The effects of various levels of distillers dried grains with solubles (DDGS) and a dacitic (rhyolitic) tuff breccia on pellet production rate and durability

Distillers dried grain with solubles (DDGS) has been associated with a reduction in pellet production efficiency and quality in animal diets, whereas some minerals may improve pellet efficiency by scouring the surface of the pelleting die holes, reducing friction. The objective of this study was to understand the relationship between DDGS and a dacitic tuff breccia (DTB) based on pellet production rate and pellet durability index (PDI). The experiment was conducted in a complete block design, with a factorial arrangement 5 × 2, and repeated on 2 d. DDGS levels (0, 4, 8, 12, and 16%) and DTB (0 and 0.25%) were the main effects. Interactions between DDGS and DTB were observed for production rate throughout the study, however, the effects were not consistent between days. DTB inclusion improved the production rate of diets containing 12% DDGS on day 1 (P = 0.010), whereas, on day 2, this positive effect was observed in DTB diets with 4 and 8% DDGS compared to their respective controls (P = 0.001). DTB inclusion had a positive main effect on PDI on day 1 (P > 0.015), however, this result was not observed on day 2 (P > 0.314). Increasing levels of DDGS in the diet had a positive influence on PDI throughout the experiment (P < 0.001). The results showed the potential of DTB in improving pellet production rate when dietary DDGS inclusion ranged from 4% to 12%.