Grain vs Grass-fed - What type of meat should we be eating?
In an attempt to learn all about our food; be more conscious of where it came from, how it was prepared and what was added to it – we have developed an interest in what the farmers are actually using to feed livestock.
Why should we be interested?
Essentially the theory is that we also ingest the food/nutrients (and chemicals) that our food consumes. Similar to mercury in certain fish, the nutrient content of meat varies depending on the diet it has been fed.
Most people believe that it’s a black and white kind of situation. Grain-fed = less nutrients. Grass-fed = nutrient rich, including higher omega-3 content. It isn't quite that simple.
There are many factors that influence the nutrient content of meat.
A large study conducted by the Cooperative Research Centre for Sheep Industry Innovation examined over 2000 lambs per year across 8 different sites in Australia. They were tested to assess the impact of different production factors on iron, zinc and omega-3 content.
For lamb, the iron content is mostly affected by age. The older the animal, the higher the iron content – on average, it’s just over double (2.1mg/100g vs 4.3mg/100g).
Zinc content remained fairly consistent across all sites, showing us that diet and farming techniques have a lesser impact on this nutrient.
Omega 3 content.
Predominately determined by the nutritional quality of the feed. Omega-3 levels ranged greatly from 11mg -112mg/100g of EPA, DHA, and DPA.
Undoubtedly, grass-fed meat contains a higher level of omega-3s as this content declines with the use of a grain-based diet.
Grass fed vs grain-fed vs grain-finished
A grass-based diet appears to produce more nutrient dense meat. However, there are three ways that an animal can be fed. In Australia, it’s standard practice to raise animals on grass-fed diets, until they’re sent to feedlots and fed a grain-based diet. This is called ‘grain-finished’. The length of time they consume the grains depends on market requirements for quality and supply, as well as seasonal conditions.
A totally grain-fed diet means the animal is fed a special diet designed to meet their nutritional needs (proteins, fats and carbs) using a range of different ingredients to keep the animal healthy. Typical ingredients include wheat, barley, sorghum, protein from lupins and field peas, and by-products of cottonseed and canola; mixed with silage or hay.
Grass-fed means they eat a diet of whatever grass is available on the farm ground. The animals forage for their food, similar to how they would in the wild.
Grass isn’t the same grass everywhere.
As a result of this ad libitum diet, the nutrient content of their food, and therefore, the meat we consume, varies widely. Seasonal variation and type of grass alters the nutrients that the animal can consume. For example, pasture such as lucerne tends to have a higher omega-3 content because it has higher levels of chloroplasts (rich in precursors of ALA). ALA is then converted to omega-3 in the animal’s rumen.
So what do we choose?
Overall it seems completely grass-fed (pasture-fed) is the most nutrient dense choice. Especially if you’re trying to get more omega-3s in your diet; which I highly recommend for a host of health benefits I won’t cover here.
In Australia we are lucky, as ‘grain-finished’ is the most common practice. We’re lucky, because studies show that the omega-3 content of the meat is determined by the overall diet.
For example, if the animal was feeding on grass most of it’s life, then ate grains for a number of days. The overall content of omega-3s is still going to be good, despite a small decline. Compared to an animal that had only fed on grains – typical in many other countries.
So then, what about organic vs grass-fed?
Ultimately, grass-fed organic meat is going to be the top choice. But if you need to choose, I’d opt for grass-fed over organic. My reasoning: Simply put, ‘organic’ doesn’t always indicate a higher nutrient density for meat (and other products), whereas studies show grass-fed does. Organic grass-fed meat means, for the most part, you'll be supporting a farm that looks after its animals, allows them to graze and live as naturally as possible, and consume a diet it was meant to eat. Ultimately resulting in a more sustainable, ethical way to farm, and more nutrient-dense end products. The higher price is worth it.
A side note on grain-feeding
A grainy misconception: Many vegans and animal rights activists suggest cutting down on our meat intake as they are fed grains and legumes that could be consumed by us, and therefore cost us space and money on crops we could otherwise be eating. This isn’t true, in Australia at least. Grain-feeding means supplementing the grass based diet with grains, hay, legumes, crop residues or oil-seed by-products. These are all second grade crops unsuitable for human consumption.
Source: Williams, P, Droulez V. Australian Red Meat Consumption - implications of changes over 20 years on nutrient composition. Food Australia 2010; 62:87-94.