Influence of Direct-fed Microbial Blend and Ferula Elaeochytris on in Vitro Rumen Fermentation Pattern and Degradability During Simulated Ruminal Acidosis

INTRODUCTION: The use of probiotics and phytobiotics has attracted interest because of their protective effect against acidosis. Ferula elaeochytris (FE) is considered a good source of bioactive compounds, mainly monoterpene α-pinene. This study aimed to investigate the effect of a direct-fed microbial blend (Pro) and FE on rumen fermentation parameters in vitro under normal and acidosis conditions. MATERIAL AND METHODS: An in vitro experiment using the Hohenheimer Futterwerttest (HFT) gas production system was conducted. An acidosis challenge was made to compare the effectiveness of the probiotics blend and FE extract on ruminal pH regulation. To generate different ruminal fermentation parameters, the design of the trial considered the 2 additives (Pro and FE) × 6 incubation times (2, 4, 8, 12, 24 and 48 h) × 2 conditions (acidosis and normal) × 2 incubation runs for each feedstuff (barley, alfalfa and straw). RESULTS: An acidosis challenge was successfully induced. The Pro and FE additives had no impact on the observed rumen fermentation parameters such as volatile fatty acid concentration or ammonia (P = 0.001). The acidosis condition decreased total in vitro degradability (IVD) by 3.5% and 21.9% for barley and straw, respectively (P < 0.001). The additives had different significant effects on the IVD of nutrients during both normal and acidosis conditions. In alfalfa samples, FE supplementation significantly decreased the IVD of all observed nutrients under the ruminal acidosis condition, although it had no effect during the normal condition. CONCLUSION: An acidosis challenge was successfully induced and the effect of additives was varied on fermentation parameters and rumen degradability of different feeds either under normal or acidosis conditions.