Faecal excretion of moxidectin in lambs and its persistence in different environmental conditions

Publication date: Available online 27 February 2019Source: Small Ruminant ResearchAuthor(s): Susana G. Hentz, Maria Angela M. Fernandes, Michelle Del Bianchi, Felix.G.R. Reyes, João Kleber G. de Souza, Fábio M. Giannotti, Alda L.G. MonteiroAbstractThe faecal excretion profile of moxidectin (MOX) was evaluated in Suffolk lambs (n = 7) with mean body weight (BW) of 36.06 ± 3.23, using a completely randomized experimental design. The animals received a single subcutaneous dose of 0.2 mg/kg BW. Faecal samples were collected 6, 12, 18, 24, 30 and 36 hours (h), and 5, 9, 14, 21, 28, 35 and 42 days after the application of MOX. The samples were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS QqQ). The method was validated showing 85.4 – 111.8% recovery and intra-day and inter-days precision values between 6.2 and 9.4%. The method limit of quantitation (LOQ) was 5.0 ng/g. The MOX showed a large excretion through the lamb faeces, with a maximum concentration (Cmax) of 22.73 ng/g at a time (Tmax) of 39.92 h. The area under the curve (AUC) value was 13292 ng h/g. Subsequently, the persistence of MOX residues in the faeces exposed to the environment was assessed using a randomized complete block design. For this purpose, thirteen Suffolk and Dorper rams, with BW of 76.43 ± 34.24 kg, were separated into two groups: control and MOX treated. Their faeces were collected in bags at Tmax after MOX application of a subcutaneous single dose of...
Source: Small Ruminant Research - Category: Zoology Source Type: research