TY - JOUR
T1 - Effects of essential oils on in vitro ruminal fermentation and ammonia release
AU - Hristov, A. N.
AU - Ropp, J. K.
AU - Zaman, S.
AU - Melgar, A.
N1 - Funding Information:
This study was supported by funds from the Idaho Agricultural Experiment Station. The authors thank Dr. W. Price for assistance with statistical evaluation of the data and the staff of the Animal and Veterinary Science Dairy Center for their conscientious care of the donor animals.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2008/6/23
Y1 - 2008/6/23
N2 - Ruminal inoculum enriched with particle-associated microorganisms was collected from two lactating dairy cows fed an alfalfa hay/cereal silage/concentrate diet 1 h before feeding and used to evaluate effects of essential oils (EO) on ruminal fermentation in short-term in vitro incubations. Ruminal ammonia N was labeled with 15N and native and hydrolyzed casein were provided as sources of amino acids. Forty EO were tested at 10 and 100 mg/l final medium concentration. Monensin-Na, and sodium laurate were also incubated at 5 and 2000 mg/l, respectively. Compared with blanks (i.e., no addition of EO), sodium laurate increased medium pH and a number of EO reduced medium pH. Both sodium laurate and monensin reduced ammonia concentrations compared to the blank. Only one of the tested EO (i.e., Caraway) slightly reduced ammonia concentration, by 8%, compared with the blank. Monensin and sodium laurate resulted in higher (i.e., 9-34%, monensin, and 29-47%, sodium laurate) 15N enrichment of ammonia N, an indication of reduced deamination of amino acids in these treatments versus the blank. Several EO (i.e., FrankMyrrh, Gardenia, Hibiscus, Eucaliptus, and Peppermint) had similar effects, but of a smaller magnitude (i.e., 5-12%). Some EO increased medium total VFA concentration, primarily through an increase in acetate concentration. Overall, effects of EO on fermentation were subtle, and it is unlikely that these moderate in vitro effects would correspond to any substantive impact on ruminal fermentation in vivo.
AB - Ruminal inoculum enriched with particle-associated microorganisms was collected from two lactating dairy cows fed an alfalfa hay/cereal silage/concentrate diet 1 h before feeding and used to evaluate effects of essential oils (EO) on ruminal fermentation in short-term in vitro incubations. Ruminal ammonia N was labeled with 15N and native and hydrolyzed casein were provided as sources of amino acids. Forty EO were tested at 10 and 100 mg/l final medium concentration. Monensin-Na, and sodium laurate were also incubated at 5 and 2000 mg/l, respectively. Compared with blanks (i.e., no addition of EO), sodium laurate increased medium pH and a number of EO reduced medium pH. Both sodium laurate and monensin reduced ammonia concentrations compared to the blank. Only one of the tested EO (i.e., Caraway) slightly reduced ammonia concentration, by 8%, compared with the blank. Monensin and sodium laurate resulted in higher (i.e., 9-34%, monensin, and 29-47%, sodium laurate) 15N enrichment of ammonia N, an indication of reduced deamination of amino acids in these treatments versus the blank. Several EO (i.e., FrankMyrrh, Gardenia, Hibiscus, Eucaliptus, and Peppermint) had similar effects, but of a smaller magnitude (i.e., 5-12%). Some EO increased medium total VFA concentration, primarily through an increase in acetate concentration. Overall, effects of EO on fermentation were subtle, and it is unlikely that these moderate in vitro effects would correspond to any substantive impact on ruminal fermentation in vivo.
UR - http://www.scopus.com/inward/record.url?scp=44649120239&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=44649120239&partnerID=8YFLogxK
U2 - 10.1016/j.anifeedsci.2007.09.034
DO - 10.1016/j.anifeedsci.2007.09.034
M3 - Article
AN - SCOPUS:44649120239
SN - 0377-8401
VL - 144
SP - 55
EP - 64
JO - Animal Feed Science and Technology
JF - Animal Feed Science and Technology
IS - 1-2
ER -