Evaluation of feedstuffs and pig diets. Energy or nutrient-based evaluation systems? II. proposal for a new nutrient-based evaluation system
Titel:
Evaluation of feedstuffs and pig diets. Energy or nutrient-based evaluation systems? II. proposal for a new nutrient-based evaluation system
Auteur:
Boisen, Sigurd Verstegen, Martin W. A.
Verschenen in:
Acta agriculturae Scandinavica. Section A, Animal science
Paginering:
Jaargang 48 (1998) nr. 2 pagina's 95-102
Jaar:
1998-05
Inhoud:
A new nutrient-based evaluation system for feedstuffs and pig diets is proposed. The proposed system is based on (i) an identification of those organic nutrient fractions that, according to their absorption, metabolism and utilization, are relevant for determining the value of the feed, and (ii) biochemically-based calculations of the potential physiological value of these fractions. The system is further based on a flexible stepwise evaluation in which the fundamental properties of the feed are related to its utilization in actual situations. Step 1 is characterized by single feedstuffs according to the digestible amounts of those nutrient fractions which are relevant for feed formulation, i.e. essential amino acids, other N-compounds, ileal digestible carbohydrates, fermentable carbohydrates, fatty acids and other lipid compounds. Step 2 involves complete diets with three complementary properties, measured according to their potential value for the pig: protein value (i.e. amount of digestible ideal protein), “fat value”; (i.e. amount of digestible triacylglycerols) and the “complemental energy value”; (i.e. potential metabolic energy generated directly from the residual digestible nutrient fractions). Step 3 predicts the production value, either a standardized value determined by standard mathematical equations, or the actual value determined by the use of computerized pig models.
Tijdschrift beschrijving