Short-term screening of multiple phytogenic compounds for their potential to modulate chewing behavior, ruminal fermentation profile, and pH in cattle fed grain-rich diets

In cattle, proper rumen functioning and digestion are intimately linked to chewing behavior. Yet, high grain feeding impairs activity, increasing the risk of subacute ruminal acidosis dysfermentation. This study aimed screen 9 different phytogenic compounds for their potential modulate meal size, rumino-reticular short-chain fatty acids (SCFA), pH during consumption in a first daily shortly thereafter cattle fed grain-rich diet. Treatments were control (total mixed ration without phytogenic) or addition compound at low dose. Phytogenic doses (all mg/kg) angelica root (6.6 66), capsaicin (10 100), gentian garlic oil (0.3 3), ginger extract (40 400), L-menthol (6.7 67), mint (15.3 153), thyme (9.4 94), thymol (5 50), groups, respectively. Before start screening experiment, cows reach conditions, confirmed with time <5.8 being 655 ± 148.2 min/d. During treatments offered controlled (2.5 kg DM 4 h) as part diet 65% concentrate. Each treatment was tested cannulated Holstein using an incomplete Latin square design. Ruminal reticular fluids sampled before after each treatment, data collected used covariates. Chewing monitored followed by 2 h complete feed restriction, then ad libitum intake phytogenic. Data showed that supplementation tended linearly increase rumination immediately when restricted (27.3, 41.9, 42.6 5.99 min control, respectively). Capsaicin increased eating (43.6, 49.4, 66.4 4.93 min) but did not affect total SCFA mean pH. Garlic reduced concentration (75.7, 71.3, 60.1 mM) decrease acetate-to-propionate ratio (2.50, 1.78, 1.87 0.177) no effect on The affected quadratically (76.1, 64.9, 81.0 4.22%), responded reintroduced (6.0, 6.3, 6.1 0.07). Mint consumption, dose (6.5, 6.7, 6.5 0.08). Thyme lower severity acidosis. Overall, demonstrated distinct dose-dependent effects beneficially influence behavior, fermentation, mitigate dairy under high-grain challenge