Effect of wilting organic pineapple by-products and jack bean (Canavalia ensiformis) foliage inclusion on silage fermentation and its nutritive value

Effect of wilting organic pineapple by-products (PBP) and Canavalia ensiformis foliage inclusion on silage ensilability and nutritive value after 30 days of storage were investigated at laboratory scale. A total of 24 silages per batch were prepared from a mixture of organic PBP and C. ensiformis foliage. Pineapple by-products were ensiled either fresh or wilted with 4 levels (0, 100, 200, 300 g/kg DM) of C. ensiformis foliage inclusion at room temperature of 25 +/- 3.6 degrees C. Wilting PBP and increasing inclusion levels of C. ensiformis decreased (P < 0.001) dry matter (DM) losses but increased (P < 0.001) DM and crude protein (CP) content of silages. However, the effect of wilting on DM loss depended (P < 0.05) on inclusion levels of C. ensiformis. In both silages, neutral detergent fibre (NDFom) decreased linearly (P < 0.01) with increasing levels of C. ensiformis. Silage from wilted PBP had less (P < 0.05) ammonia nitrogen (NH3-N) compared to silage from fresh PBP. In both silages, lactic acid increased at a decreasing rate (P < 0.01) with increasing levels of C. ensiformis and its optimal level of inclusion was 100 g/kg DM. Although volatile fatty acids were not affected (P > 0.05) by C. ensiformis inclusion, wilting decreased (P < 0.05) acetic acid contents. Cumulative net gas production (GP) of silage from wilted PBP increased following a quadratic trend (P < 0.05) with increasing levels of C. ensiformis. Although polynomial contrasts were able to provide trends based on the apriori fixed inclusion points of C. ensiformis, regression analysis showed that optimal levels for most response parameters overlapped in the range of 100-170 g/kg DM. Consequently, the greatest cumulative GP of silage from wilted PBP was recorded at 150 g/kg DM level of C. ensiformis inclusion. Metabolizable energy (ME) and net energy contents of lactation (NEL) increased at a decreasing rate (P < 0.05) with increasing level of C. ensiformis for the silage from wilted PBP. Maximum value for NE L of silage from wilted PBP was obtained at 170 g/kg DM level of C. ensiformis inclusion. Similarly, in vitro organic matter digestibility for the silage from wilted PBP followed a quadratic trend (P < 0.05) with the greatest recorded at 168 g/kg DM level of C. ensiformis inclusion. Inclusion of C. ensiformis foliage improves in vitro fermentation quality as well as nutritive value of PBP silage, and most parameters showed optimum values, which overlapped within the ranges of 100 to 170 g/kg DM levels of the legume inclusion.