Influence of essential oils (cinnamaldehyde and garlic oil) on rumen fermentation, feeding 1 behavior and performance of lactating dairy cattle

Two experiments were conducted to study the effects of Next Enhance® 300 (NE300; cinnamaldehyde and garlic oil encapsulated product) on rumen fermentation and milk production of dairy cows. In experiment 1, batch cultures of mixed rumen micro-organisms were used to study the effects of increasing concentrations of NE300 (0, 200, 300, and 400 mg/L) on ruminal fermentation in 24 h in vitro incubations. All tested doses decreased (P < 0.05) methane production, but the dose of 400 mg/L also reduced the production of volatile fatty acid (VFA). The addition of NE300 at 300 mg/L produced the most beneficial effects, reducing methane production, acetate proportion, and ammonia-N concentration, and increasing propionate proportion compared with CON, without affecting total VFA production. These results would indicate a potentially greater supply of energy for the host animal. In experiment 2, sixteen lactating dairy cows (8 rumen-cannulated) participated in a switch-back design with three 4-wk periods and 2 treatments: control (CON, unsupplemented) and NE300 (300 mg NE300/cow/d). Milk yield response was affected by a 3-way interaction among treatment, parity, and days on treatment; after 15 d on treatment, multiparous cows on NE300 produced more milk (approximately additional 3 kg/d) than multiparous cows on CON. Total rumen VFA concentrations tended (P = 0.06) to be greater in NE300 than in CON when rumen fermentation kinetics were evaluated at the end of each period (day 28). It is concluded that NE300 modifies ruminal fermentation resulting in increased milk yield in multiparous lactating dairy cows after 15 d of adaptation.