Uptake of Ivermectin from Growing Substrate to Plant Species

IGLESIAS, LUCÍA; SALLOVITZ, JUAN; SAUMELL, CARLOS; FERNÁNDEZ, SILVINA; JUNCO, MILAGROS; SAGÜES, FEDERICA; ZEGBI, SARA; LIFSHITZ, ADRÍAN

Madison

Conferencia; 27th Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP); 2019

Ivermectin (IVM) is a worldwide-used antiparasitic drug. However, its high level offaecal elimination together with its transfer from dung pats to the underlying soil as wellas the common practice of using manure for soil amendement represents a potencialrisk to plants growing in these substrates. Two trials were conducted to evaluate theuptake of IVM to: 1) a crop of ryegrass (Lolium multiflorum) and clover (Trifolium repens)growing for 120 days post treatment (dpt) in IVM-spiked soil at 3000 (High group, HG)and 90ng/g (Low group, LG); and 2) a crop of radish (Raphanus sativus) and lettuce(Lactuca sativa) growing for 60 dpt in a mix of soil and 10% IVM-spiked manure at3000ng/g. Soil, soil-manure mix and plants were sampled starting at 15 dpt and at theend of each trial. All matrices were analyzed by HPLC to quantify IVM concentration. Trial1: In HG, IVM concentration in soil decreased from 2154 ng/g to 225 ng/g; mean IVMconcentration in ryegrass ranged between 378.65ng/g and 21,74ng/g. Strikingly, clover development was delayed until 30 dpt and IVM concentration in this specie ranged between 94,09 ng/g and 4,56ng/g. Significant differences were detected between species(p=0,0374). In the LG, IVM concentration was between 22,26ng/g and 1,02ng/g inryegrass, and between 10ng/g and 1,02ng/g in clover, without statistically significant differences between species (p=0,8301). Trial 2: IVM was detected in both plant species at significant levels (p>0,05) in all the sampling times; mean IVM concentration was between10ng/g and 5ng/g in radish, and 17,70ng/g and 6,55ng/g in lettuce. IVM concentrationn the substrate decreased from 1311ng/g to 116ng/g. In conclusion, IVM concentrations insoil or composted substrate are transferred to plants during growth period, and couldbe incorporated into the food chain of both livestock and humans.