Effects of phytogenic products on in vitro rumen fermentation and methane emission in goats

This study evaluated the effects of addition of lucerne extract (LE), Artemisiae annuae extract (AAE), and mixed herbal medicine (MHM) into different goat diets on in vitro rumen fermentation and methane production. In addition to the negative control (NC), addition of monensin (MO) served as the positive control (PC). Four ruminally cannulated Nanjiang Yellow goats (45 ± 2 kg liveweight) were used as donors of ruminal fluid. The results showed: 1. compared with NC, addition of all the additives into the mixed grass diet increased propionate concentration (P<0.05). Protozoa numbers and methane production were reduced by addition of all the additives (P<0.05); 2. compared with NC, LE and AAE in the lucerne diet increased propionate concentration (P<0.05). All the additives reduced protozoa numbers (P<0.05). Methane production was decreased by addition of LE compared with NC and PC (P<0.05); 3. addition of LE into the mixed grass-concentrate diet resulted in an increase of the propionate concentration compared with NC and PC (P<0.05). Protozoa numbers were reduced by addition of LE and AAE compared with NC (P<0.05). Methane production was decreased by addition of AAE compared with NC and PC (P<0.05); 4. compared with NC, addition of AAE and MHM into the lucerne-concentrate diet resulted in an increase of propionate concentration (P<0.05). Protozoa numbers were reduced by addition of all the additives (P<0.05). Methane production was decreased by addition of AAE and MHM (P<0.05). In conclusion, addition of LE, AAE and MHM into different diets reduced methane production, increased propionate concentration and decreased protozoa numbers to a certain extent, and the inhibitory effects of the phytogenic products on methane production are more remarkable in the mixed-grass diet. The phytogenic products appear to be promising alternatives to MO in altering in vitro rumen fermentation and reducing methane production in goats.