DUNG REMOVAL BY BEETLES EXPOSED TO FECES OF SHEEP FED Guazuma ulmifolia Lam.

This study examines the relationship between the phenolic content (total phenols and tannins) of three diets for sheep (Ovis orientalis aries L.) containing Guazuma ulmifolia Lam. (Gu0: 0 %, Gu30: 30 %, and Gu60: 60 %) and the removal of feces by dung beetles fed on sheep excreta. The study was conducted in two stages: in the first, nine Pelibuey sheep (40 ± 4 kg live weight), randomly assigned to one of three groups, were fed the experimental diets (Gu0, Gu30, and Gu60). For 9 d, feces were collected and stored at 8 °C. In stage two, three dung beetle species (Canthidium pseudopuncticolle, Canthon leechi, and Canthon chiapas [Coleoptera: Scarabaeinae]) were captured, artificially paired in couples, and placed in terraria to evaluate dung removal, during 29 d. Sheep preferred the Gu30 diet, of which they consumed 33.5 ± 1.7 g of dry matter (DM) kg-1 of live weight (LW). All diets had similar chemical composition, except Gu60, which maintained a higher concentration of total tannins (3.5 ± 0.3 mg g-1 DM). In feces, Gu0 showed the highest concentration of phenols (0.507 ± 0.3 mg g-1 DM; p ≤ 0.05) and total tannins (0.317 ± 0.1 mg g-1 DM; p ≤ 0.05). Canthon leechi removed the highest amount of feces (249.6 g) and had the strongest day × diet interaction effect (p ≤ 0.05). Adding up to 30 % G. ulmifolia forage in the diet did not compromise dry matter intake of sheep and maintains good nutritional quality; the concentration of phenolic compounds in the diet and feces changed according to the proportion of G. ulmifolia in the diet. Although the beetles removed less excreta from sheep that consumed G. ulmifolia (Gu30 and Gu60), it is not possible to conclude whether phenolic compounds are responsible for this response.