**3. Feeding poultry with a balanced diet**

Since most poultry species are omnivores, it is possible to combine several feeds to create the most useful final feedstuff. Except for a few geese and ostriches, which have well-developed digestive systems, most birds are sensitive to food because of

### *Feed Sustainability and Efficiency DOI: http://dx.doi.org/10.5772/intechopen.110332*

their digestive systems. Most birds have substantially shorter digestive systems than other animals. Food passes from the mouth through the cloaca in less than three hours in chickens with rapid growth. High-performing birds require nutrient-rich diets that are considerably easier to digest to compensate for their short digestive systems and quick digestion times. Nutrient balance is crucial under these circumstances [3].

Because genetic modifications have also altered the physiology of the birds, genetic selection cannot function alone. By altering dietary needs and nutritional management, only the genetic potential of the new strain can be met. The high genetic potential of the newly selected birds can only be achieved with the help of properly formulated energy and nutrient-dense feed. Poultry, especially growing birds, is exceptional in that any change in the composition of the diet has an immediate and noticeable impact on the performance of the birds. The poultry industry has successfully taken advantage of this phenomenon (**Table 1**) [4].



### **Table 1.**

*Minimum nutrient recommendations for laying hens and meat chickens expressed as percentages or units per kg of food.*

## **4. Recent advancements in poultry nutrition**

The single biggest cost connected with raising poultry is feed. Therefore, nutritional research in chickens has focused on problems relating to finding impediments to optimal nutrient digestion and usage, as well as on methods for enhancing feed utilization. The knowledge of experts in other biological sciences, such as molecular biology, immunology, microbiology, histology, and microanalysis, is increasingly being blended with that of specialists in poultry nutrition. It is seen that most of the feed is not converted into animal products, and most of the feed goes as undigested waste. In most cases in broilers, though they are efficient in food digestion, 30% of the ingested feed goes undigested. This reveals that the effectiveness of feed utilization for animal products has improved [5].

Recent advancements in poultry nutrition have mostly focused on three domains: 1) gaining knowledge of the needs and metabolism of nutrients, 2) determining the number of nutrients and their availability in feed ingredients, and 3) designing diets at the lowest possible cost that successfully balances nutritional supply and demand. Precision feeding is the overarching goal to reduce expenses and increase economic gains. When there was uncertainty regarding the supply of essential nutrients, such as phosphorus and amino acids, or when dietary requirements were unclear, there was a historical inclination to over-formulate diets. This method is no longer permitted since it is wasteful and because excess nutrients excreted in the manure eventually become a source of pollution. Optimizing the efficiency of nutrient use involves finetuning meals to better meet the needs of the birds [6].

### **4.1 Nutrient requirement**

Nutrient requirements are difficult to define since they are always changing and affected by a wide range of variables. Two main categories of variables determine nutrient requirements: those that are unique to birds, such as their genetic makeup, sex, form, and stage of development, and those that are present in their environment.

### *Feed Sustainability and Efficiency DOI: http://dx.doi.org/10.5772/intechopen.110332*

Precision in defining the criteria depends on accuracy in both areas. The characterization of nutrient requirements for various classes of chicken has significantly advanced owing to the improved uniformity of genotypes, housing, and husbandry practices across the poultry industry. It has made it possible to make significant advancements in the definition of nutrient requirements for various classes of chickens.

### **4.2 Identifying the nutrient profile and ingredient quality**

Producers of poultry are constantly looking for ways to increase the types and quantities of the feed additives they can use in feed formulations. The prevalence of these possibilities is rising because of improvements in feed evaluation and nutritional analysis methods. The main purpose of the feed ingredients is to provide the nutrients that the bird consumes and uses for vital processes. Data on the ability of raw materials to deliver key nutrients are currently in abundance. However, the inherent heterogeneity of each raw material puts strain on the precise feed formulations. Data on variation (or matrices) for the main feed ingredients are available and used in feed formulation systems to increase precision. It is an important advance that quick diagnostics, such as near-infrared reflectance analysis, are now available to determine gross nutritional content and continually track changes in ingredient supply.

It is established that not all nutrients in foods are available for use in production and that some nutrients in foods are either excreted undigested or not utilized. As feed evaluation techniques advance, data on the availability of nutrients for chicken, particularly phosphorus and amino acids, have been growing. The greater use of digestible amino acid concentrations in feed formulations rather than the total amino acid concentrations, for instance, is a new trend. The use of digestible amino acid content is especially important in developing countries where highly digestible conventional products are not easily accessible, and diet formulations may include components with low digestibility.

By developing diets based on digestible amino acids, it is possible to increase the product categories that may be used and the proportions of alternative items that can be used in poultry diets. This assures more constant performance from the birds and improves formulation accuracy, which may also result in lower feed costs.

### **4.3 Feed formulation**

Once the nutritional requirements have been determined, the following step is to blend products and supplements to meet those requirements. A balanced diet offering the proper amounts of nutrients that are biologically available is the aim of the formulation. Commercial food producers also strive to provide a healthy diet for the cheapest price possible. The production of the least-cost feed necessitates numerous mathematical calculations due to the variety of available feedstuffs and nutritional requirements. Over time, feed formulation has changed from the straightforward balancing of a few feed ingredients for a small number of nutrients to a computer-assisted linear programming system. With commercially available formulation software, stochastic nonlinear programming systems are currently becoming more and more common. The next stage is to combine products and supplements to meet the nutritional demands after they have been identified. Since the variation in ingredient composition is nonlinear, stochastic programs are the most efficient way to combat this issue.
