Ensiling of Conocarpus erectus tree leaves with molasses, exogenous enzyme and Lactobacillus plantarum impacts on ruminal sheep biogases production and fermentation

Abstract

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.