doi: 10.15389/agrobiology.2017.4.700eng

UDC 636.084.524:637.4.04::[546.23+546.47+546.15

Supported by the grant from Russian Science Foundation under project 16-16-04047 for the development of functional egg products enriched with essential nutrients, optimal metabolic parameters and low allergenicity.



A.Sh. Kavtarashvili, I.L. Stefanova, V.S. Svitkin, E.N. Novotorov

Federal Scientific Center All-Russian Research and Technological Poultry Institute RAS, Federal Agency of Scientific Organizations,10, ul. Ptitsegradskaya, Sergiev Posad, Moscow Province, 141311 Russia, e-mail (corresponding author),,,

The authors declare no conflict of interests


Kavtarashvili A.Sh.

Svitkin V.S.

Stefanova I.L.

Novotorov E.N.

Received May 14, 2017


Different aspects of selenium, zinc, and iodine in the nutrition of laying hens are reviewed in relation to the production of functional eggs enriched with these trace elements. Selenium can be easily transferred into the eggs. Selenium is a part of certain antioxidant selenoproteins (primarily enzyme glutathione-peroxidase) improving antioxidant status and the system of antiradical defense in laying hens; these compounds can also be transferred into eggs improving the oxidative stability of yolk and albumen during egg storage (Z.G. Wang et al., 2010). Recent results of the worldwide research proved that diets for layers (and eggs as a result) should by advisably enriched simultaneously with selenium (M. Fasiangova, G. Borilova, 2017) and vitamin E since this combination of the two most active dietary antioxidants provides the best antioxidative defense in layers and the best antioxidative status of the eggs (Z. Zdunczyk et al., 2013). The organic forms of selenium are shown to be the most effective selenium sources (compared to inorganic sources) due to less toxicity for poultry, better selenium transfer to eggs and deposition into the body selenium pool, primarily in muscle tissues, which can be activated during an oxidative stress (P.F. Surai, V.I. Fisinin, 2016). The combination was also shown to be an effective protector for polyunsaturated fatty acids in yolk lipids (A.Sh. Kavtarashvili et al., 2017). Determination of optimal proportion of selenium and vitamin E in diets for layers requires further research and justification. Zinc is an integral part of antioxidative enzyme superoxide-dismutase (SOD) and lowers oxidative stresses due to the antagonism to the ions of transition metals with high redox potentials. Enrichment of eggs with zinc via high dietary zinc levels improves quality and stability of the albumen during egg storage (H. Aliarabi et al., 2007), eggshell quality, bone development, feather condition and immunity in layers (K.M. Martin, 2016). Supplementation of diets for layers with 50-80 ppm of inorganic or 500-100 ppm of organic zinc will generally not affect their productivity (K. Sahin et al., 2009). Simultaneous enrichment of eggs with selenium and zinc using their high dietary levels is complicated by the antagonism between the two elements which will be possibly overcome due to the development and investigation of their new dietary forms and sources. High dietary iodine levels provide the possibility for the production of iodine-enriched functional eggs; according to EU legislation, however, iodine level in diets of laying birds should not surpass 5 ppm (EU Commission, 2005). Several studies reported the absence of detrimental effects of higher dietary iodine doses (5-10 ppm) on overall productivity in layers while certain egg quality parameters (eggshell thickness and strength, relative albumen weight, Haugh units) decreased with the increase in dietary iodine content (M. Lichovnikova, L. Zeman, M. Cermakova, 2003). Simultaneous enrichment of eggs with selenium and iodine is possible (Yu.A. Ponomarenko, 2015) since these two elements are not antagonists (especially in their organic forms) but rather synergists; the efficiency of different sources and doses of selenium and iodine in combined diet supplementation and transfer to eggs is still to be elucidated.

Keywords: functional eggs, laying hens, selenium, zinc, iodine, dietary levels and sources, egg composition and quality.


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  1. Kavtarashvili A.Sh., Stefanova I.L., Svitkin V.S., Novotorov E.N. Functional
    egg production. I. The role of ω-3 polyunsaturated fatty acids (review). Sel’skokhozyaistvennaya biologiya [Agricultural Biology], 2017, 2: 349-366 CrossRef
  2. Fisinin V., Surai P., Papazyan T. Zhivotnovodstvo Rossii, 2008, 1: 57-61 (in Russ.).
  3. Surai P.F., Fisinin V.I. Natural antioxidants in hens’ embryogenesis and antistress defense in postnatal development (review). Sel’skokhozyaistvennaya biologiya [Agricultural Biology], 2013, 2: 3-18 CrossRef
  4. Mangiapane E., Pessione A., Pessione E. Selenium and selenoproteins: An
    overview on different biological systems. Curr. Protein Rept. Sci., 2014, 15: 598-607 CrossRef
  5. Carlson B.A., Lee B.J., Tsuji P.A., Tobe R., Park J.M., Schweizer U.,Gladyshev V.N., Hatfield D.L. Selenocysteine tRNA [Ser]Sec : From nonsense suppressor
    tRNA to the quintessential constituent in seleprotein biosynthesis. In: Selenium: its molecular biology and role in human health. D.L. Hatfield, U. Schweizer, P.A. Tsuji, V.N. Gladyshev (eds.). Springer, 2016: 3-12 CrossRef
  6. Gao H., Liu C.P., Song S.Q., Fu J. Effects of dietary selenium against lead toxicity on mRNA levels of 25 selenoprotein genes in the cartilage tissue of broiler chicken. Biol. Trace Elem. Res., 2016, 172(1): 234-241 CrossRef
  7. Nasrtdinov R.G., Andreeva A.V. V sbornike: Sovremennye dostizheniya veterinarnoi meditsiny i biotekhnologii — v sel'skokhozyaistvennoe proizvodstvo [Practical application of recent achievements of veterinary medicine and biocenology]. Ufa, 2009: 94-95 (in Russ.).
  8. Chu F.F. Doroshow J.H., Esworthy R.S. Expression, characterization and tissue
    distribution of a new cellular selenium-dependent glutathione peroxidase, GSHPx-GI. J. Biol. Chem., 1993, 268(4): 2571-2576.
  9. Ursini F., Heim S., Kiess M. Dual function of the selenoprotein PHGPx during sperm maturation. Science, 1999, 285(5432): 1393-1396 CrossRef
  10. Pappas A.C., Acamovic T., Sparks N.H.C., Surai P.F., McDevitt R.M. Effects of
    supplementing broiler breeder diets with organic Se and polyunsaturated fatty acids on egg quality. Poultry Sci., 2005, 84(6): 865-874 CrossRef
  11. Mohiti-Asli M., Shariatmadari F., Lotfollahian H., Mazuji M.T. Effects of
    supplementing layer hen diets with Se and vitamin E on egg quality, lipid oxidation and fatty acid composition during storage. Can. J. Anim. Sci., 2008, 88(3): 475-483 CrossRef
  12. Wang Z.G., Pan X.J., Zhang W.Q., Peng Z.Q., Zhao R.Q., Zhou G.H. Methionine and Se yeast supplementation of the maternal diets affects antioxidant activity of breeding eggs. Poultry Sci., 2010, 89(5): 931-937 CrossRef
  13. Surai P.F., Fisinin V.I. Selenium in livestock and other domestic animals. In: Selenium: its molecular biology and role in human health. D.L. Hatfield, U. Schweizer, P.A. Tsuji, V.N. Gladyshev (eds.). Springer, 2016: 595-606 CrossRef
  14. Gulyushin S.Yu., Kovalev V.O. State of antiradical protection system in broilers during use of selenium containing preparations on the background of toxic feed (review). Sel’skokhozyaistvennaya biologiya [Agricultural Biology], 2009, 4: 14-25 (in Russ.).
  15. Bartholomew A., Latshaw D., Swayne D.E. Changes in blood chemistry, hematology, and histology caused by a selenium/vitamin E deficiency and recovery in chicks. Biol. Trace Elem. Res., 1998, 62(1): 7-16 CrossRef
  16. Combs G.F., Hady M.M. Selenium involved with vitamin E in preventing encephalomalacia in the chick. FASEB J., 1991, 5(4): A714.
  17. Combs G.F. Clinical implications of selenium and vitamin E in poultry nutrition. Vet. Clin. Nutr., 1994, 1: 133-140.
  18. Soffietti M.G., Nebbia C., Valenza F. Chronic experimental toxicity of cystine selenate in fowls. Clinical and pathological findings. Note I. Clin. Vet., 1983, 106(5): 97-106.
  19. Khan M.Z., Szerek J., Markiewicz K. Effects of oral administration of toxic levels of lead and selenium upon concentration of different elements in the liver of broiler chicks. Zentralbl. Veterinarmed. A, 1993, 40(9-10): 652-664 CrossRef
  20. Qi Z.Y., Han B., Qin S., Hou J.W., Dong Q.A., Zhang B.X., Liu B.F. The studies of experimental organic selenium toxicosis in growing chickens. Acta Vet. Zootech. Sinica, 1992, 123: 281-284.
  21. Salyi G., Banhidi G., Szabo E., Gonye S., Ratz F. Acute selenium poisoning in
    broilers. Magyar Állatorvosok Lapja, 1993, 48: 22-26.
  22. Tishkov A.I., Voitov L.I. Veterinariya, 1989, 11: 65-67 (in Russ.).
  23. Akulov V.A., Minina L.A., Andreev M.N., Tomskikh Yu.I., Bronnikova K.A., Korenkov I.P. Sel’skokhozyaistvennaya biologiya [Agricultural Biology], 1972, 3: 430- 436 (in Russ.).
  24. Zeng H., Cao J.J., Combs G.F. Jr. Selenium in bone health: roles in antioxidant protection and cell proliferation. Nutrients, 2013, 5(1): 97-110 CrossRef
  25. Surai P.F. Selenium in poultry nutrition 1. Antioxidant properties, deficiency and toxicity. World's Poultry Sci. J., 2002, 58(3): 333-347 CrossRef
  26. Celi P., Selle P.H., Cowieson A.J. Effects of organic selenium supplementation on growth performance, nutrient utilization, oxidative stress and selenium tissue concentrations in broiler chickens. Anim. Prod. Sci., 2014, 54: 966-971 CrossRef
  27. Karpova E.A., Demidenko O.K., Il'ina O.P. Vestnik KrasGAU, 2014, 4: 207-210 (in Russ.).
  28. Radwan N.L., Salah Eldin T.A., El-Zaiat A.A., Mostafa A.S.A. Effects of dietary
    nano-selenium supplementation on selenium content and oxidative stability in table eggs and productive performance of laying hens. Int. J. Poultry Sci., 2015, 14(3): 161-176 CrossRef
  29. Mohapatra P., Swain R.K., Mishra S.K., Behera T., Swain P., Mishra S.S.,
    Behura N.C., Sabat S.C., Sethy K., Dhama K., Jayasankar P. Effects of dietary
    nano-selenium on tissue selenium deposition, antioxidant status and immune functions in layer chicks. Int. J. Pharmac., 2014, 10(3): 160-167 CrossRef
  30. Sunde R.A., Hoekstra W.G. Incorporation of selenium from selenite and selenocystine into glutathione peroxidase in the isolated perfused rat liver. Biochem. Biophys. Res. Commun., 1980, 93(4): 1181-1188 CrossRef
  31. Galochkin V.A., Galochkina V.P. Organic and mineral forms of selenium, their
    metabolism, biological availability and role. Sel’skokhozyaistvennaya biologiya [Agricultural Biology], 2011, 4: 3-15 (in Russ.)
  32. Shini S., Sultan A., Bryden W.L. Selenium biochemistry and bioavailability: Implications for animal agriculture. Agriculture, 2015, 5(4): 1277-1288 CrossRef
  33. Behne D., Kyriacopoulos A. Mammalian selenium-containing proteins. An. Rev. Nutr., 2001, 21: 453-473 CrossRef
  34. Bierla K., Dernovics M., Vacchina V., Szpunar J., Bertin G., Lobinski R. Determination of selenocysteine and selenomethionine in edible animal tissues by 2D size- exclusion reversed-phase HPLC-ICP MS following carbamidomethylation and proteolytic extraction. Anal. Bioanal. Chem., 2008, 390(7): 1789-1798 CrossRef
  35. Wolffram S. Absorption and metabolism of selenium: Difference between organic and inorganic sources. In: Biotechnology in the feed industry. T.P. Lyons, K.A. Jacques (eds.). Nottingham Univ. Press, Nottingham, UK, 1999: 547-566.
  36. Drevko B.I., Antipov V.A., Zhukov O.I., Fomenko L.A., Markova L.I., Drevko R.I., Rodionova T.N., Efremov V.I., Kharchenko V.G. Sredstvo dlya lecheniya i profilaktiki boleznei, vyzyvaemykh nedostatochnost'yu selena v organizme sel'skokhozyaistvennykh zhivotnykh i ptits. Patent RU 2051681. Zayavka № 93045743/15, 1993. Opubl. 10.01.1996. Byul. № 1 [A medicine to treat and protect farm animals and poultry against diseases caused by selenium deficit. Patent RU 2051681. Appl. № 93045743/15, 1993. Publ. January 10, 1996. Bul. № 1] (in Russ.).
  37. Papazyan T.T., Fisinin V.I., Surai P.F. Ptitsa i ptitseprodukty, 2009, 2: 21-24 (in Russ.).
  38. Papazyan T.T., Fisinin V.I., Surai P.F. Ptitsa i ptitseprodukty, 2009, 1: 37-39 (in Russ.).
  39. Skrivan M., Marounek M., Dlouhá G., Sevcíková S. Dietary selenium increases vitamin E contents of egg yolk and chicken meat. Br. Poultry Sci., 2008, 49(4): 482-486 CrossRef
  40. Tiwary A.K., Stegelmeier B.L., Panter K.E., James L.F., Hall J.O. Comparative toxicosis of sodium selenite and selenomethionine in lambs. J. Vet. Diagn. Invest., 2006, 18: 61-70 CrossRef
  41. Zdunczyk Z., Drazbo A., Jankowski J., Juskiewicz J., Czech A., Antoszkiewicz Z. The effect of different dietary levels of vitamin E and selenium on antioxidant status and immunological markers in serum of laying hens. Polish J. Vet. Sci., 2013, 16(2): 333-339 CrossRef
  42. Iqbal R., Aziz T., Sarfaraz I., Shabir R., Ansari M.S., Malik M.F., Saleem R., Zahra A., Mehwish S. Effect of vitamin E and selenium on immunity, egg production and liver function in laying hens. Middle-East J. Sci. Res., 2013, 14(9): 1165-1170.
  43. Jing C.L., Dong X.F., Wang Z.M., Liu S., Tong J.M. Comparative study of DL-selenomethionine vs sodium selenite and seleno-yeast on antioxidant activity and selenium status in laying hens. Poultry Sci., 2015, 94(5): 965-975 CrossRef
  44. Aljamal A.A., Purdum S.E., Hanford K.J. The effect of normal and excessive supplementation of selenomethionine and sodium selenite in laying hens. Intl. J. Appl. Poultry Res., 2014, 3(3): 33-38.
  45. Kavtarashvili A.SH., Novotorov E.N., Stefanova I.L., Svitkin V.S. Ptitsevodstvo, 2017, 2: 6-10 (in Russ.).
  46. Fasiangova M., Borilova G. Impact of Se supplementation on the oxidation stability of eggs. World’s Poultry Sci. J., 2017, 73(1): 175-184 CrossRef
  47. Scheideler S.E., Weber P., Monsalve D. Supplemental vitamin E and selenium effects on egg production, egg quality, and egg deposition of a-tocopherol and selenium. J. Appl. Poultry Res., 2010, 19: 354-360 CrossRef
  48. Mohiti-Asli M., Shariatmadari F., Lotfollahian H. The influence of dietary vitamin E and selenium on egg production parameters, serum and yolk cholesterol and antibody response of laying hens exposed to high environmental temperature. Arch. Geflügelk., 2010, 74(1): 43-50.
  49. Skrivan M., Bubancová I., Marounek M., Dlouhá G. Selenium and a-tocopherol content in eggs produced by hens that were fed diets supplemented with selenomethionine, sodium selenite and vitamin E. Czech J. Anim. Sci., 2010, 55(9): 388-397.
  50. Maret W. Zinc biochemistry: From a single zinc enzyme to a key element of life. Adv. Nutr., 2013, 4(1): 82-91 CrossRef
  51. Sahin K., Sahin N., Kucuk O., Hayirli A., Prasad A.S. Role of dietary zinc in heat-stressed poultry: A review. Poultry Sci., 2009, 88(10): 2176-2183 CrossRef
  52. Niles B.J., Clegg M.S., Hanna L.A., Chou S.S., Momma T.Y., Hong H., Keen C.L. Zinc deficiency-induced iron accumulation, a consequence of alterations in iron regulatory protein-binding activity, iron transporters and iron storage proteins. J. Biol. Chem., 2008, 283(8): 5168-5177 CrossRef
  53. Washabaugh M.W., Collins K.D. Dihydroorotase from Escherichia coli. Sulfhydryl group metal ion interactions. J. Biol. Chem., 1986, 261(13): 5920-5929.
  54. Tse-Dinh Y.C., Beran-Steed R.K. Escherichia coli DNA topoisomerase I is a zinc metalloprotein with three repetitive zinc-binding domains. J. Biol. Chem., 1988, 263(31): 15857-15859.
  55. Fu H.W., Moomaw J.F., Moomaw C.R., Casey P.J. Identification of a cysteine residue essential for activity of protein farnesyltransferase. Cys299 is exposed only upon removal of zinc from the enzyme. J. Biol. Chem., 1996, 271(45): 28541-28548 CrossRef
  56. Oteiza P.L., Olin K.L., Fraga C.G., Keen C.L. Oxidant defense systems in testes from zinc deficient rats. Proc. Soc. Experim. Biol. Med., 1996, 213(1): 85-91 CrossRef
  57. Kidd M.T., Ferket P.R., Qureshi M.A. Zinc metabolism with special reference to its role in immunity. World’s Poultry Sci. J., 1996, 52(3): 309-324 CrossRef
  58. Underwood E.J. The mineral nutrition of livestock. Commonwealth Agriculture Bureau, Slough, UK, 1981.
  59. Dewar W.A., Wight P.A.L., Pearson R.A., Gentle M.J. Toxic effects of high concentrations of zinc oxide in the diet of the chick and laying hen. Brit. Poultry Sci., 1983, 24(3): 397-404 CrossRef
  60. Giordano P.M., Mortvedt J.J., Mays D.A. Effect of municipal wastes on crop yields and uptake of heavy metals. J. Environ. Qual., 1975, 4: 349-399 CrossRef
  61. Kim W.K., Patterson P.H. Effects of dietary zinc supplementation on broiler performance and nitrogen loss from manure. Poultry Sci., 2004, 83(1): 34-38 CrossRef
  62. NRC. Nutrient requirements of poultry. 9th Ed. National Academic Press, Washington, D.C., 1994.
  63. Ao T., Pierce J.L., Pescatore A.J., Cantor A.H., Dawson K.A., Ford M.J., Shafer B.L. Effects of organic zinc and phytase supplementation in a maize-soybean meal diet on the performance and tissue zinc content of broiler chicks. Br. Poultry Sci., 2007, 48(6): 690-695 CrossRef
  64. Salim H.M., Jo C., Lee B.D. Zinc in broiler feeding and nutrition. Avian Biol. Res., 2008, 1(1): 5-18 CrossRef
  65. Star L., van der Klis J.D., Rapp C., Ward T.L. Bioavailability of organic and inorganic zinc sources in male broilers. Poultry Sci., 2012, 91(12): 3115-3120 CrossRef
  66. Salim H.M., Lee H.R., Jo C., Lee S.K., Lee B.D. Effect of sources and levels of zinc on the tissue mineral concentration and carcass quality of broilers. Avian Biol. Res., 2010, 3(1): 23-29 CrossRef
  67. Pimentel J.L., Cook M.E., Greger J.L. Research note: Bioavailability of zinc-methionine for chicks. Poultry Sci., 1991, 70(7): 1637-1639 CrossRef
  68. Cao J., Henry P.R., Guo R., Holwerda R.A., Toth J.P., Littell R.C., Miles R.D., Ammerman C.B. Chemical characteristics and relative bioavailability of supplemental organic zinc sources for poultry and ruminants. J. Anim. Sci., 2000, 78(8): 2039-2054 CrossRef
  69. Burrell A.L., Dozier W.A., Davis A.J., Compton M.M., Freeman M.E., Vendrell P.F., Ward T.L. Responses of broilers to dietary zinc concentrations and sources in relation to environmental implications. Br. Poultry Sci., 2004, 45(2): 225-263 CrossRef
  70. Hudson B.P., Dozier W.A., Wilson J.L., Sander J.E., Ward T.L. Reproductive performance and immune status of caged broiler breeder hens provided diets supplemented with either inorganic or organic sources of zinc from hatching to 65 wk of age. J. Appl. Poult. Res., 2004, 13(2): 349-359 CrossRef
  71. Aliarabi H., Ahmadi S.A., Hosseini-Siyar M.M., Tabatabie A., Saki K.H., Ashori N. Effect of different level and sources of zinc on egg quality and layer performance. Proc. Aust. Poultry Sci. Symp., 2007, 19: 102-105.
  72. Stefanello C., Santos T.C., Murakami A.E., Martins E.N., Carneiro T.C. Productive performance, eggshell quality, and eggshell ultrastructure of laying hens fed diets supplemented with organic trace minerals. Poultry Sci., 2014, 93(1): 104-113 CrossRef
  73. Manangi M.K., Vazques-Anon M., Richards J.D., Carter S., Knight C.D. The impact of feeding supplemental chelated trace minerals on shell quality, tibia breaking strength, and immune response in laying hens. J. Appl. Poult. Res., 2015, 24(3): 316-326 CrossRef
  74. Bahakaim A.S.A., Abdel Magied H.A., Osman S.M.H., Omar A.S., Abdel Malak N.Y., Ramadan N.A. Effect of using different levels and sources of zinc in layer’s diets on egg zinc enrichment. Egypt. Poultry Sci., 2014, 34(1): 39-56.
  75. Martin K.M. The effects of zinc supplementation from two sources on egg quality and bone health in laying hens. PhD Thes. Lincoln, Univ. of Nebraska, 2016.
  76. Onderci M., Sahin N., Sahin K., Kilic N. Antioxidant properties of chromium and zinc: in vivo effects on digestibility, lipid peroxidation, antioxidant vitamins, and some minerals under a low ambient temperature. Biol. Trace Elem. Res., 2003, 92(2): 139-150 CrossRef
  77. Bun S.D., Guo Y.M., Guo F.C., Ji F.J., Cao H. Influence of organic zinc supplementation on the antioxidant status and immune responses of broilers challenged with Eimeria tenella. Poultry Sci., 2011, 90(6): 1220-1226 CrossRef
  78. Plaimast H., Sirichakwal P.P., Puwastien P., Judprasong K., Wasantwisut E.In vitro bioaccessibility of intrinsically zinc-enriched egg and effect of cooking. J. Food Compos. Anal., 2009, 22(7-8): 627-631 CrossRef
  79. Fernandez I.B., Cruz V.C., Polycarpo G.V. Effect of dietary organic selenium and zinc on the internal egg quality of quail eggs for different periods and under different temperatures. Rev. Bras. Cienc. Avic., 2011, 13(1): 35-41 CrossRef
  80. House W.A., Welch R.M. Bioavailability of and interactions between zinc and selenium in rats fed wheat grain intrinsically labeled with 65Zn and 75Se. J. Nutr., 1989, 119(6): 916-921.
  81. Hetzel B., Mano M.T. A review of experimental studies of iodine deficiency during fetal development. J. Nutr., 1989, 119(2): 145-152.
  82. Spiridonov A., Kislova O. Ptitsevodstvo, 2011, 3: 21-25 (in Russ.).
  83. Flynn A., Moreiras O., Stehle P., Fletcher R.J., Mueller D.J.G., Rol-
    land V. Vitamins and minerals: a model for safe addition to foods. Eur. J. Nutr., 2003, 42(2): 118-130 CrossRef
  84. Lewis P.D. Responses of domestic fowl to excess iodine: a review. Brit. J. Nutr., 2004, 91(1): 29-39 CrossRef
  85. Proudman J.A., Siopes T.D. Relative and absolute photorefractoriness in turkey hens: profiles of prolactin, thyroxine, and triiodothyronine early in the reproductive cycle. Poultry Sci., 2002, 81 (8): 1218-1223 CrossRef
  86. Wentworth B.C., Ringer R.K. Thyroids. In: Avian physiology. P.D. Sturkie (ed.). Springer Verlag, 2012: 453.
  87. Podobed L.I., Stepanenko A.N., Kapitonova E.A. Rukovodstvo po mineral'nomu pitaniyu sel'skokhozyaistvennoi ptitsy [Mineral nutrition in piultry — recommendations]. Odessa, 2016 (in Russ.).
  88. Slupczynska M., Jamroz D., Orda J., Wiliczkiewicz A. Effect of various sources and levels of iodine, as well as the kind of diet, on the performance of young laying hens, iodine accumulation in eggs, egg characteristics, and morphotic and biochemical indices in blood. Poultry Sci., 2014, 93(10): 2536-2547 CrossRef
  89. Draganov I.F., Fisinin V.I., Kalashnikov V.V., Ushakov A.S. Mineral'noe pitanie zhivotnykh [Mineral nutrition of animals]. Moscow, 2012 (in Russ.).
  90. Dolinska B., Opalinski S., Zielinski M., Chojnacka K., Dobrzanski Z., Ryszka F. Iodine concentration in fodder influences the dynamics of iodine levels in hen's egg components. Biol. Trace Elem. Res., 2011, 144(1-3): 747-752 CrossRef
  91. Sumaiya S., Nayak S., Baghel R.P.S., Nayak A., Malapure C.D., Kumar R. Effect of dietary iodine on production of iodine enriched eggs. Vet. World, 2016, 9(6): 554-558 CrossRef
  92. Kroupova V., Travnicek J., Kursa J., Kratochvil P., Krabacova I. Iodine content in egg yolk during excessive intake by laying hens. Czech J. Anim. Sci., 1999, 44: 369-376.
  93. Charoensiriwatana W., Srijantr P., Tecyapant P., Wongvilairattana J. Consuming iodine enriched eggs to solve the iodine deficiency endemic for remote areas in Thailand. Nutr. J., 2010, 9: 68 CrossRef
  94. Fisinin V.I., Egorov I.A., Egorova T.V., Rozanov B.L., Yudin S.M. Ptitsa i ptitseprodukty, 2011, 4: 37-40 (in Russ.).
  95. Rottger A.S., Halle I., Wagner H., Breves G., Danicke S., Flachowsky G. The effects of iodine level and source on iodine carry-over in eggs and body tissues of laying hens. Arch. Anim. Nutr., 2012, 66(5): 385-401 CrossRef
  96. Shelor C.P., Dasgupta P.K. Review of analytical methods for the quantification of iodine in complex matrices. Anal. Chim. Acta, 2011, 702(1): 16-36 CrossRef
  97. Miskiniene M., Kepaliene I., Bobinene R., Gudaviciute D., Eider J. Application of «Jodis» as a stable source of iodine in the nutrition of laying hens. Bull. Vet. Inst. Pulawy, 2010, 54: 389-392.
  98. Opalinski S., Dolinska B., Korczynski M., Chojnacka K., Dobrzan-
    ski Z., Ryszka F. Effect of iodine-enriched yeast supplementation of diet on performance of laying hens, egg traits, and egg iodine content. Poultry Sci., 2012, 91(7): 1627-1632 CrossRef
  99. EU Commission. Commission Regulation (EC) No 1459/2005 amending the conditions for authorization of a number of feed additives belonging to the group of trace elements. Off. J. Eur. Union, 2005: L 233/8-233/10.
  100. Lichovnikova M., Zeman L., Cermakova M. The long-term effects of using a higher amount of iodine supplement on the efficiency of laying hens. Brit. Poultry Sci., 2003, 44(5): 732-734 CrossRef
  101. Yalçin S., Kahraman Z., Yalçin S., Yalçin S.S., Dedeoglu H.E. Effects of supplementary iodine on the performance and egg traits of laying hens. Brit. Poultry Sci., 2004, 45(4): 499-503 CrossRef
  102. Abdel-Malak N.Y., Osman S.M.H., Bahakaim A.S.A., Omar A.S., Rama-
    dan N.A. Effect of using different levels of iodine in layer's diets on egg iodine enrichment. Egypt. Poult. Sci., 2012, 32(4): 851-864.
  103. Serakides R., Nunes V.A., Nascimento E.F., Silva C.M., Ribeiro A.F.C. Relationship between thyroid gonads and plasmatic levels of phosphorus, calcium and alkaline phosphates in rats. Arq. Bras. Med. Vet. Zoot., 2000, 52(6): 579-585.
  104. Sumaiya S., Nayak S., Baghel R.P.S., Khare A., Malapure C.D., Kumar R. Performance and nutrient utilization in laying hens fed iodine supplemented diets. Ind. J. Anim. Nutr., 2016, 33(3): 326-330 CrossRef
  105. Saki A.A., Farisar M.A., Aliarabi H., Zamani P., Abbasinezhad M. Iodine enriched egg production in response to dietary iodine in laying hens. J. Agric. Technol., 2012, 8(4): 1255-1267.
  106. Oliva T.V., Gorshkov G.I. Sovremennye problemy nauki i obrazovaniya, 2014, 5: 612 (in Russ.).
  107. Krasnoyartsev G.V. Otechestvennoe ptitsevodstvo — osnova lechebno-profilaktiche-skikh preparatov s primeneniem skorlupy yaits. Mat. XI Int. Sci. Pract. Conf. «Fundamental and Applied Science-2015». Sheffield (UK), 2015, 14: 77-81.
  108. Hotz C.S., Fitzpatrick D.W., Trick K.D., L'Abbé M.R. Dietary iodine and selenium interact to affect thyroid hormone metabolism of rats. J. Nutr., 1997, 127(6): 1214-1218.
  109. Egorov I., Ponomarenko Yu. Kombikorma, 2007, 3: 79-80 (in Russ.).
  110. Ponomarenko Yu.A. Effect of high doses of iodine and selenium on the egg-laying capacity of hens and accumulation of these micronutrients in eggs. Rus. Agric. Sci., 2015, 41(4): 280-284 CrossRef