Abstract
The purpose of this experiment was to evaluate the effects of different levels of BSF on rumen in vitro fermentation gas production, methane (CH(4)) production, ammonia nitrogen (NH(3)-N), and volatile fatty acids (VFAs). The experiment comprised four treatments, each with five replicates. The control group contained no BSF (BSF0), and the treatment groups contained 5% (BSF5), 10% (BSF10), and 15% (BSF15) BSF, respectively. Results showed that at 3 h, 9 h, and 24 h, gas production in BSF5 and BSF10 was significantly higher than in BSF0 and BSF15 (p < 0.05). Gas production in BSF5 and BSF10 was higher than in BSF0, while gas production in BSF15 was lower than in BSF0. At 6 h and 12 h, CH(4) emission in BSF15 was significantly lower than in the other three groups (p < 0.05). There were no differences in the pH of in vitro fermentation after BSF addition (p > 0.05). At 3 h, NH(3)-N levels in BSF10 and BSF15 were significantly higher than in BSF0 and BSF5 (p < 0.05). At 6 h, NH(3)-N levels in BSF5 and BSF10 were significantly higher than in BSF0 and BSF15 (p < 0.05). Acetic acid, propionic acid, butyric acid, and total VFAs in BSF0, BSF5, and BSF10 were significantly higher than in BSF15 (p < 0.05). In conclusion, gas production, CH(4) emission, NH(3)-N, acetic acid, propionic acid, butyric acid, and VFAs were highest in BSF5 and BSF10 and lowest in BSF15.