Application of the CI component to enrich marketable eggs with iodine

The composition of iodized milk proteins containing iodotyrosines has iodine covalently bonded to the carbon atom. The authors proposed a term “CI” for it, which denotes a promising source of safe “organic” iodine in feedstuff for poultry. The aim of using this component is production of a functional product enriched with bonded iodine, namely, marketable eggs. The paper presents investigations of an effect of bonded iodine (CI component) included in the feedstuff for laying hens on the content of total iodine and iodotyrosines in eggs as well as on the balance of intake and accumulation of iodine in eggs. The experiment was carried out for eight weeks on laying hens of Lohman-lsl-classic cross. Birds of the control group received combined feed containing iodine in the form of calcium iodate on the basis of 1 mg/kg feed during the whole experiment. The hens of the experimental group received the CI component in addition to the basic diet. From the 1st to the 28th day, an amount of iodine added to the feedstuff of the birds of the experimental group in the composition of iodized milk proteins (IMP) was 0.5 mg/kg feed, and from the 29th to the 56th day it was 0.7 mg/kg feed. The content of total iodine was determined in egg yolk and white by inductively coupled plasma mass spectrometry, amounts of mono- and di-iodotyrosines by highperformance liquid chromatography with mass spectrometry detection. It has been found that inclusion of IMP containing the CI component into the diet of laying hens allows obtaining eggs with a high content (50–74 µg/egg) of iodine, which was significantly higher than the values in the control (14.99 µg/egg). Iodine in eggs was mainly (75%) in bonded, “organic” form as mono- and di-iodotyrosines. A level of iodine assimilation upon its entry into the bird’s body in a form of iodotyrosines was 25–32%, which is significantly higher than this indicator when the inorganic iodine form was used (11%). An absence of side effects for birds and improvement of their health, first of all, the reproduction system was noticed. The experiment on laying hen watering using water enriched with mono- and di-iodotyrosines also showed a positive effect in terms of accumulation of iodine in eggs. The experiment on assessment of preservation of mono- and di-iodotyrosines in eggs after heat treatment supported their high stability to an effect of high temperatures. A degree of preservation was 91%.

1. Platonova, N. M. (2015). Iodine deficiency: Current status. Clinical and Experimental Thyroidology, 11(1), 12–21. (In Russian)

2. Bost, M., Martin, A., Orgiazzi, J. (2014). Iodine deficiency: Epidemiology and nutritional prevention. Trace Elements in Medicine, 15(4), 3–7.

3. Flachowsky, G. (2007). Iodine in animal nutrition and iodine transfer from feed into food of animal origin. Lohmann Information, 42(2), 47–59.

4. Spiridonov, A. A., Murashova, E. V. (2010). Enrichment of products of animal husbandry with iodine. Norms and technologies. St. Petersburg: Beresta, 2010. (In Russian)

5. Damaziak, K., Marzec, A., Riedel, J., Szeliga, J., Koczywąs, E., Cisneros, F. et al. (2018). Effect of dietary canthaxanthin and iodine on the production performance and egg quality of laying hens. Poultry Science, 97(11), 4008–4009. https://doi.org/10.3382/ps/pey264

6. EFSA (2013). Scientific opinion on the safety and efficacy of iodine compounds (E2) as feed additives for all animal species: Calcium iodate anhydrous and potassium iodide, based on a dossier submitted by Ajay Europe SARL. EFSA Journal, 11(2), 3099–3133. https://doi.org/10.2903/j.efsa.2013.3099

7. Sozinov, B., Ermolina, C. (2014). The use of biogenic iodine compounds in the egg poultry farming. Agricultural Science Euro-North-East, 1(38), 48–51. (In Russian)

8. Opalinski, S., Dolinska, B., Korczynski, M., Chojnacka, K., Dobrzanski, Z., Ryszka, F. (2012). Effect of iodine-enriched yeast supplementation of diet on performance of laying hens, egg traits, and egg iodine content. Poultry Science, 91(7), 1627–1632. https://doi.org/10.3382/ps.2011-02031

9. Yamamura, J.-i, Adachi, T., Aoki, N., Nakajima, H., Nakamura, R., Matsuda, T. (1995). Precursor-product relationship between chicken vitellogenin and the yolk proteins: The 40 kDa yolk plasma glycoprotein is derived from the C terminal cysteine-rich domain of vitellogenin II. Biochimica et Biophysica Acta —General Subjects, 1244(2–3), 384–394. https://doi.org/10.1016/0304-4165(95)00033-8

10. Richards, M. P. (1997). Trace mineral metabolism in the avian embryo. Poultry Science, 76(1), 152–164. https://doi.org/10.1093/ps/76.1.152

11. Sumaiya, S., Nayak, S., Baghel, R. P. S., Nayak, A., Malapure, C. D., Kumar R. (2016). Effect of dietary iodine on production of iodine enriched eggs. Veterinary World, 9(6), 554–558. https://doi.org/10.14202/vetworld.2016.554-558

12. Daugeras-Bernard, N., Lachiver, F. (1980). Fonction thyroïdienne et métabolisme de l'iode chez l'embryon de Poulet Reproduction Nutrition Development, 20(1B), 203–207. [Daugeras-Bernard, N., Lachiver, F. (1980). Thyroid function and iodine metabolism in the chicken embryo. Reproduction Nutrition Development, 20(1B), 203–207. (In French)]

13. Wright, C., Leeson, H. (2018) Assessing iodine status in frontline healthcare. Journal of Nutrition Medicine and Diet Care, 4, Article 028. https://doi.org/10.23937/2572-3278.1510028

14. Sarlak, S., Tabeidian, S. A., Toghyani, M., Shahraki, A. D. F., Goli, M., Habibian, M. (2025). Organic iron and iodine in laying hen diet: Performance, egg quality, thyroid hormones, antioxidant status, serum and yolk lipids, and egg iron and iodine contents. Journal of Trace Elements and Minerals, 11, Article 100211. https://doi.org/10.1016/j.jtemin.2025.100211

15. Kulikovskii, A. V., Lisitsyn, A. B, Chernukha, I. M., Gorlov, I. F., Savchuk, S. A. (2016). Determination of iodotyrosines in food. Journal of Analytical Chemistry, 71(12), 1215–1219. https://doi.org/10.1134/S1061934816100087

16. Bakhshalinejad, R., Hassanabadi, A., Nassiri-Moghaddam, H., Zarghi, H. (2018). The effects of dietary calcium iodate on productive performance, egg quality and iodine accumulation in eggs of laying hens. Journal of Animal Physiology and Animal Nutrition, 102(3), 746–754. https://doi.org/10.1111/jpn.12873

17. Słupczyńska, M., Jamroz, D., Orda, J., Wiliczkiewicz, A. (2014). 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 Science, 93(10), 2536–2547. https://doi.org/10.3382/ps.2014-03959

18. Yalcin, S., Kahraman, Z., Yalcin, S., Yalcin, S. S., Dedeoflu, H. E. (2004). Effects of supplementary iodine on the performance and egg traits of laying hens. Bristish Poultry Science, 45(4), 499–503. https://doi.org/10.1080/00071660412331286208

19. Kaufmann, S., Wolfram, G., Delange, F., Rambeck, W. A. (1998). Iodine supplementation of laying hen feed: A supplementary measure to eliminate iodine deficiency in humans? Zeitschrift für Ernährungswissenschaft, 37, 288–293. https://doi.org/10.1007/PL00007378

20. Rizzi, C. (2020). Laying hen biodiversity: A study on the effect of age on the yield performance and quality of eggs produced by two Italian purebred hens. Acta Fytotechnica et Zootechnica, 23, 299–307. https://doi.org/10.15414/afz.2020.23.mi-fpap.296-304

21. Kavtarashvili, A. Sh., Stefanova, I. L., Svitkin, V. S., Novotorov, E. N. (2017). Functional egg production. II. The roles of selenium, zinc, and iodine. Agricultural Biology, 52(4), 700–715. (In Russian)

22. Saki, A. A., Aslani Farisar, M., Aliarabi, H., Zamain, P., Abbasinezhad, M. (2012). Iodine-enriched egg production in response to dietary iodine in laying hens. Journal of Agricultural Technology, 8(4), 1255–1267.

23. Abdel-Malak, N. Y., Osman, S. M. H., Bahakaim, A. S. A., Omar A. S., Ramadan, N. A. (2012). Effect of using different levels of iodine in layer's diets on egg iodine enrichment. Egyptian Poultry Science, 32(4), 851–864.

24. Lichovnikova, M., Zeman, L., Cermakova, M. (2003). The long-term effects of using a higher amount of iodine supplement on the efficiency of laying hens. British Poultry Science, 44(5), 732–734. https://doi.org/10.1080/00071660310001643741

25. Chen, D., Liu, Y., Xu, S. (2023). Supplemental methionine selenium effects on egg yolk physicochemical, functional, and protein structure during storage. Frontiers in Nutrition, 10, Article 1207754. https://doi.org/10.3389/fnut.2023.1207754

26. Kavtarashvili, A. Sh. (2024). Factors affecting internal and external parameters of egg quality in chicken. III. Factors affecting quality of egg yolk (A review). Ptitsevodstvo, 73(10), 61–68. (In Russian)