ANIMAL AND HUMAN NUTRITION: THE JOINING LINK
Pragati Yadav1 & Mohit Bhardwaj2
- PhD & JRF Scholar, MPUAT UDAIPUR
- PhD Scholar, GBPUAT PANTNAGAR
Nutrition is the process by which a living organism, both human and animal, physiologically absorbs and uses food to ensure growth, energy, reproduction and repair of tissues. Nutritional studies involve the study of both diets and deficiency diseases. A balanced diet is one that will provide at least the minimum nutritional requirements for energy, protein, minerals and vitamins required by an organism. An unbalanced diet, such as one low in fibre or with excessive vitamins, will have an adverse effect on the organism. Clearly the actual dietary requirements of an organism will vary according to the age, sex, level of physical activity and, in the case of females, the reproductive stage, i.e. pregnancy and lactation. Carbohydrates, proteins and fats are required in relatively large quantities to provide energy and build body tissue while only small quantities of minerals and vitamins are needed to enable the body to function properly. Fibre aids digestion by stimulating muscular activity in the digestive tract. It also facilitates the digestion of concentrates by opening them up to the action of digestive juices. Excess fibre in the diet can reduce food intake.
Nutrient deficiencies, especially of animal product-rich nutrients, are a major problem globally. Protein malnutrition continues to be a major problem globally. Protein–energy deficiency results in stunting and insufficient weight in over 175 million children. Deficiencies in micronutrients result in 50% of deaths, directly and indirectly, to children and infants less than 5 years old globally. Iron deficiency impacts 30% of the world’s population. Vitamin B12 deficiency is widespread globally being found, for instance, in 40% of children and adults in Latin America, 70% of children in Kenya, and 80% of children in India and in the elderly and vegans in Western countries. Processed red meat and probably non processed red meat have negative effects on health and mortality. Cholesterol is no longer viewed as a nutrient of concern for overconsumption. The safety and sustainability of animal products and ongoing use of animal products are discussed.
Chickens are the most abundant bird in this planet. Over the years, its production has evolved into an efficient form of farming that plays a vital role in our nutrition, particularly in regards protein supply either in the form of meat or eggs. Hens are able to lay more than 300 eggs in the year (i.e. almost 1 egg per day), with white hens producing white shelled eggs and brown hens laying brown eggs.
As the world’s population increases, the demand for poultry meat and eggs is expected to rise by 121% and 65%, respectively, by year 2050. The need us to think deeper about the phrase ‘you are what you eat’ becomes much more important when we look to the future. Foods of animal origin with enhanced functionality is at the core of research in the animal nutrition industry, all underpinned by the essential responsibility for implementing sustainable solutions. Modifying animal diets is one way to improve sustainable nutrition. Consumers are very aware of the recommendations to eat oily fish to sustain dietary omega-3 intake to support normal development and maintenance of optimal health, yet Western populations are failing to comply with the recommendation to consume 2-3 servings of fish per week. Meanwhile, the use of fish oil supplements has increased drastically, putting additional strain on the sustainability of marine resources. One solution to this problem is to optimize the feed of chickens in order to modify the lipid profile of their meat and eggs. In the past, when fish oil was added into the diet of chickens, it gave the meat a fishy taste. However, science has evolved to cost-effective successful supplementation with flaxseed oil, which results in a high alpha-linolenic acid (omega-3) feed which is naturally metabolised by the animal and deposited in the tissue as omega-3 fatty acids, without any influence on the taste of the meat. In similar fashion, the use of marine algae biomass has shown to be promising strategy to yield omega-3 enriched chicken meat. In other words, we can introduce more omega-3 fat intake into entire populations just by changing the feed of the chickens that population eats. Antioxidants are naturally occurring in the egg yolk, however, eggs can be naturally enriched to increase the level of vitamin E, carotenoids and selenium through the feed that hens receive. Selenium is an essential trace mineral, also supporting thyroid function and immunity, which cannot be produced by the body and therefore humans rely solely on diet to ensure we get enough. However, levels of this nutrient have been declining in diets across populations in UK and other EU countries in recent decades. Organic selenium (Se) sources, including Se-enriched yeast have been successfully used to increase antioxidant levels in hens, which also increases the amount of selenium the hens deposit in the eggs they produce. Vitamin D is another nutrient that few people consume enough of. Biofortification of table eggs with this important vitamin is also possible through the enrichment of the feed for laying hens. This enrichment can be a useful approach to enhance vitamin D levels in human populations. All of these feeding strategies are viable and natural routes for the development of so-called ‘designer eggs’, which are an important type of functional food. The diet provided to dairy cows is also the main factor influencing the content of functional lipids, such as conjugated linoleic acid (CLA), in milk. CLA has the potential to protect against ailments derived of metabolic syndrome. Grass-fed cows are shown to produce more CLA in their milk, and increases in milk CLA content of >2-fold have been obtained by supplementing animals with fish oil and vegetable fats, including rapeseed, soybean, sunflower and linseed oils.
“A good gut feeling” – probiotics and prebiotics are good for animals, too
Consumers are familiar with the concept of taking probiotics and/or prebiotics to influence the digestive health. These strategies are also extensively adopted in animal production to promote animal health and productivity. Promoting a healthy gut in animals can also lead to safer food by reducing the animal risk of contracting salmonellosis and campylobacteriosis, which are primary examples of diseases that can be transferred from animals to humans. The control of these diseases starts in the animal itself by reducing the occurrence of these pathogens in their gut.
The use of probiotic strains, in which live microorganisms confer a health benefit to the host, delivers consistent improvements to the performance of the animal itself. Specific strains of Bacillus and Lactobacillus spp. have been shown to reduce Campylobacter counts in poultry and improved the overall health of pigs challenged with Salmonella.
Prebiotics, on the other hand, are dietary ingredients which can be selectively fermented by the host microbiota causing specific beneficial shifts in its composition. Most prebiotics are fibre-rich compounds of varying composition [e.g. fructo-oligosaccharides (FOS)], which tend to selectively enhance lactobacilli and bifidobacteria populations and reduce the colonization by pathogenic microbes, including Salmonella spp. in the gut of chickens and pigs. It is in this context that these feeding strategies to design better food and safer food from animal origin, where the concept of personalized nutrition resonates with the animal nutrition industry. Furthermore, when this concept is coupled with that of precision nutrition and the need to define nutrient requirements of producing animals according to its life stage, genetic makeup, growing conditions when sustainability of animal production is optimized. Overall, animal farming is at the forefront of producing healthier food in a responsible manner towards people and planet alike.
Animal nutrition has pronounced direct impact not only on animal health but also indirectly through animal products on human health and through excreta on the environment. Due to increased awareness and concerns about animal health, due to increased incidence and severity of chronic non-communicable diseases in developed world that are linked to nutritional quality of (animal) food and due to increased concern about climate changes animal nutrition has gained new dimensions and additional importance. The knowledge of various factors involved became crucial for animal production in general and already gave, at least in some aspects, new importance and impulse to animal nutrition also in practice. In the review some most important effects and recent possibilities of animal nutrition to improve animal health, to improve nutritional value of animal products in regard of human health and to reduce environmental impact of animal production are discussed.
References
- Colin G. Scanes, Chapter 3 – Animal Products and Human Nutrition, Animals and Human Society, Academic Press,2018, Pages 41-64, ISBN 9780128052471, https://doi.org/10.1016/B978-0-12-805247-1.00003-4. (https://www.sciencedirect.com/science/article/pii/B9780128052471000034).
- https://khni.kerry.com/news/farming-for-a-healthier-fork-the-link-between-animal-and-human-nutrition/
- Wickens, G.E. (2001). Human and Animal Nutrition. In: Economic Botany. Springer, Dordrecht. https://doi.org/10.1007/978-94-010-0969-0_8
- Clark Spencer Larsen, Animal Source Foods and Human Health during Evolution, The Journal of Nutrition, Volume 133, Issue 11, November 2003, Pages 3893S–3897S, https://doi.org/10.1093/jn/133.11.3893S
- https://khni.kerry.com/news/farming-for-a-healthier-fork-the-link-between-animal-and-human-nutrition/
