02926nas a2200325   4500008004100000245010900041210006900150260001000219300001200229490000800241520201400249653001802263653001602281653001602297653002002313653002302333653001702356653002302373653001902396653001102415653001502426653002302441653002502464653001302489653001102502100001602513700001802529700001902547856003402566       2003                        eng d00aDung beetle activity and the development of trichostrongylid eggs into infective larvae in cattle faeces0 aDung beetle activity and the development of trichostrongylid egg  cDec 1  a157-1630 v1183 aIn the perspective to reduce the use of antiparasitic drugs, any interaction between the processes that control the development of parasite eggs into infective larval stages (L3) in dung and the activities of different dung-breeding organisms becomes of interest. The objective of the present study was to determine whether dung beetle activity affected the development of parasite larvae in cattle dung. Faeces containing eggs of parasites (predominately Cooperia spp.) were pooled according to high (250-600 epg) or low (approx. 100 epg) egg counts. Experimental dung pats were formed for each category of faeces and to half of these pats, dung beetles (20 Aphodius rufipes, 20 A. scybalarius syn. rufus) were added and kept for 12 days at 21degreesC (+/-1degreesC) and 90% RH (+/-5% RH). Beetles were then removed and the pats were divided in two where half the pat was incubated for an additional 12 days at 21degreesC (+/-1degreesC) and 90% RH (+/-5% RH) and the other half was immediately analysed. A greater number of L3 were recovered from the dung subjected to beetle activity compared with control dung (P < 0.001). However, following an additional 12 days incubation of the dung, similar numbers of L3 were recovered from beetle-affected dung with high egg counts, whereas there were significantly greater numbers of L3 derived from the control dung (P < 0.001). There was no significant difference in L3 recovery in the two categories of pats (i.e. high and low nematode egg counts). The results indicate that activity by Aphodius spp. in fresh dung can optimise conditions for nematode development to the infective larval stage if favourable environmental conditions prevail. Such synergistic effect may be due to the fact that dung beetles used in this study are dung dwellers, i.e. no substantial amount of the dung is removed or burrowed as these beetles feed, lay their eggs and the larval development takes place in brood chambers inside the dung. (C) 2003 Elsevier B.V. All rights reserved.10aAphodius spp.10aavermectins10acattle dung10acattle-nematoda10acooperia-oncophora10aDung beetles10afree-living stages10agrazing cattle10aimpact10aIVERMECTIN10anematode parasites10aostertagia-ostertagi10aSURVIVAL10asweden1 aChirico, J.1 aWiktelius, S.1 aWaller, P., J.  u<Go to ISI>://00018739790001703465nas a2200241   4500008004100000020001400041245010500055210006900160300001200229490000800241520265400249653002002903653001502923653001502938653002702953653002002980653001503000100001903015700002203034700002203056700002003078856012503098       2003                        eng d  a0931-204800aEffects of ivermectin and doramectin faecal residues on the invertebrate colonization of cattle dung0 aEffects of ivermectin and doramectin faecal residues on the inve  a481-4880 v1273 aThe effects of avermectin [ivermectin (IVM) and doramectin (DRM)] faecal residues on dung colonization and degradation by invertebrates were evaluated during late spring in the east of La Pampa province, Argentina. The study was conducted after collection of faecal material from animals (10 steers per group) allocated to the following groups: untreated control group (CG) and groups treated subcutaneously (200 lg/kg) with either DRM (DG) or a long-acting formulation of IVM (IG). Fifty pats (550 g each) per group were collected, prepared and deposited on the field on days 3, 7, 16 and 29 post-treatment (pt). Eight pats per group were recovered after 7, 14, 21, 42, 100 and 180 days post-deposition (pd) on the field. The weight, percentage of dry matter, number of arthropods and nematodes from faeces were determined. The faecal concentrations of IVM and DRM were measured by high performance liquid chromatography (HPLC) throughout the trial period to correlate the pattern of drug degradation in dung with pd time. The total number of arthropods in dungs from CG was higher (P < 0.05) than those counted between days 3 and 29 pt in IG and DG. A decrease in the number of Coleoptera larvae (P < 0.05) between days 21 and 42 days pd was observed in both treated groups. Diptera larvae counts in CG pats were significantly higher (P < 0.05) than those obtained in treated groups in the 7- and 14-day-old pats. A lower number (P < 0.05) of Collembola, compared with pats from CG, was recovered from IG and DG pats deposited at days 3 and 7 pt and exposed from day 42. The counts of Acari in pats from treated animals were lower (P < 0.05) than those observed in CG pats at 3, 8 and 16 days pt. There were no differences neither in adult Scarabaeidae recovered nor in the proportions of dung buried and destroyed by great dung beetles. Dung specific nematodes were reduced (P < 0.05) in IG and DG pats from 3 and 7 days pt compared with those of CG pats. The comparative results shown here demonstrate that the negative effects of both IVM and DRM on dung colonization are similar. The pattern of drug degradation in the environment was very slow. High residual concentrations of both active parent compounds were recovered in dungs exposed in the field for up to 180 days pd. Concentrations as high as 13 ng/g (IVM) and 101 ng/g (DRM) were measured in faeces obtained from pats deposited on day 27 pt and exposed to the environment during 180 days. The results show a decrease in invertebrate colonization of dung recovered from IVM- and DRM-treated cattle, which is in agreement with the large drug residual concentrations measured in faeces. 10acattle-nematoda10adoramectin10adung-fauna10aenvironmental toxicity10afaecal residues10aIVERMECTIN1 aSuarez, V., H.1 aLifschitz, A., L.1 aSallovitz, J., M.1 aLanusse, C., E.  uhttps://scarabnet.myspecies.info/effects-ivermectin-and-doramectin-faecal-residues-invertebrate-colonization-cattle-dung