Effects of Chopping Length and Additive on the Fermentation Quality and Aerobic Stability in Silage of Leymus chinensis

Zhiqiang Sun,Tingting Jia,Bing Wang,Zhe Wu,Run Gao,Zhu Yu,Shengyang Xu

doi:10.3390/pr8101283

Abstract

The objective of this experiment was to evaluate the effects of the chopping length and additive on the fermentation characteristics and aerobic stability in silage of Leymus chinensis. L. chinensis was chopped to 1–2 cm and 4–5 cm, and immediately ensiled with the three treatments, i.e., 2% sucrose (fresh weight basis; SU), 1 × 105 cfu/g Lactobacillus plantarum (LP) or 1 × 105 cfu/g LP plus 2% sucrose (SU+LP). Silage treated with distilled water served as the control. After silage processing for 30 and 90 d, the fermentation quality of L. chinensis silage was evaluated. The composition of the fermentation products and the pH value in the silage were determined at 1, 3, 5 and 7 d after opening the silo. The results showed that in L. chinensis silage there was a lower pH value, higher lactic acid content and better aerobic stability at the 1–2 cm length than those at the 4–5 cm (p < 0.001). When the chopping length was 4–5 cm, the addition of either LP or SU+LP increased the content of lactic acid and acetic acid, and decreased the pH value and butyric acid content, compared to those of the control and SU treatment (p < 0.001). Furthermore, combination treatment of SU+LP performed better than LP alone, and the aerobic stability time of L. chinensis silage at 4–5 cm without any additives was the worst. In conclusion, enhanced fermentation quality and aerobic stability can be obtained by processing L. chinensis silage with the shorter length. When the L. chinensis is cut longer, e.g., 4–5 cm in this study, LP or SU+LP could be used as an effective method to improve the fermentation quality and aerobic stability of L. chinensis silage.

Highlights

Leymus chinensis (Trin.) Tzvel., which is commonly known as Chinese wildrye, is a native cool-season perennial grass in the Gramineae tribe and a good forage source for ruminants [1].Nowadays, it is widely distributed on the Eurasian Steppe, including the eastern Inner MongolianPlateau and the Songnen Plain in China [2,3]
We found that the temperature of L. chinensis silage increased firstly and decreased with the increased of aerobic exposure time
SU, Lactobacillus plantarum (LP) and SU+LP were added to L. chinensis silage, which was cut into different lengths

Summary

Introduction

Leymus chinensis (Trin.) Tzvel., which is commonly known as Chinese wildrye, is a native cool-season perennial grass in the Gramineae tribe and a good forage source for ruminants [1].Nowadays, it is widely distributed on the Eurasian Steppe, including the eastern Inner MongolianPlateau and the Songnen Plain in China [2,3]. Leymus chinensis (Trin.) Tzvel., which is commonly known as Chinese wildrye, is a native cool-season perennial grass in the Gramineae tribe and a good forage source for ruminants [1]. Nowadays, it is widely distributed on the Eurasian Steppe, including the eastern Inner Mongolian. L. chinensis is usually processed for hay and silage [5]. Hay preparation is affected by external factors such as the mowing period, weather and others, and especially rain causes mildew growth and deterioration in forage grass [7,8]. Processing L. chinensis for silage is an effective way Processes 2020, 8, 1283; doi:10.3390/pr8101283 www.mdpi.com/journal/processes

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Conclusion