Chicken, pasture-raised

What's New and Beneficial About Chicken

• A recent study on the nutrient composition of breast cuts from chickens raised with and without access to the outdoors has added evidence to the value of pasture-raising for poultry. In this study, "outdoor access" meant the ability of chickens to hunt and peck in a meadow-like area planted with ryegrass, red fescue, meadow grass, and other vegetation. When breast cuts from birds with access to the outdoors were compared to breast cuts from birds denied this access, the cuts from pasture-raised poultry were determined to be higher in vitamin E, higher in monounsaturated fat, higher in omega-3 fat, lower in omega-6 fat, and lower in the ratio of omega-6s to omega-3s. All of these results suggest the greater likelihood of health benefits—including cardiovascular benefits—from pasture-raised poultry.
• Approximately two dozen recent studies on macronutrient balance in pasture-raised poultry were recently analyzed by researchers, resulting in some important health-related findings. In a variety of cuts obtained from pasture-raised birds, overall fat concentrations were found to decrease, while protein concentrations tended to increase. In other words, not only does the quality of fat improve with pasture-raising (as we have learned from a variety of different studies), but so does the balance between fat and protein, with avoidance of excess fat and strengthening of protein richness.
• In a study carried out by researchers in Italy, conventional indoor raising of chickens was compared with organic raising (some outdoor access, but mostly higher quality feed) and also with "organic plus"—meaning organic feed with meaningful time spent outdoors. While organic standards—all by themselves—were sufficient to increase the amount of omega-3 fatty acids in breast meat obtained from the chickens, it took more than organic standards to improve the breast meat in two other important respects: increase in total antioxidant nutrients and decrease in risk of oxidative damage to fats in the meat. These additional benefits were not observed in the comparison of conventional to organic breast meat, but only in the comparison of organic-plus (pastured) to organic meat. It's worth noting that in this study, "pastured" not only meant time outdoors foraging, pecking, and moving about but also the presence of outdoor space that averaged 10 square meters per bird. The authors concluded that pasture activities were directly linked to the health quality of the meat. These findings are one key reason for our recommendation that chicken be purchased not only when certified as organic, but also when genuinely pasture-raised.
• Researchers at the University of Stellenbosch in Tygerberg, South Africa have recently analyzed chicken intake for its impact on blood fats (including total cholesterol, LDL-cholesterol, and triglycerides) and they also compared this impact of chicken with the impact of red meat. All participants in this five-month study followed a prudent diet consisting of about 17% protein, 53% carbs, and 30% fat, together with an average of 20 grams of fiber per day and 200 milligrams of cholesterol. The study design included two time periods: during one time period the participants ate lean beef five days per week and lean mutton two days per week, and during a second time period, their diet contained skinless chicken five days per week and fish two days per week. Blood work during the study showed that the prudent diet helped lower total cholesterol and LDL-cholesterol regardless of whether chicken-fish or beef-mutton was eaten. However, the chicken-fish combination was shown to have more favorable effects on the composition of triglyceride (TG) fats in the blood of the participants than the lean beef-lean mutton combination. Anti-inflammatory omega-3 fats (including EPA and DHA) were higher in the TGs of participants when chicken-fish was consumed, and levels of the pro-inflammatory fatty acid arachidonic acid (AA) were lower.
• It's interesting that the researchers did not examine the difference between dark and light chicken and included both, provided that the chicken was skinless. From our perspective, the light meat versus dark meat difference is just as important as the with-skin versus without-skin difference. While a chicken breast with skin (light meat) is about 35% fat and a chicken leg with skin (dark meat) is about 44% fat, the chicken breast drops down to about 20% fat when skinned and the chicken leg only drops down to 40%. In addition, the chicken leg starts out with and retains about 125-130 milligrams of cholesterol while the chicken breast starts out with and retains about 70-90 milligrams. We expect that the participants might have seen even greater blood fat changes if skinned, light meat chicken had been consumed exclusively in comparison to lean red meats.
• Both conventional and organic raw chicken may become contaminated with potentially problematic bacteria including E.coli, Listeria, Campylobacter, and Salmonella. (This risk of contamination is a key reason to make certain that all raw chicken has been cooked properly.) In a recent report that combined 10 studies on raw chicken and analyzed them as a group, the percentage of raw chicken samples containing the bacteria listed above was very similar in conventionally raised versus organically raised chicken. However, what was not similar was the extent to which these bacteria were antibiotic-resistant. Bacteria resistant to three or more antibiotics were found 33% more often in conventional chicken. Since antibiotics cannot be used in the production of organic chicken, but are used routinely as a disease-preventing step in the raising of conventional chicken, this finding makes sense to us and is a good reason to choose organically raised chicken. Even though proper cooking of chicken should prevent exposure to unwanted bacteria, antibiotic resistance can be a problem if a person gets sick from bacteria that don't respond as expected to antibiotics.

WHFoods Recommendations

Like all of the meat-related foods that we profile on our website (including beef, lamb, and turkey), pasture-raised chicken is not a food that we view as a mandatory part of any meal plan. We recognize that many people prefer to avoid meat-related foods in their way of eating for a wide variety of reasons. At the same time, we also realize that pasture-raised chicken can be a very helpful source of nutrients: it achieves one ranking of "excellent" in our rating system (for vitamin B3), as well as four rankings of "very good" and three rankings of "good." It's also the third best source of protein among all 100 foods profiled on our website.

If you do decide to enjoy pasture-raised chicken in your meal plan, we recommend that you incorporate it into vegetable-rich recipes, with a serving size in the range of 4-6 ounces. For a great example of recipes that incorporate pasture-raised chicken in this way, look no further that the World's Healthiest Foods Meal Plan Recipes that serve as the foundation for our World's Healthiest Foods Meal Plan! You will find pasture-raised chicken being included on four out of seven days in our meal plan. Our World's Healthiest Foods Meal Plan incorporates pasture-raised chicken in this carefully measured way to provide you with great nutrient-related benefits without risking balance in your overall way of eating. At 8-9 grams of protein per ounce, what might seek like a moderate amount of chicken is actually providing you with 32-36 grams of protein in a single 4-ounce serving.

Health Benefits

Broad Nutrient Support

Chicken is perhaps best known for its high protein content, but it is a food that actually provides broad nutrient support. With respect to protein, one 4-ounce serving of pasture-raised chicken breast provides about 35 grams of protein, or 70% of the Daily Value (DV). Included in this excellent protein content are plentiful amounts of sulfur-containing amino acids like cysteine and methionine, as well as branched chain amino acids (leucine, isoleucine, and valine) that are important for support of cardiac and skeletal muscle. All B vitamins are present in chicken meat, including B1, B2, B3, B5, B6, B12, folate, biotin, and choline. (There remains controversy over the biotin content of chicken meat, which appears to be smaller than the average 10-microgram amount of biotin in chicken eggs and which seems more sensitive to the chicken's dietary intake.) Chicken is a particularly helpful food for obtaining vitamin B3, since it provides about 98% of the Dietary Reference Intake (DRI) per serving and ranks as an excellent source of this B vitamin. Four ounces of chicken breast also supplies 40% of the DRI for vitamin B6 and over 20% of the DRI for choline.

In terms of minerals, chicken is richest in selenium and provides about 57% of the DRI in a single 4-ounce serving. Zinc, copper, phosphorus, magnesium, and iron are also provided by this food.

Potential Cardiovascular Benefits

There continues to be some debate about the exact role of chicken in support of cardiovascular health. This debate is partly due to the different cuts of chicken consumed by participants in research studies. To give you a better idea of how different various forms of chicken can be in terms of their fat content, we have created the chart below.

As you can see from this chart, the number of calories in each 100-gram serving (about 3.5-4.0 ounces) of chicken remains relatively similar and changes by a maximum of about 25% despite the presence of light versus dark meat or the presence/absence of skin. However, the total fat, saturated fat, and cholesterol content varies greatly. Since several aspects of cardiovascular health are associated with each of these fat-related nutrients, and since studies have not always been able to precisely identify which cuts were consumed (or whether skin was included), these differences may have contributed to conflicting study results.

We do know, however, from a very recent study by researchers at the University of Stellenbosch in Tygerberg, South Africa, that intake of chicken—when coupled with a prudent diet that restricts total fat to 30% of calories and provided 20 grams of daily dietary fiber—can lower blood cholesterol and blood LDL-cholesterol, and, at the same time, improve the quality of triglyceride (TG) circulating around in the blood. More specifically, inclusion of chicken can increase the omega-3 content of the TGs and lower their content of arachidonic acid (AA). Since omega-3s are considered to be anti-inflammatory fatty acids, and since AA is considered to be a pro-inflammatory fatty acid, this change in the composition of the TGs with chicken consumption could be considered as providing anti-inflammatory benefits to the cardiovascular system.

Other Potential Health Benefits

Many people wonder about the potential health advantages of switching from beef to chicken, especially in the context of colon cancer risk. A first important piece of information to remember in this context is that studies on beef consumption and colon cancer typically find increased risk from high consumption (5 or more ounces per day). We're not aware of any research showing increased colon cancer risk from consumption of 3-4 ounces of beef several times per week. At this higher intake level, however, the increased risk of colon cancer associated with beef does not appear to be associated with chicken. In a recent study analyzing risk of colorectal cancer in more than 20 studies involving chicken, turkey, and fish, researchers found was no evidence of increased colorectal cancer risk, even when chicken was consumed four to five times per week. In addition, as chicken intake increased on an ounce-by-ounce basis from a very small amount (less than one ounce per week) to 4-plus ounces per week, risk of colorectal cancer was not found to increase.

It is possible to increase the omega-3 content of chicken meat—including both light and dark meat, as well as chicken skin—by feeding chickens supplemental amounts of fish meal or fish oil.

Regardless of the amount of chicken you choose to include in your meal plan, we recommend certified organic chicken that has been genuinely pasture raised. By "genuinely," we mean that it is often important to go beyond the labeling claims of "pastured" or "pasture-raised" or "free range" and ask the grocer or the chicken producer about the actual lifestyle circumstances for the chickens.

Description

Chickens belong to the bird class of animals (Aves), and all breeds of chicken come from the same genus, species, and subspecies of bird (Gallus gallus domesticus). However, within this subspecies, there are many different breeds.

When chickens are raised for meat, they are typically referred to as either "broilers" (also called "fryers") or "roasters." Fryers and broilers are usually bred for rapid growth and may reach a weight of four to five pounds in as few as five weeks and may be slaughtered as early as five weeks of age. Roasters are typically fed for a longer period of time (12 to 20 weeks) and are not slaughtered until they reach greater weights of six to 10 pounds. When not being raised for food, the natural lifespan of chickens is approximately five to 10 years, although some chickens can live much longer.

Popular breeds for broiler chickens include Cornish, White Rock, Hubbard, Barred, Cornish Cross, and Cornish Rock. There are fewer breed choices for broilers than for layers. (Among the many breeds available for egg laying are White Leghorns, Rhode Island Reds, Buff Orpingtons, Golden Coments, Red Sex Links, Isa Browns, Australorps, Black Star, Red Star, Light Sussex, and Plymouth Rock.)

While chickens are not the only birds consumed for food, they are the most commonly eaten birds in commercial food supplies. Other birds consumed for food include ducks, geese, quail, turkeys, and ostriches.

You will sometimes hear the word "fowl" being used to refer to chickens. Fowl is a broad term that includes all species within the Gallus genus of birds. The word "poultry" usually refers to any fowl that have been domesticated.

While we recommend all of our dairy products in grass-fed form (including grass-fed beef, cheese, milk, and yogurt), we cannot include chicken in this grass-fed category because chickens are not herbivores but rather omnivores. Unlike cows, who only eat plant foods and who have a special ruminant digestive system for getting optimal nourishment from grasses, chickens enjoy eating a wide variety of non-plant foods including, grubs, worms, and insects. While many chickens do enjoy grass, they still do not depend on it in their natural diet in the same way as cows. In natural pasture settings, chickens can typically find all of their naturally preferred foods, including many kinds of seeds, insects, clovers, grasses, and other vegetation. For this reason, we believe that "pasture-raised" best describes the lifestyle quality that is optimal for chickens.

History

Although the practice of domesticating fowl dates back at least as far as 2,000 BC, the raising of chickens—for food, for eggs, or simply as pets—seems to have fluctuated throughout human history. At times, both chicken eggs and chicken meat were considered as luxury foods, while at other times, these same foods have been considered as everyday staple foods.

In the U.S., "backyard chickens" have fluctuated similarly in popularity. At present, approximately 150,000 - 200,000 households in the U.S. are estimated to raise small numbers of chickens on their family property. Dozens of cities across the country have recently updated or passed new laws or ordinances for "urban chickens," with many cities setting a cap at five or six chickens per family and their residing a minimum distance of 25-50 feet away from neighboring houses.

Commercial production of chicken in the U.S. has grown continuously and dramatically over the past 30 years. In 2010, production of broiler chickens surpassed 35 billion pounds and is expected to surpass 40 billion pounds by 2020. Per capita chicken consumption was approximately 50 pounds per year in 1985 but had grown to nearly 85 pounds per year by 2005. Today that per capita consumption is down slightly to about 75 pounds, but it is expected to return to the 80-pound level by 2020. Consumption of chicken presently exceeds consumption of beef by approximately 35%.

The United States is the world's largest producer of broiler chicken, and among the U.S. states, Georgia, Arkansas, Alabama, Mississippi, and North Carolina produce the most chicken for meat purposes. (In terms of egg-laying flocks, Iowa, Ohio, Pennsylvania, Indiana, and Texas are states with the most chicken production.)

How to Select and Store

When purchasing whole chickens, look for ones that have a solid and plump shape with a rounded breast. Whether purchasing a whole chicken or chicken parts, the chicken should feel pliable when gently pressed, and it should not have an "off" smell. Do not buy chicken if the sell-by date on the label has already expired.

The color of the chicken's skin, white or yellow, does not have any bearing on its nutritional value. Regardless of color, the skin should be opaque and not spotted.

If purchasing frozen chicken, make sure that it is frozen solid and does not have any ice deposits or freezer burn. Additionally, avoid frozen chicken that has frozen liquid in the package as this may indicate that it has been defrosted and refrozen.

As described earlier in this article, we recommend certified organic chicken; in addition to this standard, we also recommend chicken that has been pasture-raised. The reason for this recommendation involves some unreliable standards with respect to the pasture raising of organic chicken.

Yet, unfortunately, while it's important to look for chicken that have been pasture-raised you need to do a little extra work to really find them. That's because of the misleading nature of labeling terms like "pastured," "pasture-raised," "free-range," or "cage-free."

Unfortunately, while legal, these labeling terms are also misleading. The term "free-range," for example, means that the hens that lay the eggs must have access to the outdoors - but the emphasis here is on "access." No standards are set for how often the hens actually go outside, how much time they must stay outside if they do go out, or what the outdoor environment must include in terms of total space or vegetation. "Pastured" and "pasture-raised" are similarly misleading terms that are not backed up by standards for actual time spent by hens in a pasture setting or standards for qualifying an outdoor space as "pasture." Use of the term "cage-free" on the label of an egg carton means what it says - but legal use of this term does not require hens to have any access to outdoor space and therefore may be used when hens have been confined indoors full-time.

With respect to organic standards, no minimal amount of days spent outdoors or time per day spent outdoors is required for production of organic chicken. Nor must any minimal amount of chicken feed be obtained from a pasture setting. In fact, standards for the pasture setting are not adequately addressed in organic chicken standards. Organic standards require strict feeding with certified organic feed, but legal use of the organic label does not require any fixed amount of feed to be obtained from a pasture setting.

So organic does assure you of higher quality feed for chickens and other desirable production conditions. However, just like the other labeling terms listed above, organic still does not assure you of chicken that has been pasture-raised. The basic issues involved with pasture-raised are not complicated. It isn't enough to provide chickens with "access" to the "outdoors"—they need regular time (usually daily) actually spent pecking, foraging, roaming around, and interacting socially in a setting with natural vegetation, insects, worms, grubs, shade, and sunlight. We suggest that you talk with your grocer and/or directly with your chicken producer to find out if these circumstances were provided for their chickens.

We think that the best strategy for enjoying the most flavorful and lowest fat form of chicken is not to purchase already skinned chicken breasts. Rather, purchase chicken breasts with the skin still intact, waiting to remove the skin until after cooking (In this way you'll improve the moisture and flavor and aroma of your chicken, while not significantly increasing the total fat content.)

Chicken should be stored in the coldest section of your refrigerator. If the store packaging is intact and secure, store it this way since this will reduce the amount of handling. Yet, if the packaging is not secure, and it seems as if the chicken liquids will leak, rewrap it securely before storing. This is very important to make sure that the chicken does not contaminate other foods in the refrigerator. Refrigerated raw chicken can keep for two to three days.

To freeze chicken, remove it from its packaging, wash it and then pat it dry. Using either aluminum foil or freezer paper, wrap the chicken parts carefully so that they are as airtight as possible. Well-wrapped frozen chicken can keep for about one year.

Many people wonder about the differences between dark meat and light meat, and how to decide which to select. We've created a table, which we included in the Health Benefits section (see above), to help explain how dark meat (in the form of a chicken leg) and light meat (in the form of a chicken breast) differ in terms of their fat-related content.

From a calorie standpoint, most people would have room for any 175-200 calorie, moderately sized (100 grams, or about 3.5 ounces) portion of chicken, regardless of its light/dark or skin/skinless quality. However, for anyone wanting to minimize their intake of animal fat, skinned chicken breast would make the most sense with less than 4 grams of total fat and only 1 gram of saturated fat. If the chicken you eat is both organic and pasture-raised, there are going to be valuable nutrients in both dark meat and light meat, and there are also going to be valuable nutrients in the skin. (The skin contains many of the same vitamins and minerals as the flesh, and a greater concentration of some fat-soluble vitamins like the retinol form of vitamin A.) The choice of light versus dark and skin-included or skin-removed is a choice that should be made in the context of your overall meal plan, how much room you have in your meal plan for fat-related nutrients including saturated fat, total fat, and cholesterol, and of course your taste preferences.

How to Enjoy

A Few Quick Serving Ideas

• Chicken salad can be prepared numerous ways and can be served for lunch or dinner. One of our favorite recipes is to combine the chicken with fresh lemon juice, and olive oil, and mix in garden peas, leeks, almonds and raisins.
• For a quick meal with an Asian flair, Healthy Sautée chopped chicken breast with your favorite vegetables. Add soy sauce, sesame seeds, ginger, garlic and/or the seasonings of your choice.
• Add pieces of diced chicken breast to white bean chili to rev up its protein and nutritional content.
• Wrap cooked chicken pieces in a whole wheat tortilla, sprinkle with chopped tomatoes and onions, top with grated cheese and broil, making yourself a healthy burrito.

For some of our favorite recipes, click Recipes.

Safety

Risk of Bacterial Contamination

Raw chicken meat—including conventional, organic, and pasture-raised—often contains measurable populations of potentially problematic bacteria, including Campylobacter, Enterococcus, Listeria, and Salmonella. Studies by the Food Safety and Inspection Service (FSIS) at the U.S. Department of Agriculture have shown that approximately one out of eight broiler chicken samples are contaminated with Salmonella, even though only 20% of these contaminated samples contain the most potentially problematic species of Salmonella, namely, Salmonella enteriditis (SE). Despite these relatively high rates of contamination, however, there have been surprisingly few SE-related recalls for chicken meat, especially in comparison to the large number of recalls for both chicken eggs and beef.

With respect to eggs, many cases of exposure have involved raw or minimally cooked egg products, and we suspect that the smaller number of chicken meat recalls is related to the lower likelihood of undercooked chicken meat in restaurants and homes. While consumers often like minimally cooked eggs (or even raw eggs), they seldom prefer undercooked or raw chicken meat.

If you decide to include chicken in your meal plan, the best way to address these contamination concerns is to use the utmost care in handling and storing chicken and to fully cook chicken before you consume it. For more details on proper handling and storing, please see our How to Select and Store and Tips for Preparing and Cooking sections. With respect to complete cooking of chicken meat, an internal temperature of 165°F (74°C) is required. A meat thermometer is your best way to determine if this cooking temperature has been reached.

Humane Treatment of Chickens

An increasing number of consumers have raised questions about the quality of life for both broiler and egg-laying chickens, and a variety of different third-party animal welfare organizations have started to offer certification for chicken producers who would like to display some label on their packaging that address animal welfare issues. In general animal welfare and humane treatment issues include

• quality of the indoor environment
• access to the outdoors
• quality of the outdoor environment
• quality of the food supply
• naturalness of the food supply
• role of forced molting
• role of beak trimming and debeaking
• flock size
• exposure to natural day/night cycles
• transport standards
• quality of slaughter methods

Slaughter, in particular, has been an area of special concern and remains an area of ongoing debate with respect to organic chicken regulations. For example, current organic regulations do not specify a limit for the time chicken can be kept at a slaughter facility, a limit on shackle time, or verification of stunning pre-scalding. One further much-debated slaughter-related issue has involved the role of electrical immobilization versus "controlled atmosphere killing" (CAK).

Unfortunately, current labeling and certification standards do not provide any easy way to assure humane treatment of chickens when purchasing chicken. Like assurance of pasture-raising, assurance of humane treatment is an issue that will require you to follow-up with your grocer or directly with the chicken producer.

One potential upcoming change in the area of humane treatment for certified organic poultry is the Organic Livestock and Poultry Practices (OLPP). While the OLPP has yet to be officially adopted by the USDA as a standard for certified organic poultry, it would work to improve conditions for chickens being raised for eventual certification as organic. Improved living conditions—including better pasture access—is one feature of the proposed regulations. For more information on the OLPP and its provisions, you can visit the Federal Register description of the proposed new regulations.

Other Controversies

Some animal foods and some plants foods have been the subject of ongoing controversy that extends well beyond the scope of food, nutrient-richness, and personal health. This controversy often involves environmental issues, or issues related to the natural lifestyle of animals or to the native habitat for plants. Chicken has been a topic of ongoing controversy in this regard. Our Controversial Foods Q & A will provide you with more detailed information about these issues.

Nutritional Profile

Introduction to Food Rating System Chart

References

• Castellini C, Boggia A, Cortina C, et al. A multicriteria approach for measuring the sustainability of different poultry production systems. Journal of Cleaner Production, Volume 37, December 2012, Pages 192-201.
• Cohen SJ, van den Munckhof T, Voets G, et al. Comparison of ESBL contamination in organic and conventional retail chicken meat. Int J Food Microbiol. 2012 Mar 15;154(3):212-4. doi: 10.1016/j.ijfoodmicro.2011.12.034.
• Dal Bosco A, Mugnai C, Mattioli S, et al. Transfer of bioactive compounds from pasture to meat in organic free-range chickens. Poult Sci. 2016 Oct 1;95(10):2464-71. doi: 10.3382/ps/pev383.Fernandes AR, Foxall C, Lovett A, et al. The assimilation of dioxins and PCBs in conventionally reared farm animals: Occurrence and biotransfer factors. Chemosphere, Volume 83, Issue 6, April 2011, Pages 815-822
• Gibbs RA, Rymer C, and Givens DI. Fatty acid composition of cooked chicken meat and chicken meat products as influenced by price range at retail. Food Chemistry, Volume 138, Issues 2-3, 1 June 2013, Pages 1749-1756.
• Kartikasari LR, Hughes RJ, Geier MS, et al. Dietary alpha-linolenic acid enhances omega-3 long chain polyunsaturated fatty acid levels in chicken tissues. Prostaglandins, Leukotrienes and Essential Fatty Acids, Volume 87, Issues 4-5, October-November 2012, Pages 103-109.
• Lee MRF, Tweed JKS, Kim EJ, et al. Beef, chicken and lamb fatty acid analysis - a simplified direct bimethylation procedure using freeze-dried material. Meat Science, Volume 92, Issue 4, December 2012, Pages 863-866.
• Lestari SI, Han F, Wang F, et al. Prevalence and antimicrobial resistance of Salmonella serovars in conventional and organic chickens from Louisiana retail stores. J Food Prot. 2009 Jun;72(6):1165-72.
• Meng L, Mao P, Guo X, et al. Evaluation of meat and egg traits of Beijing-you chickens rotationally grazing on chicory pasture in a chestnut forest. Brazilian Journal of Poultry Science, 2016, 18, Special Issue, pages 1-6.
• Miranda JM, Guarddon M, Mondragon A, et al. [Antimicrobial resistance in Enterococcus spp. strains isolated from organic chicken, conventional chicken, and turkey meat: a comparative survey. J Food Prot. 2007 Apr;70(4):1021-4.
• Monro JA, Leon R, and Puri BK. The risk of lead contamination in bone broth diets. Medical Hypotheses, Volume 80, Issue 4, April 2013, Pages 389-390
• Napolitano F, Castellini C, Naspetti S, et al. Consumer preference for chicken breast may be more affected by information on organic production than by product sensory properties. Poult Sci. 2013 Mar;92(3):820-6. doi: 10.3382/ps.2012-02633.
• Ollinger M, MacDonald J, and Madison M. Structural Change in U.S. Chicken and Turkey Slaughter. Agricultural Economic Report No. (AER-787) 48 pp, November 2000. Economic Research Service, U.S. Department of Agriculture.
• Sales J. Effects of access to pasture on performance, carcass composition, and meat quality in broilers: a meta-analysis. Poult Sci. 2014 Jun;93(6):1523-33. doi: 10.3382/ps.2013-03499.
• Smith-Spangler C, Brandeau ML, Hunter GE, et al. Are organic foods safer or healthier than conventional alternatives?: a systematic review. Ann Intern Med. 2012 Sep 4;157(5):348-66. doi: 10.7326/0003-4819-157-5-201209040-00007.
• Sossidou ENm, Bosco AD, Castellini C, et al. Effects of pasture management on poultry welfare and meat quality in organic poultry production systems. World's Poultry Science Journal, 2015, 71, 2, pages 375-384.Van Loo E, Caputo V, Nayga RM Jr, et al. Effect of organic poultry purchase frequency on consumer attitudes toward organic poultry meat. J Food Sci. 2010 Sep;75(7):S384-97. doi: 10.1111/j.1750-3841.2010.01775.x.
• Xu B, Sun J, Sun Y, et al. No evidence of decreased risk of colorectal adenomas with white meat, poultry, and fish intake: a meta-analysis of observational studies. Annals of Epidemiology, Volume 23, Issue 4, April 2013, Pages 215-222.