Effects of UV radiation on the process of wilting and application of additives at ensiling on the fermentation quality of Siberian wildrye silage on the Qinghai‐Tibetan plateau

Abstract

AbstractEffects of lactic acid bacteria (LAB) and formic acid (FA) on silage quality of ultraviolet (UV)‐radiated Siberian wildrye (Elymus sibiricus L.) were studied on the Qinghai‐Tibetan plateau. Siberian wildrye seeds were sown in early April, 2012 and harvested in 2013, 2014 and 2016. Fresh forage was radiated for 0, 4 and 8 h under ambient/laboratory UV radiation conditions during the wilting process, and then mixed with LAB inoculant (105 cfu g−1 fresh matter [FM]) and FA (3 mL kg−1 FM), respectively, no additives treatment as control. After additive treatments, chopped Siberian wildrye plants were packed in 30 cm × 40 cm polythene bags and stored in a dark room at ambient temperature (<15°C) for 90 days. Silages of UV‐radiated Siberian wildrye had higher (P < 0.05) pH and ammonia‐nitrogen (N) content, lower (P < 0.05) acetic and propionic acid content and in vitro ruminal dry matter digestibility. Compared with control, treatments with additives (especially for inoculant LAB) enhanced pH decline, increased (P > 0.05) acetic acid content, decreased (P < 0.05) butyric acid and ammonia‐N content of silages of UV‐radiated Siberian wildrye. It was concluded that the application of FA and inoculant LAB at ensiling could reduce the negative effects of extended UV radiation on the process of wilting.