Effects of wilting and additives on the ensiling quality and in vitro rumen fermentation characteristics of sudangrass silage

Abstract

Objective: This study was conducted to investigate the effects of molasses and <i>Lactobacillus plantarum</i> on the ensiling quality and <i>in vitro</i> rumen fermentation of sudangrass silage prepared with or without wilting.Methods: The ensiling experiment, measured with 3 replicates, was carried out according to a 2×4 (wilted stages×additives) factorial treatment structure. Dry matter of the fresh (210 g/kg fresh matter) or wilted (305 g/kg fresh matter) sudangrass were ensiled (packed into 5.0-L plastic jars) without additive (control) or with molasses (M), <i>Lactobacillus plantarum</i> (LP), or molasses + <i>Lactobacillus plantarum</i> (M+LP). After 60 days of ensiling, the silages were analyzed for the chemical, fermentation, and <i>in vitro</i> characteristics.Results: After 60 days of ensiling, the fermentation parameters were affected by wilted, the additives and the interactions of wilted with the additives (p<0.05). The M+LP treatment at wilted had higher lactic acid levels and V-score (p<0.05) but lower pH values and butyric acid concentrations than the other treatments. In comparison with sudangrass before ensiling, after ensiling had lower dry matter and higher non-fibrous carbohydrate. The <i>in vitro</i> gas production, <i>in vitro</i> dry matter digestibility, <i>in vitro</i> crude protein digestibility, and <i>in vitro</i> acid fiber detergent digestibility changed under the effects of the additives. Significant interactions were observed between wilted and the additives in terms of <i>in vitro</i> gas production at 48 h, asymptotic gas production, gas production rate, half time, and the average gas production rate. The total volatile fatty acid levels in the additive treatments were higher than those in the control.Conclusion: Wilting and supplementation with molasses and <i>Lactobacillus plantarum</i> had the ability to improve the ensiling quality and <i>in vitro</i> nutrient digestibility of sudangrass silage. The M+LP treatment at wilted exhibited the strongest positive effects on silage quality and <i>in vitro</i> ruminal fermentation characteristics.