Dynamics of methanogenesis, ruminal fermentation and fiber digestibility in ruminants following elimination of protozoa: a meta-analysis

Table 3 Methane emissions, ruminal VFA profiles and total-tract fiber digestibility dynamics during the linear phase and plateau phase

	Meta-regression analysis for the linear phase								Meta-analysis for the plateau phase
	Duration, wk	No. of trials	I², %	Intercept	P-value	Coefficient	P-value	Adjusted R², %	Duration, wk	No. of trials	I², %	Pooled effect size	P-value
CH₄	≤ 12	13	76.2	−5.484	0.001	0.486	0.003	76.8	≥ 11	9	0.0	0.313	0.039
TVFA	≤ 12	12	35.5	−1.883	0.008	0.132	0.048	99.9	≥ 11	19	46.7	−0.424	< 0.001
Individual VFA molar proportion
Acetate	≤ 11	11	76.8	−4.086	0.004	0.563	0.004	76.7	≥ 7	22	47.5	0.748	< 0.001
Propionate	≤ 11	11	84.5	7.306	< 0.001	−0.898	< 0.001	92.2	≥ 7	22	51.2	−0.366	0.033
Butyrate	≤ 11	11	80.6	−7.059	< 0.001	0.732	0.001	92.3	≥ 7	20	54.0	−0.582	0.002
A:P	≤ 11	10	78.6	−6.737	0.001	0.884	0.002	90.8	≥ 7	10	59.2	0.915	0.016
Total-tract fiber digestibility
NDF	≤ 23	15	55.7	−4.458	< 0.001	0.153	0.005	85.0
ADF	≤ 23	11	69.8	−6.276	0.001	0.213	0.030	45.1

I², percentage of heterogeneity across studies; Intercept, estimate of the effect size after defaunation; Coefficient, estimate of the change in effect size per week following defaunation; Adjusted R², percentage of between-study variance explained by the defaunation duration; TVFA, total VFA

ISSN: 2049-1891