University of Kentucky College of Agriculture

The use of selenium in poultry diets

2011 INTERNATIONAL POULTRY SCIENTIFIC FORUM

Toxicity and tissue selenium levels of chicken embryos resulting from in ovo selenium injection.
L. M. Macalintal, A.H. Cantor, A. J. Pescatore, K. A. Dawson, J. L. Pierce, M. J. Ford, H. D. Gillespie, and A. N. Meredith.
The effect of injecting graded levels of selenium (Se) as seleno-L-methionine (Se-Met) or sodium selenite (Na2SeO3) into the yolk of incubating eggs on embryo toxicity and tissue Se concentration was studied. On Day 10 of incubation, fertile eggs were injected with 20, 40 or 60 μg of Se as Na2SeO3 or Se-Met in a volume of 0.1 mL of phosphate buffered saline (PBS). Another treatment (sham-control) consisted of injecting 0.1 mL of PBS without Se. Four replicate groups of 25 eggs were assigned to each treatment. Embryo viability values at Day 20 of incubation were 95% for the sham-control; 86, 84 and 88% for 20, 40 and 60 μg Se as Na2SeO3; and 93, 87 and 97% for 20, 40 and 60 μg Se as Se-Met; respectively. The order of Se concentrations in Day 20 embryo tissues was liver > lung > heart > breast, regardless of the Se source. Using Se-Met as the Se source resulted in higher Se concentrations in the liver, lung, heart and breast muscle, compared with Na2SeO3. Linear increases in all tissues were obtained with increasing doses of Se. However, the change in heart and breast muscle Se concentrations was not significant above the 40 μg dose when Na2SeO3 was used (P >0.05). Regression coefficients for tissue Se concentrations vs. injected dose for all tissue were significantly greater for Se-Met than for Na2SeO3 (P < 0.01). The current study indicates that in ovo yolk sac injection of up to 60 μg of Se as either Se-Met or Na2SeO3 is not toxic to embryos and that using Se-Met results in higher tissue Se levels.

Genomic analysis of polymeric immunoglobulin receptor response to avian reovirus infection in broilers as influenced by dietary selenium. J. Read-Snyder, F.W. Edens, C.M. Ashwell, A. Cantor, and A. Pescatore.
Avian reovirus (ARV) is an economically important dsRNA virus, and secretory IgA (sIgA) is a major defense mechanism guarding against ARV invasion. This first line of defense is established through interaction between the mucosal B cell system and the polymeric immunoglobulin receptor (pIgR) protein that escorts SIgA transcellularly. A 1:1 relationship has been shown for sIgA and pIgR. At the apical surface of enterocytes, sIgA with its cleaved pIgR-secretory component are released into the intestinal lumen. Evidence shows that selenium has a negative influence on dsRNA viruses such as the avian reovirus. This work was conducted to examine, with the use of qRT-PCR, the influence of dietary selenium on tissue pIgR in broiler chickens challenged with an enteric avian reovirus (ARV-CU98 104.2 pfu/chick at day of hatch). Cobb 500 broilers were fed isocaloric Torula yeast diets with either no supplemental selenium (<0.02 ppm Se), Sel-Plex (0.3 ppm) or sodium selenite (0.3 ppm). Control and challenged birds were sampled at 14 and 21d posthatch to collect thymus, pancreas, bursa of Fabricius and liver tissues. All tissues were found to produce pIgR at 14 and 21d, but liver, pancreas, and bursa showed age related increases in pIgR expression while other tissues showed age-related decreases. ARV infection increased pIgR expression. Sel-Plex compared to selenite elevated pIgR expression in liver, a major site of IgA production. In the pancreas, selenite elevated pIgR over all other treatments. These data show that pIgR is produced in many tissues, but the results suggest that selenium induces greater pIgR expression in tissues with secretory capabilities. Induction of pIgR would facilitate transport and delivery of sIgA to combat viral and even bacterial invasion helping to explain the positive outcomes associated with selenium in disease-challenge studies.

2010 POULTRY SCIENCE ASSOCIATION ANNUAL MEETING

Effect of dietary selenium yeast (Sel-Plex) and vitamin E supplementation to broilers on meat quality characteristics of raw and marinated breast fillets.
A.D. Quant, A.J. Pescatore, J.L. Pierce, K.M. McClelland, G.R. Rentfrow, A.H. Cantor, M.J. Ford.
A study was conducted to evaluate the effects of dietary supplementation of selenium (Se) and vitamin E (Vit.E) to broilers on meat quality characteristics of raw and marinated breast fillets. This study utilized 576 Cobb500 broilers that were randomly allotted to 4 treatments with 48 pens of 12 birds/pen in a 2x2 factorial design (12 replicates/treatment). Broilers were fed a corn-soybean meal control diet with no added Se or Vit. E, supplemented with either 0.3 mg Se/kg diet as Se yeast (Sel-Plex, Alltech, Inc., Nicholasville, KY), or 30 IU Vit. E/kg as all-rac-α-tocopheryl acetate, or a diet supplemented with both Se and Vit. E. Broilers were humanely harvested at 49 and 56 d of age (raw and marinated portion, respectively) and breast fillets were sampled for analysis of meat quality characteristics. Marinated breast fillets were soaked in a 3.2% sodium pyrophosphate and 4% NaCl solution for 13 h (marinade pH: 9.74). In raw breast fillets, Se yeast supplementation significantly decreased drip loss at 3d compared with the control (P = 0.049) and Vit. E (P < 0.01) treatments, however by 7d, the only observed improvement was Se yeast compared with Vit. E (P < 0.01). Oxidative stability at 7d (as indicated by thiobarbituric acid reactive substance values) of the raw breast fillets was improved by Se yeast supplementation with (P = 0.095) or without added Vit. E (P < 0.01) compared  with the control treatment. In the marinated breast fillets, there was no effect of dietary treatment on drip loss, however oxidative stability at 7d was significantly improved by all 3 antioxidant containing treatments (P < 0.01) compared with the control. Antioxidant supplementation did not affect color stability, carcass yield (WOG, front half, saddle), breast fillet pH, cooking loss, and tenderness values in both the raw and marinated breast fillets. These results indicate that dietary supplementation of Se yeast in broiler diets decrease drip loss and improve oxidative stability in raw breast fillets, and greatly improve oxidative stability in marinated breast fillets. 

Effect of in ovo selenium injection on chick embryo viability and tissue selenium levels.
L.M. Macalintal, A.H. Cantor, A.J. Pescatore, M.J. Ford, H.D. Gillespie, J.L. Pierce, K.A. Dawson, and R.F. Power.
The effect of injecting graded levels of selenium (Se) as selenomethionine (SeMet) or sodium selenite (Na2SeO3) into the yolk of incubating eggs on embryo viability and liver Se levels was studied. Fertile eggs were obtained from white shell laying hens (Hy-Line W-36) that were fed a low Se corn-soybean meal diet. On Day 10 of incubation, eggs were candled to ensure embryo viability. The shell surface was disinfected with alcohol and a small hole was drilled over the air cell. The yolk of each of 30 eggs per treatment was then injected with 0.1 mL of a phosphate buffered saline solution providing 0, 2.5, 5, 10 or 20 μg Se as either SeMet or Na2SeO3. In a control group of eggs holes were drilled in the shell, but no injection was administered. The holes were sealed with glue and eggs were returned to the incubator. On Day 20 of incubation, eggs were candled to determine viability. Viable embryos were then killed to obtain tissue samples. Liver samples were analyzed for Se using fluorometric analysis following digestion in nitric and perchloric acids. Embryo viability values for the non-injected eggs and eggs injected with buffer without Se were 100% and 94%, respectively. Viability values for eggs injected with 2.5, 5, 10 and 20 μg Se as SeMet were 97, 94, 90 and 83%, respectively, while the respective values for eggs treated with Na2SeO3 were 87, 94, 74 and 87%. Injecting graded doses of Se resulted in linear increases (P < 0.001) in liver Se. However, the regression coefficient for Na2SeO3 was greater than that for SeMet (0.059 vs. 0.014). The results indicate that in ovo injection of Se as SeMet or Na2SeO3 at levels up to 20 μg does not have a detrimental effect on embryo viability. The effects of the SeMet and Na2SeO3 on liver Se concentrations suggest that the compounds are metabolized differently by the chick embryo.

2010 INTERNATIONAL POULTRY SCIENTIFIC FORUM

Effect of selenium yeast (Sel-Plex) and vitamin E supplementation on body weight and flock uniformity of developing broiler breeder pullets.
A.D. Quant, A.J. Pescatore, A.H. Cantor, J.L. Pierce, T. Ao, M.J. Ford, and W.D. King.
The benefits of antioxidant supplementation in broiler breeder diets have been well established for benefit to the developing embryo and chick. Few studies have examined how improvements in the antioxidant system affect broiler breeder body weight (BW) and flock uniformity. Therefore, a study was conducted to determine the effect of dietary supplementation of selenium (Se) and vitamin E (Vit. E) on BW and flock uniformity of developing broiler breeder pullets. In this experiment, 640 Cobb 500® broiler breeder pullets were allotted to 4 dietary treatments with 5 replicate floor pens of 32 birds/pen in a 2 x 2 factorial design. Dietary treatments consisted of a corn-soybean meal basal diet with no added Se or Vit. E, supplemented with 0.3 mg Se per kg diet as selenium yeast (Sel-Plex®, Alltech, Inc., Nicholasville, KY), supplemented with 30 IU Vit. E per kg as all-rac-α-tocopheryl acetate, or supplemented with both Se and Vit. E. Average pen weights were recorded weekly from 2 until 21 weeks of age and later compared to the recommended target weight defined in the Cobb Breeder Management Guide (2008). In addition, each week 10 pullets from each pen were randomly selected and weighed for determination of pen uniformity. Flock uniformity was reported as the percentage of pullets with a BW within ±15% of the mean BW for each pen. There was no effect of dietary treatment on pullet BW and pen uniformity over the 19 week period. When compared to the target BW, all treatment groups displayed mean BW above the target level. Through week 13, the values for pullets fed only Se yeast were numerically closer to the target BW than the control, displaying a significant effect in weeks 2, 6, 7 and 11 (P < 0.05). In addition, the pullets supplemented with both Se yeast and Vit. E were significantly closer to the target weight than the control group (P < 0.05) during weeks 6 and 7. The results indicate that dietary supplementation with Se yeast may be useful in achieving the ideal target BW of broiler breeder pullets throughout the early stages of development.

Effect of selenium yeast (Sel-Plex® and vitamin E supplementation on lung tissue selenium concentrations of broiler breeder pullets.
L.M. Macalintal, A.H. Cantor, A.J. Pescatore, J.L. Pierce, A.D. Quant, H.D. Gillespie, M.J. Ford, W.D. King III, and T. Ao. ,br /> There has been increased interest in improving antioxidant nutrients in target tissues. A study was conducted to determine the effect of dietary supplementation of selenium yeast (Sel-Plex®, Alltech, Inc., Nicholasville, KY) and vitamin E on Se concentration in lungs of Cobb 500® broiler breeder pullets.  A corn-soybean meal basal diet with no added Se or vitamin E was fed alone, supplemented with 0.3 mg Se per kg diet as selenium yeast, supplemented with 30 IU vitamin E per kg as all-rac-α-tocopheryl acetate, or supplemented with both selenium yeast and vitamin E.  At 21 weeks of age, lung tissue samples were collected from two randomly selected birds from each of four replicate pens of 24 pullets per treatment and stored at <20ºC for subsequent analysis.  Samples were pooled within replicate groups, homogenized and then analyzed in duplicate for Se using digestion with nitric and perchloric acids and fluorometric detection. The Se concentrations (μg/g, wet basis, mean ± SD) in lung tissue from pullets fed the basal diet alone and supplemented with vitamin E were 0.18 ± 0.027 and 0.19 ± 0.027, respectively, while the respective values for pullets supplemented with Se yeast alone and with vitamin E were 0.39 ± 0.023 and 0.34 ± 0.023.  Selenium supplementation, either alone or in combination with vitamin E, significantly increased lung tissue Se concentration (P < 0.05). The results indicate that dietary supplementation with selenium yeast is an effective method of increasing Se levels in lung tissue of broiler breeders. Enhancing the concentration of this antioxidant nutrient in lungs may be beneficial in improving the ability of poultry to handle respiratory challenges.

2008 POULTRY SCIENCE ASSOCIATION ANNUAL MEETING

Effect of selenium supplementation on egg production of broiler breeder hens.
Cantor,  A.H., A.J. Pescatore, J.L. Pierce, M.J. Ford, T. Ao, W.D. King, H.D. Gillespie, M.A. Stovall, and L.M. Macalintal.
The effect of selenium supplementation of low-selenium semi-purified diets on egg production of broiler breeder hens was evaluated. Commercial broiler breeder pullets, 1 day of age, were housed in floor pens. At 6 weeks of age, hens were given age-appropriate low-Se basal diets alone, or supplemented with 0.3 ppm Se as either sodium selenite or selenium yeast (Sel-Plex®, Alltech Inc., Nicholasville, KY). The basal diet consisted of corn, corn starch, soybean meal, torula yeast and vitamins and minerals. The vitamin supplement provided 10 IU of vitamin E per kg diet. Five pens of pullets were assigned to each dietary treatment. At 22 wk of age, the number of hens was reduced to 13 per pen and photostimulation was initiated. Treatments were continued through 40 weeks of the breeding period. Birds were limit-fed according to the breeder management guide recommendations. The unsupplemented breeder basal diet contained 0.02 ppm Se. Egg Se concentration was significantly higher for the Se yeast treatment than for the selenite treatment (0.25 vs. 0.19 ppm). Egg Se levels for these treatments were significantly higher than that for the basal treatment (0.04 ppm). Although some periodic differences were noted in egg production, dietary treatments did not result in a significant effect on overall production during the 40-week period. The results suggest that the rate of egg production was not sensitive to the low-selenium diets, possibly because the diets were supplemented with vitamin E.

2008 INTERNATIONAL POULTRY SCIENTIFIC FORUM

Effect of selenium supplementation of breeder hen diets on tissue selenium concentrations in progeny.
L.M. Macalintal, A.H. Cantor, J.L. Pierce, A.J. Pescatore, T. Ao, M.J. Ford, H.D. Gillespie, and W.D.F. King.
An experiment was conducted to examine the effect of selenium (Se) supplementation of broiler breeder hens on the Se status of their progeny. Breeder hens and roosters were fed a low-Se semi-purified basal diet alone or with 0.3 ppm supplemental Se provided by sodium selenite or Se yeast (Sel-Plex®, Alltech Inc., Nicholasville, KY). Egg Se concentration was significantly higher for the Se yeast treatment than for the selenite treatment (0.25 vs.0.19 ppm). Egg Se levels for these treatments were significantly higher than that for the basal treatment (0.04 ppm). Sixteen replicate groups of five straight-run chicks produced from each of the breeder treatment groups were housed in cages and fed a low-Se corn-soybean meal diet for 21 days. Samples of blood and liver, pooled from two or three birds from each of four pens per breeder treatment, were collected during the trial for Se analysis. On Day 1, plasma Se for the basal treatment (0.02 ppm) was significantly lower (P < 0.05) than the value for both Se-supplemented treatments (0.10 ppm). At Day 13, whole blood Se in chicks from both Se-supplemented treatments was similar (~0.05 ppm) and significantly higher than that for the basal treatment (0.04 ppm). The Se level in liver sampled on Day 1 was significantly higher for chicks from hens supplemented with Se yeast (0.52 ppm, fresh basis) compared with those from the selenite-supplemented hens (0.33 ppm). Liver Se in chicks from the basal treatment was only 0.12 ppm. By Day 22, liver Se levels in chicks from both Se-supplemented groups decreased to ~0.10 ppm but were still higher than that for the basal treatment (0.08 ppm). The results show that the Se status of progeny chicks is improved at hatching by supplementing breeder hens with Se yeast (vs. selenite). However, the benefit is not long lasting when chicks are fed a low Se diet.