Toxins, taste, fats and nutrients. These are the reasons that I choose to eat beef that's pasture raised rather than factory farmed. There's plenty of scientific debate in this field and still many things that aren't certain. Here are the factors that influence my choices based on the information I've seen.
1. Toxin free animal, toxin free fats / / Like in humans, cattle tend to store toxins in fat tissue. If you buy meat from a pasture raised, organic animal, the quality of the fat is far better for you. In contrast, if you eat a lot of fattier cuts of meat from commercially raised animals, you may also be consuming the toxins stored in that animal's fat cells from it's sub optimal diet. This can even make it more difficult for you to lose body fat.
2. The animal's diet impacts the dietary fat profile of the animal's meat / / The fatty acid profile of beef is about half saturated fat and half monounsaturated fat (it's actually a little higher in monounsaturated fats). Studies indicate that meat from cattle raised on a farm free from exogenous hormones or antibiotics also contains more omega 3s, less omega 6s, and more conjugated linoleic acid than conventionally farmed cattle. It's suggested that the Omega 6:3 ratio changes dramatically from 15:2 in conventional cattle to 3:2 in pastured raised cattle. Sure, the changes translate into small amounts, but the ratios of omegas in our diet matters and eating pasture raised cattle helps to adjust it in the right direction. Your body needs a balance of fats for optimal health, and one of my favourite sources is fattier cuts of beef. If your goals at the time can accommodate the bump in calories, don't feel like you need to stick to leaner cuts or trim the fat.
3. Just like in humans, a poor diet affects nutrient status / / There's evidence to indicate that the animal's diet also influences its broader nutrient status.
Thiamin (vitamin B 1) is a fascinating example of this. Thiamin specialises in extracting energy from carbohydrates. If you don’t have enough thiamin, you won’t be able to use carbs properly. Thiamin is also necessary to burn protein and fats, just like other B vitamins contribute to burning carbs. Like humans, animals can become thiamin deficient. And just like in humans, this happens because of a thiamin deficient diet, processed foods or a GI issue.
A 2014 review of the nutritional characteristics of beef looked at the limited number of studies that compared the nutritional profile of US grass or forage-fed and grain-finished cattle. The review noted that only one US study, published in 2009, compared the thiamin content of grass or forage-fed compared to grain-finished beef. That study reported nearly 3 x the thiamin (and 2 x riboflavin) in beef from grass-finished cattle. From this, the review concluded that in a 100 g portion, grass or forage-fed beef provides 6.1% of the US RDA for thiamin, while grain-finished beef only supplies 2.1% of the RDA (and 19 to 38% of the adult RDA for riboflavin). [Even though the study reported no nutritionally relevant difference between the feeding regimes.] It’s not a huge amount, but 0.06 g in each 100 g x multiple 100 g portions of beef in a meal or across a day adds up.
How does this happen? For ruminant animals like cattle and sheep, thiamin is normally produced by bacteria in the rumen (the first of their four chambered stomach, basically a large fermentation vat that’s home to bacteria and other micro-organisms) if the animal eats a balanced diet that includes plant roughage. However, there is also bacteria in the rumen capable of making an enzyme called thiaminase that breaks down and inactivates thiamin that the animal could normally use. If there’s an increase in the ‘dietary-concentrate-to-roughage’ ratio - ie, too much feed (grains such as corn) and not enough grass, forage or hulls - these bacteria can proliferate and produce an excessive amount of thiaminases. This results in thiamin deficiency.
A high sulfate diet can also block an animal’s ability to properly use thiamin. Feeds such as molasses, corn gluten and dried grains are often high in dietary sulfates. Feed lots present a perfect storm. Diets high in carbohydrates and low in fibre encourage thiaminase-producing bacteria to multiply in the rumen. To prevent an identified deficiency from affecting an entire stock, official documents advise farmers to switch the animals to a diet higher in roughage (at least 50 % of the diet) and add thiamin to the feed for 2 to 3 weeks before carefully reintroducing more grain in the diet to increase the animal’s size again. A serious thiamin deficiency is a death sentence.
4. It tastes better / / This is just my personal experience, but I've noticed that pastured raised beef tastes better than mass produced meat. And a lot of this taste is in the fat - it's softer, rich in flavour and adds to the meal. The rind of a T-bone isn't tough and grisly, it's delicious and palatable.
Elswyk and McNeill, Impact of grass/forage feeding versus grain finishing on beef nutrients and sensory quality: The U.S. experience, Meat Science, Volume 96, Issue 1, January 2014, 535-540.
Duckett et al, Effects of winter stocker growth rate and finishing system on: III. Tissue proximate, fatty acid, vitamin, and cholesterol content, J Anim Sci, 2009, Sep 87(9), 2961-70.
Daley et al, A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef, Nutrition Journal, 2010(9), 10.
Victorian Government Department of Economic Development, Jobs, Transport and Resources Agriculture Services and Biosecurity Operations Division, Drought Feeding and Management of Beef Cattle - A guide for farmers and land managers, April 2018.
Keinänen, et al, The thiamine deficiency syndrome M74, a reproductive disorder of Atlantic salmon (Salmo salar) feeding in the Baltic Sea, is related to the fat and thiamine content of prey fish, ICES Journal of Marine Science, Volume 69, Issue 4, May 2012, 516–528.
Environmental Working Group, Why Go Organic, Grass-Fed and Pasture-Raised?
Dr Serrano, Dietary fat ratios