Effects of a Specific Blend of Essential Oil on Rumen Degradability, Total Tract Digestibility and Fermentation Characteristics in Rumen Fistulated Cows

Abstract

Essential oils had been received much attention due to their antimicrobial properties against a wide range of microorganisms that manipulate rumen fermentation towards a better utilization of energy and protein. Six fistulated non-lactating Friesian dairy cows were used to investigate the effect of adding Crina® Ruminants (blend of essential oil) with 1g per cow per day to total mixed ration (grass silage, maize silage, soybean meal, rapeseed meal and wheat) of 7 kg per day on the in-situ rumen dry matter degradability (ISDMD) and total tract digestibility using TiO2 as marker. Fistulated cows were used as 3x2 Latin Square with factorial arrangement of treatment (with or without Crina® addition) in two periods. Each period extended for 45days (30 days pre-experimental phase and 15 days experimental phase). Ruminal fluid samples were collected to investigate the rumen fermentation parameters (ruminal pH value, volatile fatty acid (VFAs), and ammonia nitrogen (NH3N) as well as acetate propionate ratio). The results indicated that adding of Crina® to ruminant diet had significantly decreased ISDMD of grass silage and total mixed ration especially at long incubation time (12 and 48 hours). The ISDMD and in-situ rumen crude protein degradability of soybean and rapeseed meal significantly increased due to Crina® addition. Crina® had no effect on total tract digestibility of dry matter (DM), organic matter (OM), crude protein (CP), starch, ether extract (EE), crude fiber (CF) and fiber fractions. Rumen fermentation parameters did not affected due to addition of Crina®. Results concluded that Crina® could limit the degradability of grass silage, increased degradability of soybean and rapeseed meal and had no effect on rumen fermentation characteristics.