Abstract
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).
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
Introduction
Selenium (Se) is an essential trace element which is important for both human and animal health [1]. The first known biological function of Se, as a component of glutathione peroxidase (GSH-Px), was reported in 1973 [2]. GSH-Px catalyzes the reduction of hydrogen peroxide and a variety of organic hydroperoxides using glutathione (GSH) as the hydrogen donor to water and corresponding alcohols to protect cells and membranes from oxidative damage [3]. The activity level of this enzyme in liver or plasma is indicative of selenium supply to the organism. The Se status of avian species has been demonstrated to affect bird’s resistance to different diseases, antioxidant protection level, hatchability, and survival [4–7].
It is known that gray and black elemental selenium are biologically inert. Therefore, the supplementation of feed with selenium is usually limited to sodium selenite and other selenium-containing organic compound. However, the recently developed red elemental selenium has promising uses in the environmental protection from the pollution of the excessive selenium [8–11]. Zhang et al. [8] synthesized nano red elemental selenium (nano-Se) of size 5–100 nm and observed that nano-Se had a similar bioavailability in rat and much less acute toxicity in mice compared with selenite. Recently, an animal trial performed by Wang et al. [12] showed that nano-Se (20–60 nm) possesses equal efficacy in increasing the activities of GSH-Px in plasma and liver from male Kunming mice compared with selenomethionine. Therefore, this study attempted to investigate differential effects of sodium selenite and nano-Se on growth performance, tissue Se distribution, and GSH-Px activity of avian broiler.
Materials and Methods
Experimental Design
Healthy avian (n = 600) were used in this study and reared in an environmentally controlled isolation facility for 42 days. All broiler chickens had similar initial weights (44.8 ± 3.2 g). 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 basal diet used in this experiment was Se-deficient, which contained approximately 0.05 mg kg−1 total Se as determined by atomic absorption spectrophotometer (AA6501, Shimadzu Ltd., Japan). The ingredient and chemical composition were according to the National Research Council, except Se [13]. The control groups were fed basal diets without Se addition during the entire trial period. 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. In this research, nano-Se (30–80 nm) and sodium selenite were provided by Nano-Biology Lab of Zhejiang University, and the actual concentration of selenium in diet was shown in Table 1.
This feeding trial process was acceptable to the commercial producer. The experimental broilers were provided continuous lighting from incandescent lamps in the ceilings of each room, but each brood-grow battery provided an area of subdued light for sleeping and resting. Fresh water was provided on a daily basis during the first week of the experiment to all the broilers and then every other day thereafter. Remaining water from the previous day was discarded before adding fresh water, and the water intake was not measured. The feeding trial was conducted under the supervision of the Animal Care and Use Committee of the university. Body weight, feed intake, feed conversion ratio (FCR), and mortality rate were recorded and analyzed.
Sampling and Analytical Methods
Weight of all collected broilers from each room determined at 2 and 42 days were treated as initial weight and final weight, respectively. The daily weight gain (DWG, g day−1) was calculated as (mean final weight − mean initial weight)/42 (g day−1). The FCR used the following formula: total feed consumption/(total final weight − total initial weight + total mortality weight).
For the Se concentration analysis of broilers tissues, six randomly selected broilers were collected from each group at the end of the experiment and slaughtered by severing the jugular vein. The Se concentration of tissues was determined according to the method described by Tinggi [14] by hydride generation atomic absorption spectrophotometer (AA6501, Shimadzu Ltd.).
At the end of the 6-week dietary treatment, blood was collected into tubes and allowed to coagulate at 4°C for 2 h and then centrifuged (4°C, 3,000 rpm × 10 min). The supernatants were collected and used for the serum GSH-Px assays. The liver samples were also collected and homogenized using a handheld glass homogenizer, respectively, to measure the GSH-Px activity. The enzyme activity of GSH-Px was determined and expressed as specific activity (U mg−1) in liver and as unit per milliliter in serum [15, 16]. All enzymatic assays were conducted within 24 h after extraction.
Statistic Analysis
Analysis of variance was used to determine the significant (P < 0.05) difference between the tested groups. All statistics were performed using SPSS for Windows version 11.5 (SPSS, Chicago, USA).
Results
Growth Performance
DWG, FCR, and survival rate of avian broilers treated with (T-1, T-2, and T-3) or without (control) Se were shown in Table 1. Compared with the control, Se supplementation remarkably improved DWG (P < 0.05). However, analysis of data revealed no difference in DWG between treatments at 42 days, although the highest value was observed in T-3. FCR was better (P < 0.05) in Se-added groups (T-1, 1.98 ± 0.03, T-2, 1.97 ± 0.09, and T-3, 2.01 ± 0.08, respectively) than the control (2.29 ± 0.11), and there were also no significant differences between T-1, T-2, and T-3. As for the survival rate, the lowest value (P < 0.05) was observed in the control than the other treatments. No statistical differences (P > 0.05) were observed in survival rate between T-1 (97.33 ± 1.15), T-2 (98.00 ± 2.00), and T-3 (96.67 ± 1.15; Table 2).
Tissue Concentration of Selenium
The tissue distribution concentration of Se was significantly higher (P < 0.05) in Se-supplemented groups as compared to control groups (Table 3). The level of Se in muscle and liver from avian broiler increased significantly (P < 0.05) in T-3-supplemented with 0.5 mg kg−1 nano-Se than the others after 42 days of feeding. However, no remarkable difference was observed between T-1 added with 0.2 mg kg−1 sodium selenite and T-2 added with 0.2 mg kg−1 nano-Se. Furthermore, higher Se content was observed in liver and there was significantly different (P < 0.05) compared with that in muscle.
GSH-Px Activity
Specific enzyme activities for GSH-Px in serum and liver across all treatments were presented in Figs. 1 and 2. GSH-Px activities (P < 0.05) both in serum and liver were improved remarkably with the Se supplementation during the experimental period. The groups that received the sodium selenite with a concentration 0.2 mg kg−1 (T-1) showed an increasing trend in GSH-Px activity of serum and liver. However, there were no significant differences (P > 0.05) between treatments (T-1, T-2, and T-3).
Discussion
The research of different Se source for their potential use as additives in poultry was still increasing [17–19]. It was clear from our studies that the administration of Se via the basal diet had beneficial effect on avian broiler performance. In the present research, FCR was significantly reduced in groups of Se treatment compared with that of the control. Similar results were observed by Mahmoud and Edens [20] who demonstrated that the FCR of broiler chickens (Gallus gallus) is affected by dietary Se level. Similar improvements in growth performance had been reported for poultry receiving Se [21]. However, there was no significant difference among the treatment groups (T-1, T-2, and T-3) with different source and concentrations of Se. This indicated that the forms and quantity of Se was only one of the factors improving the DWG and FCR of avian broilers.
Poultry diets deficient in selenium result in poor growth and development, increased mortality, reduced egg production, decreased hatchability, pancreatic fibrosis, and muscle myopathies [22–24]. The present research result proved this point, and the control groups fed with basal diet unsupplemented with any forms of Se showed the symptoms of selenium deficiency such as lower survival rate, DWG, and higher FCR. The minimum level of supplemental selenium to sustain growth and performance in broiler chickens was 0.1 mg kg−1 according to the National Research Council. However, the Se content of basal diet was only 0.055 ± 0.007 mg kg−1 and lower than the standard. In contrast, no significant survival increases were detected, and the survival rates of all the groups supplemented with Se (T-1, T-2, and T-3) were 97.33%, 98.00%, and 96.67%, respectively, after 42 days feeding. It indicated that the nano-Se had the same biological functions as sodium selenite in avian broilers. Moreover, no remarkable significance was observed between T-2 and T-3 in the present study, and it suggested from the opposite side that the addition of 0.5 mg kg−1 nano-Se was acceptable in avian feeding.
It was obvious that the tissues with Se content were markedly increased as the dietary Se level increased. Similar results were observed in Rohman laying hens by Pan et al. [25] who reported that breast muscles and whole body, liver, kidney, spleen selenium concentrations were higher in the groups given selenium compared with that of the control. Animal studies have demonstrated that the liver is the major target organ of selenium accumulation [26]. In the present study, higher Se content was observed in liver than in muscle across all treatments.
A substantial research has also defined an important role for Se in antioxidant defense. Se is important for the control of oxidative stress, and therefore the redox state of the cell, due to its incorporation as selenocysteine into GSH-Px [27] and thioredoxin reductase [28]. In this study, broilers fed a diet deficient in Se showed decreased GSH-Px activity in serum and liver. By Supplementation of the diet with Se, both sodium selenite and nano-Se, increased the GSH-Px activity. However, GSH-Px activity was not linearly related to the concentration of the dietary nano-Se. This was not in agreement with the previous studies which showed that the GSH-Px activity increased as a logarithmic function of the dietary selenium (sodium selenite and selenomethionine) level [29]. However, it was difficult to directly assess different studies using Se because the efficacy of a Se application depended on many factors such as species composition and viability, administration level, application method, frequency of application, overall diet, bird age, overall farm hygiene, and environmental stress factors. Essentially, there was no difference in GSH-Px activities both in serum and liver from broilers fed equal gram-atoms of selenium as sodium selenite and as nano-Se in the present research. This indicated that the form of Se was only one of the factors promoting the GSH-Px activity of avian broilers.
Based on the findings of our study, nano-Se could serve as another Se form and successfully improved DWG, FCR, survival rate, tissue Se content, and the GSH-Px activity of avian broilers compared with the control. Furthermore, different tissue Se contents were observed in the groups fed with different concentration nano-Se. However, no significant differences were found in DWG, FCR, survival rate, and GSH-Px activity of serum and liver across all treatments fed with 0.2 mg kg−1 sodium selenite (T-1), 0.2 mg kg−1 nano-Se (T-2), and 0.5 mg kg−1 nano-Se (T-3), respectively. The addition, however, of a different form of Se, especially selenomethionine, the predominant chemical form of organic selenium in feedstuffs, and nano-Se to avian broilers in general requires further research to compare the bioavailability and clearly understand the functional mechanism between the Se and animals. Moreover, modern molecular techniques should be applied to study whether there are other metabolic pathways of nano-Se which differed from sodium selenite and/or selenomethionine.
References
Combs GF, Combs SB (1986) The role of selenium in nutrition. Academic, Toronto
Rotruck JT, Pope AL, Ganther HE, Swanson AB, Hafeman DG, Hoekstra WG (1973) Selenium: biochemical role as a component of glutathione peroxidase. Science 179:585–590
Rayman MP (2000) The importance of selenium to human health. Lancet 356:233–241
Dhur A, Galan P, Hercberg S (1990) Relationship between selenium, immunity and resistance against infection. Comp Biochem Physiol C 96:271–280
Avanzo JL, Junior XM, Cesar CM (2002) Role of antioxidant systems in induced nutritional pancreatic atrophy in chicken. Comp Biochem Physiol B 131:815–823
Pappas AC, Karadas F, Surai PF, Speake BK (2005) The selenium intake of the female chicken influences the selenium status of her progeny. Comp Biochem Physiol B 142:465–474
Golubkina NA, Papazyan TT (2006) Selenium distribution in eggs of avian species. Comp Biochem Phys B 145:384–388
Zhang JS, Gao XY, Zhang LD, Bao YP (2001) Biological effects of a nano red elemental selenium. Biofactors 15:27–38
Zhang JS, Wang H, Yan X, Zhang LD (2004) Comparison of short-term toxicity between nano-Se and selenite in mice. Life Sci 75:447–459
Jia X, Li N, Chen J (2005) A subchronic toxicity study of elemental nano-Se in Sprague Dawley rats. Life Sci 76:1989–2003
Huang B, Zhang J, Hou J, Chen C (2003) Free radical scavenging efficiency of nano-Se in vitro. Free Radic Biol Med 35:805–813
Wang HL, Zhang JS, Yu HQ (2007) Elemental selenium at nano size possesses lower toxicity without compromising the fundamental effect on selenoenzymes: comparison with selenomethionine in mice. Free Radical Bio Med 42:1524–1533
National Research Council (1994) Nutrient requirements of poultry, 9th revised edition. National Academy Press, Washington, DC
Tinggi U (1999) Determination of selenium in meat products by hydride generation atomic absorption spectrophotometry. J AOAC Int 82:364–367
Paglia DE, Valentine WN (1967) Studies on the quantitative and qualitative characterization of erythrocyte glutathione peroxidase. J Lab Clin Med 70:158–169
Lawrence RA, Burke RF (1976) Glutathione peroxidase activity in selenium-deficient rat liver. Biochem Biophys Res Commun 71:952–958
Utterback PL, Parsons CM, Yoon I, Butler J (2005) Effect of supplementing selenium yeast in diets of laying hens on egg selenium content. Poult Sci 84:1900–1901
Zuberbuehler CA, Messikommer RE, Arnold MM, Forrer RS, Wenk C (2006) Effects of selenium depletion and selenium repletion by choice feeding on selenium status of young and old laying hens. Physiol Behav 87:430–440
Singh H, Sodhi S, Kaur R (2006) Effects of dietary supplements of selenium, vitamin E or combinations of the two on antibody responses of broilers. Br Poult Sci 47:714–719
Mahmoud KZ, Edens FW (2005) Influence of organic selenium on hsp70 response of heat-stressed and enteropathogenic Escherichia coli-challenged broiler chickens (Gallus gallus). Comp Biochem Phys C 141:69–75
Choct M, Naylor AJ, Reinke N (2004) Selenium supplementation affects broiler growth performance, meat yield and feather coverage. Br Poult Sci 45:677–683
Gries CL, Scott ML (1972) Pathology of selenium deficiency in the chick. J Nutr 102:1287–1296
Chang WP, Hom JSH, Dietert RR, Combs GF, Marsh JA (1994) Effect of dietary vitamin E and selenium deficiency on chicken splenocyte proliferan and cell surface marker expression. Immunopharm Immunot 16:203–223
Chang WP, Combs GF, Scanes CG, Marsh JA (2005) The effects of dietary vitamin E and selenium deficiencies on plasma thyroid and thymic hormone concentrations in the chicken. Dev Comp Immunol 29:265–273
Pan C, Huang K, Zhao Y, Qin S, Chen F, Hu Q (2007) Effect of selenium source and level in hen’s diet on tissue selenium deposition and egg selenium concentrations. J Agric Food Chem 55:1027–1032
Diskin CJ, Tomasso CL, Alper JC, Glaser ML, Fliegel SE (1979) Long-term selenium exposure. Arch Intern Med 139:824–826
Segalés J, Allan GM, Domingo M (2005) Porcine circovirus diseases. Anim Health Res Rev 6:119–142
Yu HJ, Liu JQ, Böck A, Li J, Luo GM, Shen JC (2005) Engineering glutathione transferase to a novel glutathione peroxidase mimic with high catalytic efficiency. J Biol Chem 280:11930–11935
Omaye ST, Tappel AL (1974) Effect of dietary selenium on glutathione peroxidase in the chick. J Nutr 104:747–753
Acknowledgments
This study was supported by the Doctoral Natural Science Foundation of University (No. 1110XJ-030628). We also acknowledge valuable help provided by all involved workers.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Wang, Y. Differential Effects of Sodium Selenite and Nano-Se on Growth Performance, Tissue Se Distribution, and Glutathione Peroxidase Activity of Avian Broiler. Biol Trace Elem Res 128, 184–190 (2009). https://doi.org/10.1007/s12011-008-8264-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12011-008-8264-y