Moxidectin residues in tissues of lambs submitted to three endoparasite control programs.
The indiscriminate and continuous use of anthelmintic drugs has promoted the selection of resistant parasites population, the presence of drug residues in food products, and heavy environmental contamination. The aim of the present study was to determine the presence of antiparasitic drug residues in 42-days old lamb serum and tissues, submitted to three endoparasite control programs: preventive treatment (PT) using moxidectin (MOX) at every 28days; selective treatment (FEC) using MOX when fecal egg count was greater than or equal to 700; and selective treatment (FMC), using MOX when FAMACHA/FMC score was 3 and above. For this purpose, MOX residues were quantified in serum, muscle, fat, liver and kidney. Lambs were slaughtered when reaching 30kg of body weight, and after a 28-day MOX withdrawal period. Before slaughter, blood was collected to determine the concentration of MOX in serum. Tissues and organ samples were collected at slaughter. The quantitation of MOX residues was performed using liquid chromatography tandem mass spectrometry (LC-MS/MS). From the 756 tissue samples analyzed, only one sample of fat from the PT group showed residue levels (586.3μg/kg) above the maximum residue limit (MRL) of 500μg/kg. No treated lambs presented traces of MOX residues in fat and liver, suggesting possible environmental contamination. In conclusion, all weaned lambs, produced in continuous grazing and subjected to gastrointestinal parasite control programs via selective (FEC and FMC) or preventive (PT) treatment, displayed a low risk (<1%) of MOX residues above the MRL in muscle, fat, kidney, and liver.
['Fernandes|Maria Angela Machado|MAM|', 'Gilaverte|Susana|S|', 'Bianchi|Michele Dell|MD|', 'da Silva|Claudio José Araujo|CJA|', 'Molento|Marcelo Beltrão|MB|', 'Reyes|Felix Guillermo Reyes|FGR|', 'Monteiro|Alda Lucia Gomes|ALG|']
D000818:Animals D000871:Anthelmintics D001938:Brazil D004350:Drug Residues D005260:Female D018942:Macrolides D008297:Male D010273:Parasitic Diseases, Animal D011897:Random Allocation D012756:Sheep D012757:Sheep Diseases D013997:Time Factors D014018:Tissue Distribution
Moxidectin Endoparasite control Drug residues FAMACHA Macrolactones