Hemp Byproducts Shown to Be a Nutritious Feed Option for Lambs

A study from Oregon State University has found that spent hemp biomass—the main byproduct of the process used to extract cannabinoids (CBD)—can be included in lamb diets without causing any serious negative effects on animal health or meat quality. According to the researchers, these findings are especially important because hemp byproducts currently have little economic value for the hemp industry. The results of the study were published in the Journal of Animal Science.

Background and Study Purpose

Spent hemp biomass is not currently approved as livestock feed due to the potential presence of THC, which could potentially affect animal health. The authors of the study believe their work is a first step toward gaining such approval. “To our knowledge, our study is the first to evaluate the effects of feeding spent hemp biomass to livestock,” said Serkan Ates, associate professor at Oregon State University’s College of Agricultural Sciences. “The results are important for both hemp growers and livestock producers. Essentially, this product is a waste material, and livestock producers could save money by adding spent hemp biomass to their feed.”

Study Design

For the experiment, Oregon State researchers fed lambs two different amounts of spent hemp biomass (10% and 20% of total feed), then stopped feeding the biomass to assess any withdrawal effects. They then evaluated weight gain, carcass characteristics, meat quality, and health indicators in the lambs.

Key Findings

• The nutritional value of spent hemp biomass is comparable to alfalfa, which is commonly fed to lambs, and it has lower palatability but better digestibility.
• Adding 20% spent hemp biomass to the feed negatively affected feed intake in the short term, but not in the long term. Feeding 10% spent hemp biomass increased feed intake over the long term. Despite these changes, there was no effect on lamb weight.
• The quality of lamb meat was largely unchanged, except for an increase in cooking loss (weight change during cooking), which could affect meat tenderness.
• Spent hemp biomass did not harm the animals’ metabolism and even improved their antioxidant capacity.
• The lambs’ livers were not damaged, but there was a decrease in liver clearance, meaning the liver’s ability to extract or metabolize drugs was reduced.

The authors noted that this last finding requires further study, as it could affect the clearance of other medications that might be given to lambs.