---

UDC 636.52/.58:082.2

Received: April 14, 2026

Revised: April 21, 2026

Published: May 29, 2026

This is an Open Access article under the CC BY-NC-ND 4.0 license

 

The study was conducted at the experimental farm “Conservation of the State Poultry Gene Pool” of the State Poultry Research Station of the Livestock Farming Institute of the National Academy of Agrarian Sciences of Ukraine on Birkivska Barvysta egg-type chickens. The paper presents the results of evaluating the nutritional value of dry walnut leaves and compound feeds with different levels of their inclusion, as well as the specific features of nutrient utilization in the diet when this plant material was introduced into the feeding of chickens at levels of 0.5, 1.0, and 1.5%. It was established that dry walnut leaves are characterized by a high content of dry matter, protein, fiber, mineral substances, vitamin E, and pronounced antioxidant activity, and their inclusion in compound feed contributed to an increase in the nutritional and antioxidant value of the diets. The best results were obtained with the inclusion of 1% of the additive. In this group, dry matter digestibility was 77.87% versus 77.00% in the control, organic matter digestibility was 85.73 versus 84.99%, crude protein digestibility was 88.46 versus 87.16%, and nitrogen-free extractives digestibility was 88.84 versus 88.21%. The level of metabolizable energy of the feed was also the highest, at 355.15 kilocalories versus 351.75 kilocalories in the control. With the inclusion of 1.5% dry walnut leaves, the highest digestibility of crude fat and crude fiber was observed; however, this occurred without improvement in the main integral indicators of feed utilization compared with the 1% dose. According to the nitrogen balance, the inclusion of 1% of the additive was accompanied by the highest nitrogen output with the egg, at 0.893 grams per head per day, which indicates more productive utilization of nitrogenous compounds. The practical value of the obtained results lies in substantiating the expediency of using dry walnut leaves in compound feed for laying hens at the level of 1% as the one that ensures the best combination of nutrient digestibility indicators and the energy value of the diet.

References

Abbasi Rad, V., Mirzadeh, K., Mamoyi, M., Tabatabayi, S., & Zarei, M. (2014). The effect of different levels of walnut leaves (Juglans regia L.) powder and vitamin E dietary supplementation on the antioxidant activity of blood, performance and egg traits in commercial laying hens. Animal Sciences Journal, 27(104), 233–242. https://doi.org/10.22092/asj.2014.100219.

Abd El-Hack, M. E., El-Saadony, M. T., Salem, H. M., El-Tahan, A. M., Soliman, M. M., Youssef, G. B. A., Taha, A. E., Soliman, S. M., Ahmed, A. E., El-kott, A. F., Al Syaad, K. M., & Swelum, A. A. (2022). Alternatives to antibiotics for organic poultry production: types, modes of action and impacts on bird’s health and production. Poultry Science, 101(4), Article 101696. https://doi.org/10.1016/j.psj.2022.101696

Abdelli, N., Solà-Oriol, D., & Pérez, J. F. (2021). Phytogenic Feed Additives in Poultry: Achievements, Prospective and Challenges. Animals, 11(12), 3471. https://doi.org/10.3390/ani11123471

Baranovskyi, D. I., Hetmanets, O. M., & Khokhlov, A. M. (2017). Biometriia v prohramnomu seredovyshchi MS Excel: Navchalnyi posibnyk [Biometrics in the MS Excel Environment: A Tutorial]. Kharkiv: FOP Brovin O. V. (in Ukrainian).

Gaviley, O., Chorna, G., Pankova, S., & Poliakova, L. (2024). Assessment of phytochemical characteristics of walnut (Juglans regia) leaves: Determination of nutritional value and quantitative content of phenolic compounds. Research in Agricultural Sciences, 55(3), 151–157. https://doi.org/10.17097/agricultureatauni.1556731

Biswas, S., & Kim, I. H. (2025). A thorough review of phytogenic feed additives in non-ruminant nutrition: production, gut health, and environmental concerns. Journal of Animal Science and Technology, 67(3), 497–519. https://doi.org/10.5187/jast.2025.e26

Bratyshko, N. I., Ionov, I. A., Ibatullin, I. I., Prytulenko, O. V., Klymenko, T. Ye., Kotyk, A. M., Katerynych, O. O., Zhukorskyi, O. M., Haviley, O. V., Polyakova, L. L., & Hrytsenko, R. B. (2013). Efektyvna hodivlia silskohospodarskoi ptytsi [Effective feeding of farm poultry.]. Kyiv: Ahrarna nauka. (in Ukrainian).

Coles, M., Graham, B., Latorre, J., Petrone-Garcia, V., Hernandez-Velasco, H., Castellanos-Huerta, I., San, H., Hargis, B., El-Ashram, S., Shehata, A., & Tellez-Isaías, G. (2023). Essential oils as an alternative to antibiotics to reduce the incidence and severity of necrotic enteritis in broiler chickens: A brief review. Food and Nutritional Sciences, 14, 233–257. https://doi.org/10.4236/fns.2023.143016

Dinnella, C., Minicino, P., D’Andrea, A. M., & Monteleone, E. (2007). Bioavailability and stability of antioxidant activity of phenolic compounds from virgin olive oils during in vitro digestion. Journal of Agricultural and Food Chemistry, 55(21), 8423–8429. https://doi.org/10.1021/jf072244

Engberg, R. M., Jensen, B. B., & Hojberg, O. (2008). Plant of the Juglandaceae family as alternative to antibiotic growth promoters in broiler production. In Proceedings of the 16th European Symposium on Poultry Nutrition (pp. 293–296).

Eratalar, S., Yaman, A., Okur, N., & Karadeniz, T. (2017). Effects of adding walnut meal, green husk and leaves to quail feeds on egg shell and egg yolk colour. Bahçe, 46(2), 71–76.

Gadde, U., Kim, W. H., Oh, S. T., & Lillehoj, H. S. (2017). Alternatives to antibiotics for maximizing growth performance and feed efficiency in poultry: A review. Animal Health Research Reviews, 18(1), 26–45. https://doi.org/10.1017/S1466252316000207

Gaviley, O., Pankova, S., Hurenko, D., & Polyakova, L. (2025). Economic feasibility of using a phyto-supply from walnut leaves in the diets of adult chickens. The Scientific and Technical Bulletin of the Institute of Animal Science NAAS of Ukraine, 135, 27–40. https://doi.org/10.32900/2312-8402-2025-135-27-40.

Hashemi, S. R., & Davoudi, H. (2011). Herbs and their derivatives as growth and health promoters in animal nutrition. Veterinary Research Communications, 35, 169–180. https://doi.org/10.1007/s11259-010-9458-2

Ignatovich, L. S. (2023). Phytobiotics in the diets of laying hens of various crosses: Influence of the genotype on the payment of forage. Siberian Herald of Agricultural Science, 52(6), 85–93. https://doi.org/10.26898/0370-8799-2022-6-10

Ionov, I. A. (2017). Provedennia doslidiv z hodivli silskohospodarskoi ptytsi [The study was conducted on a flock of farm poultry. ]. In I. I. Ibatullin & O. M. Zhukorskyi (Eds.), Metodolohiia ta orhanizatsiia naukovykh doslidzhen u tvarynnytstvi (pp. 163–170). Kyiv: Ahrarna nauka. (in Ukrainian).

Katerynych, O., Pankova, S., Havilei, O., Ryabinina, E., Ionov, I., & Isichenko, N. (2024). Vyroshchuvannia, utrymannia ta hodivlia yaiechnykh i miaso-iaiechnykh kurei: naukovo-praktychnyi posibnyk [Rearing, Care, and Feeding of Laying and Dual-Purpose Hens: A Scientific and Practical Guide]. Agrarna nauka. https://doi.org/10.31073/978-966-540-609-9. (in Ukrainian).

Kostenko, V. M., Panko, V. V., & Syrovatko, K. M. (2008). Praktykum z hodivli silskohospodarskykh tvaryn. Chastyna I. Khimichnyi sklad, otsinka pozhyvnosti ta yakosti kormiv. RVV VDAU.

Lee, J., Oh, S., Oketch, E. O., Nawarathne, S. R., Kim, Y. B., Chathuranga, N. C., Maniraguha, V., Cruz, B. G. Sta., Seo, E., Park, H., Choi, H., Kim, J. K., Lee, D. J., Yu, M., & Heo, J. M. (2025). Dietary protein level in response to nitrogen balance along with production performance of laying hens. Journal of Animal Science and Technology, 67(6), 1313–1327. https://doi.org/10.5187/jast.2500223

Leeson, S., & Summers, J. D. (2001). Energy. In S. Leeson & J. D. Summers, Nutrition of the chicken (pp. 34–99). University Books

Lupu, A., Untea, A., Gavris, T., Olteanu, M., & Panaite, T. (2019). Quality assessment of eggs from laying hens fed with a plant mixture supplement. Scientific Papers: Animal Science & Biotechnologies, 52(1), 19–26.

Masek, A., Latos-Brozio, M., Chrzescijanska, E., & Podsedek, A. (2019). Polyphenolic profile and antioxidant activity of Juglans regia L. leaves and husk extracts. Forests, 10(11), Article 988. https://doi.org/10.3390/f10110988/

Miłek, M., Ciszkowicz, E., Lecka-Szlachta, K., Miłoś, A., Zaguła, G., Pasternakiewicz, A., & Dżugan, M. (2022). Mineral composition, antioxidant, anti-urease, and antibiofilm potential of Juglans regia leaves and unripe fruits. Acta Universitatis Cibiniensis. Series E: Food Technology, 26(1), 69–82. https://doi.org/10.2478/aucft-2022-0006

Muller-Harvey, I. (2006). Solving the mystery of tannins in nutrition and animal health. Journal of the Science of Food and Agriculture, 86(13), 2010–2037. https://doi.org/10.1002/jsfa.2577.

Nantapo, C. W. T., & Marume, U. (2025). Strategic technologies to improve phytogenic feed additive efficacy in pigs and poultry. Animal Nutrition, 23, 286–303. https://doi.org/10.1016/j.aninu.2024.06.010.

National Research Council. (1994). Nutrient requirements of poultry (9th rev. ed.). National Academies Press. https://doi.org/10.17226/2114

Nour, V., Trandafir, I., & Cosmulescu, S. (2016). Optimization of ultrasound-assisted hydroalcoholic extraction of phenolic compounds from walnut leaves using response surface methodology. Pharmaceutical Biology, 54(10), 2176–2187. https://doi.org/10.3109/13880209.2016.1150303

Oni, A. I., & Oke, O. E. (2025). Gut health modulation through phytogenics in poultry: mechanisms, benefits, and applications. Frontiers in Veterinary Science, 12. https://doi.org/10.3389/fvets.2025.1616734.

Pereira, J. A., Oliveira, I., Sousa, A., Valentão, P., Andrade, P. B., Ferreira, I. C. F. R., Ferreres, F., Bento, A., Seabra, R., & Estevinho, L. (2007). Walnut (Juglans regia L.) leaves: Phenolic compounds, antibacterial activity and antioxidant potential of different cultivars. Food and Chemical Toxicology, 45(11), 2287–2295. https://doi.org/10.1016/j.fct.2007.06.004.

Polumbryk, M., Polumbryk, O., Pasichnyi, V., Omelchenko, Kh., & Bal-Prylypko, L. V. (2016). Otsinka antyoksydantnoi aktyvnosti pryrodnykh spoluk [An assessment of the antioxidant activity of natural compounds]. Food Industry of APC, 6, 4–9. (in Ukrainian).

Popescu, R. G., Voicu, S. N., Pircalabioru, G. G., Ciceu, A., Gharbia, S., Hermenean, A., Georgescu, S. E., Panaite, T. D., & Dinischiotu, A. (2020). Effects of dietary inclusion of bilberry and walnut leaves powder on the digestive performances and health of Tetra SL laying hens. Animals, 10(5), 823. https://doi.org/10.3390/ani10050823

Ren, J., Ren, S., Yang, H., & Ji, P. (2025). Effects of phytogenic feed additive on production performance, slaughtering performance, meat quality, and intestinal flora of white-feathered broilers. Veterinary Sciences, 12(5), 396. https://doi.org/10.3390/vetsci12050396

Sharma, M. K., Dinh, T., & Adhikari, P. A. (2020). Production performance, egg quality, and small intestine histomorphology of the laying hens supplemented with phytogenic feed additive. Journal of Applied Poultry Research, 29(2), 362–371. https://doi.org/10.1016/j.japr.2019.12.001.

Suresh, S., D’Souza, P., & Marimuthu, S. (2023). Evaluation of Phytogenic Feed Additive on Egg Production, Egg Quality and Feed Intake in Layer Chicken. European Journal of Veterinary Medicine, 3(1), 12–16. https://doi.org/10.24018/ejvetmed.2023.3.1.58.

Untea, A. E., Varzaru, I., Panaite, T. D., Gavris, T., Lupu, A., & Ropota, M. (2020). The Effects of Dietary Inclusion of Bilberry and Walnut Leaves in Laying Hens’ Diets on the Antioxidant Properties of Eggs. Animals, 10(2), 191. https://doi.org/10.3390/ani10020191.

Windisch, W., Schedle, K., Plitzner, C., & Kroismayr, A. (2008). Use of phytogenic products as feed additives for swine and poultry. Journal of Animal Science, 86(14 Suppl.), E140–E148. https://doi.org/10.2527/jas.2007-0459