Sustainable feed supply for worldwide poultry production

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. Advances in poultry nutrition will contribute to meet these challenges.

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. Recent advances in science also highlight the importance of early life nutrition for later life performance, health and product quality. The first days post-hatch is a period in which various epigenetic effects occur that may be modulated by nutritional interventions. 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.

Poultry derived food products, meat and eggs, are the most important animal protein sources globally and a significant increase is forecasted in global demand. There is 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 consumers' needs will put more and more constraints on our production systems and methods. These challenges are dynamic and diverse and solutions and opportunities will require development of appropriate technology and using and advancing our knowledge base.

Safeguarding animal wellbeing and human health

Stricter biosecurity programs, a more targeted administration of antibiotics to the animals via drinking water or individual treatment, and well-designed vaccination strategies are examples of best practices implemented by farmers to reduce antibiotic usage. Besides these measures, various strategies are followed to support animal health via drinking water and/or via the feed. The application of acidifiers via the drinking water is an example of a commonly applied measure in antibiotic reduction programs in Europe. Besides its contribution to control of the microbiological quality of drinking water, the ingested organic acids also have a prolonged activity in the gut, which will assist the animals in reducing pathogen loads in the proximal intestinal tract. The use of water acidifiers can be further supported and enforced by applying feed additives which have been developed for stabilization of the gastrointestinal microbiota and promoting immune competence. 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.

Salmonella can be beaten, Campylobacter is a challenge

Improvements in management and nutrition for reducing antibiotics, will in general also contribute to Salmonella control, which is becoming even more important on the political agenda because of emerging multidrug resistant Salmonella. To control Salmonella, more specific control measures may have be taken on top of best practices for antibiotic reduction such as decontamination of raw materials and feed to mitigate risks of Salmonella entry into the farm via the feed. The use of formaldehyde is highly effective, but the application in the factory needs to be strictly controlled in order to minimize the risk of inhalation

by operators. Alternatives may be found in the application of organic acids and thermal treatments. Further measures to reduce prevalence of Salmonella can be taken to prevent colonization and transmission with specific feed additive combinations that inhibit growth, block attachment of Salmonella to the mucosa and reduce the expression of specific virulence genes. Moreover the host defense system can be promoted with immune-modulatory concepts. Strategies to reduce prevalence of Salmonella have been very successful, and various integrators operate nowadays at a prevalence level of less than 1% contaminated flocks.

The control of Campylobacter is more complex. From a human health perspective, Campylobacter is more relevant than Salmonella. From a biosecurity point of view it may be key to control the horizontal transmission via insects. From a nutrition or feed additive point of view, it does not seem to be feasible to fully prevent or eliminate Campylobacter, but it may be possible to reduce the caecal Campylobacter numbers of the birds at slaughter, which is expected to be correlated with the Campylobacter levels at broiler carcasses. Carcass treatment with antimicrobials is not allowed to date in the EU, but is an effectively applied measure to lower Campylobacter levels in various countries outside EU.

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. 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.

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 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.

Economical optimization of the feed program, precision nutrition as approach to optimize feed economics

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. 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. 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.

A very nice example of precision nutrition in layers or breeders is the split or oviposition feeding program. 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.

NIR to facilitate flexible and adequate use of ingredients

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. 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.

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 anticipate on fluctuations in raw material prices, whilst at the same time we need to have grip on variation in raw material quality and assure that the feed delivers the same high performance. Here, NIR (near-infrared spectroscopy) 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. Recent advances in our research program also indicate that it is feasible to estimate the amount of reactive lysine in specific feedstuffs by NIR. Reactive lysine is the proportion of lysine that can be utilized by the animal for protein deposition. Non-reactive lysine may be formed by Maillard-reactions during heat treatment of protein sources and cannot be utilized by birds. It is digestible, but has no biological value. Such rapid methods can be applied to discriminate protein sources that may have been under- or over-processed, for example soybean meal, rape seed meal and meat and bone meal.

Product quality demands

The genetic progress is the main success factor for the improvements we have seen the last decades in productivity in broilers and layers. However, the enormous increase in productivity may also have negative side effects. For example, there are increasing concerns about muscle myopathies in broiler chicken, in particular what is termed ‘White stripping’ and ‘Wooden breast’. The deviating visual appearance and impaired storage and cooking quality may result in downgrading and condemnation. The two myopathies are both connected with rapidly growing birds and are more common when larger body weights are required for further processing. Incidence is higher as expected in the faster growing male and the high breast yield genotypes. The solution will require an integrated approach in breeding, nutrition and management.

Sustainable feed supply for poultry production

The importance of using a holistic approach to enable successful conversion of feed into high quality poultry protein in a sustainable way is evident. These high 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.

References are available on request From the Proceedings of XXV World’s Poultry Congress