Poland currently leads the European Union in the production of broiler chicken and turkey meat for slaughter and supplies about 20% of the EU market with eggs. Such a high level of poultry production is possible thanks to modern methods of raising and breeding birds combined with genetic advances that have led to the production of new lines and hybrids adapted to rapid growth and high levels of laying.
All of this maximises the potential of various poultry species to produce high-quality food. Forecasts for both the global and Polish poultry production sectors predict a consistent upward trend, and developing a safe and effective sustainable strategy to maintain it is an urgent task. Although poultry production in Poland is at a very high level, it is a branch that must constantly improve. This is especially true for broiler meat. In this case, 50% of production is for export. This means that in the event of problems related to the disruption of supply chains (e.g., the occurrence of avian influenza, increases in raw material prices, or armed conflicts) or the inability to meet the requirements of European law (increasing welfare conditioning the sustainability of production), a situation could arise in which almost half of the poultry meat produced in Poland would not be exported, meaning huge financial consequences for domestic producers and exporters. In Poland, research work is being carried out to develop a strategy to increase the sustainability and safety of poultry production, such as the multi-year programmes entitled “Improving Domestic Sources of Plant Protein, their Production, Marketing System and Use in Feed” (Resolution No. 149/2011 of 9 August 2011) and “Increasing the Use of Domestic Feed Protein for the Sustainable Production of High-quality Animal Products” (Resolution No. 222/2015 of 15 December 2015), which analysed the potential of increasing protein security in poultry nutrition through the use of domestic sources.
17.6.4.1 Poultry feeding in the context of environmental impact
Farms emit pollutants into all components of the environment: air, soils, surface water and groundwater, thereby affecting its quality. The most common pollutants emitted by poultry farms are drugs and phosphates, but both gases (ammonia, methane, nitrous oxide, hydrogen sulphide, hydrocarbons) and dust and microbial pollutants are important. The extent of the environmental impact is closely related to production volume and feeding intensity. In the organic rearing of slaughter poultry, intensive feeding is abandoned in order to obtain a product that meets customer expectations, and the extended fattening period is reflected in the price of the final product. The environmental impact of organic farms is smaller than that of industrial farms. Emissions of pollutants from poultry farms are closely related to the number of birds, and the structure and composition of the droppings. What is in the droppings, in turn, is related to the quality of the feed provided, the amount of nutrients and the degree of feed conversion. What is of great importance here is the arrangement of feeding in such a way that the animals can make optimal use of nutrients from the feed, resulting in their reduced excretion into the environment. Better and more efficient use of feed results in less strain on the environment and improved efficiency that translates into the farm’s financial results.
17.6.4.2 General principles of poultry feeding
Nutrition is a key component of sustainable poultry production, taking into account all production elements related to waste management, increasing the share of renewable energy in the production cycle, rational use of water, materials used in poultry rearing, and technologies in the production and processing of the food manufactured.
According to the law:
- Fattening of young chickens and turkeys should be carried out on farms under veterinary supervision.
- The feeding of chickens and turkeys must be conducted with feed, the quantity and nutritional value of which must be adapted to their species, age, body weight and physiological state.
- The feed used must meet all requirements under applicable laws.
- It is prohibited to add feed additives not listed in the Register of Feed Additives and materials listed in Annex 3 to Regulation (EC) No 767/2009 of the European Parliament and of the Council of 13 July 2009 on the placing on the market and use of feed, amending European Parliament and Council Regulation (EC) No 1831/2003 and repealing Council Directive 79/373/EEC, Commission Directive 80/511/EEC, Council Directives 82/471/EEC, 83/228/EEC, 93/74/EEC, 93/113/EC and 96/25/EC and Commission Decision 2004/217/EC (OJ EU L 229, 01/09/2009, p. 1, as amended).
Modern poultry feeding methods must take into account the production potential of the birds (so that it can be fully realised), the overall quality and safety of the final product (meat, eggs), as well as environmental standards (maximum reduction of negative environmental impact by limiting the production of nuisance waste). Sustainable poultry production uses precision feeding, i.e., feeding that uses bird feed mixes that contain the exact amount of nutrients the birds need during a specific growth phase. Modern methods of mix formulation and a phased feeding system make it possible to precisely adjust the composition of feed to the needs of birds of a given age depending on the direction of production (reproduction, meat, eggs). Thanks to such methods, it is possible not only to optimise production costs but also to reduce negative environmental impacts (e.g. by reducing the excretion of nutrient elements). The basic principle that meets the criteria for sustainable poultry feeding is the principle of the so-called “limiting component”, which states that the availability of nutrients for the bird’s body is determined by the component that is in unbalanced deficiency or excess. This means that even using more nutrients in the poultry feed mix than the birds require, or, for example, not adjusting the appropriate level of metabolic energy in the feed, will result in the birds not realising their full growth/production potential. For this reason, various methods are used in sustainable poultry feeding to improve the nutritional value of the feed provided to fully utilise the nutrients they contain. These methods may include the use of baro-thermal treatments (extrusion, micronization) to inactivate anti-nutritional substances in the feed, leading to increased utilisation of feed nutrients by promoting digestion and absorption processes in poultry. Another method is the use of feed enzymes (e.g., exogenous phytase), which increases the release of phosphorus from phytate compounds (a form of phosphorus found in plants and unavailable to birds), which, on the one hand, makes it possible to reduce the level of phosphorus added to diets (economic aspect) and, on the other hand, contributes to reducing the excretion of this nutrient element with droppings (environmental aspect). Another aspect of sustainable poultry feeding (mainly slaughter poultry) is the link between the overall health of the birds and the quality of the product. This applies to the production of so-called functional foods, i.e. those that can benefit the health of consumers. By appropriately modifying the composition of feed mixes, e.g., using fish oil, rapeseed, flaxseed and/or products derived from their processing (rapeseed meal, press cake), it is possible to easily favourably influence the health-promoting properties of the obtained meat by increasing the proportion of essential polyunsaturated fatty acids (especially long-chain ones of the PUFAn-3 group) in the lipids. Such a solution makes it possible, on the one hand, to manufacture a product with increased nutritional value for the consumer, and, on the other hand, it has a beneficial effect on the health of the birds, and also allows the use of by-products from agricultural production. The idea of sustainable nutrition in this case takes into account the welfare of the birds and the benefits to the consumer.
Selecting the feed according to the direction of production (slaughter, laying), the life stage of the birds, and the facility’s capabilities is crucial here. Parent flocks will be fed differently than birds on large-scale slaughter poultry farms. Organic poultry farming will be governed by completely different feeding standards. Properly balanced feed has a major impact on the achievement of production and economic goals, as well as on the health of birds regardless of the direction of production.
Poultry nutrition within sustainable agriculture is guided by the following principles:
- Using proper poultry genetic material, characterised by a fast growth rate and good feed utilisation,
- Ensuring appropriate environmental conditions to fully exploit the genetic potential of birds,
- Compliance with the limiting component principle,
- Using local raw materials as much as possible,
- Maximising the environmental impact of poultry production.
17.6.4.3 Feed protein sources and phytogenics
In sustainable poultry production, good quality feed material, i.e. with a high digestibility of amino acids coefficient, especially the limiting amino acids (lysine, methionine, arginine and tryptophan), should be used as a source of protein first and foremost. Domestic sources of feed protein should be used as much as possible, as well as products resulting from the processing of agri-food raw materials.
Protein grains
Currently, the primary source of feed protein for all poultry species is soybean meal. This material contains about 46% protein in its composition, which has a high assimilation rate in birds. Although soy is the primary protein component in poultry feeds, its use involves heat treatment to reduce the activity of anti-nutritional substances. Another aspect is that most of the meal imported into the country is derived from genetically modified crops, and national legislation seeks to restrict the use of such raw materials in feed. In recent years, research has been conducted on the possibilities of using protein raw materials that can replace, at least partially, soybean meal in poultry nutrition. Production should pursue production/economic, environmental and social goals – focused on food quality and safety. In poultry production aimed at reducing the use of soybean meal, domestic sources of protein, which include legumes such as lupins, peas and beans, are used as partial replacements in the diet. They have a lower protein content than soybeans, but research indicates that it is possible to use them in broiler diets at the 20% level without compromising rearing performance. It is not without significance that the cultivation of legumes contributes to improving soil fertility (increasing nitrogen content, and maintaining a balance of humus in the soil) – which is part of the ideas of sustainable agricultural production. Research conducted at the Jan Kielanowski Institute of Animal Physiology and Nutrition of the Polish Academy of Sciences in Jabłonna showed that it is possible to completely replace soybean meal with a mix of rapeseed cake, yellow lupin grain, peas and potato concentrate without worsening the rearing results of broiler chickens. The use of crystalline amino acids in the diet, as well as enzymes that increase the digestibility of protein, resulted in a reduction in the excretion of nitrogen and phosphorus into the environment by birds, i.e. elements responsible for the eutrophication of water. Such additions are fully in line with the tenets of sustainable agriculture.
By-products of oilseed crop processing (press cake)
This material formed after skimming is a rich source of feed protein. The most commonly used is rapeseed or sunflower cake. In recent years, there has also been growing interest in the use of fibre hemp cake in poultry nutrition. In addition to its high protein content, press cakes also contain fibre fractions that are not well digested by birds, hence their share in the feed was low. However, research on the use of feed enzymes that increase the nutritional value of press cake for poultry, as well as the use of processing (e.g., fermentation), have increased the use of press cake in poultry nutrition.
Meat and bone meals
As of 7 September 2021, the ban on the use of meat and bone meals in poultry nutrition has been lifted, with a “cross-feeding” rule, i.e., no meal must be fed within the same animal species. This material is a rich source of protein with a good profile (well digestible) of amino acids and other nutrients for poultry. Particularly useful in poultry nutrition is fish meal, which in addition to its high protein content also contains essential polyunsaturated fatty acids of the n-3 group. Feeding this meal results in the enrichment of meat and eggs with these acids, thus creating the possibility of producing foods with functional properties. In addition, the use of meals in poultry feeding contributes to the increased use of waste generated in animal production.
Dried distillers grains with solubles (DDGS)
It is a material derived from the ethanol production process. Its protein content is high (up to 35%) with good digestibility. In addition, it contains B vitamins, as well as vitamins A and E, and is a source of minerals. Compared to other by-product materials, DDGS does not contain anti-nutritional substances for poultry. Therefore, they can be used as early as the first phase of feeding birds.
Protein from insects
As of 2021, the EU has authorised the use of insect protein in poultry nutrition (Commission Regulation (EU) 2021/1372). Protein derived from insects is now a very promising alternative to partially or completely replace soy protein in poultry feeding. Insect meal contains up to 65% protein and a highly digestible amino acid profile that is very beneficial to poultry. Despite the difficulties of producing and storing insects, the protein extracted from them is playing an increasingly important role. It is not insignificant that the production of insects as a source of feed protein also fits into the so-called “Zero Waste” policy, since agro-food waste can be used to produce insects, and therefore we get rid of environmentally burdensome waste by using it, indirectly, for feed purposes.
Protein from dried green plants, green forages and root crops
This material is mainly used in the feeding of geese. For dried green plants, it is recommended to use white clover (protein content 19.8%), alfalfa (protein content 20.2%), and grasses (protein content 20.4%). For green forages: red clover (protein content 32.0%), alfalfa (protein content 47.0%), young nettle (protein content 56.0%), young grass (protein content 39.0%). For root crops, it is recommended to use sugar beets (protein content 18.0%), fodder beets (protein content 15.0%), fodder carrots (protein content 13.0%) and fodder potatoes (protein content 22.0%).
Phytogenics
Phytogenics are bioactive substances of plant origin. Their application in poultry production (nutrition, prophylaxis and biosafety) has become important mainly since the introduction of the preventive use of antibiotics and growth promoters in animal production. The intensification of poultry production is related to increasing health problems in birds, mainly those related to the digestive tract. Phytogenics in this aspect have special potential by showing activity not only in the direct effects on the gastrointestinal environment (e.g., by having a beneficial effect on the morphological structures of the gastrointestinal tract) but also affecting the composition and activity of the bacterial microflora residing in the gastrointestinal tract. Micloflora is considered an important factor in the gut health of poultry. In addition, a growing number of research findings indicate that there is a specific regulatory axis between the microbiota in the host’s gastrointestinal tract and important physiological processes. It has also been shown that there is a relationship between gastrointestinal microbiota and meat quality in chickens. Therefore, the greatest potential for the use of phytogenics in poultry is seen in improving and preventing gastrointestinal conditions. Since one of the main diseases of the digestive system in gallinaceous poultry is coccidiosis, great attention is paid to its prevention. It was found that using Yucca schidigera extract reduces the prevalence of this disease. The effect of reducing the number of E. coli, Campylobacter jejuni and Salmonella bacteria was demonstrated when hop extract was used in the diet of broilers. A study on the use of cannabidiol extract from the Cannabis sativa fibre hemp in poultry nutrition found that it showed potential in reducing the occurrence of necrotic enteritis in chickens caused by Clostridium perfringens bacteria. Other studies have shown that herbs such as black pepper (Piper nigrum), cloves (Syzygiom aromaticum), oregano (Origanum vulgare), (thymol, carvacrol, curcumin, piperine, eugenol), and lemon thyme (thymus vulgaris) used in poultry feeding have been shown to reduce the proliferation of pathogenic bacteria. In other studies, thyme and oregano have been shown to exhibit strong antioxidant and immune system-supportive effects in various poultry species. On the other hand, the use of garlic extract, echinacea, ginseng, eucalyptus oil or moringa oleifera contributes to improving the functional properties of meat and eggs. Many bioactive substances of plant origin (nigella, carvacrol) are used to improve sanitary conditions in poultry housing. Their effect is to stabilise fermentation processes in the digestive tract and prevent the occurrence of microbial imbalances, which consequently reduces the moisture content of excreted faeces. Therefore, the use of phytogenics is an increasingly effective prophylaxis and an alternative to pharmaceuticals used in poultry production.
17.6.4.4 Detailed rules for sustainable feeding of poultry species
Broiler chickens
The feeding of broiler chickens uses complete feed mixes with a high concentration of energy, fed at will, to fully satisfy the potential of growing birds. A three-phase feeding system is most often used (e.g., d 1-10, d 11-21, d 22-42), in which mixes with nutrient concentrations strictly adapted to the age of the birds are fed. The first feeding period (usually the first 7 days) is always critical, as it largely determines the final fattening effects. Throughout the rearing period, it is critical to adjust the appropriate levels of protein and energy in the feed bearing in mind that as the birds grow, metabolic energy requirements increase and protein requirements decrease. In each phase of the birds’ growth, the feed mixes provided should be adjusted in terms of the content of limiting amino acids. When feeding broiler chickens, a single feeding system is most often used for both sexes.
Reproductive chickens
In the feeding of reproductive birds in the first 4 weeks of life, complete feed mixes are given with a high concentration of energy and nutrients to enable rapid growth. In the period between the 4th and 17th week, a reduced feed mix should be used, which will allow the body to develop properly and prepare the birds for the laying period. From the 18th week of age, calcium and protein levels in the feed mixes given to the birds should be increased. This mix is administered until the birds reach a laying rate of 2-3%.
Laying hens
Laying hens should be provided with loose feed that is fed at will because they can regulate feed intake to demand. In the pre-breeding period (up to the 17th-18th week), the fed mixes should cover the hens’ nutritional needs depending mainly on body weight. Once the birds enter the laying period, increased levels of protein (min. 18% for 1st period), (min. 17% for 2nd period), (min. 15% for 3rd period) are used in the feed, but above all, the level of calcium to phosphorus in the diet should be adjusted. It must be 12:1 because calcium is the main component of the eggshell. A prerequisite for maintaining a high laying rate over the long term is the use of feed balanced in terms of energy, amino acids, vitamins and minerals. In order to fully exploit the laying potential, it is necessary to adapt the maintenance conditions and feeding of laying hens to the recommendations of the manufacturer of the line.
Slaughter turkeys
In the case of feeding slaughter turkeys, a separate feeding system is used according to sex, since there is a pronounced sexual dimorphism in turkeys: the weight of turkey cocks is higher throughout the rearing period than that of turkey hens, in which from the 12th week of life hormonal changes intensify, the development of the oviduct and the formation of yolks take place, which makes it impossible to adjust the optimal composition of the mix – especially in terms of amino acid concentration – for both sexes at the same time. For this reason, from the age of 16 weeks, a separate feeding system is used according to sex. A four-phase feeding system is used for turkey, with full-feed crumble mixes fed at will in each period, adjusted in composition and nutrient concentration according to age, sex and type. Turkey cocks are kept until they are 20-22 weeks old, and turkey hens until they are 16 weeks old. In starter mixes, vegetable oils should be preferred as an additional source of fat, while finisher mixes may contain only animal fat. The way turkeys are fed largely depends on their production goal, which may be to maximise weight gain, improve feed conversion rate (FCR) or increase breast muscle performance. Achieving the first two production goals largely involves increasing the concentration of energy and protein (amino acids) in feed mixes without the health complications related to intensive feeding. The above goal must take into account the price aspect (raw material cost of feed mixes), the quality of feed raw materials, and the precise balancing of protein needs based on digestible amino acids.
Reproductive turkeys
Two main periods are taken into account, i.e. the rearing period (up to 30 weeks of age), during which birds are given feed mixes to cover their nutritional needs and prepare them for the laying period and semen production. In the next period – the breeding one – the mixes administered should allow the birds to maintain high breeding activity and not get too fat.
Meat ducks
The intensive feeding of ducks used for meat is similar to that of broiler chickens. Duck rearing is carried out according to the principles of intensive production, i.e. indoors, with regulated environmental conditions and specialised feeding with complete mixes. Mixes provided up to the age of 3 weeks should contain 20% protein, and in the next period – 17% protein. For feed metabolic energy, the level should be increased as the birds age.
Geese
Among farmed poultry species, geese react most unfavourably to conditions that deviate from natural ones. Similar differences also occur in the case of feeding geese, as, in this case, green forage and root crops play a very important role, and their essential participation in feeding is even advisable. The flagship example is the oat goose, which in the last 3 weeks of fattening is fed exclusively on oat grain. Proper weight gain, high slaughter performance and excellent meat flavour are then obtained. However, to realise the full potential of the oat goose, it should be fed a mix with a high proportion of roughage beforehand, so that the digestive tract is properly formed and fermentation processes take place properly. During the rest of the fattening period or when feeding reproductive geese, green fodder mixes with cereal grains can be used, or in the winter period, complete feed mixes with the addition of dried grain.