Selenium in poultry nutrition 1. Antioxidant properties, deficiency and toxicity

Influence of Select Dietary Trace Minerals and their Levels on Growth Performance, Nutrient Utilization and Minerals Balance in Male Goats

A study was conducted on eighteen male goats to evaluate the effect of incremental levels of select dietary trace minerals on growth performance, nutrient utilization and minerals balance. Animals (16.65 ± 0.53 kg average BW) were randomly divided into three groups and fed a basal diet to meet the requirement of all the nutrients except select trace minerals for 60 days. Groups were T1 (0.204 ppm Se, 35.29 ppm Zn, 7.37 ppm Cu, 39.79 ppm Mn), T2 (0.504 ppm Se, 55.29 ppm Zn, 17.37 ppm Cu, 59.79 ppm Mn), and T3 (0.804 ppm Se, 75.29 ppm Zn, 27.37 ppm Cu, 79.79 ppm Mn). Daily dry matter intake (DMI) (% BW) was lower (P < 0.05) in T3 as compared to other groups however, average daily gain (ADG) in body weight (P = 0.113) and feed: gain ratio (P = 0.102) showed subtle improvement in T2 and T3 groups. Feeding of higher levels of select trace minerals did not affect the intake and digestibility of nutrients, or plane of nutrition, however, the digestibility of non-fiber carbohydrates (NFC) increased (P = 0.004) in T2 and T3 groups than T1. The balance of N, Ca, P and Cu did not differ among the groups but balance of Zn, Mn and Se increased in T2 and T3 groups than T1 group. It is concluded that feeding higher levels of Zn (75.29 ppm), Cu (27.37 ppm), Mn (79.79 ppm) and Se (0.804 ppm) in combination, improved NFC digestibility, retention of Zn, Mn and Se and had subtle beneficial effects on the growth performance of male goats.

Optimum Doses and Forms of Selenium Maintaining Reproductive Health via Regulating Homeostasis of Gut Microbiota and Testicular Redox, Inflammation, Cell Proliferation, and Apoptosis in Roosters

BACKGROUND

There is a U-shaped relationship between dietary selenium (Se) ingestion and optimal sperm quality.

OBJECTIVES

This study aimed to investigate the optimal dietary dose and forms of Se for sperm quality of breeder roosters and the relevant mechanisms.

METHODS

In experiment 1, 18-wk-old Jingbai laying breeder roosters were fed a Se-deficient base diet (BD, 0.06 mg Se/kg), or the BD + 0.1, 0.2, 0.3, 0.4, 0.5, or 1.0 mg Se/kg for 9 wk. In experiment 2, the roosters were fed the BD or the BD + sodium selenite (SeNa), seleno-yeast (SeY), or Se-nanoparticles (SeNPs) at 0.2 mg Se/kg for 9 wk.

RESULTS

In experiment 1, added dietary 0.2 and 0.3 mg Se/kg led to higher sperm motility and lower sperm mortality than the other groups at weeks 5, 7, and/or 9. Furthermore, added dietary 0.2-0.4 mg Se/kg produced better testicular histology and/or lower testicular 8-hydroxy-deoxyguanosine than the other groups. Moreover, integrated testicular transcriptomic and cecal microbiomic analysis revealed that inflammation, cell proliferation, and apoptosis-related genes and bacteria were dysregulated by Se deficiency or excess. In experiment 2, compared with SeNa, SeNPs slightly increased sperm motility throughout the experiment, whereas SeNPs slightly reduced sperm mortality compared with SeY at week 9. Both SeY and SeNPs decreased malondialdehyde in the serum than those of SeNa, and SeNPs led to higher glutathione peroxidase (GPX) and thioredoxin reductase activities and GPX1 and B-cell lymphoma 2 protein concentrations in the testis compared with SeY and SeNa.

CONCLUSIONS

The optimal dietary Se dose for reproductive health of breeder roosters is 0.25-0.35 mg Se/kg, and SeNPs displayed better effects on reproductive health than SeNa and SeY in laying breeder roosters. The optimal doses and forms of Se maintain reproductive health of roosters associated with regulation intestinal microbiota homeostasis and/or testicular redox balance, inflammation, cell proliferation, and apoptosis.

Effects of functional nutrients on chicken intestinal epithelial cells induced with oxidative stress

The objective of this study was to investigate the protective effects of functional nutrients including various functional amino acids, vitamins, and minerals on chicken intestinal epithelial cells (cIECs) treated with oxidative stress. The cIECs were isolated from specific pathogen free eggs. Cells were exposed to 0 mM supplement (control), 20 mM threonine (Thr), 0.4 mM tryptophan (Trp), 1 mM glycine (Gly), 10 μM vitamin C (VC), 40 μM vitamin E (VE), 5 μM vitamin A (VA), 34 μM chromium (Cr), 0.42 μM selenium (Se), and 50 μM zinc (Zn) for 24 h with 6 replicates for each treatment. After 24 h, cells were further incubated with fresh culture medium (positive control, PC) or 1 mM H2O2 with different supplements (negative control, NC and each treatment). Oxidative stress was measured by cell proliferation, whereas tight junction barrier function was analyzed by fluorescein isothiocyanate (FITC)-dextran permeability and transepithelial electrical resistance (TEER). Results indicated that cell viability and TEER values were less (p < 0.05) in NC treatments with oxidative stress than in PC treatments. In addition, FITC-dextran values were greater (p < 0.05) in NC treatments with oxidative stress than in PC treatments. The supplementations of Thr, Trp, Gly, VC, and VE in cells treated with H2O2 showed greater (p < 0.05) cell viability than the supplementation of VA, Cr, Se, and Zn. The supplementations of Trp, Gly, VC, and Se in cells treated with H2O2 showed the least (p < 0.05) cellular permeability. In addition, the supplementation of Thr, VE, VA, Cr, and Zn in cells treated with H2O2 decreased (p < 0.05) cellular permeability. At 48 h, the supplementations of Thr, Trp, and Gly in cells treated with H2O2 showed the greatest (p < 0.05) TEER values among all treatments, and the supplementations of VC and VE in cells treated with H2O2 showed greater (p < 0.05) TEER values than the supplementations of VA, Cr, Se, and Zn in cells treated with H2O2. In conclusion, Thr, Trp, Gly, and VC supplements were effective in improving cell viability and intestinal barrier function of cIECs exposed to oxidative stress.

Dietary supplementation with selenium polysaccharide from selenium-enriched Phellinus linteus improves antioxidant capacity, immunity and production performance of laying hens

BACKGROUND

Selenium (Se) plays a beneficial role in the physiological function of humans and animals. Selenium polysaccharide, improving enzyme activity and regulating immunity, is the extraction from selenium-rich plants or mushrooms. This study aimed to evaluate the effect of selenium polysaccharide from selenium-enriched Phellinus linteus on the antioxidative ability, immunity, serum biochemistry, and production performance of laying hens.

METHODS

Three hundred sixty adult laying hens were randomly assigned to 4 groups. The four groups were divided as follows: CK (control group), PS group (4.2 g/kg polysaccharide), Se group (0.5 Se mg/kg), and PSSe group (4.2 g/kg with 0.5 Se mg/kg, Selenium polysaccharide).

RESULTS

After the 8 weeks, the hens were sampled and the antioxidant ability(total antioxidant (T-AOC), superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), malondialdehyde (MDA), and Nitric Oxide (NO)), immunity(Interleukin-2(IL-2), Immunoglobulin M(IgM), Immunoglobulin A(IgA), Immunoglobulin G(IgG) and interferon-gamma (IFN-γ) and secretory Immunoglobulin A(sIgA)), serum biochemistry(total protein, triglycerides, total cholesterol, glucose, glutamic-pyruvictransaminase (ALT), and aspartate transaminase (AST)) and production performance were assessed. Compared with the control group, T-AOC, SOD, CAT, GSH, IL-2, IgM, IgA, sIgA, IgG, IFN-γ, total protein, average laying rate, average egg weight, and final body were significantly increased in the PS, Se, and PSSe groups, however, the MDA and NO, triglyceride, cholesterol, glucose, AST, ALT, average daily feed consumption, and feed conversion ratio were significantly decreased in the PS, Se, and PSSe groups. The PSSe group in the immune index, antioxidant ability and serum biochemistry was improved the highest.

CONCLUSION

The result suggested that selenium polysaccharide from selenium-enriched Phellinus linteus can enhance the antioxidant ability and immunity, change serum biochemistry, providing a new method for improving the production performance of laying hens.

Dietary selenium levels modulates antioxidant, cytokine and immune response and selenoproteins mRNA expression in rats under heat stress condition

BACKGROUND

Higher environmental temperature is a major abiotic stress factor for animals and human beings. The selenium (Se) is an important trace mineral having diverse health promoting effects under stress conditions. However, studies on dietary requirement of selenium under prolonged heat stress condition are lacking. Present study discern the effect of higher dietary Se levels on antioxidant, cytokine, haemato-biochemical profile, and immune response, and the selenoproteins mRNA expression in rats under prolonged heat stress (HS) condition.

METHODS

Weaned Wistar rats (4 wk age; 67.6 ± 1.53 g BW; n = 72) housed under thermoneutral (TN) or HS conditions and fed with purified diets containing three graded Se levels were divided in six experimental groups. The groups were 1) TN control with 138 ppb Se (TN_CON), 2) HS control with 138 ppb Se (HS_CON), 3) TN with higher Se @ 291 ppb (TN_Se1), 4) HS with higher Se @ 291 ppb (HS_Se1) 5) TN with higher Se @ 460 ppb (TN_Se2), 6) HS with higher Se @ 460 ppb (HS_Se2). Rats in all the six groups were maintained in TN environmental conditions (57.3 ± 0.22 temperature humidity index; THI) for initial 28 days period. Subsequently, rats of HS groups were exposed to 77.0 ± 0.11 THI for 6 h/d in a psychrometric chamber for last fourteen days.

RESULTS

Higher dietary Se (291 and 460 ppb) significantly improved the blood hemoglobin concentration and reduced serum alanine aminotransferase activity of rats under HS conditions. The serum triiodothyronine and insulin levels were significantly higher in high dietary Se groups irrespective of the environmental conditions. Similarly, the serum reduced glutathione levels, and catalase and superoxide dismutase enzyme activity were increased and malondialdehyde levels were reduced in high dietary Se groups irrespective of stress conditions. The glutathione peroxidase (GPx) activity was significantly higher in 460 ppb dietary Se groups as compared to other groups. The serum pro-inflammatory cytokine interleukin (IL)- 1 was declined, whereas the anti-inflammatory cytokine IL-10 level was increased in high dietary Se fed rats under both HS and TN conditions with 460 ppb dietary Se groups showing pronounced effects. Further, there was heat stress- and dietary Se level dependent- up regulation in hepatic GPx and iodothyronine deiodinase-II mRNA expression and similar pattern was noticed in hepatic thioredoxin reductase mRNA expression. The selenoprotein-P mRNA expression was up regulated in 460 ppb Se fed HS group as compared to CON and Se1_C groups. High dietary Se improved the humoral immune response 7d after antigen inoculation under HS conditions whereas cell-mediated immune response was augmented in rats fed higher Se under TN condition.

CONCLUSION

It is concluded that under prolonged heat stress conditions the dietary requirement of Se may be increased to 460 ppb for improving the antioxidant status and humoral immune response, cytokine levels, modulating the thyroid and insulin hormone, and the selenoproteins mRNA expression of rats.

Quantitative Proteomic Analysis Reveals Yeast Cell Wall Products Influence the Serum Proteome Composition of Broiler Chickens

With an ever-growing market and continual financial pressures associated with the prohibition of antibiotic growth promoters, the poultry industry has had to rapidly develop non-antibiotic alternatives to increase production yields. A possible alternative is yeast and its derivatives, such as the yeast cell wall (YCW), which have been proposed to confer selected beneficial effects on the host animal. Here, the effect of YCW supplementation on the broiler chicken was investigated using a quantitative proteomic strategy, whereby serum was obtained from three groups of broilers fed with distinct YCW-based Gut Health Products (GHP) or a control basal diet. Development of a novel reagent enabled application of ProteoMiner™ technology for sample preparation and subsequent comparative quantitative proteomic analysis revealed proteins which showed a significant change in abundance (n = 167 individual proteins; p < 0.05); as well as proteins which were uniquely identified (n = 52) in, or absent (n = 37) from, GHP-fed treatment groups versus controls. An average of 7.1% of proteins showed changes in abundance with GHP supplementation. Several effects of these GHPs including immunostimulation (via elevated complement protein detection), potential alterations in the oxidative status of the animal (e.g., glutathione peroxidase and catalase), stimulation of metabolic processes (e.g., differential abundance of glyceraldehyde-3-phosphate dehydrogenase), as well as evidence of a possible hepatoprotective effect (attenuated levels of serum α-glutathione s-transferase) by one GHP feed supplement, were observed. It is proposed that specific protein detection may be indicative of GHP efficacy to stimulate broiler immune status, i.e., may be biomarkers of GHP efficacy. In summary, this work has developed a novel technology for the preparation of high dynamic range proteomic samples for LC-MS/MS analysis, is part of the growing area of livestock proteomics and, importantly, provides evidential support for beneficial effects that GHP supplementation has on the broiler chicken.

The effects of chelated micro-elements feeding in broiler breeder hens and their progeny: A review

Micro-elements are essential for the optimal feeding of broiler hens. Since the chelated micro-elements negatively affect the content of micro- and macro-minerals, there has been a tendency to apply them as an alternative to common mineral forms of micro-elements in poultry diets. This paper reviews the effects of chelates of micro-elements (iron, copper, zinc, manganese, and selenium) on broiler breeder hens' internal and external egg quality and their egg products. The use of chelated micro-elements compared to the mineral forms does not have a significant effect on the performance of broiler breeder flocks, but they have significantly positive effects on the internal and external egg quality of broiler breeder flocks. The chelated micro-elements were also better than mineral resources of micro-elements in improving fertility (0.59%), hatchability (0.81%), and reducing mortality of progeny (2.25%). Chelated micro-elements have no negative impact on blood biochemistry or the immune system of broiler breeder hens and decrease cholesterol (0.84 mmol/l) and triglycerides (0.04 mmol/l) in most cases in comparison with the other mineral forms. Therefore, chelated forms of micro-elements instead of the inorganic mineral forms in diets of broiler breeder hens provide better protection for birds and the environment and also improve egg quality.

Use of zinc oxide nanoparticles in the growing rabbit diets to mitigate hot environmental conditions for sustainable production and improved meat quality

Background

This study evaluated the modulatory effects of zinc oxide nanoparticles (ZnO-NPs) supplementations on the productive performance, blood biochemistry, carcass criteria, and meat quality of White New Zealand rabbits reared under hot conditions. A total of 125 White New Zealand male rabbits (body weight, “650 ± 11”, 30 days old) were assigned to five treatment diets: basal diets supplemented with ZnO-NPs at 0, 20, 40, 60, or 80 mg/kg for 60 days. Each treatment was replicated 25 times with one rabbit each.

Results

The body weight (BW), BW gain, and feed intake linearly increased with zinc oxide nanoparticle supplements. Supplementation of ZnO-NPs at 20, 40, 60, and 80 mg/kg significantly improved (linear, P < 0.05) the feed conversion ratio compared to the control group. Moreover, supplementation of ZnO-NPs at these inclusions 20, 40, 60, and 80 mg/kg significantly (P < 0.05) decreased the serum cholesterol, alanine aminotransferase, and aspartate aminotransferase, creatinine, and urea compared to control group. The lipid oxidation was lower, and the water holding capacity of rabbit meat was improved (P < 0.001) in rabbits fed on 20, 40, 60, and 80 mg/kg ZnO-NPs supplemented diets compared to control.

Conclusion

The results suggested that dietary supplementation of ZnO-NPs (20–80 mg/kg) can mitigate the negative impacts of heat stress on rabbit performance and health. Its supplementation improved growth performance and meat physicochemical properties, and blood biochemistry parameters of White New Zealand rabbits.

Selenium and/or vitamin E upregulate the antioxidant gene expression and parameters in broilers

BACKGROUND

In contrast to free radicals, the first line of protection is assumed to be vitamin E and selenium. The present protocol was designed to assess the roles of vitamin E and/or a selenium-rich diet that affected the blood iron and copper concentrations, liver tissue antioxidant and lipid peroxidation, and gene expression linked to antioxidants in the liver tissue of broilers. The young birds were classified according to the dietary supplement into four groups; control, vitamin E (100 mg Vitamin/kg diet), selenium (0.3 mg sodium selenite/kg diet), and vitamin E pulse selenium (100 mg vitamin/kg diet with 0.3 mg sodium selenite/kg diet) group.

RESULTS

The results of this experiment suggested that the addition of vitamin E with selenium in the broiler diet significantly increased (P ≤ 0.05) serum iron when compared with the other groups and serum copper when compared with the vitamin E group. Moreover, the supplements (vitamin E or vitamin E with selenium) positively affected the enzymatic activity of the antioxidant-related enzymes with decreased malondialdehyde (MDA),which represents lipid peroxidation in broiler liver tissue. Moreover, the two supplements significantly upregulated genes expression related to antioxidants.

CONCLUSION

Therefore, vitamin E and/or selenium can not only act as exogenous antioxidants to prevent oxidative damage by scavenging free radicals and superoxide, but also act as gene regulators, regulating the expression of endogenous antioxidant enzymes.

Influence of in-ovo vitamin E and ascorbic acid injections on chick development, hatching performance and antioxidant content in different tissues of newly-hatched quail chicks

This study determined the influence of in ovo (IO) vitamin E and ascorbic acid injections on hatching performance, chick development, and antioxidant content of different tissues in day-old quail chicks. The experiment compared a control group (C: non-injection group) and injection groups, which had the yolk sac injected with 3.75 mg α- tocopherol (T1), or had the amniotic sac injected with 0.9% saline solution (T2), 2.5 mg ascorbic acid containing 0.9% saline solution (T3), and 2.5 mg ascorbic acid solution (T4), respectively.Mean relative asymmetry (RA) of bilateral lengths increased in the T2, T3 and T4 groups, whereas it decreased in the T1 group compared to C. The highest total carotene content in the residual yolk sac (RYS) was seen for the T1 group, which was significantly higher compared to T2, T3, and T4 groups. The highest total carotene concentration in liver was in the T1 group.The concentrations of delta-tocopherol, gamma-tocopherol and total vitamin E in RYS tissue were significantly higher in the T1 group than T2, T3, and T4 groups. Alpha-tocopherol and total vitamin E levels in the liver were significantly higher in the T2 and T4 groups than C.In ovo injections of vitamin E and ascorbic acid to different embryonic sacs caused antioxidant-specific effects on developmental stability of bilateral traits, RYS absorption, concentrations of total carotene and derivatives of vitamin E in newly-hatched quail chicks.

The Effect of Sargassum siliquastrum Supplementation on Growth Performance, Cecal Fermentation, Intestine Histomorphology, and Immune Response of Japanese Quails

This study aimed to investigate the dietary effects of Sargassum siliquastrum on the growth performance, nutrient digestibility, cecal fermentation, microbial populations, antioxidant status, immune response, and intestine histomorphology of Japanese quails. A total of 450 Japanese quails, aged 7 days, weighing 27.35 ± 0.23 g, were randomly distributed to three dietary groups in a 42-day feeding experiment. Five replicates were prepared per group, with each replicate consisting of 30 chicks in a cage. The three dietary groups consisted of a basal diet (0% supplementation, which was the control) and diets supplemented with 1% and 2% of S. siliquastrum. The results showed that the S. siliquastrum-supplemented groups and the control group had a similar final body weight (FBW), average body gain (ADG), and average feed intake (ADFI). However, the S. siliquastrum-supplemented groups had a better feed conversion ratio (FCR), as well as a lower mortality rate, compared to the control group. S. siliquastrum supplementation improved the nutrient digestibility of dry matter (DM), organic matter (OM), crude proteins (CP), and crude fibers (CF) (p < 0.05). The S. siliquastrum-supplemented groups exhibited the heaviest empty intestine and cecum weights, as well as the longest intestinal and cecal lengths. Furthermore, the total volatile fatty acids (TVFA) and the propionic acid concentrations increased significantly in quails fed S. siliquastrum-supplemented diets (p < 0.05), although the concentration of NH3-N decreased (p < 0.05). The dietary inclusion of S. siliquastrum had a beneficial effect on cecal microbial populations, where the Lactobacillus sp. counts increased, and the E. coli and Clostridium perfringens counts decreased. The histopathological examination of the duodenum confirmed that S. siliquastrum dietary supplementation enhanced the height and width of the villi. Quails fed S. siliquastrum-supplemented diet exhibited the highest total antioxidant capacity, superoxide dismutase, glutathione peroxidase, and glutathione reductase activities, but the thiobarbituric acid reactive substance was decreased (p < 0.05). Serum IgA, IgG, and IgM concentrations increased considerably (p < 0.05) in S. siliquastrum-supplemented groups. In conclusion, S. siliquastrum supplementation in the diet of Japanese quail can provide beneficial effects on performance, cecal fermentation, beneficial bacteria populations, and the immune response, and could be considered as an alternative feed additive in poultry production.

Application of Selenium Nanoparticles on Sperm Quantity Indicators in Wistar Rat

Background: Antioxidant enzymes and selenium in semen plasma have vital effects on reducing lipid peroxidation of spermatozoid membrane in elderly organisms by preventing the destructive effects of reactive oxygen species. Therefore, the use of antioxidants and selenium is essential for normal testicular function and spermatogenesis. Methods: In this experimental study, 44 male Wistar rats aged 2.5 months (young) and 44 male Winstar rats aged 11 months (old) were separated into 4 groups of control, placebo, experimental 1 (0.2 mg/kg BW), and experimental 2 (0.4 mg/kg BW). Rats encountered weekly surgery after a week of receiving different treatments. Resection of their testes was used for histological studies. Results: The number of spermatocytes, spermatid, and spermatozoa in young and old rats increased during the study period. In young rats, the highest number of these cells remarked in the third and fourth weeks of the experiment using selenium nanoparticles (ranged from 165.3 to 285.3 × 106). For old rates, the highest number of the abovementioned cells observed in the second week of the experiment (ranged from 143.3 to 146.7 × 106). Variables of treatment, week, and age presented significant effects on the number of testicular germ cells. Also, applied treatments had no significant effect on the sperm quality characteristics of rats. The number of Sertoli and Leydig cells did not show a significant difference compared to the control group. The results showed a positive and highly significant correlation between spermatozoid, spermatocytes, and spermatocytes. The findings also indicated the same genetic and environmental effects on the traits. Therefore, any spermatocyte shift will have a direct influence on the spermatozoid. Conclusions: This study demonstrated that using selenium nanoparticles in young and old age groups in rats could improve testicular germ cells, especially in the old group. Therefore, with growing age and decreasing sperm quality, selenium nanoparticles can be used due to their positive effect on sperm parameters and their low health risk.

Qualidade da carne de frangos da linhagem Label Rouge suplementados com minerais biocomplexados e criados em sistema alternativo

RESUMO Objetivou-se avaliar a influência da suplementação com minerais biocomplexados sobre a qualidade da carne de frangos da linhagem Label Rouge, de ambos os sexos, criados em sistema alternativo. O delineamento experimental foi inteiramente ao acaso (DIC), disposto em esquema fatorial (3x2), sendo três dietas (controle; 0,50ppm de selênio; 0,40ppm de cromo) e dois sexos. Para a estabilidade lipídica, foi utilizado o DIC, disposto em esquema fatorial (3x2x2), sendo três dietas, dois sexos e dois tempos de armazenamento (zero e 12 meses). Os parâmetros avaliados no peito e na coxa foram: pH final, cor (L* - luminosidade, a* - índice de vermelho, b* - índice de amarelo, C* - índice de saturação e h* - ângulo de tonalidade), perda de peso por cozimento (PPC), força de cisalhamento (FC) e estabilidade lipídica. Além disso, foram avaliadas a proporção das formas químicas da mioglobina da coxa e a quantificação do conteúdo de selênio no peito. Não houve efeito isolado da dieta sobre os parâmetros físicos e químicos do peito e da coxa e sobre a concentração de selênio no peito. As fêmeas apresentaram médias superiores de L* (57,57), b* (10,55) e C* (10,60) do peito; e os machos de L* (55,09) da coxa. Entre os machos, as aves alimentadas com a dieta controle e com cromo expressaram valores superiores de FC da coxa em relação às suplementadas com selênio; para o tratamento com cromo, os machos apresentaram média superior de FC da coxa e, em contrapartida, para o tratamento com selênio, as fêmeas manifestaram a maior média. As amostras submetidas ao período de 12 meses de armazenamento mostraram maiores valores de substâncias reativas ao ácido tiobarbitúrico (TBARS) em ambos os cortes. A suplementação com cromo e selênio biocomplexados não provocou alterações na qualidade da carne; as fêmeas demonstraram melhores atributos de qualidade da carne.

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).

The effect of selenium source on the oxidative status and performance of broilers reared at standard and high ambient temperatures

1. This study investigated the oxidative status of broilers fed diets containing selenium (Se) from 14 to 35 d of age and reared at two different constant temperatures. Measurements of oxidative status included blood glutathione peroxidase (GSH-Px) and plasma total antioxidant status (TAS). Other variables included feed intake (FI), weight gain (WG), feed conversion ratio (FCR), Se levels in breast and liver tissue, jejunal villus morphometry, percentage weight of organs in relation to body weight; apparent metabolisable energy adjusted for nitrogen (AMEn); dry matter retention (DMR); fat retention (FR) and nitrogen retention (NR).2. The experiment started at 14 d of age, when 240 birds were randomly allocated to 48 pens (12 pens in four rooms). Treatments included a control diet 1 (SFC; 209.4 g/kg CP and 12.98 MJ/kg ME and no added Se containing saturated fat); diet 2 (SFSe) the control plus 12.605 mg/kg Se additive; diet 3 (USFC) was a second control diet (208.2 g/kg CP and 13.10 MJ/kg ME with no added Se containing unsaturated fat as rapeseed oil); diet 4 (USFSe) was the latter control plus 12.605 mg/kg Se additive. Two rooms were kept at a standard temperature of 20°C (ST) and two rooms were kept at high temperature of 35°C (HT).3. A temperature x Se interaction existed for GSH-Px in birds reared at ST (P < 0.05), and these birds had the highest levels of Se in liver tissue (P < 0.05). Fat x Se interactions were evident in breast tissue with highest levels in USFSe (P < 0.05). Adding Se improved jejunal VH: CD in USFSe fed birds (P < 0.001).4. Birds reared at ST had higher FI and WG than those reared at HT (P < 0.001), and had lower FCR than those reared at HT (P < 0.05). AMEn (MJ/kg DM) and FR were higher in birds fed USF diets, and lowest in birds fed SF (P < 0.50 and P < 0.001 respectively). NR was highest in birds raised at ST (P < 0.50).5. Broiler growth performance was reduced by HT. Oxidative status and Se in liver tissue was improved by adding Se in both diets.

Mineral requirements in ducks: an update

Mineral nutrition plays a critical role in growth and bone mineralization in meat ducks as well as reproductive performance in duck layers and duck breeders. In addition to improving production performance parameters, minerals are also essential to support several enzymatic systems to enhancing antioxidant ability and immune function. This review explores the biological function and metabolism of minerals in the body, as well as mineral feeding strategy of various species of ducks. Topics range from mineral requirement to the physiological role of macroelements such as calcium and phosphorus and microelements such as zinc and selenium, etc. As with the improvement of genetic evolution and upgrade of rearing system in duck production, mineral requirements and electrolyte balance are urgent to be re-evaluated using sensitive biomarkers for the modern duck breed characterized by the rapid growth rate and inadequate bone development and mineralization. For duck breeders, mineral nutrition is not only required for maximal egg production performance but also for maintaining normal embryonic development and offspring's performance. Therefore, the proper amounts of bioavailable minerals need to be supplemented to maintain the mineral nutritional state of duck species during all phases of life. In addition, more positive effects of high doses microelements supplementations have been revealed for modern meat ducks subjected to various stresses in commercial production. The nutritional factors of mineral sources, supplemental enzymes, and antinutritional factors from unconventional ingredients should be emphasized to improve the effectiveness of mineral nutrition in duck feed formulation. Organic mineral sources and phytase enzymes have been adopted to reduce the antagonistic action between mineral and antinutritional factors. Therefore, special and accurate database of mineral requirements should be established for special genotypes of ducks under different rearing conditions, including rearing factors, environmental stresses and diets supplemented with organic sources, phytase and VD₃.

Assessment of Dietary Selenium and Vitamin E on Laying Performance and Quality Parameters of Fresh and Stored Eggs in Japanese Quails

The effect of dietary supplementation with VE and Se on the laying productive performance, immunity, and the quality parameters of fresh and stored eggs was assessed. For this study, five treatments, namely control (basal diet), control plus 30 mg of VE and 0.4 mg kg-1 sodium selenite (VE30SS), control plus 30 mg of VE and 0.4 mg kg-1 of Sel-Plex® (VE30SP), control plus 120 mg VE and 0.4 mg kg-1 Sodium selenite (VE120SS), and control plus 120 mg VE and 0.4 mg kg-1 Sel-Plex (VE120SP), were examined. There was no huge impact of VE and Se on feed consumption, FCR and egg yield rate. Quality parameters of fresh egg including egg surface area, eggshell thickness, yolk selenium concentration, albumen height, and Haugh unit were significantly increased following VE and Se supplementation (p < 0.05). For stored eggs, VE and Se significantly increased egg yolk color intensity (p < 0.05). Regardless of storage temperature, eggs from birds fed with VE and Se had less weight loss during 30 days of storage. Albumen height was significantly higher in VE and Se fed birds in eggs stored at 5 °C for 15 and 30 days. The combination of Sel-Plex with either levels of VE had significantly higher blood total antioxidant capacity. Dietary VE and Selenium, notably Sel-Plex, improved the antioxidant potential of blood and egg quality of laying quails.

Comparison of toxic effects of dietary organic or inorganic selenium and prediction of selenium intake and tissue selenium concentrations in broiler chickens using feather selenium concentrations

The present experiment aimed to compare toxic effects of dietary organic or inorganic selenium (Se) and to predict of Se intake and tissue Se concentrations in broiler chickens based on feather Se concentrations. A total of four hundred twenty 7-day-old Ross 308 male broiler chicks were allotted to 1 of 7 dietary treatments in a completely randomized design. Each treatment had 6 replicates with 10 birds per replicate. Organic Se (selenium yeast) or inorganic Se (sodium selenite) was added to the basal diet at the levels of 5, 10, or 15 mg/kg Se. All experimental diets were fed to birds on an ad libitum basis for 28 d. Results indicated that a significant interaction (P < 0.01) was observed between Se sources and inclusion levels for the BW gain and feed intake of broiler chickens with inorganic Se at 15 mg/kg in diets showing a greatest negative effect. Increasing inclusion levels of Se in diets increased (linear, P < 0.01) plasma concentrations of uric acid. Increasing inclusion levels of Se in diets increased (linear, P < 0.01) relative liver weight. No significant interactions were observed between Se sources and inclusion levels in diets on hepatic antioxidant capacity. Increasing inclusion levels of Se in diets increased (linear, P < 0.01) Se concentrations in the liver, breast, and feather. The concentrations of Se in the breast, liver, and feather were greater (P < 0.05) for organic Se than for inorganic Se in diets. The toxic levels of organic or inorganic Se in broiler diets were near 7 or 9 mg/kg based on the BW gain, respectively. The prediction equations indicate that feather Se concentrations in broiler chickens can be used to predict both daily Se intake and Se concentrations in the liver and breast.

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.

Dietary supplementation with selenium-enriched earthworm powder improves antioxidative ability and immunity of laying hens

Selenium (Se) has been recognized as an essential dietary nutrient for decades, and organic Se sources rather than inorganic ones are increasingly advocated as Se supplements. Earthworms have been studied as a feed additive and animal protein source for many yr. The aim of this study was to evaluate the effect of Se-enriched earthworm powder (SEP) on the antioxidative ability and immunity of laying hens. A total of 120 27-wk-old laying hens were randomly divided into 4 groups (30 hens per group). Laying hens were fed diets supplemented with SEP having 0, 0.5, or 1 mg/kg of Se or with earthworm powder alone. After 5 wk of supplementation, serum from the hens was tested for nutritional components (protein, globulin, albumin, triglycerides, total cholesterol, and glucose), antioxidative properties (glutathione peroxidase, superoxide dismutase, catalase, and nitric oxide), and immune responses (lysozymes, immunoglobulin G, IL-2, and interferon gamma). We found that SEP with 1.0 mg/kg of Se upregulated the hens' total protein, albumin, glutathione peroxidase, superoxide dismutase, IgG, and IL-2 and downregulated triglycerides, total cholesterol, glucose, and nitric oxide. These results indicate that SEP improves antioxidative levels and immune function of laying hens, indicating potential benefit from use of SEP as a feed additive in the poultry industry.

A Review of the Varied Uses of Macroalgae as Dietary Supplements in Selected Poultry with Special Reference to Laying Hen and Broiler Chickens

Seaweeds comprise ca. 12,000 species. Global annual harvest is ca. 30.13 million metric tonnes, (valued ca. $11.7 billion USD in 2016) for various commercial applications. The growing scope of seaweed-based applications in food, agricultural fertilizers, animal feed additives, pharmaceuticals, cosmetics and personal care is expected to boost market demand. Agriculture and animal feed applications held the second largest seaweed market share in 2017, and the combined market is anticipated to reach much higher values by 2024 due to the impacts of current research and development targeting enhanced animal health and productivity. In general, seaweeds have been utilized in animal feed as a rich source of carbohydrates, protein, minerals, vitamins and dietary fibers with relatively well-balanced amino acid profiles and a unique blend of bioactive compounds. Worldwide, the animal nutrition market is largely driven by rising demand for poultry feeds, which represents ca. 47% of the total consumption for all animal nutrition. This review provides an overview of the utilization of specific seaweeds as sustainable feed sources for poultry production, including a detailed survey of seaweed-supplemented diets on growth, performance, gastrointestinal flora, disease, immunity and overall health of laying/broiler hens. Anti-microbial effects of seaweeds are also discussed.

The effect of feeding different sources and levels of selenium on growth performance and antioxidant status of broilers raised at two different temperatures

1. This study examined the effects of different dietary sources and levels of selenium (Se) on growth performance, hepatic and breast meat Se content, glutathione peroxidase (GSH-Px) activity and total antioxidant status (TAS) in blood, when fed to broilers from 14 to 35 d of age and reared at two different temperatures (20°C and 35°C). 2. Five hundred and sixty male Ross 308 broilers were reared in a single floor pen and fed the same proprietary starter diet from 0 to 14 d age (229.9 g/kg CP and 12.67 MJ/kg ME, without Se supplementation). 3. The experiment started at 14 d age, and the birds randomly assigned to 112 raised-floor pens (0.36 m² area, 5 birds/pen). Each of the seven experimental diets were offered to birds in 16 pens within four rooms. Two rooms were at 20°C and two rooms were maintained at 35°C. The experimental diets were fed from 14 to 35 d age and contained 214.9 g/kg CP and 13.11 MJ/kg ME. The experimental diets were as follows; control diet containing background Se only (0.189 mg/kg; C); low level sodium selenite (0.376 mg/kg; LSS): high level sodium selenite (0.558 mg/kg; HSS); low level commercial B Traxim® Se (0.244 mg/kg) (LBT); high level B Traxim® Se (0.448 mg/kg; HBT); low level selenised yeast (0.290 mg/kg; LSY); high level selenised yeast (0.487 mg/kg; HSY). 4. Birds consumed more when raised at 20°C compared to birds reared at 35°C (P ≤ 0.05). Birds fed lower Se level reared at 35°C had higher weight gain versus those fed higher Se level (P < 0.05). Birds fed SY had the lowest feed intake, weight gain and FCE (P < 0.05). The greatest GSH-Px activity was observed in birds fed SS diets (P < 0.001). There were interactions between diet x level for TAS, which were highest in birds fed LBT compared to birds fed HBT (P < 0.05). Breast Se content was higher in birds fed HSY compared to LSY (P < 0.001). The highest hepatic Se was seen in birds fed SY and lowest in C (P < 0.001). 5. Birds fed BT diets showed similar levels of Se to those birds fed inorganic Se, and similar levels of GSH-Px to birds fed SY. Further comparative work with broilers fed BT and other Se supplemented diets may elucidate the findings from this report.

Nanoparticles of selenium as high bioavailable and non-toxic supplement alternatives for broiler chickens

Selenium is commonly used in the poultry industry as an additive in broiler feed to improve immunity and overall health. The selenium comes in different forms, inorganic and organic selenium, as sodium selenite and selenomethionine, respectively. This study proposes the use of nanoparticles of selenium (nanoSe) for improved delivery and absorption of the trace element while causing no toxicity. Previous studies have shown the success in utilizing nanoSe in broiler feed, with increased absorption and diffusion of material into organs and tissues, and increased antioxidant capacity. However, the mechanism of nanoSe conversion remains unknown, and the gut microbiota is believed to play a significant role in the process. The use of inorganic selenium in poultry feed demonstrated a lower bioavailability in breast (P ≤ 0.01) and duodenum tissue (P ≤ 0.05), and increased accumulation in organs involved in detoxification processes as compared to organic selenium and selenium nanoparticle supplementation. Histopathological analysis showed that nanoSe did not cause any damaging effects to the tissues analysed, revealing intact epithelial cells in the digestive system and neuronal bodies in brain tissue. The results indicate that nanoparticles of selenium operate a similar way to organic selenium and could potentially be used in poultry feed as a trace element additive.

Selenium-Rich Yeast Mitigates Aluminum-Mediated Testicular Toxicity by Blocking Oxidative Stress, Inhibiting NO Production, and Disturbing Ionic Homeostasis

Aluminum (Al) poisoning has been linked to the development of several reproductive system dysfunctions. Dietary supplementation with selenium-rich yeast (SeY) has been shown to prevent a variety of pathologic conditions. In the present study, the potential protect role of SeY on Al-induced testicular toxicity was evaluated, and the possible underlying mechanisms were discussed. Mice were treated with SeY (0.1 mg/kg) and/or Al (10 mg/kg) by oral gavage for 4 weeks. Histopathologic changes were observed in the testes of Al-treated mice. Oxidative stress, ionic disturbances, and the generation of NO systems are believed to have resulted in the observed pathology. Interestingly, SeY supplementation significantly inhibited the Al-induced histopathological and molecular changes and restored these indicators to levels observed in the control animals. These results suggest that SeY exerts a testis-protective effect against Al-induced toxicity through the reduction of oxidative stress, NO production, and the maintenance of ionic homeostasis.

Effects of Zn-L-Selenomethionine on Carcass Composition, Meat Characteristics, Fatty Acid Composition, Glutathione Peroxidase Activity, and Ribonucleotide Content in Broiler Chickens

The effects of organic Zn-L-selenomethionine (Zn-L-SeMet) at 0.3 ppm on carcass composition, meat characteristics, fatty acid composition, glutathione peroxidase activity, and ribonucleotide content were compared against the commercial inorganic sodium selenite (Na-Se) and the combination of the two, in commercial broilers. A total of 540 one day-old chicks were assigned at random to 3 dietary treatments : i) commercial inorganic selenium as control or T1, ii) a 1:1 ratio of inorganic and organic selenium as T2, and iii) organic selenium as T3. Carcass composition, meat characteristics, cholesterol content, fatty acid composition, and ribonucleotide content were generally unaffected by treatments. However, discrepancy were significantly observed in glutathione peroxidase activity (GSH-Px) and water holding capacity, with organic selenium showing higher glutathione peroxidase activity (p<0.01) and lower shrinkage loss (p<0.05), respectively. These findings could be explained by the contribution of organic selenium in bioavailability of GSH-Px. However, having conducted in a commercial close house system with sufficient amount of nutritional supplementation, the present study demonstrated little or no effects of organic Zn-L-SeMet on meat characteristics, fatty acid composition, and ribonucleotide content (flavor characteristic) in broiler chickens.

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 feeding different sources of selenium on growth performance and antioxidant status of broilers

1. This study was conducted to determine the effect of different sources of selenium (Se) on breast and liver tissue deposition, apparent metabolisable energy (AME), growth performance and antioxidant status of broilers, measured as Se content in liver and breast tissues and glutathione peroxidase (GSH-Px) in blood, when used in 0-35 d broiler chicken diets. 2. A total of 200 male Ross 308 broilers were used in the feeding trial, which comprised two dietary phases, a starter from 0 to 21 d and finisher from 21 to 35 d of age. Four treatments with 10 replications each were used. A control diet (C) was formulated that was sufficient in protein and energy (230 and 215 g/kg of crude protein and 12.67 and 13.11 MJ/kg of metabolisable energy, respectively), for both phases, but contained background Se only from the feed ingredients. Diet 2 (IS) was supplemented with 10.35 g/t inorganic, elemental source of Se. Diet 3 (SY) was supplemented with 136.36 g/t selenised yeast, an organic source derived from Saccharomyces cerevisiae. Diet 4 (SS) was supplemented with 0.666 g/t sodium selenite, an inorganic source. 3. Birds fed the SY diet consumed less and weighed less than those fed IS or C (P < 0.05; 0-35 d of age), but there was no difference compared to birds fed SS diets. There were no differences in FCR or dietary AME between broilers fed different Se sources. All diets containing supplementary Se increased concentrations in the liver and breast muscle, and for GSH-Px levels in blood compared to birds fed the C diet (P < 0.001). Birds fed SY diets had greater Se levels in liver and breast tissues compared to birds fed any of the other diets (P < 0.001). 4. Diets supplemented with Se had variable effects on broiler growth performances and antioxidant status. Feeding Se from a yeast source has higher transfer into breast tissues. Feeding different sources and levels of Se to birds in a more challenging situation to induce oxidative stress may bring more conclusive results.

Impacts of Strain Variation on Response to Heat Stress and Boldo Extract Supplementation to Broiler Chickens

Simple Summary

One of the common approaches to alleviating heat-stress in poultry is nutritional manipulation using herbal extracts or their derivatives to maintain the health, welfare, and performance of birds. The present study investigated the protective effect of boldo leaf extract against the harmful effects of cyclic heat stress in two broiler strains (Arbor Acres; AA and Avian-48; AV). Administration of boldo in drinking water was able to restore growth and health traits to nearly normal values. Generally, AA chicks were better able to withstand heat stress and were also more likely to utilize boldo extract than AV chicks. The use of boldo leaf extract in poultry production can assist in mitigating the effect of heat stress, improving the antioxidant defense system, and increasing productivity and profitability.

Abstract

There is increasing interest in the use of natural antioxidant supplements in poultry diets as protection against the adverse effects of heat stress. The potential protective effect of boldo (Peumus boldus molina) leaf extract, which have antioxidant activity, were investigated against the harmful effects of heat stress in two broiler strains. Arbor Acres (AA) and Avian-48 (AV) chicks were divided into thermoneutral (TN) and heat stress (HS) groups and treated with 1 g boldo leaf extract/4 L drinking water during the heat stress period. HS reduced growth performance in both strains. The phagocytic index, phagocytic activity, and eosinophil and lymphocytes counts were significantly elevated in TN and HS AV birds but not altered in AA birds. Boldo extract treatment partially eliminated the previous negative impacts of heat stress. AA chicks were better able to withstand HS than AV chicks. Serum concentrations of total lipids and cholesterol were reduced in HS birds of both strains. Malondialdehyde, superoxide dismutase, and glutathione peroxidase levels were elevated but restored with the administration of boldo leaf extract in HS birds of both strains. Economic parameters were negatively affected by HS but restored to values close to those of the control group in boldo-treated HS birds. In conclusion, the administration of boldo leaf extract in drinking water was effective in neutralizing the harmful effects of heat stress on growth performance, blood indices, and economic parameters and improved the antioxidant defense system in heat-stressed birds.

Effects of selenium source and level in diet on glutathione peroxidase activity, tissue selenium distribution, and growth performance in poultry

Today, a few differing sources of selenium (Se), i.e. inorganic, organic, and nano forms of Se, are used as feed supplements for poultry. Published research indicates that nano-Se and organic Se possess comparable efficiency to inorganic Se in increasing GSH-Px activity of plasma and various tissues, but they deposit at higher rates in various tissues. However, there are principal differences in absorption mechanisms, metabolism, and efficiency of these three forms of Se. The aim of this review was to analyze the available literature on the effects of different Se sources and levels in the diet on glutathione peroxidase (GSH-Px) activity, tissue Se distribution and growth performance in poultry. Higher levels of Se increase GSH-Px activity in the body, but this reaches a plateau even if Se concentrations in diet increase further, while the deposition of Se in tissues increases as Se content in diet increases. In addition, many studies have shown the positive effects of adding Se to diet on growth performance in poultry. Optimal Se supplementation is necessary not only for good poultry health but also to ensure and preserve meat quality during storage and to provide human beings with this microelement.

Selenoprotein-U (SelU) knockdown triggers autophagy through PI3K-Akt-mTOR pathway inhibition in rooster Sertoli cells

Selenium (Se) is a major component of male reproduction which exerts its effects via selenoproteins. Selenoprotein U (SelU), a newly identified protein, is expressed highly in eukaryotes and possesses a conserved motif similar to that existing in other thiol-dependent redox regulating selenoproteins; however its function is unknown. To investigate the role of SelU in testis autophagic and/or apoptosis cell death mechanisms, we established a Sertoli cell (SC) model isolated from 45 day old layer roosters. Small interfering RNA (siRNA) technology was used to develop SelU-knockdown (SelU-KD) and normal (N) SC models. Consequent to transfection, electron microscopy, qPCR, and western blot were performed. The results show that the mRNA and proteins of autophagy and anti-apoptosis genes increased while that of anti-autophagic mammalian target of rapamycin (mTOR) and pro-apoptosis genes decreased significantly in SelU-KD in contrast to N cells. Simultaneously, in contrast to N cells the expression of phosphoinositide-3-kinase (PI3K) and protein kinase B (PKB/Akt) both at the mRNA and protein levels decreased significantly in SelU-KD cells. In-addition, SelU depletion altered the expression of regulatory factors and increased the mRNA of TSC (tuberous sclerosis complex) genes as compared to N cells. Extensive autophagosome formation and lysosome degradation with an intact cytoskeleton were observed in SelU-KD cells. Our data indicate that SelU deprivation elicits autophagy and reduces the expression of important growth factors in SCs by disrupting the PI3K-Akt-mTOR signaling pathway. However SelU attenuation did not induce apoptosis in rooster SCs. Taken together, we conclude that SelU is essential for the survival and normal functioning of SCs.

Glutathione as an antioxidant marker: determination of glutathione concentration in the breast muscles and liver of broilers supplemented with different selenium sources

The aim of the study was to determine the influence of different selenium sources on antioxidant properties. The glutathione (GSH) concentration and glutathione peroxidase (GPx) activity were measured in the breast muscles and liver of 60 one-day-old broiler chickens. Another goal was to compare these indices with the weights of individual tissues and the live weight of broilers. The broilers were divided into 4 groups according to the selenium source: group 1 (control), group 2 (selenized yeast), group 3 (selenomethionine), group 4 (sodium selenite). Treatment groups were supplemented with 0.2 mg of additional selenium/kg. No significant changes in the hepatic GSH concentrations (P> 0.05) were found in the experimental groups compared to control. Significantly higher GSH concentration (P< 0.05) was found in breast muscles of broilers in group 4 (sodium selenite) compared to control. However, no positive effect of selenium supplementation in the form of sodium selenite was observed. The differences in the GPx activity in breast muscles and liver between the experimental groups and the control group were not significant (P> 0.05). No significant differences were recorded in the experimental groups compared to control in relation to the GSH concentration and GPx activity measured in the tissues. A significantly positive correlation was noted between mean GPx activity in breast muscle and breast muscle weight (P< 0.01; r = 0.3790) and live weight (P< 0.05; r = 0.2690). Although changes in the GSH concentration and GPx activity were recorded in some experimental groups, the selected dose of additional selenium appeared to be too low to affect these concentrations and the antioxidant defence system.

Relative bioavailability of ultrafine sodium selenite for broilers fed a conventional corn-soybean meal diet

The particle size of selenium (Se) sources could affect Se absorption and utilization, and thus it is hypothesized that the Se bioavailability might be higher in ultrafine sodium selenite (USSe) than in sodium selenite (SSe) for broilers because of USSe's smaller particle size. An experiment was conducted to investigate the relative bioavailability of Se as USSe relative to SSe for broiler chicks fed a conventional corn-soybean meal diet. A total of 504 one-d-old Arbor Acres commercial male broilers were randomly allotted to 1 of 7 treatments with 6 replicates per treatment in a completely randomized design involving in a 2 (Se sources) × 3 (added Se levels) factorial arrangement of treatments plus a Se-unsupplemented control diet containing 0.05 mg Se/kg by analysis for 21 d. The 2 Se sources were USSe and SSe, and the 3 added Se levels were 0.15, 0.30, or 0.45 mg Se/kg. The Se concentrations, glutathione peroxidase (GSH-Px) activities, and mRNA relative abundances in plasma, liver, or pancreas of broilers on day 14 and 21 were determined. The results showed that Se concentrations, GSH-Px activities in plasma, liver, and pancreas, and mRNA relative abundances in the liver and pancreas of broilers on day 14 and 21 increased linearly (P < 0.05) as the added Se-level increased. Furthermore, a difference (P < 0.05) between USSe and SSe was detected for GSH-Px mRNA relative abundance in the pancreas of broilers on day 14. On the basis of the slope ratios from the multiple linear regression of the pancreatic GSH-Px mRNA relative abundance of broilers at 14 d of age on daily dietary analyzed Se intake, the Se bioavailability of USSe relative to SSe (100%) was 158% (P < 0.05). The results from this study indicated that the Se from USSe was more available to broilers than the Se from SSe in enhancing the pancreatic GSH-Px mRNA expression.

Long-Term Supplementation of Laying Hen Diets with Various Selenium Sources as a Method for the Fortification of Eggs with Selenium

The following study focuses on a comparison of the effectiveness of egg content enrichment with selenium (Se) via application of sodium selenite (Na-selenite), selenium-enriched yeast (Se-Yeast), or selenomethionine (Se-Met) in laying hen diets. Two hundred sixteen laying hens were divided into four treatments, each comprising eighteen replications, and each with three hens per cage. Animals were fed a basal diet without Se supplementation (control: selenium content 0.058 mg/kg), with the addition of Na-selenite, Se-Yeast, or Se-Met in amounts equivalent to 0.3 mg/kg of added selenium. The egg quality, the selenium content in eggs after the third and the fifth months of using Se supplementation, and the selenium level in the liver were determined. Enrichment of egg content with selenium was the most effective (382 μg/kg) via application of dietary Se-Met. Application of Na-selenite and Se-Yeast led to a similar effect on Se-accretion in egg content (255.9 and 258.9 μg/kg, respectively). Additionally, the calculated average Se concentration in one fresh egg was also higher in eggs from hens that received selenium additives in their diet and was far higher, almost three times higher for Se-Met addition, than the concentrations in controls. Se-accretion in the liver wet tissue was greater following application of Se-Yeast in the diet than following other treatments. These results indicate that the use of selenomethionine in the laying hen diet is the best method of enriching eggs with this micronutrient. In turn, the eggs obtained in this way can be an excellent source of highly bioavailable selenium in the human diet.

The effects of dietary Selenium-yeast level on glutathione peroxidase activity, tissue Selenium content, growth performance, and carcass and meat quality of broilers

The present study was conducted to assess effects of selenium (Se)-yeast supplementation on glutathione peroxidase activity, Se levels in tissues, growth performance, carcass, and meat composition in broilers. A total of 275 one-d-old Cobb 500 broilers of both sexes were randomly allotted to 1 of 5 treatments during a 42-d period. The 5 treatments differed only in Se content: group 1 had no additional Se (background only); groups 2, 3, and 4 received 0.3 mg/kg of added Se from the beginning of the trial until d 21, whereas in the second half of the study (from d 22 to 42), these groups received 0.3, 0.6, and 0.9 mg/kg of added Se, respectively; and group 5 received 0.9 mg/kg of Se for the entire experimental period. At the end of the study, the control group showed significantly lower (P < 0.01) glutathione peroxidase activity in blood plasma compared to Se-supplemented groups. Regarding Se concentration in various tissues, the groups receiving Se yeast showed higher plasma, feces, and meat Se contents than the control group (P < 0.01). Supplementation of Se improved broilers' body weight, weight gain and feed conversion ratio (P < 0.01). Dressing percentage was lower in the control group and the group with 0.3 mg/kg of added Se compared to other experimental groups (0.6 and 0.9 mg/kg of dietary Se). The proportion of less valuable carcass parts (wings and legs) was higher (P < 0.01) in the group fed the basal diet compared to groups supplemented with 0.9 mg/kg of Se. Initial and ultimate pH values differed among experimental groups (P < 0.05). Supplementation of Se improved the broiler's antioxidative resistance, growth performance, carcass quality, and chemical composition of meat.

Review on docosahexaenoic acid in poultry and swine nutrition: Consequence of enriched animal products on performance and health characteristics

Omega-3 polyunsaturated fatty acids (n-3 PUFA) are linked to a variety of health benefits against human disorders and disease. However, the typical western diet is generally low in n-3 PUFA and high in n-6 PUFA, suggesting that the recommended intake of these essential fatty acids is seldom achieved. Therefore, dietary enrichment of animal meat and eggs with n-3 PUFA could help increase consumption of these fatty acids. Fish oils and microalgae (MA) are rich sources of long chain n-3 PUFA, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Feeding these marine products has been shown to increase DHA content of tissues and yolk, however, this may also lead to an increased requirement for anti-oxidants to prevent oxidative deterioration and associated negative sensory attributes. Nonetheless, increased DHA has been linked to promising results in animal growth, fertility, immunity and bone strength in both pigs and poultry. These findings suggest that feeding DHA-rich ingredients to mono-gastric can enrich human diets as well as providing additional benefits to the animal.

Effect of sodium selenite and selenium yeast on performance, egg quality, antioxidant capacity, and selenium deposition of laying hens

This study compared the effects of sodium selenite and selenium yeast and their combination on laying performance, egg quality, antioxidant capacity, and selenium (Se) contents in tissues and eggs. Two-hundred-eighty-eight Jing Hong layers that were similar in laying rate (87.5 ± 0.38%) and body weight (1.70 ± 0.02 kg) were randomly distributed into 4 treatments for 11 wk (from 203 d old to 279 d old) with 9 replicates of 8 hens per replicate. The diets (corn-soybean meal diet) were supplemented with 0 [blank control (BC)], 0.3 mg/kg Se from sodium selenite (SS), 0.15 mg/kg Se from sodium selenite and 0.15 mg/kg Se from Se yeast (SS+SY), or 0.3 mg/kg Se from Se yeast (SY). Results showed that the laying rate of the SS+SY group increased significantly (P < 0.05) compared to the BC and SY groups. There were no differences (P > 0.05) in egg quality between the Se-supplemented diets and the BC diet. The serum glutathione peroxidase (GSH-Px) activity was increased (P < 0.01) in hens fed Se-supplemented diets compared to the BC diet. The liver superoxide dismutase (SOD) activity of the SY group was increased significantly (P < 0.05) compared to the BC group. Significant increase (P < 0.01) due to SY supplementation was noted in the serum vitamin E content compared to BC and SS. Layers fed Se-supplemented diets had higher (P < 0.01) contents of Se in the serum, liver, and kidney compared to the BC diet. Compared to BC, Se content in eggs was significantly increased (P < 0.05) by feeding supplementary Se. In conclusion, the effects of SS and Se yeast were approximately equal in promoting antioxidant capacity of laying hens, while Se yeast is easier to deposit into eggs and tissues. The diet with added equal amounts of the 2 sources of Se was more cost effective and affordable than a comparable amount of Se yeast to obtain the promising production performance and nearly similar Se deposition.

Combined effects of retinol, ascorbic acid and α-tocopherol on diurnal variations in rectal temperature of Black Harco pullets subjected to heat stress

The experiment was performed with the aim of determining the effect of co-administration of antioxidant vitamins, retinol, ascorbic acid and α-tocopherol on rectal temperature (RT) fluctuations in pullets during the hot-dry season in Nigeria. Forty-eight Black Harco pullets, aged 16 weeks and weighing 1.5 ± 0.03 kg were divided by simple random sampling into two groups, consisting of 28 treated and 20 control Black Harco pullets. The RTs of 28 treated and 20 control Black Harco pullets were measured hourly for 3 days, 3 days apart, from 06:00 to 19:00 h (GMT + 1) with a standard clinical thermometer. The treated pullets were administered individually with the vitamins orally in water, while the control pullets were given only water. The lowest hourly RT of 40.9 ± 0.04 °C was obtained in treated pullets at 06:00 h, while the highest value of 41.1 ± 0.01 °C was recorded from 17:00 to 19:00 h (P < 0.001). In control pullets, the RT rose significantly from 41.0 ± 0.03 °C at 06:00 h to the maximum value of 41.6 ± 0.04 °C at 15:00 h (P < 0.001). The pullets co-administered with retinol, ascorbic acid and α-tocopherol had consistently lower RT values than those of control pullets, especially during the hot hours of the day, from 13:00 to 17:00 h. It is concluded that co-administration of retinol, ascorbic acid and α-tocopherol, by preventing a rise in body temperature, ameliorated heat stress, and may enhance productivity of pullets reared under unfavourable, thermal environment conditions.

Levels of supplementation of inorganic selenium and vitamin E for meat quail aged 0 to 14 and 14 to 35 days

Two experiments were carried out to determine the levels of supplementation of inorganic selenium (Se) and vitamin E (VE) in diets of quails aged 0-14 and 14-35 days old. A completely randomized design was used in a factorial design (Se = 0.1125; 0.2250; 0.3375 and 0.4500 mg kg^-1  diet^-1  × VE = 10; 23; 36 and 49 IU kg^-1  diet^-1 ). In experiment 1, quail (n = 2,400) were aged 0-14 days and were divided into 16 treatments, with three replicates of 50 birds. In experiment 2, quail (n = 1,680) were aged 14-35 days and were divided into the same treatments, with three replicates of 35 birds. At age 0-14 days, the levels of VE did not affect performance (p > .05); however, the feed conversion (FC) was influenced by a quadratic effect (p = .0515), according to the level of Se, with a higher level estimated at 0.29 mg Se kg^-1  diet^-1 . At age 14-35 days, there was a linear effect with interaction (Se × VE), for FC (p = .0150) and weight gain (WG; p = .0266). FC (Se, p = .0048 and VE, p = .0019) and WG (Se, p = .0049 and VE, p = .0068) improved linearly with increasing levels of Se and VE. The feed intake (FI) decreased linearly (p = .0582) as a function of VE. The carcass yield showed a quadratic effect (p = .0056) on the levels of VE, with a higher yield estimation of 27.24 IU VE/kg of diet. It can be concluded that the optimum level of supplementation at age 0-14 days was 0.29 mg Se kg^-1  diet^-1 and 10 IU VE kg^-1  diet^-1 and at age 14-35 days, it was 0.4500 mg Se kg^-1  diet^-1 and 49 IU of VE kg^-1  diet^-1 .

The role of the antioxidant system during intense endurance exercise: lessons from migrating birds

During migration, birds substantially increase their metabolic rate and burn fats as fuel and yet somehow avoid succumbing to overwhelming oxidative damage. The physiological means by which vertebrates such as migrating birds can counteract an increased production of reactive species (RS) are rather limited: they can upregulate their endogenous antioxidant system and/or consume dietary antioxidants (prophylactically or therapeutically). Thus, birds can alter different components of their antioxidant system to respond to the demands of long-duration flights, but much remains to be discovered about the complexities of RS production and antioxidant protection throughout migration. Here, we use bird migration as an example to discuss how RS are produced during endurance exercise and how the complex antioxidant system can protect against cellular damage caused by RS. Understanding how a bird's antioxidant system responds during migration can lend insights into how antioxidants protect birds during other life-history stages when metabolic rate may be high, and how antioxidants protect other vertebrates from oxidative damage during endurance exercise.

Aflatoxin B1 Induced Systemic Toxicity in Poultry and Rescue Effects of Selenium and Zinc

Among many challenges, exposure to aflatoxins, particularly aflatoxin B₁ (AFB₁), is one of the major concerns in poultry industry. AFB₁ intoxication results in decreased meat/egg production, hepatotoxicity, nephrotoxicity, disturbance in gastrointestinal tract (GIT) and reproduction, immune suppression, and increased disease susceptibility. Selenium (Se) and zinc (Zn), in dietary supplementation, offer easy, cost-effective, and efficient ways to neutralize the toxic effect of AFB₁. In the current review, we discussed the impact of AFB₁ on poultry industry, its biotransformation, and organ-specific noxious effects, along with the action mechanism of AFB₁-induced toxicity. Moreover, we explained the biological and detoxifying roles of Se and Zn in avian species as well as the protection mechanism of these two trace elements. Ultimately, we discussed the use of Se and Zn supplementation against AFB₁-induced toxicity in poultry birds.

Interplay between autophagy and apoptosis in selenium deficient cardiomyocytes in chicken

Dietary selenium (Se) deficiency can cause heart dysfunction, however the exact mechanism remains unclear. To understand this mechanism, 180day-old chicks, divided into two groups, C (control group) and L (low Se group), were fed with either a Se-sufficient (0.23mg/kg) or Se-deficient (0.033mg/kg) diets for 25days, respectively. Heart tissues and blood samples were collected. In L group, the activities of serum creatine kinase (CK) and creatine kinase-myoglobin (CK-MB) increased and typical ultrastructural apoptotic features were observed. Se deficiency up-regulated the mRNA levels of Cysteinyl aspartate specific proteinase 3 (Caspase-3), Cysteinyl aspartate specific proteinase 8 (Caspase-8), Cysteinyl aspartate specific proteinase 9 (Caspase-9), B cell lymphoma/leukemia 2 (Bcl-2), Bcl-2 Associated X Protein (Bax), (P<0.05), whereas, the mRNA levels of Microtubuleassociated protein light chains 3-1 (LC3-1), Autophagy associated gene 5 (ATG-5), Mammalian target of rapamycin (mTOR), Dynein and Becline-1 were down-regulated (P<0.05). Noticeably, Microtubuleassociated protein light chains 3-2 (LC3-2) mRNA level increased (P<0.05) by 20%. Western blot results showed that Se deficiency decreased the expression of Becline-1 and LC3-1 protein, however, the expression of Bax, Caspase-3 and Cysteinyl aspartate specific proteinase 12 (Caspase-12) increased at protein levels. The present study revealed that Se deficiency induced apoptosis while inhibited autophagy in chicken cardiomyocytes through Bax/Bcl-2 inhibition and caspases-mediated cleavage of Becline-1. Moreover, correlation analysis illustrates that apoptosis and autophagy might function contradictorily. Altogether we conclude that Se deficient chicken cardiomyocytes experienced apoptosis rather than autophagy which is considered to be more pro-survival.