PSVI-2 - The effect of ground pumpkin seed on reducing the parasite burden in young, growing lambs

Abstract: Parasite management is the costliest health expense in the small ruminant industry today. The difficulty of managing parasites is magnified through the development of resistance to chemical de-wormers leading to anthelmintic resistance. Pumpkin seeds have anthelmintic properties, which have been observed in previous in-vitro studies. Therefore, the objective of this experiment was to evaluate the effect of ground pumpkin seeds (PS) as a natural anthelmintic by monitoring lamb fecal egg count (FEC), FAMACHA eye score (FAM), and packed cell volume (PCV). We hypothesized that ground (PS) would minimize feed sorting and refusal and reduce parasite burden in naturally parasitized growing lambs. A total of thirty lambs were blocked by sex, weight, and pre-treatment FEC into fifteen pens and randomly assigned one of three treatments. All treatments incorporated a basal diet with a ground PS supplement meal as top dressing at rates of either 0 (CON), 100 (A), or 200 (B) grams/head/day during a two-week feeding period. Data were analyzed using PROC MIXED in SAS. Lamb body weight (BW) and health parameters were measured once a week except for lamb FEC, which was collected twice a week. There were no treatment x day interactions for lamb PCV (31%, 32%, and 29%; P=0.28) or FEC (8490, 8693, and 16897; P=0.49) for lambs offered CON, A, and B diets, respectively. However, there was a treatment x day interaction for lamb FAM whereas lambs offered diet A had the lowest (1.1) score, lambs offered diet B (1.4) had the highest score, and lambs offered the CON diet (1.3) being intermediate (P=0.0084). Additionally, it was observed that lamb dry matter intake (DMI) decreased (1012, 951, and 744 g; P< 0.001) as PS inclusion rate increased in the diet for CON, A, and B diets, respectively. This is further supported by a decrease in lamb average daily gain (ADG; 269, 162, 55 g/d; P</em>=0.02) for CON, A, and B diets, respectively. To assess compensatory gain, lamb BW was collected one month after the conclusion of the PS supplementation feeding period and there were no differences in post-treatment ADG (311, 350, and 350 g/d; P=0.53) for CON, A, and B diets, respectively. These data demonstrate that offering lambs ground PS was not effective in decreasing parasite burden. Despite our efforts to improve PS palatability through grinding, decreased feed intake for lambs offered diets A and B negatively impacted lamb growth and had no effect on reducing parasite burden. Further investigation is required to determine a preferred method of feeding PS to encourage DMI and reduce parasitic burden in small ruminants.