The selenium intake of the female chicken influences the selenium status of her progeny

Maternal dietary supplementation with grape seed extract in reproductive hens increases fertility in females but decreases semen quality in males of the F1 generation

Genetic selection in parental broiler breeders has increased their susceptibility to metabolic disorders and reproductive dysfunction. We have recently shown that maternal dietary grape seed extract (GSE) supplementation in hens improves fertility parameters, egg quality, oxidative stress in different tissues and the quality of F1 chicks. Here, we analysed the growth and fertility (both female and male) of the F1 generation animals and the quality of their offspring (F2 generation). Eggs issued from hens supplemented with GSE presented lower ROS production than control hens, suggesting a change in the embryonic environment. However, this did not affect the growth nor the body composition of male and female F1s from hatching to adulthood (37 weeks of age). At 37 weeks of age, the biochemistry analysis of the GSE-F1 muscle has revealed an increase in sensitivity to oxidative stress and a slight change in lipid composition. Both male and female F1-GSE groups presented a delay in puberty with a lower testis volume at 30 weeks of age and lower ovary development at 26 weeks of age. Adult GSE-F1 males did not present histological alterations of seminiferous tubules or semen production, but the semen quality was degraded due to higher oxidative stress and DNA-damaged spermatozoa compared with control F1 animals. In adult GSE-F1 females, despite the delay in puberty, the females laid more eggs of better quality (fewer broken eggs and a higher hatching rate). At hatching, the weight of the chicks from GSE-F1 females was reduced, and this effect was stronger in F2 male chicks (F2) compared with F2 control chicks (F2), because of the lower muscle volume. In conclusion, we can raise the hypothesis that maternal dietary GSE supplementation produces eggs with change in embryonic metabolism, which may affect in adulthood the fertility. The data obtained from the F1-GSE group pointed to a sex-specific modification with higher egg quality in females but semen sensitive to stress in males. Finally, male F2 chicks were leaner than control chicks. Thus, maternal dietary grape seed extract (GSE) supplementation in hens may impact on the fertility of the offspring in a sex-specific manner in subsequent generations.

Effects of dietary supplementation with vitamin E, selenium yeast or both on egg incubation response, embryonic development, keet quality, and posthatch growth of helmeted guinea fowl breeders

This study investigated the effects of dietary supplementation with vitamin E (vit. E), selenium yeast (Se yeast), or both on egg incubation response, embryonic development, keet quality, and posthatch growth of helmeted guinea fowls. Two hundred and forty 24-week old helmeted guinea fowl hens (average weight 1.75 + 0.22 kg) and cocks (average weight 2.15 + 0.20 kg) were assigned into 24 pens; each pen housed 10 hens and 2 cocks. There were four dietary treatments consisting of a basal diet (control), basal diet supplemented with vit. E (30 IU/kg), Se yeast (0.3 mg/kg Se), or both. Six pens were assigned to each treatment. Egg incubation response were estimated using 504 settable eggs sampled from each treatment collected during 15 to 17 weeks in lay. A total of 72 fertile eggs sampled from each treatment were used for the estimation of embryonic development. Quality of day-old keets hatched was scored based on physical conditions, while posthatch growth was measured for 21 days. Guinea fowl breeders fed diet supplemented with both vit. E and Se yeast produced the highest (P < 0.05) number of fertile eggs, percentage fertility, number of hatchlings, hatchability of total eggs, and hatchability of fertile eggs. Supplementation with vit. E + Se yeast resulted in the heaviest (P < 0.05) embryo weight, relative embryo weight, least (P < 0.05) yolk sac weight, and relative yolk sac weight on 25 days of incubation. Hatchlings from breeders fed diet supplemented with Se yeast and vit. E + Se yeast showed normal swallowed yolk. Supplementation of maternal diet with vit. E, Se yeast, and vit. E + Se yeast resulted in improved (P < 0.05) feed conversion ratio of subsequent hatchlings during 1 to 7-day posthatch growth. It can be concluded that dietary supplementation of vit. E + Se yeast in guinea fowl breeders resulted in improved egg fertility, hatchability, heavier embryo weights, hatchlings of good quality, and improved posthatch growth during the first 7 days.

Laying performance, immune response, serum biochemical parameters and egg quality traits of female turkeys fed diet incorporated with organic selenium

An experiment was conducted to investigate the effects of organic selenium (Se) supplementation on laying performance, immune response, serum biochemical parameters and egg quality traits of female turkeys. Female turkeys (96; 16 wks old) were randomly distributed into 4 treatment groups with 4 replicates and 6 birds each (4 × 4 × 6) for a period of 24 weeks. The basal diet (T1) contained 0 mg Se/kg diet and the three experimental diets were supplemented with 0.2, 0.4 and 0.6 mg Se/kg diet (T2, T3 and T4 respectively). Age at sexual maturity, egg number and egg weight differed significantly in 0.4 mg Se/kg treated group (T3) than the other dietary treatment groups (T2 or T4). Humoral (29th weeks) and in vivo cell mediated immune response (30th weeks) were significantly improved in 0.4 or 0.6 mg Se treated group. Se supplemented groups, i.e. T3 and T4 decreased significantly in serum cholesterol and uric acid concentration whereas significant increase were recorded in total protein, albumin and alkaline phosphatase (ALP). No significant differences were observed in serum aspartate amino transferase (AST) and alanine amino transferase (ALT) concentration among the experimental groups. Egg quality traits, viz. shape, albumin and yolk index, shell thickness did not differ significantly among Se supplemented groups, whereas albumin and yolk weight and Haugh unit score were significantly higher in 0.4 mg Se/kg treated (T3) group. Thus, this study demonstrates that that dietary supplementation of 0.4 mg/Se kg diet has a beneficial effect on laying performance, immune responses, serum biochemical and egg quality traits in laying turkeys.

Nutritional modulation of the antioxidant capacities in poultry: the case of selenium

Natural antioxidants play important roles in maintaining chicken health, productive and reproductive performance of breeders, layers, rearing birds, and growing broilers. There is a wide range of antioxidant molecules in the body: vitamin E, carotenoids, selenium, ascorbic acid, coenzyme Q, carnitine, taurine, antioxidant enzymes, etc. In the body all antioxidants work together to create the antioxidant network called "antioxidant systems" with Se being the "chief-executive." Analysis of the current data on selenium roles in antioxidant defenses in poultry clearly showed its modulatory effect at the level of breeders, developing embryos, newly hatched chicks, and postnatal chickens. On the one hand, Se is involved in the expression and synthesis of 25 selenoproteins, including GSH-Px, TrxR, and SepP. On the other hand, Se affects non-enzymatic (vitamin E, CoQ, and GSH) and enzymatic (SOD) antioxidant defense mechanisms helping build strong antioxidant defenses. Se efficiency depends on the level of supplementation and form of dietary Se, organic Se sources being more effective modulators of the antioxidant systems in poultry than sodium selenite. Moreover, Se levels in eggs from some wild avian species are close to those found in chicken eggs after 0.3 ppm organic Se supplementation and a search for most effective dietary form of organic Se is a priority in poultry nutrition. Antioxidant/prooxidant (redox) balance of the gut and the role/interactions of Se and microbiota in maintaining gut health would be a priority for future poultry research.

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.

EFFECT OF ANTIOXIDANT SUPPLEMENTATION IN DIETS OF ROOSTERS DURING THE POST-PEAK PHASE ON REPRODUCTION AND PRODUCTION CHARACTERISTICS OF OFFSPRING

Abstract This study aimed to evaluate the effects of antioxidant supplementation in diets of breeding roosters during the post-peak phase on reproduction characteristics and muscle performance of offspring in two similar breeder houses from a local company. Treatments consisted of a control diet and a diet supplemented with antioxidants (8 ppm canthaxanthin + 40 ppm lycopene + 150 ppm vitamin C). During the 66th week of age, eggs were incubated, and offspring were housed. Dietary supplementation of the blend of antioxidant resulted in higher (p<0.05) weights of testicles, crests, dewlaps, dewlap thickness, and number of perforations (53.35 x 25.30) in relation to non-supplemented roosters. There was no significant effect (p>0.05) of supplementation of the antioxidant blend on weight gain and breast weight and count and diameter of muscle fibers of offspring at 7 days of age. Feed conversion and weight gain from 14 to 35 days were better (p<0.05) in offspring from supplemented roosters. The supplementation of an antioxidant blend in roosters improved reproductive characteristics assessed and feed conversion and weight gain of offspring.

Maternal Selenium Supplementation Enhanced Skeletal Muscle Development Through Increasing Protein Synthesis and SelW mRNA Levels of their Offspring

The present study aimed to investigate the influence of maternal selenium supplementation on the skeletal muscle development of the offspring. A total of 720 Ross 308 broiler breeders at 24-week-old were allocated into 3 treatments with 6 replicates of 40 hens each and fed with 0 mg/kg-(group Se/C), 0.5 mg/kg organic-(group Se/O), and 0.5 mg/kg inorganic-(group Se/I) selenium, respectively for 8 weeks. The male offspring from each nutritional treatment were divided and housed into 8 cages of 12 birds each and fed with a commercial diet supplemented with selenium from Na₂SeO₃ at 0.15 mg/kg. Results showed that Se/O group had the highest selenium deposition (P < 0.05) in the egg yolk and albumen. Furthermore, maternal selenium supplementation promoted breast muscle yield; increased serum insulin and IGF-I concentration; upregulated AKT, mammalian target of rapamycin (mTOR), P70S6K, Myf5, MyoD, MyoG, and SelW mRNA levels; and improved the phosphorylation of AKT at Serine 473 residue, mTOR at Serine 2448 residue, and FOXO at Serine 256 residue in skeletal muscles of the offspring. In contrast, the hens' diet supplemented with selenium could result in reduction of uric acid level in serum and downregulation of Atrogin-1 and MuRF1 mRNA levels in the skeletal muscle of the offspring. Additionally, no significant effect on the skeletal muscle development post-hatch was observed between organic and inorganic selenium supplementation. In conclusion, maternal organic selenium supplementation improved selenium deposition in egg; however, no significant effect has been detected on the breast muscle development of the offspring of broiler breeder compared with inorganic selenium supplementation.

Effects of Maternal Zinc Glycine on Mortality, Zinc Concentration, and Antioxidant Status in a Developing Embryo and 1-Day-Old Chick

This study was conducted to investigate the effects of maternal zinc glycine (Zn-Gly) supplementation as an alternative for zinc sulfate (ZnSO₄) on mortality, zinc (Zn) concentration, and antioxidant status in a developing embryo and 1-day-old chick. Six hundred 39-week-old broiler breeders were randomly assigned to 6 treatments, each treatment including 5 replicates with 20 birds each. Six treatments received a basal diet (control, 24 mg Zn/kg diet) or a basal diet supplemented with ZnSO₄ (80 mg Zn/kg) or Zn-Gly (20, 40, 60, or 80 mg Zn/kg), respectively. The experiment lasted for 8 weeks after a 4-week pre-experiment with a basal diet. At the last week, 100 eggs per replicate were randomly collected for incubation. Compared with the control treatment, Zn supplementation decreased (P < 0.05) embryo mortalities of the late stage and the whole period, increased (P < 0.05) liver Zn concentration in the embryo of d9, d19, and 1-day-old chick, and improved (P < 0.05) antioxidant status in the embryo of d19 and 1-day-old chick. Compared with the ZnSO₄ treatment, 80 mg Zn/kg Zn-Gly treatment significantly decreased (P < 0.05) the late stage embryo mortality and increased (P < 0.05) liver Zn concentration in the embryo of d9, d19, and 1-day-old chick. The 80 mg Zn/kg Zn-Gly treatment significantly increased (P < 0.05) copper-zinc superoxide dismutase activity in d19 embryo and 1-day-old chick, total superoxide dismutase activity in 1-day-old chick, and copper-zinc superoxide dismutase messenger RNA (mRNA) abundance of d9 embryo and 1-day-old chick than that in ZnSO₄ treatment. The liver metallothionein concentration of the developing embryo and 1-day-old chick and its mRNA abundance of d19 embryo were also significantly increased (P < 0.05) in the 80 mg Zn/kg Zn-Gly treatment in comparison with ZnSO₄ treatment. In conclusion, maternal Zn supplementation decreased embryo mortalities of the late stage and the whole period by increasing liver Zn concentration and antioxidant status in d19 embryo and 1-day-old chick, and 80 mg Zn/kg from Zn-Gly treatment was the optimum choice.

Selenium in Poultry Nutrition: from Sodium Selenite to Organic Selenium Sources

Selenium (Se) is an essential element in poultry nutrition and its bio-efficacy depends on its chemical form. A growing body of research proves that organic forms of Se, mainly selenomethionine (SeMet), in poultry diets have a range of important advantages over traditional sodium selenite. In fact, the organic Se concept considers SeMet as a storage form of Se in the chicken body. As chickens are not able to synthesize SeMet, its provision through diet is a key strategy to fight commercially relevant stresses. Indeed, in stress conditions, when increased selenoprotein expression requires additional Se, while its provision via feed usually decreases due to a reduction in feed consumption, Se reserves in the body (mainly in the muscles) could help maintain an effective antioxidant defense and prevent detrimental consequences of stresses. The poultry industry is looking for the most effective sources of organic Se for commercial use. In this review, advantages and disadvantages of main organic Se sources for poultry (Se-yeast, SeMet, and OH-SeMet) are analyzed, and future directions for the development of new Se sources are identified.

A comparison of fat-soluble antioxidants in wild and farm-reared chukar partridges (Alectoris chukar)

This study assessed differences in antioxidant (carotenoid, retinol, retinol-ester, vitamin E and coenzyme Q₁₀) composition of egg yolk and tissue in chukar partridges (Alectoris chukar) newly hatched from eggs of birds maintained in captivity on commercial maize-soybean based diets and birds from the wild whose diet was obtained from the natural environment. All eggs were incubated in a commercial hatchery. Day-old chicks from both groups were sacrificed and dissected for antioxidant analysis. Fat soluble antioxidant concentrations of egg yolk and tissues were determined by HPLC. Total carotenoids, retinol, alpha-tocopherol, and total vitamin E concentration of wild egg yolks were significantly higher compared to yolks from farm-reared birds (p<0.05). However, gamma tocopherol, and coenzyme Q₁₀ were not significantly different in the yolks of either wild or farmed birds (p>0.05). The concentration of total carotenoids in all tissues of wild chukar one-day old partridges was significantly higher than in farmed one-day old chukar partridge tissues (p<0.05). Alpha tocopherol, free-retinol, retinol-esters and total vitamin A were significantly higher in most tissues of wild chukar when compared to farmed chicks (p<0.05). Coenzyme Q₁₀ concentrations of heart, kidney and brain tissues of farm-reared chukar day old chicks were significantly higher than tissues from wild birds, although leg and breast tissues of wild chicks were significantly higher than in farmed birds (p<0.05). These findings suggest that maternal access to antioxidants in the diet of farmed chukar partridges could positively influence fat soluble antioxidant concentrations in the egg yolk and tissues of day old chicks.

Antioxidant systems in chick embryo development. Part 1. Vitamin E, carotenoids and selenium

Chick viability is known to be an important factor determining profitability of the poultry industry. Chick embryo tissues contain a high proportion of highly polyunsaturated fatty acids in the lipid fraction and therefore need antioxidant defence. The antioxidant system of the developing embryo and newly hatched chick includes the antioxidant enzymes (superoxide dismutase, glutathione peroxidase, catalase), water-soluble antioxidants (ascorbic acid, taurine, carnitine, glutathione, etc.), fat-soluble antioxidants (vitamin E, carotenoids, coenzyme Q) as well as selenium (Se). In fact, the high levels of endogenous antioxidants within the egg and embryonic tissues can clearly serve as a major adaptive mechanism for the protection of the tissue during the oxidative stress experienced at hatching. It has been shown that among different nutrients in the maternal diet which could significantly affect chick embryo development and their viability in the early posthatch life, natural antioxidants have been suggested to play a central role. Our data indicate that increased supplementation of the maternal diet can substantially increase concentrations of vitamin E, carotenoids (especially canthaxanthin) and Se in developing chick tissues and significantly decrease susceptibility to lipid peroxidation being effective nutritional tools to deal with various commercial stresses in poultry production.

Can feeding the broiler breeder improve chick quality and offspring performance?

The impact of nutrition on the performance of broiler breeders in terms of bodyweight profile, egg production, egg size and shell quality, mortality, fertility and hatchability has been well documented. However, studies on the direct effects of breeder nutrition on subsequent chick quality and offspring performance are limited. The present paper reviews the nutritional factors in broiler breeders that may improve chick quality and progeny performance. Recent research has suggested that the feeding of low crude protein and medium to high energy breeder diets in both rearing and laying period will not only have a positive impact on egg production, egg size, breeder fertility, hatchability and embryonic livability, but also on offspring performance. Improvements include better chick quality, higher chick weight, lower mortality, increased immune responses, enhanced litter quality and broiler growth. Breast-meat yield in the progeny can be improved as the energy to protein ratio increases from the rearing phase to the laying phase, indicating that nutrition of pullets can also affect growth and yields. The effects of maternal diet on offspring performance may depend on the sex of the progeny, with male broilers responding more than female broilers to breeders’ dietary protein and energy concentrations. However, little work has been conducted on the effects of individual amino acids in breeder diets on the subsequent generation. There seems to be some benefits with the use of long-chain poly-unsaturated fats in breeder diets on carcass quality of offspring, but these effects appear inconsistent at this stage. There is substantial evidence that confirms the direct effects of vitamin D and E, and trace minerals, especially in organic form, such as selenium, zinc and manganese, on chick quality and progeny performance. In fact, the impact of breeder nutrition on progeny performance in the field is more likely to be greater under conditions of poor breeder-flock uniformity, low vitamin and trace mineral contents or certain types of stress in the broiler house.

Effects of high selenium and fat supplementation on growth performance and thyroid hormones concentration of broilers

A total of 400, as hatched, broilers were used to investigate the effect of increase of selenium and energy intake on thyroid hormone metabolism, growth and liver fatty acid profile. There were 5 replicates of 4 dietary treatments namely, TA (0.289mg Se per kg diet and adequate energy content), TB (0.583mg Se per kg diet and adequate energy content), TC (0.267mg Se per kg diet and 9% increase of energy content) and TD (0.576mg Se per kg diet and 9% increase of energy content). Diets were isonitrogenous. Zinc L-selenomethionine complex was used to increase Se content and corn oil was used to increase the energy content. The experiment lasted 42 days. Broiler growth performance was not significantly affected by dietary treatments. Liver glutathione peroxidase (GPx) activity increased (P<0.05) in broilers fed high Se and energy diets compared to other ones. Whole blood GPx activity was higher in Se supplemented groups however, it was reduced by age. Thyroid hormone concentrations were unaffected by dietary treatments. A significant increase of linoleic and arachidonic acid concentration (P<0.001) was observed in the liver of broilers fed diets with moderately increased energy content and supplemented with Se compared to those fed diets with moderately increased energy content alone. In conclusion, zinc L-selenomethionine complex and moderate increase of energy content did not affect growth rate or thyroid hormone metabolism but led to increased liver fatty acid content and hepatic GPx activity.

Meta-analysis of selenium accumulation and expression of antioxidant enzymes in chicken tissues

A meta-analysis integrating results of 40 selenium (Se) supplementation experiments that originated from 35 different controlled randomized trials was carried out in an attempt to identify significant factors that affect tissue Se accumulation in chicken. Examined factors included: Se source (12 different sources examined), type of chicken (laying hens or broilers), age of birds at the beginning of supplementation, duration of supplementation, year during which the study was conducted, sex of birds, number of chickens per treatment, method of analysis, tissue type, concentration of Se determined and Se added to feed. A correlation analysis was also carried out between tissue Se concentration and glutathione peroxidase activity. Data analysis showed that the factors significantly affecting tissue Se concentration include type of chicken (P=0.006), type of tissue (P<0.001) and the analytical method used (P=0.014). Although Se source was not found to affect tissue Se concentration (overall P>0.05), certain inorganic (sodium selenite), calcium selenite, sodium selenate and organic sources (B-Traxim Se), Se-yeast, Se-malt, Se-enriched cabbage and Se-enriched garlic as well as background Se level from feed ingredients were found to significantly affect tissue Se concentration. The Se accumulation rate (estimated as linear regression coefficient of Se concentrations to Se added to feed) discriminated between the various tissues with highest values estimated in the leg muscle and lowest in blood plasma. Correlation analysis has also shown that tissue Se concentration (pooled data) was correlated to Se added to feed (r=0.529, P<0.01, log values) and to glutathione peroxidase activity (r=0.332, P=0.0478), with the latter not being correlated with Se added to feed. Although significant factors affecting Se concentration were reported in the present study, they do not necessarily indicate the in vivo function of the antioxidant system or the level of accumulated Se as other factors, not examined in the present study, may interact at the level of trace element absorption, distribution and retention.

Regulation of selenoprotein P concentration and expression by different sources of selenium in broiler breeders and their offspring

An 8-wk experiment using 180 Lingnan Yellow broiler breeders was conducted to investigate the effect of different sources of Se on the concentration and gene expression of selenoprotein P (SEPP1) in broiler breeders and their offspring. After receiving a low-Se basal diet for 8 wk, broiler breeders were randomly allocated to 3 treatments (6 replicates per treatment) and fed corn-soy-based diets supplemented with 0.15 mg/kg of Se from sodium selenite (SS), Se-enriched yeast (SY), and selenomethionine (SM), respectively. Fertile eggs from different replicates were collected during the last week of the experiment and then incubated in different incubator trays in the same incubator. The concentrations and mRNA levels of SEPP1 were determined in liver and kidney of broiler breeders and their offspring, as well as the serum SEPP1 concentration. Compared with SS, both SY and SM significantly increased (P < 0.05) the concentration and mRNA level of SEPP1 in 1-d-old chicks. In broiler breeders, the serum and liver SEPP1 concentrations were notably increased by the use of organic Se (P < 0.05), whereas no differences were found in the kidney. Moreover, the SEPP1 mRNA level in the liver was remarkably elevated (P < 0.05) in organic Se treatments, but also no differences were observed in the kidney. Results of this study indicate that the use of organic Se (SY or SM) in maternal diets is very effective for increasing the concentration and mRNA level of SEPP1, especially in their offspring. No differences between SY and SM were observed.

Effect of selenium sources on the expression of cellular glutathione peroxidase and cytoplasmic thioredoxin reductase in the liver and kidney of broiler breeders and their offspring

In total, 180 Lingnan Yellow broiler breeders were used to investigate the effect of different sources of selenium (Se) on the expression of cellular glutathione peroxidase (GPx1) and cytoplasmic thioredoxin reductase (TrxR1) in the liver and kidney of broiler breeders and their offspring by quantitative real-time PCR. There were 6 replicates of 3 dietary treatments. Broiler breeders were fed corn-soy-based diets supplemented with 0.15 mg/kg of Se from sodium selenite, Se-enriched yeast (SY), or selenomethionine (SM). At the end of the feeding trial, liver and kidney mRNA levels of GPx1 and TrxR1 were determined by quantitative real-time PCR, as well as the activity of GPx1 and TrxR1 in liver and kidney of breeders and their offspring. The results showed that, compared with sodium selenite, SY or SM significantly increased (P < 0.05) the activity of TrxR1 in the liver and kidney of broiler breeders and their offspring but not the GPx1 activity. The liver GPx1 and TrxR1 mRNA levels in SY or SM groups were higher (P < 0.05) than that in the sodium selenite group. And the kidney TrxR1 mRNA levels were also significantly increased (P < 0.05) by using SY or SM, whereas there was no significant difference in the kidney GPx1 mRNA levels between the organic or inorganic sources of Se used.

Influence of dietary selenomethionine supplementation on performance and selenium status of broiler breeders and their subsequent progeny

The study was conducted to investigate the effects of dietary maternal selenomethionine or sodium selenite supplementation on performance and selenium status of broiler breeders and their next generation. Two hundred and forty 39-week-old Lingnan yellow broiler breeders were allocated randomly into two treatments, each of which included three replicates of 40 birds. Pretreatment period was 2 weeks, and the experiment lasted 8 weeks. The groups were fed the same basal diet supplemented with 0.30 mg selenium/kg of sodium selenite or selenomethionine. After incubation, 180 chicks from the same parental treatment group were randomly divided into three replicates, with 60 birds per replicate. All the offspring were fed the same diet containing 0.04 mg selenium/kg, and the experiment also lasted 8 weeks. Birth rate was greater (p < 0.05) in hens fed with selenomethionine than that in hens fed with sodium selenite. The selenium concentration in serum, liver, kidney, and breast muscle of broiler breeders, selenium deposition in the yolk, and albumen and tissues' (liver, kidney, breast muscle) selenium concentrations of 1-day-old chicks were significantly (p < 0.01) increased by maternal selenomethionine supplementation compared with maternal sodium selenite supplementation. The antioxidant status of 1-day-old chicks was greatly improved by maternal selenomethionine intake in comparison with maternal sodium selenite intake and was evidenced by the increased glutathione peroxidase activity in breast muscle (p < 0.05), superoxide dismutase activity in breast muscle and kidney (p < 0.05), glutathione concentration in kidney (p < 0.01), total antioxidant capability in breast muscle and liver (p < 0.05), and decreased malondialdehyde concentration in liver and pancreas (p < 0.05) of 1-day-old chicks. Feed utilization was better (p < 0.05), and mortality was lower (p < 0.05) in the progeny from hens fed with selenomethionine throughout the 8-week growing period compared with those from hens fed with sodium selenite. In summary, we concluded that maternal selenomethionine supplementation increased birth rate and Se deposition in serum and tissues of broiler breeders as well as in egg yolk and egg albumen more than maternal sodium selenite supplementation. Furthermore, maternal selenomethionine intake was also superior to maternal sodium selenite intake in improving the tissues Se deposition and antioxidant status of 1-day-old chicks and increasing the performance of the progeny during 8 weeks of post-hatch life.

Effect of selenium-enriched probiotics on laying performance, egg quality, egg selenium content, and egg glutathione peroxidase activity

A 35-day experiment was conducted to evaluate the effect of selenium-enriched probiotics (SP) on laying performance, egg quality, egg selenium (Se) content, and egg glutathione peroxidase (GPX) activity. Five hundred 58-week-old Rohman laying hens were randomly allotted to 5 dietary treatments of 100 each. Each treatment had 5 replicates, and each replicate had 5 cages with 4 hens per cage. The SP was supplemented to a corn-soybean-meal basal diet at 3 different levels that supplied total Se at 0.2, 0.5, and 1.0 mg/kg. The basal diet served as a blank control, while the basal diet with supplemental probiotics served as a probiotics control. The results showed that dietary SP supplementation not only increased (p < 0.05) the rate of egg laying, day egg weight, mean egg weight, egg Se content, and egg GPX activity but also decreased (p < 0.05) the feed:egg ratio and egg cholesterol content. The egg Se content was gradually increased (p < 0.05) along with the increasing level of dietary Se. The SP supplementation also slowed down (p < 0.05) the drop of Haugh units (HU) of eggs stored at room temperature. The egg GPX activity had a positive correlation (p < 0.01) with egg Se content and a negative correlation (p < 0.01) with egg HU drop. These results suggested that Se contents, GPX activity, and HU of eggs were affected by the dietary Se level, whereas the egg-laying performance and egg cholesterol content were affected by the dietary probiotics. It was concluded that this SP is an effective feed additive that combines the organic Se benefit for hen and human health with the probiotics benefit for laying hen production performance. It was also suggested that the eggs from hens fed this SP can serve as a nutraceutical food with high Se and low cholesterol contents for both healthy people and patients with hyperlipidemia, fatty liver, or cardiovascular disease.

Brooding temperatures for chicks acclimated to heat during incubation: effects on post-hatch intestinal development and body weight under heat stress

1. The objective was to evaluate the effects of brooding temperature on intestinal development, oxidative organ damage, and performance of chicks acclimated to high temperature during incubation. The effects of acclimation and brooding temperatures on slaughter weights of broilers under heat stress were also investigated. 2. Eggs were incubated at either 378 degrees C (INC(Cont)) or heat-acclimated at 395 degrees C for 6 h daily from d 10 to d 18 of incubation (INC(H)). Brooding temperatures at floor level were set at 32, 335 and 35 degrees C (Bt(32), Bt(335), Bt(35), respectively) for the first 5 d. The temperature was reduced gradually to 30 degrees C from d 6 to d 10. From 21 to 42 d, broilers from INC(Cont) Bt(32) and INC(H) Bt(32) and Bt(35) were divided into two groups; half from each group was exposed to daily cyclic higher ambient temperatures, while the other half was reared at control temperature. 3. INC(H) chicks had lower jejunum, but greater liver and residual yolk sac weights than INC(Cont) chicks on the day of hatching. Although INC(H) chicks from Bt(335) and Bt(35) had lighter body weights than Bt(32) on d 5, no significant differences were observed in the body weight of broilers among treatments at 10 and 21 d. 4. Similar jejunum protein, alkaline phosphatase, maltase, glutathione, and malondialdehyde contents of chicks from INC(Cont) and INC(H) suggested that heat acclimation during incubation has no effect on jejunum enzyme activity or oxidative status of chicks. 5. Taking into account INC(H) Bt(35) chicks having lower T(3) levels on d 5, lower heterophil/lymphocyte (H/L) ratios and similar weights at 42 d under heat stress compared with control broilers, the results suggested that although higher brooding temperatures had no effect on body weights of INC(H) chicks during the brooding period, those broilers may able to cope better with heat stress.

Differential effects of sodium selenite and nano-Se on growth performance, tissue se distribution, and glutathione peroxidase activity of avian broiler

The present research evaluated differential effects of sodium selenite and nano-Se on growth performance, tissue Se distribution, and glutathione peroxidase (GSH-Px) activity of avian broiler. Broilers were randomly segregated into 12 groups so that three replicates were available for each of the three treatments (T-1, T-2, and T-3) and control groups. The control groups were fed basal diets without Se addition. T-1, T-2, and T-3 were fed with diets containing 0.2 mg kg(-1) sodium selenite, 0.2 mg kg(-1) nano-Se, and 0.5 mg kg(-1) nano-Se, respectively. Compared with the control, Se supplementation remarkably improved daily weight gain and survival rate and decreased feed conversion ratio (P < 0.05). However, no significant difference was observed between T-1, T-2, and T-3. The tissue Se content was significantly higher (P < 0.05) in Se-supplemented groups than the control, and T-3 showed the highest. Furthermore, higher Se content was observed in liver, and there was a significant difference (P < 0.05) compared with that in muscle. As for serum and hepatic GSH-Px activities, Se supplementation remarkably improved GSH-Px activity (P < 0.05), and there was no significant difference (P > 0.05) between treatments (T-1, T-2, and T-3).

Variation in trace element contents among chicken, turkey, duck, goose, and pigeon eggs analyzed by inductively coupled plasma mass spectrometry (ICP-MS)

Despite substantial interest in the trace element content of eggs by poultry breeders, nutritionists, and environmental scientists, available data about trace elements levels in eggs are scarce. Trace element contents in yolk and albumen of chicken, turkey, duck, goose, and pigeon eggs were analyzed to establish a baseline dataset and assess differences among trace element content in avian species. We measured the selenium (Se), zinc (Zn), manganese (Mn), cobalt (Co), copper (Cu), molybdenum (Mo), vanadium (V), chromium (Cr), nickel (Ni), arsenic (As), cadmium (Cd), and thallium (Tl) contents in both yolk and albumen by inductively coupled plasma mass spectrometry. One hundred twenty eggs deriving from 24 birds of each species, reared in the same poultry farm in northern Greece, were used; bird feed was common and based on cereals and legumes and contained no added vitamins or microminerals. Trace element contents in yolks were far higher than those in albumen, except for V and Ni. In yolks, the highest content for Se, Mo, and Tl were in pigeon eggs, for Zn, Mn, Cu, and Cr in turkey eggs, and for Co and Ni in goose eggs. In albumen, Se was highest in duck eggs, while Zn, Mn, and Co in pigeon ones. It is concluded that there is a substantial, up to threefold, variation for trace element contents in eggs among different domestic avian species offered the same feed.

The selenium levels of mothers and their neonates using hair, breast milk, meconium, and maternal and umbilical cord blood in Van Basin

The objective of the present study is to calculate linear regressions between a mother and her child with respect to their selenium concentration (ng/g) in the following traits: maternal blood and umbilical cord blood, maternal and child hair, maternal milk and child umbilical cord blood, maternal milk and meconium, maternal blood plasma, and child meconium. The data were collected at Research Hospital of the University of Yüzüncü Yil from 30 pairs of mothers and their newborn baby. The mean maternal serum Se level in 30 mothers was 68.52 +/- 3.57 ng/g and cord plasma level was 119.90 +/- 18.08 ng/g. The Se concentration in maternal and neonatal hair was 330.84 +/- 39.03 and 1,124.76 +/- 186.84 ng/g, respectively. The Se concentration of maternal milk at day 14 after delivery was determined as 68.63 +/- 7.78 ng/g (n = 13) and the concentration of Se was 418.90 +/- 45.49 ng/g (n = 22) for meconium of neonatal. There was no significant difference between maternal blood and milk Se levels. However, hair Se concentration was significantly higher than milk and maternal blood Se level. For each trait comparison, the average absolute difference in log(10)-transformed Se concentration was calculated between a mother and her child. The observed average absolute difference was compared with a test distribution of 1,000 resampled bootstrap averages where the number of samples was maintained but the relationship between a mother and her child was randomized among samples (alpha = 0.05).

Selenium distribution in eggs of avian species

We studied the effect of egg mass of eight different avian species on Se distribution between egg components and the effect of incubation on Se accumulation by chicken eggshell and shell membrane. Eight groups of birds received a diet without Se supplementation. Unfertile eggs were collected after 35 days of feeding; yolk, albumen, shell and shell membrane were assayed separately for Se. All avian species studied showed identical Se concentration in yolk-albumen complex equal to 38.7 microg Se/100 g, reflecting a linear correlation between yolk-albumen mass and Se content. Shells and shell membrane Se accumulation showed quadratic correlation with the appropriate mass thus explaining unusually high Se concentration in ostrich shell and shell membrane, that reached values 1785 and 1904 microg Se/kg respectively. Incubation of fertile eggs decreased eggshell Se content, the effect being more expressed in eggs from hens fed sodium selenite compared to organic Se utilization (Sel-Plex). It was concluded that shell might be an additional Se source for an embryo.

Maternal diet influences gene expression in intestine of offspring in chicken (Gallus gallus)

The diet of the mother during pregnancy influences the onset of different diseases and health-related traits in the offspring. We investigated the influence of the mother hen diet on the intestinal gene expression pattern in the offspring. Hens received for 11 weeks either a commercial feed or a commercial feed supplemented with vitamins and minerals. The offspring of the two groups showed no changes in growth rate or feed conversion. Of this offspring, gene expression patterns in the intestine were measured at 3 and 14 days of age with an intestinal cDNA-microarray. Between the two groups, 11 genes were found to be differentially expressed both at 3 and 14 days of age. Thus, these genes were differently regulated when the intestine is developing as well as when the intestine is more mature. Genes that are differentially expressed at day 3 and/or day 14 affect intestinal turnover, proliferation and development, metabolism and feed absorption. To confirm that differences in gene expression are related to intestinal development, we investigated intestinal proliferation. This indeed also showed differences in proliferation between the two groups at day 3 and day 14 of age. The gene expression and proliferation results indicate that feed of the hens influences the functionality of intestine of the offspring at day 3 and 14 of age.

Interspecies variation in yolk selenium concentrations among eggs of free-living birds: The effect of phylogeny

Birds deposit the trace element selenium (Se) into their eggs because an adequate supply of this micronutrient is essential for embryonic development. Although there is considerable interest in egg Se with regard to topics as diverse as poultry nutrition and environmental pollution, data on the natural levels of Se in eggs of free-living avian species are currently very limited. To address this lack of information, we measured the yolk Se concentrations in eggs of 14 avian species collected in the wild. The concentrations (ng/g wet yolk) varied from 394 to 2238, with a mean value of 1040. Values (means+/-SD) for eggs from the UK, Canada and New Zealand were, respectively, 522+/-192 (3 species), 1194+/-584 (8 species) and 1147+/-200 (3 species). However, analysis by appropriate statistical models indicates that the effect of phylogenetic relatedness among these species is so significant that it removes any effect of geographical location. In particular, species belonging to the order Passeriformes displayed significantly higher yolk Se levels than Non-Passeriforme species. In marked contrast to the free-living species, our previously published data indicate that the Se concentration in egg yolk of the domestic chicken is only about 100 ng/g wet yolk when the birds are maintained on a basal commercial diet without supplementary Se. The results reveal an extensive interspecies variation in yolk Se (across a 6-fold range) for eggs collected from the wild. Nevertheless, the Se concentrations in the yolks of all the free-living species were far higher (4-21-fold) than that achieved in the yolk of the domestic chicken consuming a standard basal diet.