Farming

The Role of Poultry in Human Nutrition

Chicken meat and eggs are the best source of quality protein and are badly needed by the many millions of people who live in poverty. In sub-Saharan Africa (SSA) and South Asia malnutrition (poor nutrition) and undernutrition (inadequate nutrition) are closely associated with poverty. These conditions affect the immune system. The HIV/AIDS epidemic sweeping through countries in SSA stems partly from extreme poverty and, with it, poor nutrition.

Wide variation in consumption of poultry meat and eggs

A recent survey of several countries found that 34 percent of the people surveyed in South Asia and 59 percent in SSA were suffering from severe energy deficiency. Both groups obtained 67 percent of their energy from staple foods (cereal grains, grain legumes, starchy roots, and tubers) containing small quantities of only low-quality protein. Their average per capita egg consumption was only 42 per year, compared with a global average of 153.

Stunting and wasting in children under five years of age, and slow mental development was seen mainly in rural areas of SSA. Eight out of ten of those affected were among the poor. Diseases such as kwashiorkor and marasmus, both seen in underweight children, are associated with inadequate dietary energy and protein. Pregnant and lactating women and young children are particularly vulnerable.

In SSA, only 8 percent of dietary energy comes from animal protein, compared with an average of 17 percent in all developing countries, and 28 percent in China.

Chicken meat and eggs: a valuable source of protein and almost all of the essential nutrients 

Chicken meat and eggs provide not only high-quality protein but also important vitamins and minerals. Worldwide, 2 billion people depend on rice as their staple food. Most eat polished white rice stripped of many essential fats, the B complex vitamins, and several minerals. Other cereal grains are usually deficient in critical nutrients. For example, maize (corn) is a staple food in some regions, but the niacin it contains is unavailable. Maize consumption without supplements causes pellagra. Invariably the protein content of grains is low and of poor quality. Net protein utilization (NPU) is an index of protein quality, calculated by multiplying protein digestibility by biological value. NPU of grains is generally less than 40. Rice is the exception, with an NPU of about 60, but it is low in protein (7.5 percent). NPU of chicken eggs is 87.

Generally, cereals lack the most important amino acids for humans – lysine, threonine, the sulfur-bearing amino acids (methionine and cysteine), and occasionally tryptophan. Eggs and chicken meat are rich in these essential amino acids. Eggs are also high in lutein which lowers the risk of cataracts and macular degeneration, particularly among people living in developing countries.

Advantages of chicken meat and eggs compared to other animal proteins

In developing countries, the diet of people living in cities usually contains more animal protein than that of rural people, mainly because urban people are more prosperous, but also because they generally have access to a wider variety of foods at local markets. In low-income countries, commercially produced chicken meat is well placed to satisfy the demands of a rapidly increasing affluent, middle class who can afford to pay for broiler chickens. Facilities and infrastructure for producing broiler chickens can be established quickly and soon start generating. Not only is chicken meat seen as healthy meat, but it is also the cheapest of all livestock meats.

A major advantage of eggs and poultry meat as human food is that there are no major taboos on their consumption. In addition, a chicken provides a meal for the average family without the need for a refrigerator to store leftovers. Meat from other livestock such as pigs and cattle is kept mainly for special festive occasions and celebrations, partly because of a lack of storage facilities (no refrigerator or electricity supply). Eggs can be purchased relatively and when hard-boiled will last for several weeks. It can be taken to school safely by children for lunch.

Scavenging chickens provide cheap eggs and meat

Scavenging family poultry provides much-needed protein and income, and contributes to food security for many families living in poor rural regions of developing countries. The eggs and meat produced by their own or neighbors’ small poultry flocks are the only eggs and poultry meat that the majority of these families are ever likely to eat. This makes family poultry increasingly important as the world’s population pushes towards 7 billion people. Furthermore, it is not difficult to improve the nutritional value of the egg, to become a functional food.

Poultry has a major role to play in developing countries. Produce is relatively inexpensive and widely available. The commercial poultry industry provides employment and is growing rapidly. To produce 1 kg of meat from a commercial broiler chicken only about 1.7 kg of feed is needed. Poultry production has a less detrimental impact on the environment than other livestock and uses less water. Semi-scavenging backyard indigenous poultry are extremely important in providing income and high-quality protein in the diets of rural people whose traditional foods are typically rich in carbohydrates but low in protein. The vexed question of the cholesterol content of eggs and human health seems to have been exaggerated.

The nutritional benefits of chicken meat compared with other meats

Chicken meat is white meat, distinguished from other meats such as beef and lamb by its lower iron content (0.7 mg compared with 2 mg/100 g). Chicken meat has several advantages over other meats. The fat content of cooked chicken varies depending on whether it is cooked with t e skin on or off, the portion of the bird, and the bird’s diet and breed. Breast meat contains less than 3g fat/100 g. An average value for dark meat (skin off) is 5 to 7 g/100 g. About half of the fat from chicken meat is made up of the desirable monounsaturated fats, and only one-third of the less healthy saturated fats. There are much higher proportions of saturated fats in most cuts of red meat, which also vary considerably in total fat. Chicken meat is therefore seen as healthy meat.

Chicken meat does not contain the trans fats that contribute to coronary heart disease and can be found in high amounts in beef and lamb. In Canada, values of 2 to 5 percent have been reported for beef and as high as 8 percent for lamb. The World Cancer Research Fund and others have suggested that the consumption of large amounts (more than 500 g/week) of red meat, particularly processed meat, but not chicken meat, may be unhealthy.

Poultry meat is rich in the omega-3 fats 

Poultry meat is an important provider of essential polyunsaturated fatty acids (PUFAs), especially the omega (n)-3 fatty acids. Scavenging chickens are a particularly good source because of their varied diet. The amounts of these important fatty acids can be increased more easily in chicken meat than in other livestock meats; so too can some trace minerals and vitamins. The recommended dietary intake (RDIs) of niacin can be met with 100 g of chicken meat per day for adults and 50 g for infants. By feeding broiler chickens only small amounts of a supplement rich in alpha-linolenic acid (an n-3 PUFA), such as flaxseed, the n-3 PUFA in thigh meat can be increased from 86 mg to 283 mg/100 g, and that in the minced carcass from 93 to 400 mg/100 g. To a large extent, the fat contents of the different portions determine the content and enrichment of PUFAs, so dark chicken meat always contains more PUFAs than white breast meat.

Poultry meat can be enriched with several important dietary nutrients. Unlike most other meats, chicken meat can also easily be enriched with several other important nutrients. A recent study showed that by adding 0.24 mg of selenium (as organic selenium) per kilogram of feed, the selenium content of breast meat was increased from 8.6 μg to 41 μg/100g, which is more than 65 percent of the RDI. The same amount of selenium in the form of inorganic sodium selenite also increased selenium in the breast meat, but only to 16 μg/100g. Selenium deficiency is becoming more widespread in humans because soils are becoming depleted and the foods grown on them are therefore lower in selenium. The RDI of selenium is 55 μg per day. Selenium is a powerful antioxidant and plays a role in the prevention of some forms of cancer. A deficiency of selenium can cause Keshan’s disease, a heart ailment in the young, which is common in parts of China, and cognitive decline in adults. Enriched poultry meat could help alleviate this condition.

Chicken meat can make many positive contributions to the diet of those on low incomes. Although not all meat is seen as healthy, chicken meat is, and is frequently more affordable than other meats. It is of consistently high quality, is low in saturated fats, can be enriched with some essential nutrients, and is sought after worldwide.

The importance of poultry meat and eggs, especially for children and women

To illustrate just how important poultry can be in the developing world, this information note examines a typical diet of a three-year-old girl living in Papua New Guinea, weighing about 10 kg and with an energy intake of 4 000 kJ/day. Her diet might consist of a small amount of rice (50 g/day) but mainly sweet potato, taro, yams, and cassava. Her family of five keeps a small flock of nine hens and a cockerel. These should produce approximately 12 eggs and one chicken, yielding 780 g of edible meat, each week. This will give each member of the family 22 g of meat a day, and the child receives five of the 12 eggs each week, or 36 g of edible egg per day.

These are mostly for a child of three to four years of age, but RDIs have not been determined for people living in developing countries and are likely to be generous (by perhaps 20 percent), especially if “the law of diminishing returns” applies to nutrient utilization so that a low nutrient intake is used with greater efficiency, particularly from animal products.

The eggs and meat will provide the girl with all the critical amino acids and vitamin K she needs, 30 percent of the RDI for folate, 66 percent for vitamin B12, 30 percent for biotin, and 29 percent for iodine. Iron is especially important and often deficient, particularly in the diet of women in developing countries. It is known that the iron in meat and, to a lesser extent eggs, is highly available, unlike the iron in vegetables; the iron in the chicken meat and eggs is likely to meet more than 14 percent of the girl’s daily requirement.

Folic acid in poultry meat and eggs is especially important during pregnancy

Folic acid deficiency is of major concern in almost all developing countries and has been shown to lead to neural tube defects. These can occur very early in pregnancy, resulting in severe defects of the brain and spinal cord, stillbirths, and early child mortality. Green leafy vegetables and fruit are good sources of folic acid, but up to half can be lost in cooking. Assuming that she is not a vegetarian, the 45 μg in the meat and eggs, will provide a pregnant woman with 23 percent of her RDI for folic acid (200 μg/day, although this figure varies widely). The folic acid concentration in eggs can be increased substantially by feeding hens a folic acid-enriched diet.

Poultry meat and eggs are widely available, relatively inexpensive, and can be of central importance in helping to meet shortfalls in essential nutrients, particularly of impoverished people. The incidence of several common metabolic diseases associated with deficiencies of critical dietary minerals, vitamins, and amino acids can be reduced by the contribution of poultry products rich in all essential nutrients except vitamin C.

Important To Note | Unless all the necessary precautions are taken along the poultry production, marketing, and processing chains, poultry meat and eggs can be contaminated by infectious agents that are harmful to humans. Poultry products can also be contaminated with antimicrobial and anti-parasitic drugs or pesticides used on farms. The ingestion of antimicrobials can cause antimicrobial-resistant bacteria to develop in humans. Only natural health facilitation at poultry farms can provide an honest reward to both chickens and humans. An international network of laboratories, alert systems, and collaboration among authorities should assist in solving food safety problems as their responsibilities.

President

The divine scriptures are God’s beacons to the world. Surely God offered His trust to the heavens and the earth, and the hills, but they shrank from bearing it and were afraid of it. And man undertook it.
Back to top button