Nutritional requirements of modern broilers

To maximize the benefits of amino acids in the diet of poultry and pigs, it is necessary to understand the response of animals to each amino acid and take into account their interactions.

A balanced and precise supply of amino acids in the feed makes it possible to avoid superfluous dietary intakes. This specifically reduces excessive protein intake, which degrades the quality of the intestinal bacterial flora.

Beyond protein-based synthesis, amino acids such as threonine, valine and arginine play a fundamental role in the development of proteins involved in the immune system and intestinal integrity. The evaluation of their dietary intakes and their precise dosage in feed allows to respond to the specific problems related to animal health that producers face.

-Including the new industrial amino acids: L-valine + L-isoleucine + L-arginine, we can achieve a significant protein reduction in the diet of broilers and reduction of the cost of feed, histidine and glycine + serine are the next amino acids limitations that must be considered.

Enzymes are natural proteins. They are organic chemical compounds of a protein nature that accelerate the speed of a thermodynamically possible chemical reaction.

Enzymes are secreted by all animals as part of the feeding and digestion process. The stomach, small intestine, and pancreas all secrete a wide range of enzymes to digest carbohydrates (main source of energy), lipids (also a good source of energy), proteins (amino acids), and mineral complexes.

Enzymes literally split or break large compounds (eg, starch) into small pieces (such as maltose and dextrin) and eventually building blocks or units (in the case of starch, glucose being - a simple sugar). These simple compounds are absorbed to be used by the animal for the purpose of maintenance and production. Without the digestion process provided by enzymes, practically no nutrient can be absorbed.

First, they need a suitable substrate. Therefore, a protease cannot break down a carbohydrate, nor can a phytase work on a protein. Therefore, there must be a combination between each enzyme and its substrate. The enzyme recognizes and attaches itself to the substrate in a mechanism that resembles the figure of a key analog block. Second, they need a suitable environment in terms of acidity or alkalinity. For example, enzymes secreted in the small intestine work better in a higher pH environment.

The enzymes secreted by the animal are called endogenous. Those added to the animal's diet are called exogenous. Commercial (exogenous) enzymes are used to enhance the natural process of digestion. Examples include amylase (starch), lipase (lipid) and protease (protein). Other enzymes are used to provide substrates for digestion that are not digested by the animal. This includes phytase (phytic phosphorus), xylanase (arabinoxylan), glucanase (Beta-Glucans), mannanase (beta-mannan) fiber components.

Most commercial enzymes have been of the latter form, although amylases and proteases are being used more frequently and successfully.

Exogenous enzymes are also natural proteins, produced by controlled microbial fermentation, and work under the same principles as endogenous enzymes. Like their endogenous counterparts, they also require a suitable substrate and correct pH conditions to exert their full effect. In addition, there are a few other requirements for exogenous enzymes: they must be stable under various feed processing and storage conditions, they must be safe for human operators, and of course, their use must improve profitability for the producer of the enzymes and animals.

Today, we can easily expect a 10% improvement in phosphorus digestibility over a modern phytase. Similarly, a glucanase or xylanase enzyme can improve Metabolizable Energy in feed by 50 kcal/kg, or even more (up to 150 kcal/kg, it is reasonable in low-quality cereals). Lastly, a protease improves protein digestibility by around 2-5% depending on the type of ingredients used. In the animal industry where profit margins are currently

 Small, such improvements as those conferred by exogenous enzymes are indeed substantial and attractive.

- A next-generation protease can improve protein digestibility by 16% and decrease soybean meal inclusion by 8%

In conclusion, enzymes are natural, safe, and important for the animal. Supplementation in food improves the process of digestion, and reduces the amount of nutrients excreted in the stool. This, in turn, improves animal performance, profitability and reduces environmental pollution.

For precision, cost-effective and environmentally friendly nutrition it is necessary to go from available phosphorus and total calcium to fair digestible phosphorus and ileal digestible calcium, the scientific community has a duty to offer this information.

Digestible phosphorus represents that portion of phosphorus in the diet that can be used in the animal's body. For the efficient production of animal products, it is required that the correct amount of nutritionally adequate feed be supplied to the animal. To achieve this goal, the characteristics of digestion and use of this type of feed must be well understood (Olayiwola Adeola, 2013).

Phosphorus is an essential mineral element, which in most vertebrates is the second dietary requirement after calcium. The satisfactory performance, growth, reproduction and welfare of animals depend on an adequate supply of phosphorus in the diet. Approximately 75% of the body's phosphorus is stored in the skeleton as the main component of hydroxyapatite, the main building block of bone (Adeola, 2016).

The dietary imbalance of Calcium and Phosphorus is not only possible due to the deficiency of macrominerals in the feed but also due to the excess of some of them, which leads to interference in the absorption of the other (Williams et al., 2000).

Research where it was observed that the digestibility of Phosphorus and its absorption depends largely on the presence of Calcium in the intestine and calcium absorption, since too much Calcium limits the activity of phytases and the bioavailability of Phosphorus (Angel and Tamin, 2003; Tamin et al., 2004; Selle et al, 2009).

The lack of available information is undoubtedly a clear limitation for an adequate formulation of the requirement of digestible macrominerals and therefore of their relationship, but the revision of formulas to arrive at better approximations will optimize the use of phytases and reduce the amount of skeletal disorders in chickens. If a 100% Ca digestibility is assumed, an error is clearly being made, but if there is also a phytase in the formula, the Total Calcium obtained from the laboratory analysis may be less than that of the formula, which would still be an error. (Ángel, 2017).

Currently there are not enough research works on the digestibility of Calcium present in ingredients used in poultry so that the formulation can evolve towards a system that considers the relationship between the two macrominerals expressed in the same terms (Ca dig / P dig), but Every time there is a greater awareness of the need for this information and more research centers are added to carry out the determinations. Until now, a range of Ca digestibility between 20-30% has been reported for soybeans and corn (Ángel and Tamin, 2003; Tamin et al., 2004; Roulleau, 2014), while for calcium carbonate its digestibility is at least It doubles, but it could even triple, according to the origin, resistance and shape (Anwar et al., 2016; Angel, 2017). The Ca present in phosphates is the one with the highest digestibility, since it can take values between 60 and 68% (Roulleau, 2014).

Before the use of phytases in commercial diets, the interference of Ca with the absorption of P present in phytate was already known. In 1984 Ballam et al. already reported a significant increase in phytate hydrolysis.

It can also interfere with the absorption of other minerals

Different energy evaluation systems have been used to formulate poultry diets including digestible energy, total digestible nutrients, true metabolizable energy EMv, apparent metabolizable energy (EMa), and effective energy EEF. AME values of raw materials are most often used to formulate poultry diets. The net energy system (NE) is currently used for the formulation of pig and bovine diets and there is interest for its application in the formulation of poultry.

Every energy evaluation system has some limitations. The AME system, for example, depends on the age, the species and the level of feed consumption. The NE system takes AME one step further and incorporates the energy lost in the form of heat when calculating the energy available for the production of meat and eggs. The NE system is therefore the most accurate representation of energy available for productive purposes. NE prediction requires accurate measurement of feed AME value and also accurate measurement of fasting and total heat production using nutritionally balanced diets. Currently, there is limited information on the NE values of various ingredients for poultry feed formulation.

The optimal particle size for broilers is influenced by the shape of the feed, the age and sex of the animal, its health, and the raw materials used. The optimal particle size in corn-based feeds is coarser than that of wheat-based feeds. For starter batches, the appropriate average particle size is in the range of 900µm -1100µm, while adult birds prefer particles between 1,100µm and 1,500µm. For male birds, the optimal particle size is coarser than for females. In general, it is recommended that you start with a finer granulation and increase the particle size throughout the growing period.

A coarse grain size slightly reduces the digestibility of nutrients, but improves the performance of the gizzard and therefore the performance of the animal, thus overcoming the reducing effect of metabolizing energy.

 

Nutrition is the major impacting variable upon broiler productivity, profitability, and welfare.

Knowledge of the make-up of the diet being fed to the birds will mean that farm managers can ensure that:

•Feed levels and consumption will provide adequate levels of daily nutrient intake (feed intake multiplied by nutrient content).

•There is proper and expected balance between feed nutrients.

•Routine laboratory analysis of diets can be usefully interpreted and correct actions taken such as:

-Alerting the provider of possible discrepancies.

-Appropriate management of feed programs.

-Design diets that maximize the profitability of the entire production chain.

-Formulate feed to maximize performance and not to minimize feed cost.

-It is better to invest to win and not save to lose.

An economical diet is not necessarily the one that produces the best economic return to the company.

With the high cost of raw materials, enzymes, industrial amino acids and formulating with ileal digestible phosphorus are very good options to reduce costs without affecting the performance of the animals.

More effective and modern non-linear programming software is needed to achieve optimal feed formulation online in real time.

The challenge is no longer to formulate the ration with the lowest cost, but the one that brings the highest economic return to the business (Antonio Mario Penz).

Nutrition will contribute much more to the poultry industry, when we are in possession of real-time information such as weight gain, feed conversion, water consumption, chicken mortality.

Online formulation. That is, today, using knowledge of NIR -Near Infrared Spectroscopy-, it is possible to determine the composition of the ingredients at the moment they go to the mixer and, according to their immediate composition, before the next batch, to identify the differences of the nutritional composition of these ingredients and reformat the next batch according to what is going on before the mixer.

This allows us, instead of creating a safety margin, based on the historical information of the nutritional composition of the ingredients, to reduce this safety margin, ensuring greater precision in the process.

This system allows to identify this margin of safety in real time and, immediately, to change the next mix.

The NIR Multi Online Analyzer monitors and adjusts in real time the quality of the flour in the mill. Automate grinding, create homogeneous products, avoid waste, and improve feed safety transparency.

Note: in a balanced feed factory of the same diet, three types of feed can come out (Dr. Douglas Zaviezo):

1- The one formulated by the nutritionist.

2-The one that comes out of the mixer.

3-The one that reaches the peak of broilers.

It is very important for all poultry companies to reduce this variation through online nutrition in real time.

The feed ingredients used for broiler diets should be fresh and of high quality both in terms of digestibility of nutrients and physical quality. The main ingredients included in broiler diets are:

• Corn
• Wheat
• Sorghum
• Broken Rice
• Soybean meal
• Full fat soya
• Sunflower meal
• Oils and fat
• Limestone
• Phosphate
• Salt
• Sodium bicarbonate
• Mineral and vitamins
• Other additives such as enzymes, mycotoxin binders

Broilers require energy for tissue growth, maintenance, and activity. The major sources of energy in poultry feeds are typically cereal grains (primarily carbohydrate) and fats or oils. Dietary energy levels are expressed in kilocalories (kcal)/kg or kcal/lb of Metabolizable Energy (ME), as this represents the energy available to the broiler.

Feed proteins, such as those found in cereal grains and soybean meal, are complex compounds which are broken down by digestion into amino acids (AA). These AA are absorbed and assembled into body proteins which are used in the construction of body tissue (e.g. muscles, nerves, skin, and feathers). Dietary crude protein levels do not indicate the quality of the proteins in feed ingredients. Dietary protein quality is based on the level, balance and digestibility of essential AA in the final mixed feed.

The modern broiler is responsive to dietary digestible AA density and will respond well, in terms of growth, feed efficiency, and carcass component yield, to diets properly balanced in AA as recommended. Higher levels of digestible AA have been shown to further improve broiler performance and processing yields. However, feed ingredient prices and meat product values will determine the economically appropriate nutrient density to be fed.

Providing the proper levels and balance of macro minerals are important to support growth, skeletal development, the immune system, and FCR, as well as to maintain litter quality. They are particularly important in high-performing broilers. The macro minerals involved are calcium, phosphorus, sodium, potassium, and chloride. Calcium and phosphorous are particularly important for proper skeletal development. Excess levels of sodium, phosphorous, and chloride can cause increased water consumption and subsequent litter quality issues.

Trace minerals and vitamins are required for all metabolic functions. The appropriate supplementary levels of these micro-nutrients depend on the feed ingredients used, the feed manufacturing process, feed handling logistics (e.g. storage conditions and length of time in farm feed bins), and local circumstances (e.g. soils can vary in their trace mineral content and feed ingredients grown in some geographic areas may be deficient in some elements). There are usually separate recommendations proposed for some vitamins, depending on the cereal grains (e.g. wheat versus corn) included in the diet.

•Decreased feed wastage.

•Reduced selective feeding.

•Decreased ingredient segregation.

•Less time and energy expended for eating.

•Destruction of pathogenic organisms.

•Thermal modification of starch and protein.

•Improved feed palatability

Poor quality crumble or pellets will result in reduced feed intake and poorer biological performance. On the farm, attention should be given to managing feed distribution to minimize physical deterioration in crumble and pellets

1. Release the minimum and maximum level in the use of commercially available amino acids, maximizing their use.

2. Formulate based on digestible amino acids, with ideal levels of protein.

3. Provide the adequate level of Metabolizable Energy.

4. Eliminate the minimal restriction on crude protein.

5. Eliminate minimal grease or oil restriction.

6. In the near future we will formulate more precise diets in birds with Net Energy, digestible calcium and phosphorus and perhaps digestible sodium, chlorine and potassium.

7. Advanced software that determines nutritional requirements in different microclimates and estimates individual bird variation, in addition to making accurate growth predictions.

8. In ovo sexing already exists.

9. Genetics will continue to advance, it is possible that broiler breeders in the future will be genetically sexed and produce only male chickens and light breeders produce only females.

10. In ovo nutrition, nanonutrition and immunonutrition will bring significant advances in animal nutrition.

11. In the near future we will formulate based on: genetics, genomics, epigenomics and metagenomics of broilers.

12. With precision nutrition and using innovative ingredients of good quality we can predict by 2022 a weight in broilers of 4.0 pounds in 25 days of age.