EFFECT OF ZINC CITRATE, SELENIUM CITRATE AND GERMANIUM CITRATE ON BIOCHEMICAL PARAMETERS OF RABBIT BLOOD UNDER HEAT STRESS

Abstract

Global climate change and increasing environmental temperatures in many regions of the world contribute to mammalian heat stress, which leads to disorders of homeostatic processes in their body. Rabbits do not have sweat glands and cannot effectively regulate their body temperature. In recent years, the use of nanotechnology in animal nutrition to mitigate the negative effects of high temperatures has become a subject of special attention. Nanoparticles are characterised by high bioavailability, surface activity, catalytic and adsorption properties, which allows them to easily interact with mammalian cells. Therefore, the purpose of our study was to determine the effect of zinc citrate, selenium citrate and germanium citrate, produced by nanotechnology, on the biochemical parameters of rabbit blood under heat stress. The study was conducted on young rabbits of the Thermon White breed from 35 to 78 days of age. During the experiment, the temperature in the room was increased from 28.9 to 30°C from 12 to 16 hours using electric adjustable heaters. Animals for the study were formed into control and experimental groups I, II and III of 6 animals each. The control group was fed pelleted feed and given water with unrestricted access. Rabbits in experimental groups I, II and III consumed pelleted feed as in the control group, but received trace element citrates with water during the day: Experimental group I – zinc citrate – 60 mg Zn/l or 12 mg Zn/kg body weight; group II – selenium citrate – 300 μg Se/l or 60 μg Se/kg body weight; group III – germanium citrate – 62.5 μg Ge/l or 12.5 μg Ge/kg body weight. The biochemical parameters of rabbits' blood were studied on day 14 of the preparatory period and on days 14 and 29 of supplementation in the experimental period under conditions of heat stress. The experimental data were calculated by analysis of variance (ANOVA). To identify statistical differences between the control and experimental groups, the a posteriori criterion was used – the Tukey HSD method, differences were considered significant at P≤0.05. It was established that the addition of trace element citrates to the diet of rabbits had a positive effect on mitigating the negative effects of elevated temperatures to varying degrees. In particular, zinc citrate feeding under conditions of heat stress was associated with a lower creatinine level (p<0,05), a decrease in aspartate aminotransferase activity (p<0,01), alanine aminotransferase (p<0,05) and a decrease in cholesterol content (p<0,001) on day 29 of the study. The use of selenium citrate in the diet of animals led to an increase in albumin content (p<0,05), lower creatinine level (p<0,05), decreased aspartate aminotransferase activity (p<0,01), alanine aminotransferase (p<0,05) and lower cholesterol content (p<0,01) at the final stage of the study. The addition of germanium citrate to water resulted in a higher cholesterol content (p<0,05) at the final stage of the study.