SUMMARY
Article Details: Received: 2020-08-31 | Accepted: 2020-11-16 | Available online: 2021-06-30https://doi.org/10.15414/afz.2021.24.02.137-140The aim of this study was to analyse the gross energy (GE) value of egg yolk from hens feed with different vegetable oils addition and based on gained results calculate the linear regression between GE and dry matter % (DM) in yolk. Total 66 hens Lohmann brown lite were divided in to 11 groups according to concentration and type of used vegetable oil (pumpkin oil 3%, flax seed oil 3%, indian hemp seed oil 2.5% and 5%, grape seed oil 2.5% and 5%, olive oil 2.5 and 5%, apricot seed oil 2.5% and 5%). Hens were in 40th week of life and were housed per 6 in cage. From each group eight eggs were randomly selected. In total 88 egg yolks were separated and analysed for DM and GE content. The highest yolk GE was detected in group with 3% pumpkin oil addition (1639 kJ/100g) followed by groups with 2.5 and 5% indian hemp seed oil addition 1632 and 1632 kJ/100g, respectively. Difference between these three groups compared to yolk GE content (1584 kJ/100g) in control group was significant (P<0.05). All other added oils increased the yolk GE (P>0.05). GE concertation of yolk can be calculated as follows: GE = -17.34 + (32.73 * DM), R2 = 0.819.Keywords: laying hens, egg yolk gross energy, regressionReferencesAntova, G. A. et al. (2019). Comparative analysis of nutrient content and energy of eggs from different chicken genotypes. Journal of the Science of Food and Agriculture, 99(13), 5890–5898. https://doi.org/10.1002/jsfa.9863AOAC. (2000). Official methods of analysis AOAC. International 17th edition. Association of Analytical Communities, Gaithersburg.Benková, J. (2008). Artificial hatching of poultry is nothing simple. Slovenský chov, 13(6), 45-47. In Slovak.Gálik, B.et al. (2014). The effect of dietary Rhus coriaria L. on table eggs yolk nutrients composition. Acta fytotechnica et zootechnica, 17(3), 93–95. https://doi.org/10.15414/afz.2014.17.03.93-95Herkel, R. et al. (2016). Fatty acid profile and nutritional composition of table eggs after supplementation by pumpkin and flaxseed oils. Acta Veterinaria Brno, 85(3), 277–283. https://doi.org/10.2754/avb201685030277Hrncár, C. & Bujko, J. (2012). Effect of pre-storage incubation of hatching eggs on hatchability of poultry. Acta fytotechnica et zootechnica, 15(2), 34-37. http://www.acta.fapz.uniag.sk/journal/index.php/on_line/article/view/31Javad, N. et al. (2011). Effects of amino acids and metabolizable energy on egg characteristics and broiler breeder performance. African Journal of Biotechnology, 10(49), 10066–10071. https://doi.org/10.5897/ajb11.1268Noble, R. C. et al. (1996). Yolk lipids and their fatty acids in the wild and captive ostrich (Struthio camelus). Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 113(4), 753–756. https://doi.org/10.1016/0305-0491(95)02097-7Pearson, R. A. & Herron, K. M. (1981). Effects of energy and protein allowances during lay on the reproductive performance of broiler breeder hens. British Poultry Science, 22(3), 227–239. https://doi.org/10.1080/00071688108447881Pišteková, V. et al. (2011). The quality comparison of eggs laid by laying hens kept in battery cages and in a deep litter system. Czech Journal of Animal Science, 51(7), 318–325. https://doi.org/10.17221/3945-cjasRadu-Rusu, R. et al. (2014). Chemical features, cholesterol and energy content of table hen eggs from conventional and alternative farming systems. South African Journal of Animal Science, 44(1), 33. https://doi.org/10.4314/sajas.v44i1.5Roe, M. et al. (2013). Nutrient analysis of eggs. Analytical Report (revised version). UK Government, Department of Health and Social Care. Retrieved December 10, 2020 from https://assets.publishing.service.gov.uk/government/uploads/system/ uploads/attachment_data/file/167973/Nutrient_analysis_of_ eggs_Analytical_Report.pdfRoztocilová, A. et al. (2018). Effect of purple wheat RU 687- 12 on performance parameters of laying hens at the end of the lay. In NutriNET 2018. Proceedings of reviewed scientific papers. Mendel University in Brno (pp. 92–97).Vojtaššáková, A. et al. (2000). Milk and eggs. Food nutrition tables. Výskumný ústav potravinársky, Bratislava. In Slovak.Van der Wagt, I. et al. (2020). A review on yolk sac utilization in poultry. Poultry Science, 99(4), 2162–2175. https://doi.org/10.1016/j.psj.2019.11.041Zhang, Y. (2016). Studies on chicken hatchability and its relation with egg yolk metabolites. Dissertation thesis. GeorgAugust-University, Göttingen.