Optimizing the utilization of winged bean (Psophocarpus tetragonolobus (L.) DC.) tubers as a replacement for cassava chips in ruminant diets through pelleting: an in vitro gas technique study.

Background: Enhancing the utilization of winged bean tubers (WBT) in ruminant diets is gaining prominence due to the instability of traditional feeds, like cassava chips. Previous studies have shown limited outcomes in fermentation processes and complex quality improvement methods. Pelleting offers a promising approach to improving tuber utilization, while the in vitro gas technique provides insights into digestion and gas production.

Results: This study explored the effects of pelleting WBT on gas production and digestion, supporting their integration as a sustainable alternative to cassava chips in ruminant diets. A completely randomized design (CRD) with a 2 × 3 (+ 1) factorial arrangement was used. Factor A comprised of WBT powder (a1) and WBT pellets (a2). Factor B included three substitution levels for cassava chips: b1 (33%), b2 (66%), and b3 (100%). Replacing cassava chips with 100% WBT powder or 66% and 100% WBT pellets resulted in significantly higher levels of Gas "a" (P < 0.01). The greatest gas production was observed when both WBT powder and pellet forms replaced cassava chips at a 33% replacement (P < 0.01). The replacement of cassava chips with WBT, either in powder or pellet form, did not result in significant differences in the in vitro degradation of the diet. Cassava chips-based diets produced significantly higher total volatile fatty acids (TVFAs) than the other diets (P = 0.013). Replacing cassava chips with 100% WBT pellets yielded the lowest methane gas production (P = 0.02).

Conclusion: The pelletization of WBT has been found to have no adverse impact on rumen fermentation or digestibility. The WBT pellets have emerged as a notably promising alternative to cassava chips; nonetheless, the impact on TVFAs levels warrant careful consideration when utilizing them.