Is Pasture Raised Chicken More Nutritious?
When we consider nutrition, most of us would intuitively expect that a pasture raised chicken wins out over a conventional chicken raised in a crowded, enclosed barn. It just makes obvious sense that a chicken in a better environment is a better chicken. But I’ve been curious about the current state of research on the topic, and what that research means for the way we promote pasture raised chicken’s nutritional aspects.
What Can We Learn from Research?
I’ve assembled quite a list of research citations (see bibliography at the end) to characterize the findings. Not surprisingly, the research confirms our basic intuition that pasture raised chicken has specific nutrients in higher concentrations than conventional chicken. Some of the research is based on chickens with less than ideal outdoor access, more what I’d characterize as free range. I suspect, although I can’t prove it without doing independent studies that for all these items truly pasture raised chickens would exhibit even better attributes.
I’ll cover the main findings.
And then I’ll tear it all up and suggest another way to think about food.
Collagen is an fascinating protein. Investigation continues to uncover new roles collagen plays, but at present we know that it is essential to joint support, bone density, skin health, and wound repair. Interestingly, collagen also appears to stabilize blood sugar levels and regulate blood pressure.
Pasture raised chicken has 15% more collagen than conventional chicken. To my mind, this isn’t a shocking nutritional advantage. I suspect a person could satisfy their daily collagen requirements with any chicken, perhaps just eating a little extra conventional chicken to make up for their shortcomings. But as a farmer I find this collagen statistic interesting because it indicates that a pasture raised chicken is structurally a different chicken, with significant muscular-skeletal development a conventional chicken lacks.
Feel like you need to maximize collagen intake in you diet? Cuts with the skin on, especially the wings or skin cracklings, will have more skin collagen. Hard working, tougher muscles tend to have more intramuscular collagen. But above all, make bone broth because that extracts and concentrates all the collagen in the bones, tendons, and cartilages.
Fat Profile, Particularly Omega 3
Covering any topic related to dietary fat can be exhausting. Much misunderstanding persists about the dietary role of fats in our diets. Saturated fat, unsaturated fat, polyunsaturated fat, trans fat, Omega 3, Omega 6, Omega 9, good fat, bad fat. There are many different opinions, and many credentialed experts ready to argue ceaselessly for opposing viewpoints.
Rather than participating in medical mud wrestling, I’ll just state that pasture raised chicken has 2.3x the amount of Omega 3 and 3x the amount of long chain Omega 3. It has a lower Omega 6 to Omega 3 ratio and more unsaturated fats as well. I tend to believe that these values are important, but I’ll leave it to the reader to draw conclusions.
If you want more of these fats in your diet, I recommend the dark meat portions (drumsticks and thighs). That’s what I reach for whenever I have the choice. The dark meat is higher in intramuscular fat than the breast. The liver should also be higher in fat content.
Vitamin E functions crucially as an antioxidant, preventing tissue damage. Apparently it is an overachiever in the vitamin world since other roles for Vitamin E continue to be discovered. It participates in immune response, enables vitamin K absorption, mediates inter-cell signaling, and regulates gene expression.
Pasture raised chickens test out at 30% higher Vitamin E levels than confinement barn chickens.
As with the collagen topic, I’m fascinated more about what it tells me about the chickens than what it tells me about getting my vitamins. I know that conventional chickens are supplemented with fairly high doses of Vitamin E. Without it, they’d develop severe muscle and nerve damage. But pasture raised chickens are storing the extra Vitamin E in their bodies. This suggests that pasture raised chickens are facing less oxidation damage and immune system stress, so they have spare Vitamin E to store.
As with the fats described above, Vitamin E is fat soluble and will likely be more prevalent in the dark meat and liver.
Limits of Research
We should recognize the important limitations of depending on research for factual claims for or against the health of any product. Research is limited by the funding and policy agendas of governments and influential corporations. Unfavorable findings can be buried while favorable findings advance toward publication. Reproducibility of experimental results continues to be a problem in all branches of science. The scientific method works well, but perverse incentives plague our best efforts to be unbiased.
A few years ago I was at an auction for a defunct egg farm. In looking through the manual for a rusty old egg washing machine I found a whitepaper by a trade group for egg farmers from the early 1970s. It warned about the shift in public opinion regarding eggs and cholesterol, and it outlined a publicity counterattack strategy. During the fifty intervening years, research and public opinion on these topics have shifted several times. The research gradually gained clarity as the consensus came to understand that cholesterol exists in multiple forms, each one having a complex role in biology. It seems that the early overreaction against eggs was probably misguided and that cholesterol content of specific foods do not necessarily correlate with cholesterol-related cardiology problems. But the path to get there was obstructed by vested interests on all sides, each angling for an advantage. Along the way, both the heart-health researchers and the egg industry pulled some fast ones, giving false or flimsy research to the public and creating lasting confusion.
I believe that scientific methods do gradually bring us to truths, but the process crawls along slowly. And we can never know whether the topic has been studied sufficiently until we’re long past the point of conclusion.
Let Marketing Be Thy Food
We’ve all heard the quote (misattributed to Hippocrates), “Let food be thy medicine and medicine be thy food.” In one sense, I get it. But in the American context, where we obsess about hyper-specific health issues while indulging consistently unhealthy lifestyles, this advice seems to prime us for food hucksterism. “Eat more tomatoes for Lycopene!” “Goji berries give you Vitamin A, so take a handful.” “Blueberries give you manganese, eat a cupful every morning!” All these foods are sold to us for their vitamins and minerals, as if human diets are implausibly difficult to balance without outside expertise.
Choosing food has become a fraught impossibility, requiring expert opinion and science. Our focus on particularizing everything into discrete nutrition renders each of us incompetent. Pity our ancestral hunter-gatherers, who had no help to decide whether a fish or a rabbit had a higher dose of Vitamin D.
What is most clever about this nutritional sales pitch approach is that all the promoted attributes are invisible. I’ve never seen the Vitamin C C6H8O6 molecules in an orange. I can’t tell by picking it up whether spinach has Iron in it or not. Our relation to the chemical contents remain distant, notional.
This all leads to a sense of self doubt, because it lets us wonder if we’re not getting the right amount of some important vitamin. This puts us right in the crosshairs of the nutritional marketing cannon.
A company selling food for its vitamin content benefits by engendering this feeling of inadequacy in the public. Americans seem to have become dependent on marketing departments to tell them what to eat. I believe that this “Eat more <insert food here> to get more <insert nutrient>” approach to food has become a widespread type of eating disorder.
Wrong Direction, Different Direction
Rather than chasing Omega 3 in chicken or manganese in blueberries, I propose choosing food based on more intuitive, more human standards.
So as not to be incessantly self-serving, let’s take blueberries as an example since I don’t sell them. I eat blueberries and enjoy them. To me they are an seasonal marker of late July and early August in our part of Upstate New York, associated with pleasant memories of picking them every year at Dave Ingall’s Organic U-Pick farm with my family. I eat blueberries because I like the taste, because they make me feel great, because I enjoy picking them on breezy summer evenings, because I respect the farmer who grows them, because I cherish the shared experience of picking them. Manganese has nothing to do with it.
Looking at blueberries as my model, I see five criteria. I propose choosing food based on taste, internal feedback, charm, production integrity, and human connection. For instance, choose a ribeye steak for its incomparable flavor, a fermented dill pickle because it is soothing, a camembert cheese for the tang that reflects a specific pasture in July, a chicken raised by a farmer doing the right thing, or a spaghetti sauce recipe that has been a family tradition for generations. These are the truly important food criteria. Not every food needs to be top ranked in each category, but I believe that truly good foods are the ones that score high on most of these rankings.
Necessarily, in following these guiding principles nobody would end up eating identically as I do. That’s fine; that’s actually ideal. But nobody would end up eating bland, self-destructive, uninteresting, irresponsibly produced, lonely meals either. Instead we would focus on the food, the experience, the values, and the people rather than obsessing about invisible nutritional attributes.
I’ll never make a nutrient claim for our pasture raised chicken, despite my belief that this is the best way to raise chicken and despite my intuition that the best chickens have superior nutrition. I’ll never tell anyone that it will fix a problem, cure a disease, improve test results, or extend a lifespan. That approach devalues the chicken and misunderstands humans.
Our pasture raised chicken is not a vitamin, mineral, or protein supplement. Even, for instance, if I could prove that it has more Vitamin E or other vitamins than any other chicken in the world, I still wouldn’t sell it as a vitamin supplement. This chicken is too special to be just a health supplement. I think our food can be much more to us than its constituent microscopic particles.
Reference for further research as listed below. Thanks to Collette Lentz and Mike Badger for many of these references. I’d be interested in learning about other studies if anyone has links to journal-published studies.
- Almasi, A., Andrassyne, B. G., Milisits, G., Kustosne, P., & Suto, Z. (2015). Effects of different rearing systems on muscle and meat quality traits of slow- and medium-growing male chickens. British Poultry Science, 56(3), 320–324. https://doi.org/10.1080/00071668.2015.1016478
- Bartlett, J. R. (2015). Comparing the Effects of Conventional and Pastured Poultry Production Systems on Broiler Performance and Meat Quality. Journal of Agriculture and Life Sciences, 2(1), 29–36. http://jalsnet.com/journals/Vol_2_No_1_June_2015/5.pdf
- Boz, M. A., Sarıca, M., & Yamak, U. S. (2016). Production traits of artificially and naturally hatched geese in intensive and free-range systems – II: slaughter, carcass and meat quality traits. British Poultry Science, 58(2), 166–176. https://doi.org/10.1080/00071668.2016.1261998
- Chen, X., Jiang, W., Tan, H., Xu, G., Zhang, X., Wei, S., & Wang, X. (2013). Effects of outdoor access on growth performance, carcass composition, and meat characteristics of broiler chickens. Poultry Science, 92(2), 435–443. https://doi.org/10.3382/ps.2012-02360
- dal Bosco, A., Mugnai, C., Mattioli, S., Rosati, A., Ruggeri, S., Ranucci, D., & Castellini, C. (2016). Transfer of bioactive compounds from pasture to meat in organic free-range chickens. Poultry Science, 95(10), 2464–2471. https://doi.org/10.3382/ps/pev383
- Dalziel, C. J., Kliem, K. E., & Givens, D. I. (2015). Fat and fatty acid composition of cooked meat from UK retail chickens labelled as from organic and non-organic production systems. Food Chemistry, 179, 103–108. https://doi.org/10.1016/j.foodchem.2015.01.118
- Geldenhuys, G., Muller, N., & Hoffman, L. C. (2016). The influence of season on the sensory profile of Egyptian goose (Alopochen aegyptiacus) meat. Poultry Science, 95(9), 2174–2185. https://doi.org/10.3382/ps/pew135
- Jaturasitha, S., Chaiwang, N., Kayan, A., & Kreuzer, M. (2016). Nutritional strategies to improve the lipid composition of meat, with emphasis on Thailand and Asia. Meat Science, 120, 157–166. https://doi.org/10.1016/j.meatsci.2016.04.014
- Jiang, S., Gou, Z., Li, L., Lin, X., & Jiang, Z. (2017). Growth performance, carcass traits and meat quality of yellow-feathered broilers fed graded levels of alfalfa meal with or without wheat. Animal Science Journal, 89(3), 561–569. https://doi.org/10.1111/asj.12968
- Kim, H. J., Kim, H. J., Jeon, J., Nam, K. C., Shim, K. S., Jung, J. H., Kim, K. S., Choi, Y., Kim, S. H., & Jang, A. (2020). Comparison of the quality characteristics of chicken breast meat from conventional and animal welfare farms under refrigerated storage. Poultry Science, 99(3), 1788–1796. https://doi.org/10.1016/j.psj.2019.12.009
- Koçer, B., Bozkurt, M., Ege, G., Tüzün, A. E., Konak, R., & Olgun, O. (2018). Effects of a meal feeding regimen and the availability of fresh alfalfa on growth performance and meat and bone quality of broiler genotypes. British Poultry Science, 59(3), 318–329. https://doi.org/10.1080/00071668.2018.1440378
- Mikulski, D., Celej, J., Jankowski, J., Majewska, T., & Mikulska, M. (2011). Growth Performance, Carcass Traits and Meat Quality of Slower-growing and Fast-growing Chickens Raised with and without Outdoor Access. Asian-Australasian Journal of Animal Sciences, 24(10), 1407–1416. https://doi.org/10.5713/ajas.2011.11038
- Milićević, D., Vranić, D., Mašić, Z., Parunović, N., Trbović, D., Nedeljković-Trailović, J., & Petrović, Z. (2014). The role of total fats, saturated/unsaturated fatty acids and cholesterol content in chicken meat as cardiovascular risk factors. Lipids in Health and Disease, 13(1). https://doi.org/10.1186/1476-511x-13-42
- Popova, Teodora; Petkov, Evgeni; Ignatova, Maya. Fatty acid composition of breast meat in two lines of slow-growing chickens reared conventionally or on pasture. Food Science and Applied Biotechnology, [S.l.], v. 1, n. 1, p. 70-76, mar. 2018. ISSN 2603-3380. https://doi.org/10.30721/fsab2018.v1.i1.7.
- Robertson, J., M. S. Vipond, D. Tapsfield, and J. P. Greaves. 1966. Studies on the composition of feed: Some differences in the composition of broiler and free range chickens. Br. J. Nutr. 20: 675-687.
- Sales, J. (2014). Effects of access to pasture on performance, carcass composition, and meat quality in broilers: A meta-analysis. Poultry Science, 93(6), 1523–1533. https://doi.org/10.3382/ps.2013-03499
- Song, Y., Li, Y., Zheng, S., Dai, W., Shen, X., Zhang, Y., Zhao, W., Chang, G., Xu, Q., & Chen, G. (2017). Effects of forage feeding versus grain feeding on the growth performance and meat quality of Yangzhou geese. British Poultry Science, 58(4), 397–401. https://doi.org/10.1080/00071668.2017.1307942
- Sossidou, E., dal Bosco, A., Castellini, C., & Grashorn, M. (2015). Effects of pasture management on poultry welfare and meat quality in organic poultry production systems. World’s Poultry Science Journal, 71(2), 375–384. https://doi.org/10.1017/s0043933915000379
- Średnicka-Tober, D., Barański, M., Seal, C., Sanderson, R., Benbrook, C., Steinshamn, H., Gromadzka-Ostrowska, J., Rembiałkowska, E., Skwarło-Sońta, K., Eyre, M., Cozzi, G., Krogh Larsen, M., Jordon, T., Niggli, U., Sakowski, T., Calder, P. C., Burdge, G. C., Sotiraki, S., Stefanakis, A., . . . Leifert, C. (2016). Composition differences between organic and conventional meat: a systematic literature review and meta-analysis. British Journal of Nutrition, 115(6), 994–1011. https://doi.org/10.1017/s0007114515005073
- Stadig, L. M., Rodenburg, T. B., Reubens, B., Aerts, J., Duquenne, B., & Tuyttens, F. A. (2016). Effects of free-range access on production parameters and meat quality, composition and taste in slow-growing broiler chickens. Poultry Science, 95(12), 2971–2978. https://doi.org/10.3382/ps/pew226
- Tong, H., Cai, J., Lu, J., Wang, Q., Shao, D., & Zou, J. (2015). Effects of outdoor access days on growth performance, carcass yield, meat quality, and lymphoid organ index of a local chicken breed. Poultry Science, 94(6), 1115–1121. https://doi.org/10.3382/ps/pev032
- Tong, H., Wang, Q., Lu, J., Zou, J., Chang, L., & Fu, S. (2014). Effect of free-range days on a local chicken breed: Growth performance, carcass yield, meat quality, and lymphoid organ index. Poultry Science, 93(8), 1883–1889. https://doi.org/10.3382/ps.2013-03470
- Tufarelli, V., Ragni, M., & Laudadio, V. (2018). Feeding Forage in Poultry: A Promising Alternative for the Future of Production Systems. Agriculture, 8(6), 81. https://doi.org/10.3390/agriculture8060081