Effects of mixtures of lauric and myristic acid on rumen methanogens and methanogenesis in vitro.
OBJECTIVE
To identify the most effective mixture of non-esterified lauric (C12) and myristic (C14) acid in suppressing ruminal methanogenesis, and to investigate their effects on the methanogenic population.


RESULTS
C12/C14 mixtures were incubated with rumen fluid using the Hohenheim gas test apparatus. Methane production and the numbers of Archaea declined with an increasing proportion of C12. With a 2 : 1 proportion of C12/C14, the maximum methane-suppressing effect (96%) was achieved similar to that with C12 alone. The proportions of the individual methanogenic orders of total methanogens were altered by varying the C12/C14 ratio.


CONCLUSIONS
Although C14 alone had no effect on methanogenesis, C14 enhanced the methane-suppressing effect of C12 in certain mixtures.


CONCLUSIONS
The results support strategies for an environment-friendly ruminant nutrition as it was demonstrated that part of the less palatable C12 could be replaced by C14 without losing its methane-suppressing potential.
Soliva
C R
CR
Institute of Animal Science, Animal Nutrition, Institute of Food Science, Laboratory of Food Microbiology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland. carla.soliva@inw.agrl.ethz.ch
Hindrichsen
I K
IK
Meile
L
L
Kreuzer
M
M
Machmüller
A
A
D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D019605:Euryarchaeota / Q000187:drug effects* / Q000254:growth & development; D007850:Lauric Acids / Q000494:pharmacology*; D008697:Methane / Q000378:metabolism; D019814:Myristic Acid / Q000494:pharmacology*; D012417:Rumen / Q000382:microbiology*
D000890:Anti-Infective Agents; D004338:Drug Combinations; D007850:Lauric Acids; D019814:Myristic Acid; C030358:lauric acid; D008697:Methane