglyceride (TRG) levels increased with 0.97 mg/kg (P < 0.05), and gama-glutamil transferase (GGT) levels decreased with the inclusion of 1.19 mg/kg (P < 0.05). No significant effects on IGF-1 and GHR gene expression were found (P > 0.05). In conclusion, the inclusion of 1.30 mg/kg of Zn-L-SeMet in diets of heat-stressed broilers improved growth performance from 1 to 42 days of age. An inclusion of 0.71 mg/kg reduced mortality rate, while 0.97 mg and 1.19 mg increased and reduced TRG and GGT levels, respectively.

Preventing bacterial disease in poultry in the post-antibiotic era: a case for innate immunity modulation as an alternative to antibiotic use

The widespread use of antibiotics in the poultry industry has led to the emergence of antibiotic-resistant bacteria, which pose a significant health risk to humans and animals. These public health concerns, which have led to legislation limiting antibiotic use in animals, drive the need to find alternative strategies for controlling and treating bacterial infections. Modulation of the avian innate immune system using immunostimulatory compounds provides a promising solution to enhance poultry immune responses to a broad range of bacterial infections without the risk of generating antibiotic resistance. An array of immunomodulatory compounds have been investigated for their impact on poultry performance and immune responses. However, further research is required to identify compounds capable of controlling bacterial infections without detrimentally affecting bird performance. It is also crucial to determine the safety and effectiveness of these compounds in conjunction with poultry vaccines. This review provides an overview of the various immune modulators known to enhance innate immunity against avian bacterial pathogens in chickens, and describes the mechanisms involved.

Effects of Dietary Vitamin E on Intramuscular Fat Deposition and Transcriptome Profile of the Pectoral Muscle of Broilers

Vitamin E is an essential micronutrient for animals. The aim of this study was to determine the effect of vitamin E on intramuscular fat (IMF) deposition and the transcriptome profile of the pectoral muscle in broiler chickens. Arbor Acres chickens were divided into five treatment groups fed a basal diet supplemented with 0, 20, 50, 75, and 100 IU/kg dietary DL-α-tocopheryl acetate (vitamin E), respectively. Body weight, carcass performance, and IMF content were recorded. Transcriptome profiles of the pectoral muscles of 35-day-old chickens in the control and treatment groups (100 IU/kg of vitamin E) were obtained by RNA sequencing. The results showed that diets supplemented with 100 IU/kg of vitamin E significantly increased IMF deposition in chickens on day 35. In total, 159 differentially expressed genes (DEGs), including 57 up-regulated and 102 down-regulated genes, were identified in the treatment (100 IU/kg vitamin E) group compared to the control group. These DEGs were significantly enriched in 13 Gene Ontology terms involved in muscle development and lipid metabolism; three signaling pathways, including the mitogen-activated protein kinase and FoxO signaling pathways, which play key roles in muscular and lipid metabolism; 28 biofunctional categories associated with skeletal and muscular system development; 17 lipid metabolism functional categories; and three lipid metabolism and muscle development-related networks. The DEGs, pathways, functional categories, and networks identified in this study provide new insights into the regulatory roles of vitamin E on IMF deposition in broilers. Therefore, diets supplemented with 100 IU/kg of vitamin E will be more beneficial to broiler production.

Effects of cumin (Cuminum cyminum L.) essential oil and chronic heat stress on growth performance, carcass characteristics, serum biochemistry, antioxidant enzyme activity, and intestinal microbiology in broiler chickens

This study was conducted on 600 one-day-old male broiler chicks, using a 2 × 6 factorial design (ambient temperature, A x feed additive, F), for a period of 42 days. The chicks assigned to different groups were exposed to thermoneutral (TN, 24 ± 1 °C) and constant heat stress (HT, 36 ± 1 °C) conditions, and were only fed on a basal diet, and a basal diet supplemented with either 100 mg/kg chloramphenicol, 50 IU/kg α-tocopherol, or 200, 400, and 600 mg/kg of cumin essential oil (CEO). The results showed that heat stress adversely affected performance and carcass characteristics, and increased both the mortality rate and footpad lesions. Moreover, constant chronic heat stress showed negative effects on serum biochemistry and the intestinal microbiota, increased antioxidant activity in both the plasma and breast meat, and increased counts of the pathogenic microorganisms in the small intestine. On the other hand, dietary CEO supplementation positively affected these parameters. CEO had a slight effect on performance, carcass characteristics, mortality rate and the incidence of footpad lesions. When compared to the control group, it was determined that CEO generally had a positive effect on lipid peroxidation in the plasma and tissues and decreased antioxidant enzyme activity. Furthermore, CEO positively affected serum biochemistry and counts of beneficial microorganisms in the small intestine.

Liver fat metabolism of broilers regulated by Bacillus amyloliquefaciens TL via stimulating IGF-1 secretion and regulating the IGF signaling pathway

Bacillus amyloliquefaciens TL (B.A-TL) is well-known for its capability of promoting protein synthesis and lipid metabolism, in particular, the abdominal fat deposition in broilers. However, the underlying molecular mechanism remains unclear. In our study, the regulations of lipid metabolism of broilers by B.A-TL were explored both in vivo and in vitro. The metabolites of B.A-TL were used to simulate in vitro the effect of B.A-TL on liver metabolism based on the chicken hepatocellular carcinoma cell line (i.e., LMH cells). The effects of B.A-TL on lipid metabolism by regulating insulin/IGF signaling pathways were investigated by applying the signal pathway inhibitors in vitro. The results showed that the B.A-TL metabolites enhanced hepatic lipid synthesis and stimulated the secretion of IGF-1. The liver transcriptome analysis revealed the significantly upregulated expressions of four genes (SI, AMY2A, PCK1, and FASN) in the B.A-TL treatment group, mainly involved in carbohydrate digestion and absorption as well as biomacromolecule metabolism, with a particularly prominent effect on fatty acid synthase (FASN). Results of cellular assays showed that B.A-TL metabolites were involved in the insulin/IGF signaling pathway, regulating the expressions of lipid metabolism genes (e.g., FASN, ACCα, LPIN, and ACOX) and the FASN protein, ultimately regulating the lipid metabolism via the IGF/PI3K/FASN pathway in broilers.

Effects of Dietary Vitamin E, Vitamin C, Selenium and Their Combination on Carcass Characteristics, Oxidative Stability and Breast Meat Quality of Broiler Chickens Exposed to Cyclic Heat Stress

Simple Summary

High ambient temperatures present challenging environmental factors in the poultry meat industry, causing heat stress. Heat stress impairs animal health and welfare, growth performance, and productivity, and deteriorates meat quality and its oxidative stability, resulting in economic losses. To mitigate the negative effects of heat stress, several nutritional strategies have been proposed, with vitamin and mineral supplementation being one of the most promising. Several studies reported that the addition of vitamins E and C, as well as selenium, to broiler diets improved the production performance and meat quality of broilers reared under heat stress. Due to the synergistic effects of these antioxidants against the oxidative damage to lipids, combined supplementation could be even more effective in alleviating the symptoms of heat stress on meat quality than supplementation alone, but this has not yet been studied. The results of the present study indicate positive effects of the supplementation with vitamin E on the oxidative stability of breast meat. However, no synergistic effects of the added antioxidants on the measured parameters were observed.

Abstract

The present study was conducted to investigate the effects of dietary supplementation with vitamin E, vitamin C, and Se, alone or in combination, on carcass characteristics, oxidative stability and meat quality parameters of breast meat from broilers exposed to cyclic heat stress (HS), and stored under different conditions. A total of 120 one-day-old male Ross 308 broilers were randomly assigned to six dietary treatments: NRC (minimal nutrition requirements), AVI (commercial nutritional recommendations for Ross 308 broilers), AVI + vitE (as AVI + 200 IU vitamin E/kg feed), AVI + vitC (as AVI + 250 mg vitamin C/kg feed), AVI + Se (as AVI + 0.2 mg Se/kg feed), and AVI + ECSe (as AVI + vitE + vitC + Se). From day 26 onwards, all birds were exposed to a high ambient temperature (31 °C) for 8 h per day. The results showed that dietary vitamin E alone or in combination with vitamin C and Se significantly increased the α-tocopherol content and decreased the malondialdehyde (MDA) content in breast meat. Although no obvious synergistic effects of the added antioxidants were observed, the addition of higher levels of vitamin E, vitamin C and Se to broiler diets had no adverse effects on carcass traits, oxidative stability and meat quality parameters when supplemented either alone or in combination.

Effect of Dietary Enrichment with Flaxseed, Vitamin E and Selenium, and of Market Class on the Broiler Breast Meat-Part 1: Nutritional and Functional Traits

The effect of dietary enrichment with flaxseed, selenium and vitamin E, and market class on the nutritional and functional value of breast meat was evaluated. A completely randomized block design was set up, where the experimental unit (n = 6000 birds) received conventional or enriched diet and was slaughtered at 37 (light class), 47 (medium class), or 57 (heavy class) days of life. Hence, functional and standard Pectoralis major muscles from every market class were analyzed for FA composition, inorganic elements and vitamin E. Lipid metabolism indices and health lipid indicators were assessed along with the nutritional value. A multiple linear model revealed that in breasts, the dietary treatment significantly influenced (p < 0.05) the FA profile, lipid metabolism and health lipid indices, while the slaughtering weight was related (p < 0.05) to most of elements (e.g., Na, Mg, K, Mn, and Se) and vitamin E. The interdependence of the two factors had strong relations (p < 0.05) with total PUFAs, including linolenic acid, desaturase activities, health lipid indices, trace essential elements and vitamin E. Consequently, enriched meat from heavy chickens showed the best functional and nutritional traits. Overall, the study pointed out that both market class and dietary manipulation are two relevant factors to consider for producing breast meat with higher nutritional and functional value.

Effects of Selenium as a Dietary Source on Performance, Inflammation, Cell Damage, and Reproduction of Livestock Induced by Heat Stress: A Review

Heat stress as a result of global warming has harmful consequences for livestock and is thus becoming an urgent issue for animal husbandry worldwide. Ruminants, growing pigs, and poultry are very susceptible to heat stress because of their fast growth, rapid metabolism, high production levels, and sensitivity to temperature. Heat stress compromises the efficiency of animal husbandry by affecting performance, gastrointestinal health, reproductive physiology, and causing cell damage. Selenium (Se) is an essential nutritional trace element for livestock production, which acts as a structural component in at least 25 selenoproteins (SELs); it is involved in thyroid hormone synthesis, and plays a key role in the antioxidant defense system. Dietary Se supplementation has been confirmed to support gastrointestinal health, production performance, and reproductive physiology under conditions of heat stress. The underlying mechanisms include the regulation of nutrient digestibility influenced by gastrointestinal microorganisms, antioxidant status, and immunocompetence. Moreover, heat stress damage to the gastrointestinal and mammary barrier is closely related to cell physiological functions, such as the fluidity and stability of cellular membranes, and the inhibition of receptors as well as transmembrane transport protein function. Se also plays an important role in inhibiting cell apoptosis and reducing cell inflammatory response induced by heat stress. This review highlights the progress of research regarding the dietary supplementation of Se in the mitigation of heat stress, addressing its mechanism and explaining the effect of Se on cell damage caused by heat stress, in order to provide a theoretical reference for the use of Se to mitigate heat stress in livestock.

An updated review on behavior of domestic quail with reference to the negative effect of heat stress

Japanese quail originated from the wildlife environment and was first domesticated in Japan in 1595. Japanese quail has widely distributed in various parts of the world. This bird is characterized by its rapid growth rate, high rate of egg production, much lower space requirements, small size, good reproductive potential, short life cycle, resistance to diseases, early sexual maturity (from 39 to 50 days), better laying ability and shorter time of hatching compared with the different species of poultry. All these characteristics rendered it an excellent laboratory animal and a good economical animal protein source (for both egg and meat). Thermal stress was found to be the major limiting variable in poultry production, directly influencing bird welfare conditions. Previous research showed that heat stress in the production environment, induced by high ambient temperatures, may have a direct detrimental effect on welfare, meat quality, carcass characteristics, productivity, egg mass and egg quality. Furthermore, heat stress directly decreases quails' reproductive performance. As tiny, ground-dwelling birds, quail may appear unable to handle extreme temperatures, yet they have methods of fighting the heat. This review will help in developing and strengthening the core of the quail-based poultry sector. In addition, it provides aggregate information on the characteristics of the quail bird as a production unit in poultry farms as well as being an animal model for laboratory experiments. Also, this review provided deep insight into the domestication process and the impact of heat stress on production characteristics, which altered the domestic or Japanese quail substantially.

Poultry Response to Heat Stress: Its Physiological, Metabolic, and Genetic Implications on Meat Production and Quality Including Strategies to Improve Broiler Production in a Warming World

The continuous increase in poultry production over the last decades to meet the high growing demand and provide food security has attracted much concern due to the recent negative impacts of the most challenging environmental stressor, heat stress (HS), on birds. The poultry industry has responded by adopting different environmental strategies such as the use of environmentally controlled sheds and modern ventilation systems. However, such strategies are not long-term solutions and it cost so much for farmers to practice. The detrimental effects of HS include the reduction in growth, deterioration of meat quality as it reduces water-holding capacity, pH and increases drip loss in meat consequently changing the normal color, taste and texture of chicken meat. HS causes poor meat quality by impairing protein synthesis and augmenting undesirable fat in meat. Studies previously conducted show that HS negatively affects the skeletal muscle growth and development by changing its effects on myogenic regulatory factors, insulin growth factor-1, and heat-shock proteins. The focus of this article is in 3-fold: (1) to identify the mechanism of heat stress that causes meat production and quality loss in chicken; (2) to discuss the physiological, metabolic and genetic changes triggered by HS causing setback to the world poultry industry; (3) to identify the research gaps to be addressed in future studies.

The impact of vitamin E and/or selenium dietary supplementation on growth parameters and expression levels of the growth-related genes in broilers

BACKGROUND

Broilers are continuously stressed because of the rapid growth rate and the environmental issues associated with industrialized poultry production systems, which lead to higher susceptibility for infection with pathogens. It is well known that vitamin E (Vit. E) and selenium (Se) supplementation have protective functions in such stressful conditions. This protocol was to investigate the impact of Vit. E and/or Se on the production performance, some serum biochemistry, and expression of some growth-related gene in the liver tissue of the broilers. The day-old chicks were allotted into four groups according to the supplement; Control group and groups supplemented with Vit. E and/or Se into Vit. E group (100 mg Vit. E/kg diet), Se group (0.3 mg sodium selenite/kg diet), and Vit E + Se group that supplemented with both Vit. E and Se.

RESULTS

The data of the present experiment showed that dietary inclusion of Vit. E and/or Se significantly (P ≤ 0.05) improved the production parameters without any side effect on the general health status of the broilers, which indicated by normal serum biochemical parameters. Moreover, the treatments positively affected the expression of some genes related to growth performance including growth hormone receptor (GHR) and insulin-like growth factor 1 (IGF1) in the liver tissue of broilers.

CONCLUSION

Dietary supplementation of Vit. E and/or Se improved the production parameters and upregulate the growth-related genes without effect on the general health status of the broilers.

Algae-based antioxidant containing selenium yeast (Economase®) enhanced the growth performance, oxidative stability, and meat quality of broiler chickens

Objective

An experiment was conducted to determine the effect of algae-based antioxidant containing Se yeast (EconomasE^®) on the growth performance, visceral organ weight, meat quality, and oxidative stability of broiler chickens.

Methods

Nine hundred sixty, day-old male broiler chickens (Cobb, 43.97±0.55 g) were divided into three dietary treatments and allocated into 12 deep litter pens in a completely randomized design giving 4 replicate cages for each treatment. Three dietary treatments were: i) control (CON, basal diet with sufficient nutrient), ii) vitamin E (VitE, basal diet supplemented with 100 IU VitE), and iii) Algae-based antioxidant containing Se yeast (EcoE, basal diet supplemented with 0.2% algae-based antioxidant containing Se yeast: EconomasE^®). Maize soybean meal based basal diets were formulated to meet or exceed the nutrition requirement for broiler chickens. Chickens were fed ad-libitum experimental diets during the 42 days experiment period. On days 21 and 42, body weight and feed intake were measured to calculate the feed conversion ratio of the chickens. Intestine and visceral organs were measured together with meat quality and oxidative stability on days 14 and 42.

Results

Chickens fed with EcoE showed improved (p<0.05) growth performance, meat quality, and higher (p<0.05) oxidative stability compared to the chicken fed on CON. Moreover, broiler chickens fed with EcoE showed similar (p<0.05) growth performance with better (p<0.05) meat quality and higher oxidative stability compared to the broiler chickens fed VitE (p<0.05).

Conclusion

The algae-based antioxidant containing Se yeast can be supplemented into commercial broiler diets as a substitution of VitE while maintaining growth performance with enhancing meat quality and oxidative stability of the broiler chickens.

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

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

Technological Quality, Amino Acid and Fatty Acid Profile of Broiler Meat Enhanced by Dietary Inclusion of Black Soldier Fly Larvae

We evaluated the effects of full-fat black soldier fly larvae (BSFL) on broiler carcass composition, cut yield, and breast meat quality. Broilers were fed for 42 days with up to 20% dietary inclusion of BSFL (0, 5, 10, 15, and 20%). On day 42, 120 broilers were slaughtered, and images were taken using computed tomography. Breasts, drumsticks, and thighs were collected for cut yield determination. The pH, color, lipid oxidation, cooking loss, shear force, amino acid profile, and fatty acid profile of the breast meat were assessed. There was no dietary effect on carcass composition or meat quality parameters except for fatty and amino acids compositions. When 20% BSFL was included in the diet, individual fatty and amino acids, such as lauric and myristic acids, aspartic acid, glutamine, and lysine, increased by 22.0-, 5.50-, 1.08-, 1.06-, and 1.06-fold, respectively (p < 0.05). Although total polyunsaturated fatty acids decreased, eicosapentaenoic fatty acids (EPA) increased by 78% in the 20% BSFL inclusion group. In conclusion, up to 20%, dietary full-fat BSFL did not affect key meat characteristics but positively increased the levels of the health-claimable omega-3 fatty acid EPA.

Climate change and heat stress: Impact on production, reproduction and growth performance of poultry and its mitigation using genetic strategies

Heat stress is an important environmental determinant which adversely affects the performance of poultry worldwide. The present communication reviews the impact of heat stress on production, reproduction and growth performance of poultry, and its alleviation using genetic strategies. The adverse effects of high environmental temperature on poultry include decrease in growth rate, body weight, egg production, egg weight, egg quality, meat quality, semen quality, fertility and hatchability, which cause vast financial losses to the poultry industry. High ambient temperature has an antagonistic effect on performance traits of the poultry. Thus, selection of birds for high performance has increased their susceptibility to heat stress. Additionally, heat burden during transportation of birds from one place to another leads to reduced meat quality, increased mortality and welfare issues. Molecular markers are being explored nowadays to recognize the potential candidate genes related to production, reproduction and growth traits for selecting poultry birds to enhance thermo-tolerance and resistance against diseases. In conclusion, there is a critical need of formulating selection strategies based on genetic markers and exploring more genes in addition to HSP25, 70, 90, H1, RB1CC, BAG3, PDK, ID1, Na, F, dw and K responsible for thermoregulation, to improve the overall performance of poultry along with their ability to tolerate heat stress conditions.

Effects of zinc oxide nanoparticles on regulatory appetite and heat stress protein genes in broiler chickens subjected to heat stress

This study was conducted to explore the effect of the zinc oxide nanoparticles (ZnONPs) supplement on the regulatory appetite and heat stress (HS) genes in broiler chickens raised under high or normal ambient temperatures. In this study, 240 one-day-old male broiler chicks (Cobb 500) were randomly assigned to 48 battery cages. From day 1, these 48 cages were randomly subjected to four different treatment strategies: Control (wherein, their basal diet included 60 mg/kg of ZnO), ZNONPs 40 (wherein basal diet included 40 mg/kg of ZnONPs), ZnONPs 60 (basal diet included 60 mg/kg of ZnONPs), and ZnONPs 100 (basal diet included 100 mg/kg of ZnONPs). Thereafter, from day 22 to 42, the chickens from each dietary treatment group were subjected to different temperature stresses either normal (23 ± 1 °C constant) or HS (34 ± 1 °C for 6 h/d), which divided them into eight different treatment groups. Our findings revealed that dietary ZnONPs altered the gene expression of cholecystokinin (ileum), heat stress proteins (HSP) 70 (jejunum and ileum), and HSP 90 (duodenum, jejunum, and ileum). The gene expression of ghrelin was affected by the interaction between the ZnONPs concentration and temperature in the duodenum and stomach. More studies are required to elucidate its complex physiological and biochemical functions of the regulation of gene expression within the intestine in heat-stressed broiler chickens.

The Effect of Dietary Supplementation with Inorganic or Organic Selenium on the Nutritional Quality and Shelf Life of Goose Meat and Liver

Simple Summary

Geese have a unique ability among aquatic poultry species to efficiently utilize high-fiber feedstuffs, however research investigating concentrate feeding strategies in the farm setting is limited. This experiment investigated the effect of dietary supplementation with inorganic or organic selenium on nutritional quality and shelf life of goose meat and liver samples. Differences between geese supplemented with I-Se and O-Se were detected for several parameters, yet these differences were less tangible than those between geese not supplemented with additional selenium (CON) and geese supplemented with additional selenium (I-Se and O-Se). Overall, it was concluded that supplementation with additional dietary selenium in both the inorganic and organic forms improved nutritional quality and shelf life of goose meat and liver samples.

Abstract

Ninety-six male goslings were allocated and assigned to treatment using a completely randomized design. Dietary treatments included a basal diet consisting of corn, wheat, and soybean meal with either no additional selenium (CON), 0.3 mg/kg of inorganic selenium (I-Se; sodium selenite), or 0.3 mg/kg of organic selenium (O-Se; selenium-enriched yeast). After a 56-day feeding period, geese were slaughtered on a common ending day and two geese per pen (n = 24) were used for the analyses conducted in this study. Meat (equal portions of the breast and thigh meat) and liver were collected and evaluated for proximate composition, fatty acid profile, pH, phenolic content, thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVB-N) over a 9-day storage period at 4 °C. The meat and liver samples from geese supplemented I-Se or O-Se had greater (p < 0.01) lipid content compared with geese not supplemented with additional selenium. At the conclusion of the 9-day storage period, meat and liver samples from geese supplemented I-Se or O-Se had lower (p < 0.05) pH values, greater (p < 0.05) phenolic content, lower (p < 0.05) TBARS values, and lower (p < 0.05) TVB-N compared with geese not supplemented with additional selenium (CON).

Supplementation of minerals and vitamins in broiler diets: effect on performance and bone quality

Abstract Differences in growth rate and carcass composition of broilers may require higher levels of vitamins and minerals with higher bioavailability. The aim of this trial was to supplement commercial diets for broilers with optimized levels of vitamins and with different mineral sources to assess the effect on performance, carcass yield and bone quality. A total of 1,800 Cobb Slow male broiler chicks were distributed into a 2 x 2 factorial completely randomized design (vitamin programs - optimized and commercial versus mineral sources - inorganic [sulfates] and carbo-amino-phospho-chelate, CAPC). The vitamin D3 metabolite, 25 (OH) D3, was included in the optimized vitamin premix. Birds and feed leftovers were weekly weighed. Data was subjected to statistical analysis using the GLM procedure of SAS software. Supplementing diets with a combination of optimized vitamin programs and CAPC as mineral source resulted in better feed conversion at 42 days of age (P<0.05). Supplementation with CAPC minerals resulted in a lower red index (*a) (P<0.05) in the adjacent thigh muscles and drumstick bones of broilers when thawed and roasted, indicating less bone porosity. The inclusion rates of mineral sources with higher bioavailability can be reduced, decreasing the negative impact of mineral excretion and the polluting effect on the environment.

Effect of Vitamin E Supplementation on Deposition and Gene Expression Profiling of Abdominal Fat in Broiler Chickens

The aim of this study was to study the regulation of abdominal fat deposition by DL-α-tocopherol acetate (vitamin E) in broilers. Diets supplemented with 50 IU vitamin E significantly diminished abdominal fat deposition in broilers at day 35. Transcriptome sequencing results for abdominal fat tissues of the control (FC) and 50 IU vitamin E-supplemented (FT) groups identified 602 differentially expressed genes (DEGs), which were enriched in cellular process, cell and cell part, and binding Gene Ontology terms. Pathway functional analysis revealed that the DEGs were enriched in 42 metabolic pathways. Notably, the most enriched pathway, fatty acid biosynthesis, was found to play a key role in lipid metabolism. Further, the key regulators of lipid metabolism, including fatty acid synthase, acetyl-CoA carboxylase alpha, and acyl-CoA synthetase long-chain family member 1, demonstrated decreased expression following vitamin E supplementation. Herein, we have identified pathways and genes regulated by vitamin E, thereby providing novel insights into the nutrients regulating abdominal fat deposition in broilers.

Structure-related differential proteins identification for sous-vide cooking hairtail (Trichiurus lepturus) product

Optimal heating parameters for sous-vide cooking hairtail (Trichiurus lepturus) were selected and the differential proteins related to texture change were clarified using proteomics. Heating under 68 °C for 20 min was chosen to be the desirable heating parameter. Texture profile analysis (TPA) showed the texture of hairtail changed more severely during heat-up process than heating preservation process. Most of the high-content proteins did not change much during heating preservation. 169 kinds of proteins were identified as differential expressed proteins. Actin cytoplasmic 1, myosin heavy chain 1 and myosin heavy chain were the most variable structural proteins during heat-up process, with the change fold of 32.4, 29.1 and 18.8, respectively, while the highest structure proteins changing fold during heat preservation process were 16.7, 4.7 and 3.9, respectively, much lower than that of heat-up process. The partial deformation of structure-related proteins under sous-vide cooking was a vital factor in reserving the texture of hairtail.

Oxidative stress mitigation by antioxidants - An overview on their chemistry and influences on health status

The present review paper focuses on the chemistry of oxidative stress mitigation by antioxidants. Oxidative stress is understood as a lack of balance between the pro-oxidant and the antioxidant species. Reactive oxygen species in limited amounts are necessary for cell homeostasis and redox signaling. Excessive reactive oxygenated/nitrogenated species production, which counteracts the organism's defense systems, is known as oxidative stress. Sustained attack of endogenous and exogenous ROS results in conformational and oxidative alterations in key biomolecules. Chronic oxidative stress is associated with oxidative modifications occurring in key biomolecules: lipid peroxidation, protein carbonylation, carbonyl (aldehyde/ketone) adduct formation, nitration, sulfoxidation, DNA impairment such strand breaks or nucleobase oxidation. Oxidative stress is tightly linked to the development of cancer, diabetes, neurodegeneration, cardiovascular diseases, rheumatoid arthritis, kidney disease, eye disease. The deleterious action of reactive oxygenated species and their role in the onset and progression of pathologies are discussed. The results of oxidative attack become themselves sources of oxidative stress, becoming part of a vicious cycle that amplifies oxidative impairment. The term antioxidant refers to a compound that is able to impede or retard oxidation, acting at a lower concentration compared to that of the protected substrate. Antioxidant intervention against the radicalic lipid peroxidation can involve different mechanisms. Chain breaking antioxidants are called primary antioxidants, acting by scavenging radical species, converting them into more stable radicals or non-radical species. Secondary antioxidants quench singlet oxygen, decompose peroxides, chelate prooxidative metal ions, inhibit oxidative enzymes. Moreover, four reactivity-based lines of defense have been identified: preventative antioxidants, radical scavengers, repair antioxidants, and those relying on adaptation mechanisms. The specific mechanism of a series of endogenous and exogenous antioxidants in particular aspects of oxidative stress, is detailed. The final section resumes critical conclusions regarding antioxidant supplementation.

Effects of Selenium-Enriched Yeast on Performance, Egg Quality, Antioxidant Balance, and Egg Selenium Content in Laying Ducks

This study investigated the effects of dietary selenium-enriched yeast (Se yeast) supplementation on the laying performance, egg quality, plasma antioxidant balance, and egg selenium (Se) content in laying Longyan ducks. A total of 480 32-week-old ducks were randomly divided into four dietary treatments, each consisting of six replicates of 20 ducks. The dietary treatments were a control basal diet and basal diets with supplementation of 0.05, 0.15, and 0.25 mg Se/kg via Se yeast. The analyzed Se contents of the four diets were 0.15, 0.21, 0.36, and 0.43 mg Se/kg, respectively. Dietary Se yeast supplementation had no apparent effects on laying performance and egg quality (p > 0.05), but it improved the antioxidant balance of ducks, as inferred by greater glutathione peroxidase and catalase activities, and decreased the malondialdehyde content in plasma of ducks (p < 0.05). It was suggested that the Se content in the basal diet containing 0.15 mg/kg of Se requirement is adequate for productive performance, but not for the antioxidant balance of laying ducks. Besides that, the Se contents in the yolk, albumen, and whole egg increased linearly as the Se supplementation levels increased. With more feeding days, the Se contents in the yolk and whole egg from non-Se-yeast-supplemented ducks increased linearly (p < 0.05), while those from Se-yeast-supplemented ducks showed a quadratic relationship (p < 0.05). In conclusion, the Se content of the basal diet at 0.15 mg/kg was adequate for laying performance and egg quality traits in laying ducks. Dietary Se yeast supplementation is beneficial to improve the antioxidant balance of laying ducks and increase the Se deposition in eggs for producing Se-enriched eggs. Based on the quadratic model or the quadratic broken-line model analyses, supplemental 0.19 mg Se/kg via Se yeast, with a total equivalent of 0.34 mg Se/kg in the diet, could provide the optimum antioxidant balance in laying ducks. Dietary supplementation of 0.25 mg Se/kg via Se yeast, with a total equivalent of 0.40 mg Se/kg in the diet, could lead to achieving the desired Se content in the whole egg.

Metabolism and biological activity of α-tocopherol derived from vitamin E-enriched transgenic maize in broilers

BACKGROUND

The aim of this study was to investigate the metabolism of α-tocopherol derived from vitamin E-enriched transgenic maize (VER) and its effects on antioxidant and immune functions in broilers aged 1-42 days. A total of 360 1-day-old male broilers were randomly divided into three groups containing six replicates with 20 broilers per replicate. The negative control (NC) group and the positive control (PC) group were given non-GM maize and non-GM maize plus exogenous vitamin E (VE), respectively, and the VER group was given VER, replacing the non-GM maize given to the NC group. Between days 1 and 21 and days 22 and 42, VE levels were 4.38 and 4.63 mg kg^-1 in the NC group, and 14.11 and 14.91 mg kg^-1 in the PC and VER group, respectively.

RESULTS

The results showed that α-tocopherol from both VER and additives increased α-tocopherol transfer protein and cytochrome P450 concentrations. Serum α-tocopherol and α-tocopherylquinone levels of broilers in the PC and VER groups were also significantly higher than those in the NC group (P < 0.05). Compared with the NC group, broilers in both groups that received α-tocopherol had reduced NF-κB p65 concentrations, significantly decreased serum prostaglandin E₂ , interleukin-6, malondialdehyde, and hydrogen peroxide levels (P < 0.05), and significantly increased glutathione, glutathione peroxidase, and total antioxidant capacity (P < 0.05).

CONCLUSION

In summary, both VER and non-GM maize fortified with exogenous VE showed similar effects on broilers, indicating that the α-tocopherol in VER has sufficient biological activity. © 2020 Society of Chemical Industry.

Selenium-enriched Saccharomyces cerevisiae improves the meat quality of broiler chickens via activation of the glutathione and thioredoxin systems

The aim of this study was to investigate the effects of selenium (Se)-enriched Saccharomyces cerevisiae (SSC) on meat quality and to elucidate the underlying mechanisms in broilers. A total of 200 one-day-old Arbor Acres broiler chickens were randomly allocated to one of four treatments with 5 replications of 10 chickens each. Group 1 served as a control and was fed a basal diet without Se supplementation, while groups 2, 3, and 4 were fed the basal diet supplemented with S. cerevisiae (SC), sodium selenite (SS), and SSC, respectively. Breast muscle samples were collected to evaluate meat quality, selenium concentration, oxidative stability, and the mRNA levels of antioxidant enzyme genes on day 42. As compared with groups 1 and 2, SS and SSC supplementation increased Se concentration, glutathione peroxidase (GPx) and thioredoxin reductase (TR) activities, total antioxidant capacity, and the mRNA levels of GPx-1, GPx-4, TR-1, and TR-3 (P < 0.05) and decreased drip loss and malondialdehyde (MDA) content (P < 0.05). As compared with group 3, SSC supplementation increased pH, lightness, yellowness, Se concentration, GPx and superoxide dismutase activities, and the mRNA levels of GPx-1 and GPx-4 (P < 0.05) but decreased drip loss and MDA content (P < 0.05). Thus, SSC improved meat quality and oxidative stability by activating the glutathione and thioredoxin systems, which should be attributed to the combined roles of Se and SC.

Effect of dietary β-1,3-glucan supplementation and heat stress on growth performance, nutrient digestibility, meat quality, organ weight, ileum microbiota, and immunity in broilers

The objective of this study was to determine the effect of dietary β-1,3-glucan supplementation and heat stress (HS) on growth performance, nutrient digestibility, meat quality, organ weight, ileum microbiota, and immunity in broiler. A total of 1,440 1-day-old Ross 308 male chicks with an average initial BW of 43.06 ± 1.94 g were sorted into 6 (2 × 3) treatments, 14 replications per treatment. This trail included 2 factors: the dosage of β-1,3-glucan (0, 100 g/T, and 200 g/T) and feeding condition (HS and normal). During the whole trial, significant impacts were observed in BW gain, feed intake，feed conversion rate, and the digestibility of DM and energy between normal treatments and HS treatments (P < 0.05). From day 21 to 35, HS-challenged birds fed the diet with 200 g/T β-1,3-glucan had a lower feed conversion rate than those fed the diet with 0 or 100 g/T β-1,3-glucan (P < 0.05). Moreover, the HS-exposed birds that fed the diet with β-1,3-glucan indicated a greater energy digestibility than those fed the nontreatment diet (P < 0.05). Besides, β-1,3-glucan supplementation could elevate meat pH of all birds and decrease cooking loss significantly of HS-exposed birds (P < 0.05). The HS birds fed the β-1,3-glucan diet obtained a reduced amount of Escherichia coli in the ileum than those fed the nontreatment diet (P < 0.05). Besides, β-1,3-glucan supplementation lowered the level of tumor necrosis factor-α in HS-exposed birds significantly (P < 0.05). These results indicated 100 and 200 g/T β-1,3-glucan supplementation, under HS condition or not, can increase growth performance without a negative response on immunity. Under HS condition, the addition of β-1,3-glucan at dosage from 100 to 200 g/T in the diet can increase energy digestibility, decrease cooking loss, reduce E. coli mount in the ileum, and the tumor necrosis factor-α concentration.

Strategies to Combat Heat Stress in Broiler Chickens: Unveiling the Roles of Selenium, Vitamin E and Vitamin C

Heat stress compromises efficient poultry production by impairing growth performance and increasing mortality. Mechanisms to dissipate excess heat divert energy from efficient production. This includes increased energy expenditure for respiration, oxidative stress and micronutrient absorption. The fortification of diets with particular feed additives has been known as one of the most important approaches to minimize the negative impacts of heat stress on broiler production. In this context, the promising functional feed additives appeared to be selenium and vitamins E and C. The fortification of broiler diets with these feed additives has been proven to enhance the function of vital organs, immune system response and growth performance of broilers under heat stress. The current review highlights recent successful experiences in the alleviation of heat stress symptoms in broilers using the above-mentioned additives. Selenium and vitamins E and C enhanced production performance in broiler chickens challenged with acute heat stress. The combination of these additives, by employing multiple mechanisms and through synergistic effects, improves heat stress symptoms more efficiently than their individual forms. Emerging literature reveals that selenium and vitamins E and C are involved in close interactions to protect proteins and lipids from oxidative damage and boost immune system function.

Antioxidative effects of supplementing linseed oil-enriched diets with α-tocopherol, ascorbic acid, selenium, or their combination on carcass and meat quality in broilers

In a previous study, we examined the synergistic effects of the dietary supranutritional supplementation with vitamin E, vitamin C, and Se on the in vivo antioxidative status of broilers under conditions of dietary oxidative stress induced by feeding a diet high in n-3 PUFA. In this study, we examined the effect of their inclusion on the quality characteristics and oxidative stability of raw or cooked meat, both fresh or after a long-term frozen storage. Four hundred 21-day-old Ross 308 male broilers were allocated to 5 experimental groups fed 5% linseed oil-enriched finisher diets (days 21 to 40): Cont (recommended levels of vitamin E, C, and selenium), +E (200 IU vitamin E/kg feed), +C (250 mg vitamin C/kg feed), +Se (0.2 mg selenium/kg feed), or +ECSe (concentrations as in the sole supplementation, combined). Animal performance and carcass characteristics were monitored at the age of 40 D. Breast meat samples of 12 chickens per group were analysed fresh, fresh after frozen storage, cooked fresh, and cooked after frozen storage (2 × 2 factorial design) for parameters of meat quality (water-holding capacity—WHC, pH, and color) and oxidative stability (concentrations of vitamin E, malondialdehyde—MDA, antioxidant capacity of the water-soluble compounds—ACW, and fatty acid composition).

Vitamin E alone (+E) and combined with Se and vitamin C (+ECSe) increased the α-tocopherol concentration in breast muscle, and showed similar protective effects against lipid peroxidation measured as MDA regardless of the frozen storage or cooking. The sole supplementation of vitamin C or selenium showed no effects on the meat quality parameters. In conclusion, the dietary supranutritional inclusion of vitamin E inhibited the lipid peroxidation in fresh, frozen stored, cooked fresh, and frozen stored meat in broilers fed with diets rich in n-3 PUFAs. Even though no clear synergistic effects of the supranutritional supplementation of vitamin C and Se with vitamin E were detected, their dietary inclusion did not negatively affect broilers carcass and meat quality parameters.

Effect of Glutamine on Antioxidant Capacity and Lipid Peroxidation in the Breast Muscle of Heat-stressed Broilers via Antioxidant Genes and HSP70 Pathway

This study investigated whether Glutamine (Gln) could be used as an additive to improve antioxidant capacity in the breast muscle of heat-stressed broilers. Two hundred and forty 22-day-old Arbor Acres broilers in the G1, G2, G3, and G4 groups (n = 60 each) were housed in a cyclic hot environment and fed the basal diet with 0%, 0.5%, 1.0%, and 1.5% Gln, respectively. Compared with the G1 group, dietary 1.5% Gln increased (p < 0.05) pH and b* values, but decreased (p < 0.05) L* cooking loss, drip loss, and water loss rate in breast meat of heat-stressed broilers. Malondialdehyde levels in the breast muscle were lower (p < 0.05) in 1.0% and 1.5% Gln groups than that of the heat-stress group. Compared with the G1 group, dietary 1.5% Gln increased (p < 0.05) catalase (CAT), glutathione, glutathione peroxidase (GSH-Px,) and total antioxidant capacity in the breast muscle of heat-stressed broilers. Furthermore, the CAT, GSH-Px, HSP70 mRNA expression levels, and HSP70 protein expression levels were increased (p < 0.05) in the G3 and G4 groups compared with the G1 group. In sum, Gln alleviated antioxidant capacity and lipid peroxidation in the breast muscle of heat-stressed broilers through antioxidant genes and HSP70 pathways.

Growth Performance and Characterization of Meat Quality of Broiler Chickens Supplemented with Betaine and Antioxidants under Cyclic Heat Stress

Heat stress (HS) causes oxidative stress, which compromises broiler performance and meat quality. The aim of this study was to determine whether dietary antioxidants could be used as an amelioration strategy. Seventy-two day-old-male Ross-308 chicks were exposed to either thermoneutral or cyclical heat stress conditions. Diets were either control commercial diet (CON), CON plus betaine (BET), or with a combination of betaine, selenized yeast, and vitamin E (BET + AOX). Heat stress increased the rectal temperature (p < 0.001), respiration rate (p < 0.001), decreased blood pCO₂ (p = 0.002), and increased blood pH (p = 0.02), which indicated the HS broilers had respiratory alkalosis. Final body weight was decreased by HS (p < 0.001), whereas it was improved with BET (p = 0.05). Heat stress reduced cooking loss (p = 0.007) and no effect on drip loss, while BET decreased the drip loss (p = 0.01). Heat stress reduced the myofibril fragmentation index (p < 0.001) and increased thiobarbituric acid reactive substances (p < 0.001), while these were improved with the combination of BET + AOX (p = 0.003). In conclusion, BET overall improved growth rates and product quality in this small university study, whereas some additional benefits were provided by AOX on product quality in both TN and HS broilers.

Avian Stress-Related Transcriptome and Selenotranscriptome: Role during Exposure to Heavy Metals and Heat Stress

Selenium, through incorporation into selenoproteins, is one of the key elements of the antioxidant system. Over the past few years there has been increased interest in exploring those molecular mechanisms in chicken, responsible for the development of this protection system. In more detail, Cd/Pb poisoning and heat stress increase oxidation, mRNA levels of inflammatory proteins, and apoptotic proteins. Selenium seems to enhance the antioxidant status and alleviates these effects via upregulation of antioxidant proteins and other molecular effects. In this review, we analyze avian transcriptome key elements with particular emphasis on interactions with heavy metals and on relation to heat stress.