Hemp Byproducts as Livestock Feed: Safe, Nutritious & Sustainable

As hemp cultivation expands globally, producers are seeking ways to turn every part of the plant into value. One of the most promising opportunities? Feeding hemp byproducts—like seed cake and spent biomass—to livestock. Recent research shows these leftovers are not only nutrient‑rich but can be used safely, provided a simple withdrawal period is observed. In this post, we unpack the benefits, address safety concerns around THC, and explore the evolving Australian landscape for hemp‑fed animals.

Nutritional Powerhouse in Every Bite

Hempseed cake (the press‑cake left after oil extraction) and spent biomass (the leafy stalks and flower waste after CBD removal) pack a serious nutritional punch:

• High protein: Often 30–50% crude protein—on par with soybean or cottonseed meal—making it an excellent supplement for ruminants.
• Healthy fats & micronutrients: Rich in omega‑3/6 fatty acids, antioxidants, minerals and vitamins that support animal health.
• Digestible fibre: Especially in pelleted form, hemp biomass provides a good source of roughage.

Case in point: Australian trials feeding sheep pelleted hemp residues observed improved fibre digestibility and energy‑yielding fermentation in the rumen—translating to more efficient feed conversion⁺.

Safety First: Managing THC in Milk & Meat

A top concern has been whether trace THC (the psychoactive compound) could accumulate in animal products. The latest Oregon State University study provides clear reassurance:

1. Feeding phase: Dairy cows consumed a diet containing 13% spent hemp biomass by dry weight for 28 days.
2. Withdrawal phase: Cows were then switched to a hemp‑free diet.
3. Result: After 15 days, THC became undetectable in both milk and tissue samples.

“Two weeks of withdrawal … eliminates any risk of ingesting THC from milk,” explains Dr Massimo Bionaz at OSU.

This finding means that by simply ceasing hemp feed two weeks before milking or slaughter, farmers can ensure zero THC residues in food products.

🔗 Read more about the OSU findings »

The Australian Context: Trials & Regulation

While international research paves the way, Australia’s regulations are just beginning to catch up:

• Current rules: Only processed, de‑seeded hemp fractions (e.g., defatted meal) are permitted in food‑animal feeds. Raw biomass (hay, silage, stubble) remains prohibited until zero‑THC safety is proven in local trials.
• FSANZ standards: Any detectable THC in meat or milk is treated as a contaminant, with a maximum allowable residue of zero.
• Regulatory progress:
  • The WA Department of Primary Industries (DPIRD) conducted sheep–hemp feeding trials in 2024, finding normal health and growth with only trace, manageable THC levels.
  • In May 2025, the APVMA reclassified certain hemp feed ingredients as “Excluded Nutritional/Dietary” (END), streamlining pet‑food and supplement approvals.

Ongoing Phase 2 trials in Western Australia are now focusing on THC clearance timelines—mirroring the OSU approach—to establish an approved withdrawal period for our local producers.

Why Farmers & the Industry Should Pay Attention

For Farmers:

• Additional revenue stream: Selling or repurposing hemp waste for feed can boost farm profitability and reduce disposal costs.
• Drought resilience: Hemp’s hardiness and summer biomass can supplement forage when pasture yields drop.

For the Hemp Sector:

• Full‐value harvest: Creating demand for byproducts strengthens the whole supply chain—from seed oil to animal feed.
• Brand differentiation: Marketing “sustainably fed” dairy or meat can resonate with eco‑conscious consumers.

For Sustainability:

• Waste‐to‐resource: Turning crop leftovers into feed exemplifies circular agriculture, lowering environmental impact.
• Reduced imports: Replacing imported protein feeds (like soy) with home‑grown hemp meal cuts supply‑chain emissions.

Best Practices & Takeaways

1. Formulate wisely: Limit raw hemp inclusion rates; consider pelleting or mixing with other feeds to optimise rumen health.
2. Observe withdrawal: Ensure a 15–21 day hemp‑free period before milking or slaughter.
3. Monitor quality: Test hemp byproducts for THC content and nutrient levels to maintain consistency.
4. Stay informed: Watch for FSANZ updates on THC tolerance and APVMA guidance on hemp feeds.

Looking Ahead

With clear safety data emerging and regulations evolving, hemp byproducts are poised to become a valuable feed across Australian farms. By adopting best practices now, growers and feedlots can lead the way in sustainable, low‑waste agriculture—fueling healthier animals and greener food systems.

Have questions or want to discuss hemp feed trials on your farm? Reach out to our team at:  [email protected]

— Margaret River Hemp Co.

⁺ Reference: DPIRD “Opening the gates to hemp‑fed livestock” pilot study, WA Department of Primary Industries, 2024.