Pojava elemenata u tragovima u goveđem mesu

The occurrence of trace metals (Cu, Zn) was determined in cattle meat from the vicinity of a metallurgical plant. Copper and zinc concentrations in 62 samples of muscles and liver collected from (31) cows were quantified and compared with results in other countries. In our study mean muscle Zn and Cu concentrations were higher in liver (67.314; 44.205 mg/kg w. wt) compared to muscle (38.865; 1.993 mg/kg w. wt). It can be concluded that bioaccumulation of Zn and Cu in cattle meat in industrial areas could be slightly enhanced, differently in dependence on the types of industry prevailing in various countries.Pojava elemenata u tragovima (Cu, Zn) određivana je u mesu goveda uzgajanih u blizini metalurškog postrojenja. Koncentracije bakra i cinka u 62 uzorka mišića i jetre uzetih od 31 krave kvantificirane su i uspoređene s rezultatima iz drugih zemalja. U našem su ispitivanju koncentracije Cu i Zn bile više u jetri (67,314; 44,205 mg/kg v. t.) od onih u mišićju (38,865; 1,993 mg/kg v. t.). Može se zaključiti da bi bioakumulacija Zn i Cu u mesu goveda mogla biti nešto povećana i različita ovisno o vrsti industrije koja prevladava u raznim zemljama

Vplyv prídavku humínových látok u mladých prasiat na rast, parametre exkrécie a mikrobiológiu trusu

The aim of this research was to investigate the influence of dietary humic substances on growth efficiency, faeces indicators, and the bacteriological composition of faeces in piglets. Twenty-four crossbred young pigs (Slovakian White x Landrace) in total were allotted into two groups: the experimental and the control groups. They were fed a diet with humic substances supplemented at 0.5% in the experimental group. In this study, there were no significant differences in the monitored production indicators of piglets. The addition of humic substances increased the dry matter of faeces in the experimental group (P < 0.001). Other indicators in the faeces samples were not significantly affected by dietary treatment. We observed a significant decrease in the counts of coliform bacteria in the faeces (P < 0.05) of the experimental group. The results also showed a tendency to increase the counts of the lactic acid bacteria and a decrease in the counts of the Enterobacteriaceae in the piglets’ experimental group compared to the control group. A decrease in coliform bacteria counts in the faeces of experimental animals showed a positive effect on the microbiota in the intestine. It was concluded that the addition of humic substances to the diet of piglets could have a positive impact on gut flora without having a negative effect on production performance or other fecal characteristics.Cieľom tejto štúdie bolo hodnotiť vplyv humínových látok v krmive na rastovú výkonnosť, vlastnosti trusu a bakteriologické zloženie vzoriek trusu u prasiatok. Celkom 24 krížencov (Slovenská biela × Landrace) bolo rozdelených do dvoch skupín: kontrolná skupina a experimentálna skupina. Boli kŕmené kŕmnou zmesou doplnenou o prídavok humínových látok v množstve 0,5% v experimentálnej skupine. V tejto štúdii neboli zistené signifikantné rozdiely v sledovaných produkčných ukazovateľoch prasiatok (telesná hmotnosť, prírastok telesnej hmotnosti a konverzia krmiva). Suplementácia humínových látok zvýšila obsah sušiny v truse v porovnaní v experimentálnej skupine (P < 0,001). Ostatné sledované parametre vo vzorkách trusu neboli významne ovplyvnené príjmom krmiva s prídavkom humínových látok. Pozorovali sme významný pokles počtu koliformných baktérií vo výkaloch (P < 0,05) experimentálnej skupiny. Výsledky tiež ukázali tendenciu zvyšovania počtu baktérií mliečneho kvasenia a poklesu počtu Enterobacteriaceae v experimentálnej skupine prasiatok v porovnaní s kontrolnou skupinou. Pokles počtu koliformných baktérií vo výkaloch pokusných zvierat preukázal pozitívny vplyv na črevnú mikroflóru. Dospelo sa k záveru, že prídavok humínových látok do krmiva prasiatok by mohol mať pozitívny vplyv na črevnú flóru bez negatívneho vplyvu na produkčné parametre alebo iné vlastnosti trusu

Effect of humic acid substances on proteolytic activity in intestine, digestibility of crude protein and protein content in the blood of broiler chickens

Article Details: Received: 2020-10-18 | Accepted: 2020-11-27 | Available online: 2021-01-31https://doi.org/10.15414/afz.2021.24.mi-prap.159-163The objective of the study was to investigate the effects of dietary intake of humic substances (HS) on the proteolytic activity and the digestibility of crude protein (CP) measured as the apparent assimilable mass coefficient of CP corrected for protein catabolism (AMCN) in the intestine as well as on the total protein and albumin content in the serum of broiler chickens (Cobb 500, n=120). Chickens (groups A, B, C / negative control) were fed with mixtures with CP (g.kg-1 DM) – Hyd1 230.20 (d 1-7), Hyd2 222.20 (d 8-28), Hyd3 209.40 (d 29-37) for 37 days. The humic substances were added into diets of experimental groups in the feed additive according to the content of humic/fulvic acids (HA/FA; g.kg-1) A 4.55/0.35, B 3.99/0.35, C 2.85/0.25. The body weights and feed consumption were measured once a week. The average daily weight gains and the feed conversion ratio were calculated. The dietary intake of HS had a positive effect on the increase of proteolytic activities in the intestinal apparatus and caused the significant enhancement of AMCN of birds from experimental groups on days 17, 24 and 31. However, the values of the total protein and the albumin in the serum were significantly decreased in the groups after intake of HA/FA 4.55/0.35 or 3.99/0.35 in the feed.Keywords: gut of poultry, humates, enzymatic activity, crude protein, albuminReferencesArif, M. et al. (2016). Impacts of dietary humic acid supplementation on growth performance, some blood metabolites and carcass traits of broiler chicks. Indian Journal of Animal Sciences, 86(9), 1073–1078.Broderick, G. A. (1987). Determination of protein degradation rates using a rumen in vitro system containing inhibitors of microbial nitrogen metabolism. British Journal of Nutrition, 58(3), 463–475. 10.1079/bjn19870114 Carvalho, L. H. M., De Koe, T. and Tavares, P. B. (1998). An improved molybdenum blue method for simultaneous determination of inorganic phosphate and arsenate. Ecotoxicology and Environmental Restoration, 1(1), 13–19.Cunniff, P. (1995). Official Methods of Analysis of Association of Official Analytical Chemists. 16th edn., Arlington, Va, USA: AOAC International.Daněk, P., Paseka, A., Smola, J., Ondráček, J., Bečková, R. and Rozkot, M. (2005). Influence of lecithin emulsifier on the utilisation of nutrients and growth of piglets after weaning. Czech Journal of Animal Science,50, 459–465. https://doi.org/10.17221/4245-CJASEuropean Commission (2009). Commission Regulation (EC) No 152/2009 of 27 January 2009 laying down the methods of sampling and analysis for the official control of feed. Official Journal of European Union, 54, 1–130.Gomez-Rosales, S. and Angeles, M. D. (2015). Addition of a worm leachate as source of humic substances in the drinking water of broiler chickens. Asian-Australasian Journal of Animal Sciences, 28(2), 215–222. 10.5713/ajas.14.0321Grieninger, G. and Granick, S. (1975). Synthesis and differentiation of plasma proteins in cultured embryonic chicken liver cells: a system for study of regulation of protein synthesis. Proceedings of the National Academy of Sciences of USA, 72(12), 5007–5011. 10.1073/pnas.72.12.5007Gugliemo C. G. and Karasov W. H. (1993). Endogenous mass and energy losses in ruffed grouse. The Auk, 110(2), 386–390.Jamdar, S. N., Harikumar, P. (2005). Autolytic degradation of chicken intestinal proteins. Bioresource Technol., 96(11), 1276–1284. https://doi.org/10.1016/j.biortech.2004.10.014Kočí, Š. et al. (1994). The nutrient requirements and nutrient value of feeds for poultry. 1. ed.1 Nitra: Research institute of animal production, 46 pp.McMurphy, C. P., Duff, G. C., Sanders, S. R., Cuneo, S. P. and Chirase, N. K. (2011). Effects of supplementing humates on rumen fermentation in Holstein steers. South African Journal of Animal Science, 41(2), 134–140. 10.4314/sajas.v41i2.71017Ozturk, E. et al. (2014). Performance, meat quality, meat mineral contents and caecal microbial population responses to humic substances administered in drinking water in broilers. British Poultry Science, 55(5), 668–674. 10.1080/00071668.2014.960807 Van Loon, J. C. (1980). Analytical Atomic Absorption Spectroscopy, Selected methods. New York: Academic press, 337 pp.Van Soest, P. J., Robertson, J. B. and Lewis, B. A. (1991). Methods for dietary fiber, neutral detergent fibre, and nonstarch polysaccharides in relation to animal nutrition. Journal of Dairy Science, 74(10), 3583–3597. https://doi.org/10.3168/jds.S0022-0302(91)78551-2Windisch, W. et al. (2008). Use of phytogenic products as feed additives for swine and poultry. Journal of Animal Science, 86(14 Suppl), E140-E148. 10.2527/jas.2007-0459

Evaluation of the growth performance and some blood parameters in broilers with the addition of humic substances in the diet

Article Details: Received: 2020-10-21 | Accepted: 2020-11-27 | Available online: 2021-01-31https://doi.org/10.15414/afz.2021.24.mi-prap.150-154The effect of the administration of two humic preparations on a selected production and biochemical parameters were monitored in an experiment with broiler chickens of the Cobb 500 breed. There were not observed statistically significant differences between the control group and the experimental groups in the achieved average live weight and the feed conversion ratio in the 37-day experiment. The statistically significant differences (P˂0.001 and P˂0.05) were between the content of calcium, phosphorus and chlorides in the blood of the control group compared to the experimental groups. As for magnesium in the blood, we did not find significant differences (P≥0.05) between the groups. As far as the parameters of the energy profile are concerned, the content of glucose and cholesterol was statistically significantly higher in the control group in comparison with the experimental groups (P˂0.05). The concentrations of triglycerides were statistically significantly higher in the experimental groups (P≤0.05, resp. 0.01, resp. 0.001) compared to the control group.Keywords: nutrition, humic substances, production, blood, broilersReferences ARPAŠOVÁ, H. et al. (2016). Use of humic acid in nutrition of broiler chickens. Slovenský chov, 32-33. In Slovak.AVCI, M. et al. (2007). Effects of humic acid at different levels on growth performance, carcass yields and some biochemical parameters of quails. Journal of Animal and Veterinary Advances, 6(1), 1-4.BAHODARI, Z. et al. (2017). The effect of earthworm meal with vermi-humus on growth performance, haematology, immunity, intestinal microbiota, carcass characteristics, and meal quality of broiler chickens. Livestock Science, 202, 74-81. https://doi.org/10.1016/j.livsci.2017.05.010EL-ZAIAT, H. M. et al. (2018). Impact of humic acid as an organic additive on ruminal fermentation constituents, blood parameters and milk production in goats and their kids growth rate. Journal of Animal and Feed Science, 27(2), 105-113. https://doi.org/10.22358/jafs/92074/2018HAKAN, K. et al. (2012). Effects of boric acid and humate supplementation on performance and egg quality parameters of laying hens. Brazilian Journal of Poultry Science, 14(4), 233-304. https://doi.org/10.1590/S1516-635X2012000400008 JAĎUTTOVÁ, I. et al. (2019). The effect of dietary humic substances on the fattening performance, carcass weight, blood biochemistry parameters and bone mineral profile of broiler chickens. Acta Veterinaria Brno, 88, 307-313. https://doi.org/10.2754/avb201988030307MAJEWSKA, M. et al. (2017). Influence of humic acid supplemented to sheep diets on rumen enzymatic activity. Medycyna Weterynaryjna, 73(12), 770-773. https://doi.org/10.21521/mw.5822MUDROŇOVÁ, D. et al. (2020) The effect of humic substances on gut microbiota and immune response of broilers. Food and Agricultural Immunology, 31(1), 137-149. https://doi.org/10.1080/09540105.2019.1707780NAGARAJU, R. et al. (2014). Effect of dietary supplementation oh humic acids on performance of broilers. Indian Journal of Animal Science, 84(4), 447-452. https://doi.org/PMC6811714PISTOVÁ, V. et al. (2017). The effect of the humic substances, garlic (Allium sativum L.), wormwood (Artemisia absinthium) and walnut (Juglans regia) on carcass parameters of broiler chickens. Scientific Papers Animal Science and Biotechnologies, 50(1), 234-237.RZASA, A. et al. (2014). Humic-fatty acid preparation in growing rabbits nutrition. Journal of Polish Agricultural Universities, 17(3), 1-6.TERRY, S. A. et al. (2018). Effect of humic substances on rumen fermentation, nutrient digestibility, methane emissions, and rumen microbiota in beef heifers. Journal of Animal Science, 96(9), 3863-3877. https://doi.org/10.1093/jas/sky265.TICHA, A. et al. (2009). Humic substances influence on cholesterol absorption. Klinicka biochemie a metabolizmus, 17(1), 37-41. In Czech.VAŠKO, L. et al. (2012). Humic acids in nutrition and effect on metabolism and health production. Slovenský chov, 5, 40-41. In Slovak.WANG, Q., et al. (2008). Effects of supplemental humic substances on growth performance, blood characteristics and meat quality in finishing pigs. Livestock Science, 117(2-3), 270-274. https://doi.org/10.1016/j.livsci.2007.12.024YORUK, M. A. et al. (2004). The effects of supplementation of humate and probiotic on egg production and quality parameters during the late laying period in hens. Poultry Science, 83(1), 84-88. https://doi.org/10.1093/ps/83.1.8

Evaluation of the technical condition of medium-sized boilers

The recent trend in the steam and electricity production has been both to increase the efficiency of the facility and to keep tightening legislation concerning emission limits. The lifetime of energy equipment is greatly influenced by the operating temperature, pressure and operating characteristics. The new conditions lead the operator to more often changes of these parameters, which has negative influence to the facility in terms of service life. Precise knowledge of the facility being operated and the ability to predict the residual life of its key parts in time is therefore necessary. A new methodology for determining the residual life and evaluating problematic situations of medium size boilers was developed at Brno University of Technology. Its approaches and advantages will be presented in this paper. The methodology provides the user with approaches for the lifetime evaluation of an equipment as a whole, based on detailed knowledge of the equipment being investigated and the ongoing damage. Additionally, if the equipment is continuously evaluated, it is possible to extend the inspection interval or to achieve a significantly higher lifetime of the entire equipment, thereby reducing the economic cost. If defined criteria are met, the methodology also allows inclusion of FEM and CFD simulations for achieving higher relevance of the results

Effects of low protein diets with amino acids supplementation on biochemical and faeces parameters in weaned piglets

Article Details: Received: 2019-09-19 | Accepted: 2019-10-01 | Available online: 2019-09-30https://doi.org/10.15414/afz.2019.22.03.71-75The goal of this study was to determine the effects of a  low-protein diet supplemented with crystalline amino acids on the biochemical parameters in the blood serum, and the indicators of fermentation in the faeces in 12 crossbred piglets. The weaned piglets (at 28 days of age) were divided into two groups with 6 piglets each. The control diet contained 195 g/kg crude protein and the experimental diet contained 167 g/kg. The experimental diet was supplemented with lysine, methionine and threonine to achieve a more ideal amino acid pattern. The blood collections from the sinus ophthalmicus for the determination of the biochemical parameters were performed 2 times at 2 weekly intervals in both groups. The faeces were taken from the rectum at the end of the study period. The decrease in the dietary crude protein content of the experimental group was manifested by a significant decrease of the blood urea level (3.77 mmol/l average concentration) compared to the control group (4.97 mmol/l average concentration) (P <0.001). The serum concentrations of other components showed no significant statistical changes between the control and experimental groups. The results of the fermentation process analysis indicated that the acetate and the butyrate concentration decreased in the experimental group compared to the control group (P <0.05; 0.01, respectively). The decrease crude protein intake in the experimental group revealed significant lover levels of ammonia (P <0.001) and crude protein (P <0.01) compared to the control group.Keywords: pigs, amino acids, proteins, metabolism, fermentationReferencesAOAC Association of Official Analytical Chemists International (2001) In Horwitz, W. (Ed.). Official Methods of Analysis. 17th ed. Arlington: AOAC Inc.BALL, M. E. E. et al. (2013) The effect of level of crude protein and available lysine on finishing pig performance, nitrogen balance and nutrient digestibility. In Asian-Australasian Journal of Animal Sciences, vol. 26, no. 4, pp. 564–572. doi:https://doi.org/10.5713/ajas.2012.12177BIKKER, P. et al. (2006) The effect of dietary protein and fermentable carbohydrates levels on growth performance and intestinal characteristics in newly weaned piglets. In Journal of Animal Science, vol. 84, no.12, pp. 3337–3345. doi:https://doi.org/10.2527/jas.2006-076DOUBEK, J. et al. (2010) Interpretation of Basic Biochemistry and Haematology Findings in Animals. Brno: Noviko. 102 p. (in Czech).FANG, L. H. et al. (2019) Effects of dietary energy and crude protein levels on growth performance, blood profiles, and nutrient digestibility in weaning pigs. In Asian-Australasian journal of animal sciences, vol. 32, no.4, pp. 556–563. doi:https://doi.org/10.5713/ajas.18.0294FIGUEROA, J. L. et al. (2002) Nitrogen metabolism and growth performance of gilts fed standard corn-soybean meal diets or low-crude protein, amino acid supplemented diets. In Journal of Animal Science, vol. 80, no.11, pp. 2911–2919. doi:https://doi.org/10.2527/2002.80112911xHAN, K. and LEE, H. J. (2000) The role of synthetic amino acids in monogastric animal production. Review. In AsianAustralasian Journal of Animal Sciences, vol. 13, no. 4, pp. 543– 560. doi:https://doi.org/10.5713/ajas.2000.543HE, L. et al. (2016) Low-protein diets affect ileal amino acid digestibility and gene expression of digestive enzymes in growing and finishing pigs. In Amino Acids, vol. 48, no. 1, pp. 21–30. doi:https://doi.org/10.1007/s00726-015-2059-1HEO, J. M. et al. (2008) Effects of feeding low protein diets to piglets on plasma urea nitrogen, faecal ammonia nitrogen, the incidence of diarrhoea and performance after weaning. In Archives of Animal Nutrition, vol. 62, no. 5, pp. 343–358. doi:https://doi.org/10.1080/17450390802327811HTOO, J. K. et al. (2007) Effect of dietary protein content on ileal amino acid digestibility, growth performance, and formation of microbial metabolites in ileal and cecal digesta of early-weaned pigs. In Journal of Animal Science, vol. 85, no. 12, pp. 3303–3312. doi:https://doi.org/10.2527/jas.2007-0105JIAO, X. et al. (2016) Effects of amino acids supplementation in low crude protein diets on growth performance, carcass traits and serum parameters in finishing gilts. In Animal Science Journal, vol. 87, no. 10, pp. 1252– 1257. doi: https://doi. org/10.1111/asj.12542KERR, B. J. (2006) Opportunities for utilizing crystalline amino acids in swine. In Advances in Pork Production, vol. 17, pp. 245–254.KIM, S. W., CHEN, H. and PARNSEN, W. (2019) Regulatory Role of Amino Acids in Pigs Fed on Protein-restricted Diets. In Current Protein & Peptide Science, vol. 20, no. 2, pp. 132–138. doi:https://doi.org/10.2174/1389203719666180517100746KRAFT, W. and DÜRR, M. U. (2001) 30. Reference values. In Hajko & Hajková: Clinical Laboratory Diagnosis in Veterinary Medicine (Slovak/Czech edition). Bratislava: VEDA. 365 pp.LIAO, S. F., WANG, T. and REGMI, N. (2015) Lysine nutrition in swine and the related monogastric animals: Muscle protein biosynthesis and beyond. In SpringerPlus, vol. 4, p. 147. doi:https://doi.org/10.1186/s40064-015-0927-5PENG, X. et al. (2016) Effects of low-protein diets supplemented with indispensable amino acids on growth performance, intestinal morphology and immunological parameters in 13 to 35 kg pigs. In Animal, vol. 10, no. 11, pp. 1812–1820. doi:https://doi.org/10.1017/S1751731116000999NATIONAL RESEARCH COUNCIL (2012) Nutrient Requirements of Swine. 11th rev. ed. Washington: National Academies Press. 400 pp.NICHOLS, N. L. and BERTOLO, R. F. (2008) Luminal threonine concentration acutely affects intestinal mucosal protein and mucin synthesis in piglets. In The Journal of Nutrition, vol. 138, no. 7, pp.1298–1303. doi:https://doi.org/10.1093/jn/138.7.1298NYACHOTI, C. M. et al. (2006) Performance responses and indicators of gastrointestinal health in early-weaned pigs fed low-protein amino acid-supplemented diets. In Journal of Animal Science, vol. 84, no.1, pp.125–134. doi:https://doi.org/10.2527/2006.841125xREGMI, N. et al. (2018) Effects of dietary lysine levels on the concentrations of selected nutrient metabolites in blood plasma of late‐stage finishing pigs. In Journal of animal physiology and animal nutrition, vol. 102, no. 2, pp. 403– 409. doi:https://doi.org/10.1111/jpn.12714ROTH, F. X. and RACZEK, N. N. (2003) Nutritive effectiveness of sorbic acid: effects in piglet feeding. In Kraftfutter, vol. 86, pp.105–110.SALDANA, C. I. et al. (1994) Digestible threonine requirements of starter and finisher pigs. In Journal of Animal Science, vol. 72, no.1, pp. 144–150. doi:https://doi.org/10.2527/1994.721144xŠIMEČEK, K., ZEMAN, L. and HEGER, J. (1994) The nutrient requirements and nutrient value of feed for pigs. Nitra: VUŽV. 77 p. (in Slovak).TOLEDO, J. B. et al. (2014) Reduction of the crude protein content of diets supplemented with essential amino acids for piglets weighing 15 to 30 kilograms. In Revista Brasileira de Zootecnia, vol. 43, no. 6, pp. 301–309. doi:https://doi.org/10.1590/S1516-35982014000600004WANG, Y. et al. (2018) Advances in low-protein diets for swine. In Journal of animal science and biotechnology, vol. 9, 60. doi:https://doi.org/10.1186/s40104-018-0276-

Effect of Humic Substances on the Production Parameters of Pheasant Hens

Received: 2015-07-15   |   Accepted: 2015-11-03   |   Available online: 2016-04-23dx.doi.org/10.15414/afz.2016.19.01.11-14There were observed the effects ofadministrationof humicsubstances on health, feed conversion, productionparameters, egg qualityandhatchabilityofpheasants. The supplement of humicsubstances at the concentration 0.5% in the feed mixture significantly influenced the hatchability percentage of pheasant chicks.The hatchability 72.9% was achieved in the group without addition of humic substances.On the contrary, the hatchability 83.4% was achieved in the experimental group in the case of addition of humic substances.The pheasants of the experimental grouphadahigher consumption of feed by 0.27 kgper 1 kg ofproduced eggs, lower production of eggsper one henand the weight of eggs was lower by 1.15 g. Keywords: pheasant, humic substances production, eggs, hatchabilityReferences ABDEL-MAGEED, M.A.A. (2012) Effect of dietary humic substances supplementation on performance and immunity of Japanese quail. Egyptian Poultry Science, vol. 32, no. 3, pp. 645-660.ARAFAT, R.Y. et al. (2015) Effect of dietary humic acid via drinking water onthe performance and egg quality of commercial layers. American Journal of Biology and Life Sciences, vol. 3, no. 2, pp. 26-30.EL-HUSSEINY, O.M., ABDALLAH, A.G. and ABDEL-LATIF, K.O. (2008) The influence of biological feed additives on broiler performance. International Journal of Poultry Science, vol. 7, no. 9, pp. 862-871.EMEA (1999) Committee for veterinary medicinal products. Humic acids and their sodium salts. [Online] Last modified April 21, 2008. Retrieved October 10, 2015 from http://www.emea.eu.int/pdfs/vet/mrls/055499en.pdfEREN, M. et al. (2000) Broyler yemlerine katilan humatlarin besi performansi, serum mineral konsantrasyonu ve kemik külü üzerine etkileri. Ankara Üniversitesi Veteriner Fakültesi Dergisi, vol. 47, no. 3, pp. 255-263.ESENBUĞA, N. et al. (2008) Effects of dietary humate supplementation to broilers on performance, slaughter, carcass and meat colour. In Journal of the Science of Food and Agriculture, vol. 88, no. 7, pp. 1201-1207. doi:http://dx.doi.org/10.1002/jsfa.3199HAYIRLI, A. et al. (2005) Nutrition Practice to Alleviate the Adverse Effects of Stress on Laying Performance, Metabolic Profile, and Egg Quality in Peak Producing Hens: I. The Humate Supplementation. Asian-Australian Journal of Animal Science, vol. 18, no. 9, pp. 1310-1319.KARAOGLU, M. et al. (2004) Effect of supplemental humate at different levels on the growth performance, slaughter and carcass traits of broilers. International Journal of Poultry Science, vol. 3, no. 6, pp. 406-410.KOCABAĞLI, N. et al. (2002) The effects of dietary humate supplementation on broiler growth and carcass yield. Poultry Science, vol. 81, no. 2, pp. 227-230.KUCUKERSAN, S. et al. (2005) The effects of humic acid on egg production and egg traits of laying hen.Veterinary Medicine (in Czech), vol. 50, no. 9, pp. 406-410.MIRNAWATI, Y.R. and MARLIDA, Y. (2013) Effects of humic acid addition via drinking water on the performance of broilers fed diets containing fermented and non-fermented palm kernel cake. Archiva Zootechnica, vol. 16, no. 1, pp. 41-53.OZTURK, E. et al. (2009) Effects of dietary humic substances on egg production and egg shell quality of hens after peak laying period. African Journal of Biotechnology, vol. 8, no. 6, pp. 1155-1159.OZTURK, E. et al. (2012) Performance, carcass, gastrointestinal tract and meat quality traits, and selected blood parameters of broilers fed diets supplemented with humic substances. Journal of the Science of Food and Agriculture, vol. 92, no. 1, pp. 59-65. doi:http://dx.doi.org/10.1002/jsfa.4541SKOKANOVÁ, M. and DERCOVÁ, K. (2008) Humic acids. The origin and structure. Chemické Listy, vol. 102, no. 4, pp. 262-268 (in Slovak).STEVENSON, F.J. (1994) Humus Chemistry: Genesis, composition, reactions. 2. ed. New York: Wiley.VESELÁ, L. et al. (2005) Structure and properties of natural humic substances type oxihumolit. Chemické Listy, vol. 99, no. 10, pp. 711-717 (in Czech).YÖRÜK, M.A. et al. (2004) The effects of supplementation of humate and probiotic on egg production and quality parameters during the late laying period in hens. Poultry Science, vol. 83, no. 1, pp. 84-88.