Effects of a blend of essential oils on milk yield and feed efficiency of lactating dairy cows

Abstract

Objective: Our objective was to assess the effect on milk yield and feed efficiency of a combination of essential oils (eugenol, geranyl acetate, and coriander). Materials and Methods: Forty-eight Holstein cows (621 ± 61.3 kg of BW and 167 ± 83.8 DIM, 15 primiparous and 33 multiparous) were allocated to 2 treatments for 8 consecutive weeks in a completely randomized design. Treatments consisted of no supplementation (CTRL) or supplementation (AGL) of 1 g/d of Agolin Ruminant (Agolin, Bière, Switzerland) in the TMR. All cows were fed a common TMR (just differing in the presence or absence of Agolin Ruminant) twice daily. Milk production, milk composition, and feed intake of individual cows were recorded daily, and feed efficiency was calculated. Rumen fluid samples were collected from all cows throughout the study to determine pH and VFA profile and estimate methane concentrations. Results and Discussion: Compared with CTRL, cows fed AGL produced more ECM after 4 wk of exposure to treatments, and because DMI did not differ between treatments, feed efficiency increased over time. Estimated rumen methane concentrations of cows fed AGL were lower compared with those fed CTRL during wk 4 to 8. Implications and Applications: It is concluded that Agolin Ruminant increased milk production and feed efficiency after 4 wk of feeding the additive. This improvement could be attributed to a marginal improvement of rumen fermentation as indicated by decreases in in vitro estimates in rumen methane production.