Study of soil-plant (potato and beetroot)-animal cycle of nutritive and hazardous minerals in a rabbit model

Potato and beetroot were grown on soils previously treated with heavy metal salts. Each particular microelement had a high concentration in both potat o and beetroot [cadmium (Cd) 3.7 and 55.4, lead (Pb) 8.1 and 3.0, and mercu ry (Hg) 5.8 and 6.8 mg/kg dry matter, respectively]. In a metabolic balance trial 16 New Zealand White rabbits were fed 50 grams of basal diet and pot ato or beetroot ad libitum. The apparent digestibility of major nutrients a nd the accumulation of the microelements in different organs were investiga ted. Both potato and beetroot samples of high Pb and Hg content had the sig nificantly (p < 0.05) lowest digestibility of organic matter and nitrogen-f ree extract. The Cd ingested from both potato and beetroot accumulated in t he kidneys and liver (2.85 and 1.48 as well as 0.459 and 0.265 mg/kg, respe ctively). All the microelements (Cd, Pb and Hg) accumulated in the testicle s (0.196, 0.32 and 0.199 mg/kg, respectively), reducing the rate of spermat ogenesis. The tissue retention of heavy metals depends not only on the elem ent itself, but also upon the 'carrier' feedstuff.