Scientists in Australia are trying to find a cannabis plant that could be fed to sheep without making them high.
Farm Weekly reports the study, titled ‘Opening the gates to hemp-grazed livestock in Australia’, has already seen a pilot completed, led by the Department of Primary Industries and Regional Development and funded by AgriFutures Australia, in collaboration with the ChemCentre and Charles Sturt University.
The pilot included trials in Western Australia and New South Wales and found industrial hemp has merit as a summer crop for livestock such as sheep and cattle. Scientists have been feeding a flock of 15 Merino sheep in NSW with cannabis from WA, to discover if THC ends up in their meat.
It suggested that remnants of crops harvested from the medicinal cannabis and industrial hemp industries of Australia could be fed to livestock, however the crop will need to no longer contain THC, as THC is considered a contaminant in supplied animal products unless a safe allowed level is set by food regulators.
The current acceptable level of THC in food coming from animals is zero, as there is a lack of data on the topic.
Despite this, the pilot study has sparked further research to explore the nutritional value of cannabis and ways to meet market regulations.
Project lead Dr Bronwyn Blake said the pilot experiments on the 15 Merino sheep in NSW showed there were no adverse effects on feed intake or animal performance from consuming hemp stubble, even as the hemp chosen had a slightly higher THC content to push the parameters.
She added: “The sheep were fed three diets and five replicates per treatment and measured for digestibility, performance and carcase traits over a period of 56 days.
“The experiment showed the digestibility of dry and organic matter were higher for both hemp diets compared with the control, though it is not clear why.
“The most profound outcome was the increase in minor volatile fatty acids, suggesting an improvement in energy availability and a change in the composition of the gut microbial population, which may account for the improved digestibility.”
While the results would not meet regulatory requirements as THC was detected in all measured tissues, it was at extremely low levels, which Blake said was encouraging.
She said: “The results suggest there is plenty of scope to develop management practices for feeding hemp biomass to ruminants like sheep, goats and cattle, which may meet regulatory requirements for zero THC levels in animal products.”
The project has now progressed to phase two to investigate pathways to market for livestock fed hemp including clearance rates for THC.
Blake said she is excited about phase two, which will provide insight into the half-life, or breakdown, of THC in livestock and how long it takes THC to be eliminated from various tissues in animals fed industrial hemp.
She added: “Ultimately, this research will provide the foundation from which an industry code of practice could be developed to feed hemp forage to ruminants and create an opportunity for this useful, diverse crop to be integrated into the whole farm business.”
