If you’re weighing up whether flaxseed (linseed) is worth adding to your herd’s ration, you’re not alone. Flaxseed Oil or Flaxseed Cake is one of the most talked-about supplements in cattle nutrition circles right now — and unlike a lot of feed trends, there’s solid research behind it, whether you’re running a dairy herd or beef operation. Below, we’ve broken down what the science actually shows, in plain language, so you can decide whether adding flaxseed oil or cake to your herd’s feed is worth a conversation with your nutritionist.

What Is Flaxseed Oil, and Why Feed It to Cattle?

Flaxseed Oil (also called linseed oil) is naturally rich in alpha-linolenic acid (ALA) — an omega-3 fatty acid. Feeding it to cattle, either as an extruded/processed seed or as oil, increases the omega-3 content of milk and meat while lowering the omega-6:omega-3 ratio — a ratio that’s linked to inflammation in both animals and the humans consuming the end product.

The catch: cattle are ruminants, and the microbes in the rumen naturally break down (biohydrogenate) most unsaturated fats before they can do any good. That’s why processing matters — extruding or otherwise treating the flaxseed helps protect the beneficial fats long enough for the animal to actually absorb them.

The Research: What Happens When You Feed It to Dairy Cows

A large-scale commercial farm study followed over 500 Israeli-Holstein dairy cows across an 18-month trial, starting supplementation three weeks before calving and continuing through lactation. Here’s what it found when cows were fed extruded flaxseed (EFLX) compared to a standard diet:

• MILK PRODUCTION & QUALITY:
  • Milk yield increased by around 4.5% (roughly 1.8 kg more per cow per day)
  • Milk fat and protein percentages were slightly lower
  • Omega-3 content in milk nearly quadrupled, and the omega-6:omega-3 ratio dropped from 13.0 down to 4.1 (this means more beneficial omega-3 fats are present relative to omega-6 – see below for why this matters)
  • Milk fat contained about 20% more unsaturated fatty acids overall

• HERD HEALTH:
  • Ketosis incidence dropped noticeably (from around 31% to 23.5% of cows), and cases that did occur were milder
  • Mortality rates fell sharply — from 4.6% in the control group to just 0.7% in cows fed flaxseed

• FERTILITY:
  • Conception rates at first or second insemination weren’t significantly different, however, cows on flaxseed took around 17–18 fewer days, on average, to conceive after first service and after calving — a meaningful trend, even though it didn’t reach full statistical significance

What About Beef Cattle?

• Feeding whole, rolled, or milled flaxseed oil or extruded flaxseed cake increases ALA and its longer-chain omega-3 relatives in muscle.
• The omega-6:omega-3 ratio in meat drops significantly — in some studies, from around 5.85:1 down to below 4.1:1 (a lower ratio here is the goal — it means the meat carries proportionally more of the beneficial omega-3 fats; see below for why that matters)
• Flaxseed Oil also boosts conjugated linoleic acid (CLA) levels, another fatty acid linked to health benefits in humans
• Saturated fat content in the meat itself is largely unaffected — the improvement is specifically in the type of unsaturated fat, not a wholesale fat reduction
• Some studies note a small increase in internal fat and USDA yield grade, with sensory panels rating flavour and tenderness as generally comparable to control diets (though a couple of trials noted a slightly more pronounced flavour in flaxseed-fed beef).

INCREASED INTERNAL FAT & YIELD GRADE: a benefit to the animal/producer

A peer-reviewed feedlot trial (Maddock et al., 2006, Journal of Animal Science) found that feeding flaxseed to yearling beef heifers significantly increased USDA yield grade (rising from around 2.9 in control cattle to roughly 3.2 in flax-fed groups), alongside improved average daily gain and feed efficiency — with no negative effect on daily feed intake, 12th-rib fat thickness, or loin muscle area. Sensory panels in the same and related studies rated tenderness and flavour as generally comparable to control-fed cattle.

Why the Omega-6:Omega-3 Ratio Actually Matters

Modern diets — for both animals as well as humans — have shifted heavily toward omega-6 fats, with ratios far higher than what’s considered ideal. For cattle, a high omega-6:omega-3 ratio is associated with low-grade chronic inflammation, liver absesses, rumen burn, reproductive problems, severe bloat, and laminitis. A ratio between 4:1 and 10:1 is generally considered a healthier target.

For humans, a big part of why flaxseed-enriched milk and meat are marketed as “value-added” products — the fatty acid profile itself is a genuine, measurable point of difference, not just a marketing angle.

DON’T CONFUSE THE 2 USES OF FLAXSEED:

bloat prevention typically uses plain flaxseed/linseed oil as a drench or top-dress, which is a different product and application from the extruded/processed flaxseed used in the milk-production research above. Farmers interested in bloat control specifically should talk to their vet about dosing, since this is a treatment/preventative use rather than a ration additive.

The Bottom Line for Farmers

The research is genuinely encouraging: better milk yield, meaningfully lower ketosis and mortality rates, a trend toward improved fertility, and a healthier fatty acid profile in the end product — all from a supplement that’s relatively straightforward to add to an existing ration, provided it’s properly processed.

As with any ration change, the right inclusion rate and format (extruded, rolled, milled, or oil) will depend on your herd, your current feed setup, and your goals — so it’s worth discussing with your nutritionist before making the switch.

*It is advised to consult with your veterinarian/nutritionist before introducing any new supplements to your cattle’s routine.