Table 6. Liquid and particulate passage rates and rumen volumes in lambs fed either fresh winter forage rape or fresh perennial ryegrass.

Passage rate parameters	Forage rape	Perennial ryegrass	P b
	(n = 6) a	(n = 6) a
Liquid phase c
Rumen liquid passage rate k (/h)	0.103 ±0.0096	0.193 ±0.0096	<0.001
Liquid retention time (h)	10.4 ±1.24	5.2 ±0.19	0.002
Rumen liquid volume (L)	5.05 ±0.346	5.16 ±0.379	0.845
Particulate phase d
First compartment passage rate (c 1, /h)	0.037 ±0.0065	0.060 ±0.0059	0.029
Second compartment passage rate (c 2, /h)	0.046 ±0.0162	0.071 ±0.0162	0.287
Rumen mean retention time (h)	28.3 ±3.19	18.3 ±2.91	0.045
Caecum mean retention time (h)	26.2 ±5.49	22.0 ±5.49	0.609

^a The number of animals sampled. Values are means ± SEM.

^b P value for the difference between forage rape and perennial ryegrass.

^c Rumen liquid passage rate and rumen liquid volume were estimated using the method of Faichney [20] with Co-EDTA as the marker.

^d Rumen particulate passage rate was estimated using the method of Dhanoa et al. [21] with Cr-modanted fibre as the marker.