Enteric methane production in lactating dairy cows with continuous feeding of essential oils or rotational feeding of essential oils and lauric acid

• Published in: Journal of dairy science 2017-05, Vol.100 (5), p.3563-3575
• Main Authors: Klop, G., Dijkstra, J., Dieho, K., Hendriks, W.H., Bannink, A.
• Format: Article
• Language: English
• Subjects: Animal Feed; Animals; Cattle; Dairy cow; Diet - veterinary; Essential oils; Female; Lactation; Lauric acid; Lauric Acids; Methane; Methane - biosynthesis; Milk - metabolism; Oils, Volatile - metabolism; Rumen - metabolism
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2016-12033

Rumen microbes can adapt to feed additives, which may make the decrease in enteric CH4 production upon feeding an additive a transient response only. This study investigated alternate feeding of 2 CH4 mitigating feed additives with a different mode of action on persistency of lowering CH4 production compared with feeding a single additive over a period of 10 wk. Four pairs of cows were selected, and within pairs, cows were randomly assigned to either the control (AR-AR) or the alternating (AR-LA) concentrate treatment. The AR concentrate contained a blend of essential oils (Agolin Ruminant, Agolin SA, Bière, Switzerland; 0.17 g/kg of dry matter) and the LA concentrate contained lauric acid (C12:0; 65 g/kg of dry matter). A basal concentrate without Agolin Ruminant and lauric acid was fed during the pretreatment period (2 wk). Thereafter, the cows assigned to the AR-AR treatment received the AR concentrate during all 10 treatment weeks (5 periods of 2 wk each), whereas cows assigned to the AR-LA treatment received AR and LA concentrates rotated on a weekly basis. Methane emission was measured in climate respiration chambers during periods 1, 3, and 5. From period 3 onward, dry matter intake and milk protein concentration were reduced with the AR-LA treatment. Milk fat concentration was not affected, but the proportion of C12:0 in milk fat increased upon feeding C12:0. Molar proportions of acetate and propionate in rumen fluid were lower and higher, respectively, with the AR-LA than with the AR-AR treatment. Methane yield (g/kg of dry matter intake) and intensity (g/kg of fat- and protein-corrected milk yield) were not affected by treatment. Methane yield and intensity were significantly lower (12 and 11%, respectively) in period 1 compared with the pretreatment period, but no significant difference relative to pretreatment period was observed in period 3 (numerically 9 and 7% lower, respectively) and in period 5 (numerically 8 and 4% lower, respectively). Results indicate a transient decrease in CH4 yield and intensity in time, but no improvement in extent or persistency of the decline in CH4 due to rotational feeding of essential oils and C12:0 in lactating dairy cows.