Forty-five Pelibuey sheep were experimentally infested with nematodes to evaluate the effect of three free condensed tannin (FCT) levels of Lysiloma acapulcensis on fecal egg counts (FECs), packed cell volumes (PCV), ocular mucosa colors (OMC), average daily gain (ADG), and adult nematode count. Five treatments were used: 12.5, 25.0, and 37.5 mg of FCT kg-1 of body weight (BW); sterile water (control); and ivermectine (0.22 mg kg-1 of BW) as chemical group. The data were processed through repeated measurement analysis. Even though the three FCT doses decreased (P < 0.05) the FEC, the highest reduction was obtained with 37.5 mg kg-1 of BW. No differences were observed in PCV and OMC. Higher ADG (P < 0.05) was observed with 37.5 mg kg-1 of BW of FCT. The count of adult nematodes (females and males) in the higher dose of FCT was similar to chemical treatment. Dose of 37.5 mg kg-1 of BW decreased the parasite infection and improved the lamb performance. Therefore, this dose could be used as a nutraceutic product in sheep production.
Keywords: Ivermectine; Lysiloma acapulcensis; Nematodes; Pelibuey; Sheep; Tannins.