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Federal researchers have discovered that cows that eat a hemp-based diet do not retain appreciable levels of THC or CBD in their bodies. This research could be great news for both the cattle and the hemp industries, as it suggests that humans can consume hemp-fed meat or dairy without the risk of getting stoned or failing a drug test for cannabis. 

Researchers from the US Department of Agriculture (USDA) partnered with North Dakota State University (NDSU) to research the viability of feeding cows a diet of hempseed cake. This dried material is a natural byproduct that is created when cannabis oil is extracted from hemp seeds. Hemp producers are able to compress this leftover material into cakes, but have so far found little use for this excess byproduct.

Earlier research has already suggested that hempseed cake could be an excellent source of protein and fiber for cattle, but farmers are not legally allowed to feed cows cannabis. Before now, researchers had no idea whether or not hemp-fed beef or milk would retain significant amounts of cannabinoids that could be passed on to humans who consume it. For this reason, the USDA continues to block farmers from feeding hemp to any livestock meant for human consumption.

The new USDA and NDSU study may help resolve these issues. To conduct their research, scientists fed a group of healthy heifers a diet containing 20% hempseed cake for 111 days. Over the course of the study, researchers took tissue samples from the cows and tested them for THC and CBD content. At the end of the feeding period, researchers could only detect tiny trace levels of cannabinoids in the animals’ fat. And absolutely zero THC or CBD was detected in liver, kidney, or muscle samples.

“According to our exposure assessment, it would be very difficult for a human to consume enough fat from cattle fed with hempseed cake to exceed regulatory guidelines for dietary THC exposure,” David Smith of the Animal Metabolism-Agricultural Chemicals Research Unit in Fargo, North Dakota, said in a statement. “From a food safety view point, hempseed cake having low cannabinoid content can be a suitable source of crude protein and fiber in cattle feed while offering industrial hemp producers a potential market for this byproduct of hempseed oil extraction.”

This research could help convince the federal government to allow hemp farmers to sell their excess hempseed byproduct to cattle farmers. This would be a win for the cattle industry also, because cows themselves can benefit from eating a hemp-based diet. Last year, a federally-funded study found that a CBD-rich diet can help reduce stress in cattle. And since stressed-out cows are more likely to get sick, a hemp diet could potentially increase their lifespan.