Impacts of humic acids in nutrition on haematological and biochemical parameters of brown hares

Anotace: Humic substances are natural organic substances resulting from the decomposition of mainly plant but also animal residues. The objective of our study was to test if the humic acids can negatively/positively affect brown hares health status. As the main indicators for this evaluation, we chose haematological and biochemical blood tests. In this study, we used 24 brown hares (12 males and 12 females) in the age of 12-24 months. As part of the 6-month experiment, we planned three blood samplings (at the beginning of the experiment and then after three and six months). Animals were divided into three groups at the beginning of the experiment (n = 8/group): CG (control group, 0-11KKZ standard diet without additives), EG1 group (experimental group 1, received 0-10KK/D standard feed + 1% of Humac Natur AFM – humic acids), and EG2 group (experimental group 2, received 0-10KK/D standard feed + 1% of Humac Natur AFM – humic acids, enriched with green feed – clover-grass mixture). We found a statistically significant difference between the control group and the EG2 group in the RBC parameter (P < 0.05) after three months of consumption. We found a statistically significant decrease in urea levels in both experimental groups compared to the control group (P < 0.001), as well as a decrease in urea concentration in the EG2 group compared to the EG1 group (P < 0.01); decrease in cholesterol levels in the experimental groups compared to the control, and between EG1 and the control group, this decrease was statistically significant (P < 0.05); and we recorded a statistically significant increase of triglycerides in the EG2 group compared to the other groups (P < 0.01). Based on the obtained results, we can evaluate the use of 1% humic acid as a feed additive as safe for feeding hares.