Calliandra calothyrsus and Arachis pintoi supplementation effects on animal health and gastrointestinal nematodes infestation and condensed tannin extract effects on (Haemonchus contortus) larval motility.

摘要

Experimentation, in vivo and in vitro, was conducted to determine the effects of condensed tannins (CT) in various tropical legumes and to evaluate their use as a means to reduce internal parasite infestation in goats. In Exp. 1, fresh leaves of Calliandra (Calliandra calothyrsus) and Arachis (Arachis pintoi) forages were used for dietary supplementation during 4 months and the results analyzed using repeated measures. Eight naturally parasite-infested, growing Boer goats, grazing Panicum maximum were randomly allocated, four to each of two supplemental forage treatments. Animals of one treatment with initial body weight (BW) = 18.8+/-0.5 kg received supplementation of freshly cut Arachis from September to December 2006; those of a second treatment 14.4+/-0.5 kg received Calliandra for 84 d. On day zero all animals were orally dewormed using the commercial anthelmintic Ivomec RTM (2mg/kg of BW). Fecal samples for determining egg counts and blood samples to determine packed cell volume (PCV) were collected every 21 days. Feces were obtained directly from the rectum and blood was collected in EDTA vaccutainer tubes via jugular venipuncture. Scoring for anemia by the FAMACHA method and BW measurements were also taken. Data were analyzed using the MIXED procedure of SAS and Tukey t-test for mean comparisons. The fecal egg counts (FEC) were log transformed prior to statistical analysis. As a part of this experiment in vitro dry matter digestibility (IVDMD) of the two supplemental forages was determined. Significant differences were detected between Calliandra and Arachis in content of dry matter (DM; 969.7 vs. 955.9 g/kg) and crude protein (CP; 18.4 vs. 14.9 g/kg), respectively. Calliandra showed lower IVDMD (P < 0.001) but higher CP and condensed tannins (CT; P < 0.01) than Arachis. Neutral detergent fiber (NDF) percentages of 61.1 and 58.8 for Calliandra and Arachis, respectively, did not differ at P = 0.05. In Exp. 1, FEC (5262 vs. 7644 eggs/g; P < 0.001) and FAMACHA scores (2.5 vs. 2.9; P < 0.02) were lower, while average daily gain (ADG; 11.1 vs. -34.7 g; P < 0.02) and PCV (22.3 vs. 20.5; P = 0.13) were greater for Calliandra than for Arachis.;In Exp. 2, three purified tannins from Calliandra, Lespedeza ( Sericea lespedeza), Prairie acacia (Acacia angustissima var. hirta), and three commercially available tannin monomers (ellagitannins, gallotannins and catechins) were used in vitro to determine their effect on larval migration inhibition rates (% LMI) of infective third-stage larvae of Haemonchus contortus, using a Sephadex LH-20 column. Calliandra was chosen to include in the in vitro study because of its anthelmintic activity (12.04% CT) measured in Exp.1, while Lespedeza and Acacia tannins were included because of their known anthelmintic activity.;In the larval migration assay (Exp. 2), LMI rates of H. contortus increased in the presence of 2 and 4 mg of purified tannin/ml as Lespedeza and Calliandra extracts. Acacia extract had no dose-related effect on LMI rates. H. contortus LMI exhibited a dose dependent response (P < 0.01) to 1, 2 and 4 mg/ml of ellagitannins and gallotannins. Ranking of monomers according to their inhibitory activity was: ellagitannins > gallotannins > catechins.