Nutrient profile and availability of co-products from bioethanol processing

Area of Science:

• Animal Science
• Nutritional Biochemistry
• Ruminant Nutrition

Background:

• Bioethanol co-products like dried distiller's grains with solubles (DDGS) are abundant in North America.
• Variations in nutrient profiles and availability of DDGS can lead to imbalanced animal diets, negatively affecting performance.

Purpose of the Study:

• To compare nutrient profiles, energy values, and rumen degradation characteristics of three DDGS types (100% wheat, and two corn-wheat blends).
• To assess variability within different batches of each DDGS type.

Main Methods:

• Analysis of protein and carbohydrate sub-fractions using the Cornell Net Carbohydrate and Protein System (CNCPS).
• Calculation of energy values (TDN, DE, ME, NEL, NEm, NEg).
• In situ rumen degradation studies for dry matter (DDM), organic matter (DOM), crude protein (DCP), neutral detergent fiber (DNDF), and starch (Dstarch) at 36 and 72 hours.

Main Results:

• Wheat DDGS showed distinct protein fractions compared to blends, with higher slowly degradable protein and lower intermediate protein.
• Wheat DDGS had higher sugar content but lower starch and digestible fiber.
• Corn-wheat blends, particularly BDDGS2 (50:50 corn:wheat), exhibited higher calculated energy values.
• Significant differences in nutrient composition and rumen degradation were found between DDGS types and even between batches of the same DDGS type.

Conclusions:

• Significant variations exist in protein and carbohydrate fractions among different DDGS types and batches.
• Rumen degradation characteristics (DDM, DOM, DCP, DNDF, Dstarch) also differ significantly based on DDGS type and batch.
• These findings underscore the importance of considering both DDGS type and specific batch variations for accurate ruminant diet formulation.