333 - Assessment of Spent Hemp Biomass as a Potential Feedstuff in Ruminant Diets

The 2018 Farm Bill removed hemp (Cannabis sativa) from the Controlled Substances Act, classifying it as an agricultural product. The process of cannabidiol extraction from hemp yields large quantities of spent hemp biomass (SHB) that may potentially be included in animal diets. However, the use of SHB in animal diets has not been approved by FDA yet since its effect on animal health, production and product quality is still unknown. Thus, a feeding study was carried out to investigate the effects of varying levels of SHB and a four-week withdrawal period on feed intake and liveweight gains of weaned lambs. A total of 35 weaned, male Polypay lambs kept in single pens were randomly assigned to five feeding treatments (n=7) and fed diets containing either no SHB (CON) or SHB at 10% (LH1) or 20% (HH1) for 4 weeks with 4 weeks withdrawal from SHB, or SHB at 10 (LH2) or 20% (HH2) for 8 weeks. The nutritive analysis of the SHB indicated a high quality feed, with 20% (DM) crude protein and 27% NDF. Dry matter (DM) intake of lambs was negatively affected by 20% SHB during the first period. In the second period, DM intake was larger in lambs fed 10% SHB vs. CON, with the largest feed intake observed in HH1 lambs. In contrast, none of the performance data, including liveweight gains, were different across the groups and periods. Feeding 20% SHB decreased plasma cholesterol, NEFA, BHBA, Ca, and Cl and increased urea and Mg, while 10% SHB increased glucose, cholesterol, and NEFA. Our findings indicated that 10% SHB can be included in ruminant diets without causing any detrimental effect on performance with a possible positive effect on feed intake. The long-term feeding of 20% SHB strongly affects the metabolism.