The use of pumpkin seeds as an alternative anthelmintic to reduce parasite burden in naturally infected lambs.

Parasite control continues to be an important management consideration for small ruminant producers worldwide because of the increased cost associated with anthelmintic treatment and the growing risk of parasite resistance to commercially available anthelmintics. As an alternative, pumpkin seeds (PS) have demonstrated anthelmintic properties in vitro that may be applied on-farm to control parasitic infection. Therefore, the objective of these experiments was to evaluate lamb growth and monitor parasite burden in lambs offered PS supplemented growing diets by measuring lamb body weight (BW), dry matter intake (DMI), average daily gain (ADG), fecal egg count (FEC), FAMACHA eye score (FAM), and packed cell volume (PCV). We hypothesized that the supplementation of PS would decrease parasite burden in growing lambs. Analysis of data included fixed effects of pen and treatment, random effect of lamb, with repeated effect of week. In Experiment 1, all lambs were fed a common pelleted diet for 28 days. The control group (CON) was supplemented with 0.21 kg as fed/hd/day of whole shell corn while the PS group was supplemented with 0.45 kg as fed/hd/day. These treatments were isocaloric and limit fed. At the conclusion of the supplementation period (d 28), lamb BW was lesser for those lambs offered PS when compared with CON (P < 0.01). In addition, there was evidence of compensatory gain as lamb ADG tended to be greater post-treatment for PS lambs when compared with CON lambs (P = 0.14). Lamb FAM and log10(FEC) did not differ between treatments (P > 0.05). However, lamb PCV was greater (P < 0.01) for PS supplemented lambs when compared with CON lambs during the duration of the supplementation period (Week 1-4). In Experiment 2, lambs were fed a common meal diet with differing concentrations of ground PS (0-g [A], 100-g [B], and 200-g [C], respectively) for 14 days. Lamb BW at the conclusion of the supplementation period (d 14) and lamb ADG had linear effects whereas the concentration of PS in the diet increased, lamb BW decreased (P < 0.01). Additionally, there was no evidence of post-treatment compensatory growth (P < 0.33) and no differences in lamb PCV, log10FEC, and FAM (P > 0.12). Under the conditions of these experiments, animal growth decreased, and parasite burden remained unchanged for lamb offered PS. Additional research may be considered to better understand a preferred method of PS feed delivery that does not negatively impact lamb DMI and growth.