Methane inhibition by Asparagopsis taxiformis with rumen fluid collected from ventral and central location – a pilot study

Figures & data

Figure 1. Illustration of the rumen fluid collection sites in the central and ventral rumen (modified from Physiology of Domestic Animals, Sjaastad et. al. 2016, reprinted with permission).

Figure 2. Cumulative gas pressure (pounds of force per square inch of area, psi) (top) and cumulative gas production (mL/g dry matter, DM) (bottom) over time of incubation for control (feed without inhibitor), inhibitor (feed with inhibitor seaweed, Asparagopsis taxiformis) and blanks (buffered rumen fluid without feed, without inhibitor).

Figure 3. Effect of rumen sampling site (central, ventral) and treatment [without/with methane (CH₄)-inhibitor Asparagopsis taxiformis) on (a) total gas yield, (b) CH₄ yield, and (c) the proportion of CH₄ to total gas production. Least square means (LSM) carrying no common upper-case superscript are different at P < 0.05 between central and ventral rumen location. The LSM carrying no common lower-case superscript are different at P < 0.05 between with/without inhibitor treatment within location.

Table 1. Effect of rumen fluid collection site (central, ventral) and treatment (with/without inhibitor Asparagopsis taxiformis) on rumen fermentation parameters after 24 h in vitro incubation.

Rumen location	Central		Ventral			P-values
Treatment	Control	Inhibitor	Control	Inhibitor	SEM	Loca tion	Treat ment	L × T
Trait
pH	6.50	6.53	6.51	6.51	0.017	0.82	0.74	0.54
NH3-N, mmol/L	12.2	10.5	12.2	10.7	0.292	0.55	<0.001	0.45
Total SCFA, mmol/L	76.2	65.5	71.5	65.0	0.757	0.29	0.002	0.38
Molar proportion, mmol/mol
Acetate (C2)	64.8	55.3	65.1	55.5	0.671	0.65	<0.001	0.75
Propionate (C3)	20.0	26.3	19.7	26.1	0.667	0.20	<0.001	0.87
Butyrate	12.4	15.9	12.2	15.7	0.505	0.67	<0.001	0.79
iso butyrate	0.622	0.521	0.689	0.610	0.096	< 0.001	<0.001	0.37
Valerate	1.13	1.21	1.15	1.26	0.063	0.12	<0.001	0.54
iso valerate	1.07	0.771	1.13	0.892	0.196	0.003	<0.001	0.30
C2/C3	3.24	2.11	3.31	2.12	0.400	0.37	<0.001	0.67

Data are least square means, unless otherwise stated.

NH₃-N: ammonia nitrogen, SCFA: short-chain fatty acids