SUSTAINABLE POULTRY NUTRITION

Summary  

Poultry derived food products are the most important animal protein sources globally. But the poultry industry is facing various challenges in its value chain. Production needs to be environmentally sound and social responsible with the prerequisite that it also has to be economically viable. According to the World Health Organization (WHO, 2014) antimicrobial resistance has reach alarming levels and strategies need to be developed to reduce the use of antibiotics, both in humans and animals. Advances in poultry nutrition will contribute to meet these challenges. The importance of early life nutrition for later life performance, health and product quality is highlighted in science. The first days post-hatch is a period in which various epigenetic effects occur that may be modulated by nutritional interventions. Targeted feed additive strategies can be applied to control microbial quality of feed and water and support gut health. It will contribute to establish a responsible, prudent use of antibiotics and will also fit in strategies to reduce the prevalence of food pathogens such as Salmonella. Precision nutrition methods and tools, such as dynamic feed evaluation and animal models, can be implemented to economically optimize the feed program and reduce emissions into the environment. Sustainable feed supply meeting market demands is feasible and will require a multidisciplinary approach of all stakeholders in the value chain. 

Keywords: poultry industry challenges, sustainable poultry nutrition, early life nutrition, antimicrobial resistance, precision nutrition 

Introduction  

For an optimal utilization of earth’s surface for producing food, 35% - 40% of the recommended daily protein consumption of adults should come from animal protein (van Zanten, 2016). Poultry meat and eggs are the most important animal protein sources globally and a significant increase is forecasted in global demand. The global production of poultry meat in 2016 were estimated to be respectively 117 million tonnes (FAO, 2017). The International Feed Industry Federation (IFIF) estimates that annual global feed production approaches 1 billion tonnes, of which 45% is for poultry. IFIF also cites FAO’s outlook for poultry protein production to be over 200 MMT by 2050, greater than a 100% increase from 2010. The overall increase (2010-50) in animal and aqua protein production expectation is 60% ranging from 38% for pork to 104% for poultry (aqua by 90%).  

But there is also a significant number of challenges facing the poultry and allied industries with respect to sustainable global production of poultry meat and eggs where market demands and consumer needs will put more constraints on our production systems and methods (Alders, 2016). In addition, the on average worldwide productivity of farm animals is 30-40% below their genetic potential because of suboptimal conditions and health status. These challenges are dynamic and diverse and solutions and opportunities will require development of appropriate technology and using and advancing our knowledge base.  

Sustainable livestock farming is based on three pillars: environmentally sound, social responsible and economically viable. For all these pillars, innovation will be key and hence, advances in animal nutrition will play an important role, where we have concrete challenges in economical optimization of the value chain and meeting product quality demands, whilst safeguarding animal wellbeing and human health.   

Early life interventions have an effect on bird performance  

Birds are confronted with various stressful events during their life, especially in critical transition periods such as hatch and transport. An example here is the welfare concerns of early hatched chicks not having access to feed and water for up to 2 days. This has a negative impact not only on body weight loss, but also on important early life developments. Various important conditions for life performance are already being determined during the embryonic development and in the very first days and weeks of life post-hatch, partly mediated via epigenetic effects.

Nutrition And the host microbiota interactions in early life seem to play a significant role in development of the gut, immune competence and muscle and skeletal cell development. Recent Information For example suggests that newly hatched layer chickens that have been deprived of food had a distinct development of innate and adaptive immunity and responded differently to a non-infectious lung challenge. Similar to food deprivation, antibiotic treatment of day-old chicks may have significant impact on early-life microbiota which is not beneficial for the birds in relation to develop appropriate immune competence. Evidence is accumulating that newly hatched chicks having delayed access to food and prophylactic antibiotic treatments are undesirable challenges and interventions in early life in our production systems.  Provision of nutrition and water during the immediate post-hatch period and during transit from hatchery to farm has shown promising effects on broiler performance and health in the first days and weeks of life. Early life interventions do not per se result in higher market weights or improved feed efficiency in each flock, but it will contribute to more stable and consistent performance and a reduced risk of birds developing health problems.  

The need for antibiotics in food production globally can be reduced by applying feed farm-health management strategies  

To supply safe and nutritious food is our licence to produce. Various quality and safety demands are applicable here, with absence of foodborne pathogens and multidrug resistant bacteria as top priority. The rapid development of antimicrobial resistance (AMR) urges the need for effective strategies to reduce antibiotic use in animal production. The World Health Organization (WHO, 2014) predicts that if no additional measures are taken,the annual death toll attributable to AMR may rise to 10 million and exceed other causes such as cancer in 2050. Multidrug resistant Salmonella and E.coli are regarded by the WHO as priority pathogens to combat. 

 

Antibiotics are applied in animal production as antimicrobial growth promoters (AGP) to improve efficiency of production and as prophylactic and therapeutic medical treatments for animal health. Van Boeckel et al. (2015) recently estimated that the total antibiotic usage in animal production of 228 countries in scope was 63,151 tons in 2010. Antibiotic use is expected to rise by 67% by 2030, and to nearly double in Brazil, Russia, India, China and South Africa if no additional restrictions on their use are taken. Especially the prophylactic use of antibiotics and their application as a growth-promotor are currently under pressure in many countries including the USA and China. These concerns overrule the contribution that AGP may have economically.  A drastic reduction of antibiotic use can be achieved by moving to a new farming model based on an integrated and multi-stakeholder collaboration that integrates feed, farm and health management.   

The starting point of any antibiotic reduction programme is assurance of feed and drinking water quality. It is evident that the risk of mycotoxins or presence of anti-nutritional factors needs to be managed in feed. In addition, the feed should be free of Salmonella spp and the total microbial counts or Enterobacteriacae need to be below a specific number. However, the use of feed and water in a feeding system imposes specific risks for microbial contamination and spoilage that are often underestimated. Water acidification with acids (organic and inorganic) is an example of a commonly applied measure in antibiotic reduction programmes, not only to assure the microbiological quality of drinking water, but also to control microbial levels in feeding systems and feeders. The ingested acids also have a prolonged activity in the gut, which may assist in reducing pathogen loads in the proximal intestinal tract. This in contrast to formaldehyde treatment for microbial decontamination of feed which, although highly effective, will lose its activity shortly after its application.   

Water and feed acidification will contribute to maintaining a stable microbiota in poultry. The efficacy of organic and inorganic acids can be further enhanced by inclusion of medium chain fatty acids or other natural antimicrobial compounds that exert a broad spectrum antimicrobial activity at relative neutral pH ranges. Another important intervention focus could be directed towards strengthening the mucosal barrier function. Butyrate in combination with specific phytochemicals (plant extracts), has pronounced effects on the mucosal barrier function by increasing mucus production, epithelial cell proliferation and modulation of the gut associated immune system. Combining feed additives,with different functions and mode of actions,is a promising strategy not only to support animals in an AGP-free feed programme, but is also expected to have prophylactic effects.  

Besides feed additives, there are opportunities to manipulate the nutrient and ingredient composition of the diet to further support animal health. De Vries (2015) reviewed the area of increasing use of fibre in poultry diets and addressed the question of whether fibre was a bonus or a burden. The impact of altering feed structure by using different sources of fibre as well as modifying feed particle size has been widely studied by many authors targeting the development of the proventriculus and gizzard and thereby improving gut health, reducing litter moisture associated problems, and increasing nutrient utilization.  

The package of measures of very strict policies for application of antibiotics, adopting best practices in biosecurity and farm management and the use of smart feed additive programs has led after the ban on AGP in 2006 to a further significant reduction in antibiotic usage of 72% in broiler production in the Netherlands from 2009 to 2016. A very positive observation in relation to AMR is that decreased use in antibiotics indeed also reduced the prevalence of some AMR bacteria, including multidrug resistant E.coli and Campylobacter.  Precision nutrition to improve performance and sustainability  From an economical point of view we need in general to meet nutrient requirements of the birds in the most efficient and economical way and assure that animals are in good health to exploit their potential. Precision nutrition and modelling are here promising fields of research where recent advances have shown promising effect.  Efficient use of resources e.g. feed ingredients will benefit environmentally sound production. In this respect, use and conversion of co-products from the food and biofuel industry to highly nutritious animal products is contributing to sustainable production as well. One of the challenges in our industry is to be flexible with our raw material usage in order to manage higher use of low quality ingredients and anticipation fluctuations in raw material prices, whilst at the same time need to have gripon variation in raw material quality and assure that the feed delivers the same high performance. Here, NIR can be a useful tool for rapid and accurate estimation of the nutritional value of feed ingredients. Besides rapid estimation of the gross chemical composition of ingredients and recalculation methods to adjust the nutritional value, direct NIR based estimations of metabolizable energy content may be feasible for specific raw materials (Valdes and Leeson, 1992; Garnsworthy et al., 2000; Owens et al., 2009; Losada et al., 2009 and 2010).  In relation to feed safety, mycotoxins are probably one of the most important risk factors that need to be controlled. Rather effective strategies have already been developed to reduce the risk and impact that for example aflatoxin may have on birds health with the use of mycotoxin solutions (Murugesan et al., 2015). It is also encouraging to note, that rapid diagnostics are now more widespread globally adopted for quality control to take appropriate measures once mycotoxin contamination in raw materials is detected. It is an essential part of feed quality assurance and with the right measures the risks can be mitigated, which will prevent unexpected performance losses and health problems.  Precision nutrition requires accurate and detailed insight in the nutritional value of the various feed ingredients and matches nutrient supply as closely as possible with nutrient requirements of animals of different ages and production stages. The progress in growth potential, feed efficiency and breast meat yield has changed dramatically nutrient requirements of broiler chickens in the last decades. Tools such as growth models are nowadays applied to assess the dynamic relation between genetic potential, nutrient supply and growth with accurate predictions of nutrient requirements (de los Mozos, 2016). More feed phases have been introduced in broiler nutrition to meet requirements more accurately and more economically. The dietary amino acid and energy supply is optimized and safety margins in feed formulation can be reduced leading to cost-savings and reduced N-excretion. The same counts for phosphorus, where more dynamic approaches have been introduced taking into account more accurate estimations of phosphorus digestibility in broilers, calcium availability and the non-linear efficacy of phytase  

Application of this knowledge can lead to significant reduced P-output into the environment.  Transition from rearing to production is a period in which pullets undergo many changes (transport, environment, diet…) and the rapid increase in egg production is not always synchronized with a sufficient feed intake. A study of de los Mozos (2017) aimed to assess contrasting nutritional alternatives to support early production in layers through feeding strategies that promote total nutrient intake during the pre-peak phase.The usage of low energy diets improved production early phases. Moreover, itseffect might be higher with the addition of the blend of a phenolic compound with slow release C12, medium chain fatty acids and target release organic acids; as intestinal health modulator.  

Another example of precision nutrition in layers or breeders is the split or oviposition feeding program (de los Mozos 2012a,b; 2015a). As the name implies two diets differing in nutrient (energy, amino acids and/or minerals) levels are offered the bird using a single feed line. The morning (07:30-14:30h) and afternoon (14:30 to 07:30) diets are formulated to be better suited to hourly nutrient demands of egg production (i.e., matching nutrient required for yolk that is relatively constant; and albumen and shell that are more variable). Unlike energy, animals have limited capacity to maintain pools of amino acids and calcium in reserve and optimizing their availability through the diet at the right moment is crucial. Split feeding has been shown to significantly improve feed utilization, health as well as production of eggs with sound egg shells. Based on Life Cycle Analysis there were significant improvements in sustainability with split feeding as compared to conventional feeding practices. Split feeding program is more economical, N- and P-emission can be reduced (by resp. 10.0 and 4.1%) and egg shell quality is improved.  

Sustainable feed supply for poultry production  

The importance of using a holistic approach to enable successful conversion of feed into high quality poultry protein ina sustainable way is evident. Thesehigh producing animals have to be able to consume, digest, absorb and convert sufficient nutrients to meet their genetic potential, and do this consistently from flock to flock regardless of season. In order to do this successfully and achieve high consistent production with acceptable risk will require increased use of existing technology, developing new technology and expanding our knowledge and information network.