Effects of different dl-selenomethionine and sodium selenite levels on growth performance, immune functions and serum thyroid hormones concentrations in broilers

This trial was conducted in a 2 × 3 + 1 factorial arrangement based on a completely randomized design to evaluate the effects of different dl-selenomethionine (dl-Se-Met) and sodium selenite (SS) levels on growth performance, immune functions and serum thyroid hormones concentrations in broilers. A total of 840 Ross 308 broilers (7 days old) were allocated by body weight to seven treatments (three replicates of 40 birds each treatment) including (1) basal diet (containing 0.04 mg of selenium (Se)/kg; control) without supplementary Se; (2, 3 and 4) basal diet + 0.05, 0.15 or 0.25 mg/kg Se as SS; (5, 6 and 7) basal diet + 0.05, 0.15 or 0.25 mg/kg Se as dl-Se-Met. The experiment lasted 42 days. The results revealed that dietary Se supplementation improved (p < 0.05) average daily gain, feed efficiency, immune organ index, serum immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM) and triiodothyronine (T3 ) concentrations and decreased (p < 0.01) thyroxine (T4 )/T3 ratio in serum compared with the control. Broilers receiving the dl-Se-Met-supplemented diets had higher (p < 0.05) feed efficiency, thymus index, the amounts of IgA, IgG, IgM and T3 as well as lower (p < 0.05) serum T4 concentrations and T4 /T3 ratio than those consuming the SS-supplemented diets. Serum IgA and IgM levels of broilers fed 0.15 mg Se/kg were significantly higher (p < 0.05) than those of broilers fed 0.05 or 0.25 mg Se/kg. In summary, we concluded that dl-Se-Met is more effective than SS in increasing immunity and promoting conversion of T4 to T3 , thus providing an effective way to improve the growth performance of broilers. Besides, based on a consideration of all experiment indices, 0.15 mg Se/kg was suggested to be the optimal level of Se supplementation under the conditions of this study.

Efficacy of selenium from hydroponically produced selenium-enriched kale sprout (Brassica oleracea var. alboglabra L.) in broilers

An experiment was conducted to determine the efficacy of Se from hydroponically produced Se-enriched kale sprout (HPSeKS) on performance, carcass characteristics, tissue Se concentration, and physiological responses of broilers in comparison to that of Se from Se-enriched yeast and sodium selenite. Three hundred and sixty male broilers, 10 days of age, were assigned to 6 groups, 4 replicates of 15 broilers each, according to the completely randomized design. The dietary treatments were the following: T1: control diet; T2: control diet plus 0.3 mg Se/kg from sodium selenite; T3: control diet plus 0.3 mg Se/kg from Se-enriched yeast; and T4, T5, and T6: control diet plus 0.3, 1.0, and 2.0 mg Se/kg from HPSeKS, respectively. The results found that dietary Se supplementation did not (p > 0.05) alter performance and carcass characteristics of broilers. Se supplementation increased (p < 0.05) Se concentrations in the liver and kidney of broilers. Heart tissue Se concentration of broilers fed Se from sodium selenite was lower (p < 0.05) than that of broilers fed Se from HPSeKS and Se-enriched yeast. Selenium from HPSeKS increased higher (p < 0.05) GSH-Px activity when compared to Se from sodium selenite and Se-enriched yeast. The results indicated that the efficacy of Se from HPSeKS was comparable in increasing tissue Se concentration, but higher in improving GSH-Px activity in Rbc when compared to those of Se from Se-enriched yeast.

The effect of replacing inorganic trace minerals with organic Bioplex® and Sel-Plex® on the performance and meat quality of broilers

The aim of this study was to compare the performance and carcass quality of broilers fed diets containing either a commercial inorganic mineral premix (control) or organic trace minerals (OTM) (Sel-Plex® (Se) and Bioplex® copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe)) in a commercial environment. Four identical houses with a total of 119,500 mixed-sex broiler chickens were used (two treatments × two replicates). Birds were fed identical corn/soybean based rations differing only in mineral form and levels. The inorganic treatment (control) provided Cu, Zn, Fe, Mn and Se at levels of 8, 44, 55, 66 and 0.2 ppm, respectively. The OTM contained 5.5, 22, 5.5, 22 and 0.3 ppm of Cu, Zn, Fe, Mn and Se respectively. Growth and feed conversion during the 35-day trial were not influenced (P > 0.05) by treatments. Over the entire trial period and during the first week of production, birds showed significantly lower (P < 0.05) mortality with the OTM treatment. Between 14 and 31 days, sudden death syndrome was lower (P < 0.05) with the OTM diet. OTM improved feathering at 21 days of age (P < 0.001) and lowered carcass skin tearing (P < 0.05). There was no effect of OTM on carcass yield, breast meat pH, drip loss or on meat colour (L* and b* values). However, birds fed organic minerals had redder breast meat (a*) (P < 0.05) on days three and five after slaughter. The results showed that, under commercial conditions, using lower levels of OTM (except Se) in feed relative to inorganic controls can maintain broiler performance.

Effect of supplementing organic selenium on performance, carcass traits, oxidative parameters and immune responses in commercial broiler chickens

An experiment was conducted to determine the effect of supplementing various concentrations (0, 100, 200, 300, or 400 μg/kg diet) of organic Se on growth performance, carcass traits, oxidative stress, and immune responses in commercial broiler chickens reared in open-sided poultry house under tropical climatic conditions. Each diet was fed ad libitum to eight replicates consisting of six birds in each pen from 1 to 42 d of age. Body weight gain and feed efficiency, and relative weight of liver, abdominal fat and ready to cook yields were not affected (p>0.05) by organic Se supplementation to broiler diets. Lipid peroxidation in plasma decreased, while activities of glutathione peroxidase and glutathione reductase in plasma increased (p<0.01) linearly with Se concentration in diet. The ratios between heterophyls and lymphocytes and relative weight of lymphoid organs (bursa, spleen, and thymus), and antibody production to Newcastle disease vaccination were not affected (p>0.05) by Se supplementation to broiler diets. However, the cell-mediated immunity (lymphocyte proliferation ratio) increased (p<0.01) linearly with dietary Se concentration. The results of the present study indicate that the supplementation of Se did not influence body weight and feed efficiency. However, supplementation of Se increased antioxidant status and lymphocyte proliferation in broiler chickens.

Comparative study of a new organic selenium source v. seleno-yeast and mineral selenium sources on muscle selenium enrichment and selenium digestibility in broiler chickens

Two experiments were conducted on broiler chickens to compare the effect of a new organic Se source, 2-hydroxy-4-methylselenobutanoic acid (HMSeBA; SO), with two practical Se additives, sodium selenite (SS) and Se yeast (SY). The relative bioavailability of the different Se sources was compared on muscle (pectoralis major) total Se, selenomethionine (SeMet) and selenocysteine (SeCys) concentrations and apparent digestibility of total Se (ADSe). In the first experiment, from day (d) 0 to d21, Se sources were tested at different supplied levels and compared with an unsupplemented diet (NC). No significant effects were observed on growth performance during the experimental period. However, the different Se sources and levels improved muscle Se concentration compared with the NC, with a significant source effect in the following order: SS < SY < SO (P<0·05). Seleno-amino acids speciation results for NC, SY and SO at 0·3 mg Se/kg feed indicated that muscle Se was only present as SeMet or SeCys, showing a full conversion of Se by the bird. The second experiment (d0-d24) compared SS, SY or SO at 0·3 mg Se/kg feed. The ADSe measurements carried out between d20 and d23 were 24, 46 and 49% for SS, SY and SO, respectively, with significant differences between the organic and mineral Se sources (P<0·05). These results confirmed the higher bioavailability of organic Se sources compared with the mineral source and demonstrated a significantly better efficiency of HMSeBA compared with SY for muscle Se enrichment.

Selenium-enriched Candida utilis: Efficient preparation with l-methionine and antioxidant capacity in rats

Selenium-enriched Candida utilis has attracted much attention due to its expanding application in food and feed additives. The objective of this study was to efficiently prepare selenium-enriched C. utilis and to investigate the effects of the prepared yeast on antioxidant capacity in rats. A batch culture of selenium-enriched C. utilis was first carried out, and the addition of sodium selenite (Na(2)SeO(3)) after all glucose had been consumed was found to favor higher intracellular glutathione and organic selenium content. Moreover, l-methionine boosted yeast cell growth and glutathione biosynthesis, and prevented glutathione from leaking to the extracellular space that can be caused by Na(2)SeO(3). We therefore developed a two-stage culture strategy involving supplementation with l-methionine and Na(2)SeO(3) at separate culture phases to improve the performance of selenized C. utilis. Using this two-stage culture strategy, intracellular glutathione content reached 18.6 mg/g and 15.5mg/g, respectively, in batch and fed-batch systems, and organic selenium content reached 905.2 μg/g and 984.7 μg/g, respectively. The effects of selenium-enriched C. utilis on the activities of antioxidant related enzymes in rats were investigated, and the prepared selenium-enriched C. utilis was shown to be an optimal dietary supplement for enhancing antioxidant capacity in rats.

Effects of nano-selenium on performance, meat quality, immune function, oxidation resistance, and tissue selenium content in broilers

This study was conducted to investigate the effect of nano-selenium (nano-Se) on performance, meat quality, immune function, oxidation resistance, and tissue selenium content in broilers. A total of five hundred forty 1-d-old male Arbor Acres broilers were randomly allotted to 1 of 5 treatments with each treatment being applied to 6 replicates of 18 chicks. The 5 treatments consisted of corn-soybean meal-based diets supplemented with 0.0, 0.3, 0.5, 1.0, or 2.0 mg/kg of nano-Se. The selenium content of the unsupplemented control diet was 0.09 mg/kg for the starter phase (0 to 21 d) and 0.08 mg/kg for the grower phase (22 to 42 d). There were no significant differences (P > 0.05) in performance, meat color, or immune organ index (thymus, bursa, and spleen) due to supplementation with nano-Se. On d 42, a significant quadratic effect of nano-Se was observed on glutathione peroxidase activity, free radical inhibition, contents of IgM, glutathione, and malondialdehyde in serum, on glutathione peroxidase activity, free radical inhibition in liver, and on glutathione peroxidase activity in muscle, with birds fed 0.30 mg/kg of nano-Se exhibiting the best effect and birds fed 2.0 mg/kg of nano-Se showing the worst effect on these parameters. Liver and muscle selenium content increased linearly and quadratically as the dietary nano-Se level increased (P < 0.01), and reached the highest value when 2.0 mg/kg of nano-Se was fed. Based on a consideration of all experiment indexes, 0.3 to 0.5 mg/kg is suggested to be the optimum level of supplementation of nano-Se, and the maximum supplementation of nano-Se could not be more than 1.0 mg/kg in broilers.

Effects of dietary sodium selenite and selenium yeast on antioxidant enzyme activities and oxidative stability of chicken breast meat

The effects of sodium selenite (SS) and selenium yeast (SY) alone and in combination (MS) on the selenium (Se) content, antioxidant enzyme activities (AEA), total antioxidant capacity (TAC), and oxidative stability of chicken breast meat were investigated. The results showed that the highest (p < 0.05) glutathione peroxidase (GSH-Px) activity was found in the SS-supplemented chicken breast meat; however, SY and MS treatments significantly increased (p < 0.05) the Se content and the activities of catalase (CAT), total superoxide dismutase (T-SOD), and TAC, but decreased (p < 0.05) the malondialdehyde (MDA) content at 42 days of age. Twelve days of storage at 4 °C decreased (p < 0.05) the activity of the GSH-Px, but CAT, T-SOD, and TAC remained stable. SY decreased the lipid oxidation more effectively in chicken breast meat. It was concluded that SY and MS are more effective than SS in increasing the AEA, TAC, and oxidative stability of chicken breast meat.

Options for the production of selenized chicken meat

A 42-day experiment was conducted to compare the effects of various levels of sodium selenite (SS) and Se-enriched yeast (SY) on chicken productivity, carcass traits, and breast Se concentration. Six hundred 1-day-old Cobb 500 broiler chicks were placed on 1 of 6 experimental treatments. The treatments consisted of feeding a diet without Se supplementation (basal diet) or basal diet with 0.6 mg/kg supplemented Se supplied by SS, SY, or a mix of the two (0.45 SS + 0.15 SY; 0.3 SS + 0.3 SY; 0.15 SS + 0.45 SY). Chicks in all Se-supplemented treatments had significantly higher final body weight and eviscerated weight than those on the basal diet (P < 0,05) and no significant differences were observed among selenium source (P < 0.05). Also, chicks in all Se-supplemented treatments had significantly higher Se contents in breast tissue than the control group (P < 0.05). Replacing SS by SY in the broiler diets resulted in increased concentrations of Se in the breast (P < 0.01). Strong correlations were found between breast Se concentrations and the level of SY supplementation of the broiler diet (r = 0.992). The results from this experiment indicate that SY is a superior source of selenium for the production of selenized meat, and can be used, without any detrimental effect on chicken performance, for adding nutritional value to broiler meat and thus safely improving human selenium intake.

Effect of dietary supplementation of trace elements on blood chemistry and selected immunological indices depending on the age of broiler chickens

This study was performed to determine the effects of dietary supplementation of Cu, Zn, Fe, Mn and Se on some haematological, immunological and enzymatic indices in blood of broilers at the age of 21, 35 and 42 days. The basal diets (BDs) for Groups 1 and 2 were supplemented with the equivalent amounts of trace elements in an inorganic form (Cu sulphate 5 mg·kg-1 DM, Fe sulphate, Zn oxide, Mn oxide 50 mg·kg-1 DM), however sodium selenite or selenized yeast (Sel-Plex) were given at a dose of Se 0.3 mg·kg-1 DM, respectively. Groups 3 and 4 received the same BD´s but with the substantially reduced amount of supplemented nutrients in the organic “proteinated” form (Bioplex Cu 2.5 mg·kg-1 DM, Bioplex Fe, Bioplex Zn, Bioplex Mn 10 mg·kg-1 DM), except for selenium that was given at a dose of Se 0.3 mg·kg-1 DM as sodium selenite or Sel-Plex, respectively. The supplementation of restricted doses of trace elements in the organic forms into the diet did not affect studied haematological, immunological, enzymatic indices. At the age of 21 days, the activity of GSH-Px was significantly higher in the groups supplemented with sodium selenite later no differences due to the administered form of Se were found. This indicates that the GSH-Px activity reached a plateau in all groups of broilers at the 21, 35 and 42 day, except for GSH-Px activity in the groups of birds supplemented with selenized yeast on day 21. In Addition, significant age dependent changes were observed in blood chemistry, but the different treatments did not influence these changes. Base on our results, the doses of organic forms of trace elements supplemented into the diets for poultry can be restricted to 50% (Bioplex Cu) and 20% (Bioplex Fe, Bioplex Zn and Bioplex Mn) without influencing the blood chemistry of broilers.