A Pilot Study on the Use of Pumpkin Waste as Cattle Feed

Pumpkin seed pulp discarded from pumpkin processing plants is rich in β-carotene and has high nutritional value, making it a potential functional feed ingredient. However, concerns remain regarding residual pesticides, such as heptachlor, and the occurrence of volunteer pumpkins due to undigested pumpkin seeds in the feed. Therefore, the present study was conducted with the aim of supplying pumpkin seed pulp as a highly functional feed while ensuring its safety. Methods: In this study, pumpkin waste was processed into cattle feed by grinding and drying, and the residual pesticide and β-carotene content were measured for each cultivation field of the raw pumpkins. A pilot feeding trial was conducted with 13 cattle (7 in the treatment group and 6 in the control group) and blood component analysis was performed along with a literature review. Results: Variations in heptachlor concentrations were observed depending on the cultivation field of the raw pumpkins, with some samples exceeding the Japanese regulatory limit for animal feed. The pumpkin seed pulp flakes (PSPF) con-tained high levels of β-carotene, and blood tests before and after the feeding trial sug-gested absorption of β-carotene in the cattle. Maintaining high plasma β-carotene concentrations in cattle has been associated with improved immune function and re-productive performance. Conclusions: Our study demonstrates that flakes made from pumpkin seed pulp are a promising, environmentally friendly feed ingredient rich in natural β-carotene. By tracing the cultivation fields of the raw pumpkins, the safety of the feed can be ensured.