Here is another article from the Paleo Diet, it discusses the difference between grass and grain fed beef. It is a very interesting article and even though I don’t eat meat, i like to think that grass fed animals have a better life 🙂
Changes in Cattle Husbandry and Feeding Practices since the Industrial Revolution
Since their initial domestication, almost 800 breeds of cattle have been developed1 as specific traits (milk production, meat, heat tolerance, behavior etc.) were selected by humans overseeing breeding and reproduction. Throughout most of recorded history, cattle were typically fed by providing them free access to pastures, grasslands and range land2. Only in the past 150-200 years have these animal husbandry practices substantially changed…
Technological developments of the early and mid 19th century such as the steam engine, mechanical reaper, and railroads allowed for increased grain harvests and efficient transport of both grain and cattle, which in turn spawned the practice of feeding grain (corn primarily) to cattle sequestered in feedlots3. In the U.S., prior to 1850 virtually all cattle were free range or pasture fed and typically slaughtered at 4-5 years of age3. By about 1885, the science of rapidly fattening cattle in feedlots had advanced to the point where it was possible to produce a 545 kg steer ready for slaughter in 24 months and which exhibited “marbled meat”3. Wild animals and free ranging or pasture fed cattle rarely display this trait4. Marbled meat results from excessive triacylglycerol accumulation in muscle interfascicular adipocytes. Such meat typically has greatly increased total and saturated fatty acid contents, reduced protein (by energy), a lower proportion of omega-3 fatty acids, higher omega-6 fatty acids and a higher omega-6/omega-63 fatty acid ratio.
Modern feedlot operations involving as many as 100,000 cattle emerged in the 1950s and have developed to the point where a characteristically obese (30 % body fat) 545 kg pound steer can be brought to slaughter in 14 months. Although 99% of all the beef consumed in the U.S. is now produced from grain-fed, feedlot cattle, virtually no beef was produced in this manner as recently as 200 years ago. Accordingly, cattle meat (muscle tissue) with high total fat, low protein (by energy), high absolute saturated fatty acid content, low omega-3 fatty acid content, high omega-6 fatty acid content and an elevated omega-6/omega-3 fatty acid ratio represents a recent component of human diets that may adversely influence health and well being.
Grain Fed, Feed Lot Cattle: Nutritional Consequences for Humans
The practice of feeding grain and concentrated feed to cattle sequestered for long periods in feedlots is not necessarily benign, but rather yields meat with a number of potentially deleterious nutritional characteristics, particularly when compared to either wild animals or grass fed cattle.
Grass vs. Grain Fed Beef: Omega 3 and Omega 6 Fatty Acids
There is little argument that grass fed cattle accumulates more omega-3 fatty acids in their tissues than grain fed cattle. This nutrient amplification in tissues occurs because the concentration of (alpha linolenic acid [ALA]) in pasture grass is 10 to 15 times higher than in grain or typical feedlot concentrates25. In mammals the liver represents the primary tissue which chain elongates and desaturates into long chain omega-3 fatty acids which then can be deposited in muscles and other tissues.
Not only do feed lot cattle maintain lower omega-3 fatty acids in their tissues than grass fed cattle, but a characteristic increase in the total omega-6 fatty acids occurs as a result of grain feeding. Because typical cereals fed to cattle such as maize (omega-3/ omega-6 = 70.7) and sorghum (omega-6/ omega-3 = 16.2) contain very little 18:3n3 and much higher 18:2n642, the cattle’s tissues reflect the fatty acid balance of the grains they consume.
The case for increasing omega-3 fatty acids in the U.S. diet has broad and wide sweeping potential to improve human health. Specifically, omega-3 fatty acids and their balance with omega-6 fatty acids play an important role in the prevention and treatment of coronary heart disease, hypertension, type 2 diabetes, arthritis and other inflammatory diseases, autoimmune diseases, and cancer.
Dietary Saturated Fat
From per capita data it can be inferred that the average U.S. citizen consumes 82 g of beef per day45, with ground beef (42%), steaks (20%), and processed beef (13%) comprising the bulk of the beef consumed. Ground beef, choice and prime USDA quality steaks and processed beef (frankfurters, lunch meats etc.) represent some of the highest total fat and saturated fat sources found in any cuts of beef. An 82g serving of fatty (22% fat) ground beef can contain 8.8g or more of saturated fat, whereas a comparable serving of lean (2.5% fat) grass fed beef may contain as little as 1.2g of saturated fat. Hence a daily reduction of up to 7.6g of saturated fat could be achieved in this scenario involving only displacement of high fat beef with lean grass fed beef.
Saturated fat intakes of < 10 % total energy are recommended to reduce the risk of cardiovascular disease. Accordingly in a 2,200 kcal diet, saturated fat (9 kcal/g) should be limited to 24.4g. Thus, the savings accrued (7.6g of saturated fat) in this scenario by replacing fatty ground beef with lean grass fed beef represents a substantial 31% reduction in total saturated fat.
Dietary Protein
Because of it’s inherently low fat content (2.6% by weight), grass fed beef is also a high protein food averaging 76.5% protein by total energy. Contrast these values to USDA Choice (+) beef with only 48.7% protein by energy, or USDA Prime (o) beef with 40.8% protein by energy, or worse still, fatty ground beef with 20.3% protein by energy. A litany of recent human studies demonstrates that isocaloric replacement of dietary fat by lean protein has numerous health promoting effects.
Potential Health Improvements by Increasing Grass Fed Beef Consumption
A number of scenarios involving improvements in human health can be envisioned by including more and more lean grass fed beef into the diets of U.S. citizens. These scenarios are dependent upon the specific foods and food groups that would be potentially displaced by grass fed beef and by the amount of grass fed beef that would included in the diet. The health impact of such scenarios could range from minimal to highly significant.
