Effect of Thermal Pre-treatment of Oilseed Feed on Fatty Acid Profiles and Protein Fermentability

Abstract

Abstract Oilseeds, abundant in protein and fats, offer the potential for enhancing dairy ration and milk quality. However, anti-nutritional factors in raw oilseeds restrict their efficient utilization. Employing thermal treatments serves the dual purpose of safeguarding fatty acids and proteins from rumen biohydrogenation and degradation while deactivating anti-nutritional elements. This comparative study applied moist heat treatments (boiling and autoclaving) and dry heat treatments (roasting and extruding) to five oilseed feeds—kidney bean, soybean, mung bean, jack bean, sesame, and palm kernel meal. Gas chromatography analyzed the fatty acids profile, while in vitro methods studied protein degradation, reflected in ammonia concentration in the rumen. Results indicate that heat treatment type insignificantly alters nutrient content, except for protein. Changes in nutrient content vary among seed types, with a fat content decrease of 30-70% in all materials except soybeans, which exhibit a 10% reduction. Protein degradation is influenced by both material type and heat treatment, with roasting significantly reducing degradation compared to other methods. Fatty acid concentration responses to heating are inconsistent, though an impact on short-chain fatty acids (SCFA) is observed. In conclusion, roasting is the most effective and practical thermal protection method, preserving protein quality without significantly altering fatty acid profiles.