Use of zeolite for the elimination of heavy metals from chicken eggs

The publication materials reflect the results of scientific research conducted under the conditions of the vivarium of the State Research Control Institute of Veterinary Medicines and Feed Additives. It was established that the introduction of chromium sulfate in the amount of 2 mg/kg and cadmium sulfate in the amount of 3 mg/kg of live weight into the body of laying hens caused their significant accumulation in eggs compared to their content in the control group. To reduce the concentration of heavy metals in chicken eggs, zeolite 3 % of the feed mass was fed in the form of 1–3 mm grain size (TU 05792908.002-97. “Feed Zeolite”, produced at the Sokyrnytskyi Zeolite Plant of the Ministry of Emergency Situations of Ukraine, Khust District, Zakarpattia Region. It was established that the natural mineral contributed to eliminating Chromium and Cadmium from egg components (yolk, white, shell) relative to the control. When zeolite was introduced into the diet of poultry, 3 % of the feed weight to all experimental groups, compared with groups without its introduction, contributed to a decrease in the content of heavy metals in the studied samples of egg components. With a chromium load, a 1.7-fold decrease was noted in the white (Р < 0.05) and yolk, and a 1.8-fold (Р < 0.01) decrease in the shell, and samples with a cadmium load, a decrease of this metal in the protein, yolk, and shell was, respectively, 1.5 (Р < 0.05); 1.6 (Р < 0.05) and 3.2 (Р < 0.001) times the indicator of the experimental group without a sorbent. A similar tendency to decrease the content of heavy metals is observed with the combined introduction of toxicants. They found a slight increase in the weight of the egg in the test groups after correction with zeolite, namely: in the first group by 3.7 %, respectively, in the third – by 1.9 % against the background of a decrease in the indicator in the second group by 1.6 %. Eggs of hens of the first experimental group exceeded their control counterparts by 0.9 % in terms of shell thickness. In contrast, those of the second and third groups, on the contrary, were inferior in terms of shell thickness by 1.2 and 0.6 %, respectively. In the experimental groups, there is a tendency to increase the percentage of the shell by 1.9 in the first group, by 2.8 % in the second, and by 4.0 % in the third group relative to the control. Introducing the first group of natural zeolite into birds' diet contributes to the thickening of eggshells by 6.6 % compared to the indicator without the mineral. The same trend is observed in the second and third groups, respectively – by 7.1 % and 5.0 %; however, the difference between the groups is unlikely. A tendency to increase in the experimental groups with the use of zeolite in the percentage of egg mass in the first group by 1.9 %, in the second group by 1.8, and in the third group by 2.3, relative to the indicator without the mineral, was also revealed. In the experimental groups, there are changes in the components of the egg compared to the control indicator: an increase in the shelling percentage in the first, second and third groups, respectively, by 1.0, 4.0, and 1.9 %. Regarding egg productivity, a decrease is observed relative to the control in experimental groups with chromium-cadmium total and separate load, which was 19.6, respectively; 40.2 and 29.7 %. An increase in egg production has been established when mineral sorbent is used in the diet of poultry. Gross egg production in hens of the second group with chromium load increased by 11.1 % when consumed with zeolite compound feed. The lowest number of eggs during the experimental period was obtained from hens of the second group with cadmium load. The introduction of natural minerals into the diet increased their number during the experimental period by 8.3 %. In the third group, the number of eggs increased by 10.7 % during the experimental period with the combined load of heavy metals and zeolite. A similar trend is observed in the experimental groups regarding the number of eggs obtained per average laying hen. The results of the conducted research confirm that chromium and cadmium ions affect the productivity and quality of chicken products, and the introduction of fodder zeolite in the amount of 3 % of the mass of compound feed into the diet of poultry improves the level of their mineral nutrition, laying and the indicator of the marketable quality of eggs.