Efecto de la temperatura de extrusión, humedad y contenido del aceite de girasol sobre las propiedades funcionales y digestibilidad de alimentos para ganado bovino

Abstract

Preparation of extruded products with high oil content, presents a technological challenge, due oil decreases specific mechanic force but also acts as a lubricant, and forms starch-lipid complexes; thus, decreasing starch gelatinization. This research aimed to evaluate the effect of temperature, moisture, and sunflower oil content, on the extrusion process of bovine cattle feed. Two main ingredients were used for each diet: alfalfa (Medicago sativa L.), and bean (Phaseolus vulgaris L.). The obtained results showed that high temperature, moisture, and oil content, decreased bulk density, and hardness (P < 0.05). Oil content-temperature interaction increased both bulk density and hardness, while moisture-oil content interaction increased (P < 0.05) hardness. Optimization was performed based on the physicochemical characteristics of commercial feeds, showing that the best bean diets were obtained at 121oC, 14% moisture content with 0% sunflower oil; 120oC and 16% moisture content with 3.5% sunflower oil; and, 142oC and 15% moisture content with 7% sunflower oil. Effective degradability ranged from 87.4 - 90.4% for all extruded diets; and none of them showed significant differences between bean and alfalfa (P < 0.05), which opens a high potential opportunity of producing high concentrations of CLA from sunflower oil at a ruminal level.