Ensiling ofConocarpus erectustree leaves with molasses, exogenous enzyme andLactobacillus plantarumimpacts on ruminal sheep biogases production and fermentation

This study was performed to evaluate the effect of applying molasses (5% w/w) (M), exogenous enzyme (cellulase; 6 millions U kg−1) (E) and Lactobacillus plantarum (3 × 105 cfu g−1 of fresh material) (LAB) on the ensiling characteristics of Conocarpus erectus leaves. Eight treatments were studied; (1) without additive (conocarpus silage: CS), (2) CS + E (CSE), (3) CS + M (CSM), (4) CS + LAB (CSL), (5) CS + E + M (CSEM), (6) CS + E + LAB (CSEL), (7) CS + M + LAB (CSML) and (8) CS + E + M + LAB (CSEML). The lowest amount (P < 0.05) of ash-free neutral detergent fiber (NDF) and ash-free acid detergent fiber were observed for CSE. The pH only affected by addition of molasses (P < 0.05), while the concentration of ammonia-N of Conocarpus silage was affected (P < 0.05) by molasses, meanwhile it decreased significantly for CSEM and CSM. The results of gas production parameter and in vitro digestibility showed that the use of silage additives leads to increase (P < 0.05) the coefficients b and c for CSML. The cumulative gas production in all hours significantly increased in treatment CSEML, CSML and CSL (P  < 0.05). The highest amount (P < 0.05) of produced gas, organic matter disappearance, apparently degraded substrate (ADS) and microbial crude protein (MCP) were affected by silage additives and increased for CSE (519 and 485 mg g−1 of DM, respectively). In addition, ADS and MCP were affected (P < 0.05) by silage additives and increased for CSE (519 and 485 mg g−1 of DM, respectively). The concentration of short-chain fatty acids (SCFA) increased (P < 0.05) significantly for CSML (0.414 mmol l−1). However, the amount of metabolizable energy (ME) and pH were not affected by experimental treatment (P  > 0.05). In vitro digestibility of dry matter (DMD) and in vitro digestibility of NDF (NDFD) increased (P < 0.05) for CSML and the highest concentration of ammonia-N was observed in silage without additive. The result of these experiments showed due to the positive effect of a treatment containing molasses and lactic acid bacteria (CSML), maybe the treatment with it will be effective in improving the nutritional value of conocarpus leaves in ruminants.