Is hemp (Cannabis sativa) safe to feed pregnant sheep?

Authors: Green, Benedict; GARDNER, DALE - Retired ARS Employee; Stonecipher, Clinton; Welch, Kevin; Lee, Stephen; SULLIVAN, TINA - Kansas State University; WESTMORELAND, F - Utah State University; Cook, Daniel

Submitted to: Translational Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2025
Publication Date: 7/22/2025
Citation: Green, B.T., Gardner, D.R., Stonecipher, C.A., Welch, K.D., Lee, S.T., Sullivan, T., Westmoreland, F.M., Cook, D. 2025. Is hemp (Cannabis sativa) safe to feed pregnant sheep?. Translational Animal Science. 9. Article txaf093. https://doi.org/10.1093/tas/txaf093.
DOI: https://doi.org/10.1093/tas/txaf093

Interpretive Summary: Cannabis sativa (varieties for industrial use or animal feed are termed hemp), and its extracted biproducts are being considered for animal feed due to their high protein content. However, if hemp disrupts fertility and reproduction in livestock, it should not be used as a feed source. There were no significant fetal deformities or weight differences between the treatment groups, and as expected, the lamb weights significantly increased over time. These results suggest that this plant may have the potential to be a suitable protein source for sheep.

Technical Abstract: Cannabis sativa (varieties for industrial use or animal feed are termed hemp), and its extracted biproducts are being considered for animal feed due to their high protein content. However, if hemp disrupts fertility and reproduction in livestock, it should not be used as a feed source. We hypothesized that the phytocannabinoids in hemp would disrupt fertility and reproduction, cause craniofacial defects, and low birth weight in lambs. To test this hypothesis, pregnant ewes were dosed with hemp at 150 mg/kg body weight per day total cannabinoids, and from gestational days 10 to 20. The most prevalent cannabinoids in the plant material were cannabidiolic acid (CBDA) at a concentration of 23.2 mg/g, and cannabidiol (CBD) at a concentration of 5.8 mg/g. After 10 days of dosing with hemp, a serum sample was obtained from each of the ewes, CBDA was measured at a concentration of 652 ± 38 ng/mL and CBD was measured at 16 ± 0.9 ng/mL. The average gestation length for lambs from the hemp treated ewes was 148 ± 0.38 days, and the average gestation length for lambs from the grass hay treated ewes was 149 ± 0.38 days (P = 0.2306, t-test). The numbers of male and female lambs did not significantly vary from expected (50:50) (P = 0.32, one-tailed binomial test). There were no significant fetal deformities or weight differences between the treatment groups, and as expected, the lamb weights significantly increased over time (P < 0.05). These results suggest that this plant may have the potential to be a suitable protein source for sheep.