Poultry diets: A review of some of the main nutrients found in them

Poultry diet formulation must always consider the inclusion of certain key nutrients. When formulating diets for poultry, the energy level is usually selected as a starting point.  An appropriate energy level is one that is likely to result in the lowest feed cost per unit of product (weight gain or eggs). The cost of feed per unit of product, in turn, is determined by the cost per unit weight of the diet and the amount of diet required to produce a unit of product.

The energy level of diets is often used as the basis for establishing most nutrient concentrations in a serving.

This approach to diet formulation in poultry farming is based on the concept that poultry tend to eat to meet their energy needs, assuming that the diet is adequate in essential nutrients.

However, such an assumption should be made with caution and with an understanding of its possible limitations.

Besides energy and nutrient balance, there are other factors that affect food intake like:

• Bulk density of diets
• Environmental temperature

The latter can have a considerable impact on pultry’s feed consumption, especially in adult birds. This is due to the fact that feed consumption decreases as environmental temperature rises.

At temperatures above 30°C, the decrease in feed consumption can be 2.5 to 4g for every 1°C increase.

Carbohydrates

Dietary carbohydrates are important sources of energy for poultry. Cereals such as corn, sorghum, wheat and barley contribute most of the carbohydrates to the birds’ diet. Most of these carbohydrates are found as starch, which poultry can digest easily.

Other carbohydrates are found in varying concentrations in cereals and protein supplements. These include polysaccharides such as cellulose, hemicellulose, pentosans, and oligosaccharides (such as stachyose and raffinose), all of which are poorly digested by poultry.

Therefore, these types of carbohydrates have a minor contribution in regards to meeting the energy needs of poultry. Sometimes even having negative effects on digestive processes when they are present in high concentrations within the diet.

• For example, pentosans in rye and beta-glucans in barley increase the viscosity of digest and therefore interfere with nutrient utilization.

Supplementation of diets containing rye or barley with appropriate supplemental enzyme preparations improves nutrient utilization and growth of young poultry.

Proteins and aminoacids