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Effects of different silage forages on cecal fermentation in rabbits: In vitro gas production
The aim of this study was to evaluate the cecal fermentation of beans (Phaseolus vulgaris), faba beans (Vicia faba), common vetch (Vicia sativa), ryegrass (Lolium perenne), and barley (Hordeum vulgare) as silages in rabbits. In vitro gas production was performed using cecal contents from three rabbits (New Zealand, LW 2.5 k). Rabbits were fed forage silage and water ad libitum prior to cecal content collection. The rabbit’s caeca was emptied and pooled cecal contents were mixed before used for in vitro cultures. Chemical composition of forage species was determined and samples were weighed (0.800 g of DM) in 125 ml flasks and incubated with 90 ml of solution and 10 ml of cecal content, which previously diluted (50:50 with buffer solution). Gas production (GP) was measured at 1,2,3,4, 8, 10, 12, 24, 36 and 48 hours in three runs of inoculations. GP was calculated (ml/g DM), in order to evaluate the differences between forage species. Data were analyzed as a completely randomized design with contrasts used to compare means, significance was declared at P < 0.05. Crude protein was greater (P<0.05) in common vetch followed by faba beans and beans, than the other species. NDF and ADF contents was lower (P<0.05) in beans and common vetch, ME and SCFA was greater (P<0.05) in faba beans and ryegrass, and less in barley silage. In vitro GP (fraction B) was greater (P<0.05) in rye grass and faba beans than the rest of the silages. Lag time has greater in common vetch (P<0.05) than the rest of the silages. Results suggested that ensiling ryegrass or faba beans are suitable for rabbits feeding compared with barley forage.
Table 1. Chemical composition (g /kg DM) and in vitro gas production (IVGP, ml gas/ g DM) of forage silages species in rabbits.
Item |
Barley |
Ryegrass |
Beans |
Common vech |
Faba beans |
SEM |
P-value |
OM |
969ab |
973a |
955b |
961ab |
965ab |
3.0 |
0.005 |
CP |
46d |
139c |
146bc |
179a |
157b |
3.5 |
0.001 |
NDF |
613a |
651a |
516b |
476b |
658a |
14.3 |
0.001 |
ADF |
598a |
586a |
489b |
450b |
621a |
14.6 |
0.001 |
ADL |
100f |
127e |
156c |
164b |
174a |
3.5 |
0.001 |
ME |
10.3c |
20.0a |
16.6b |
17.3b |
20.3a |
0.5 |
0.001 |
SCFA |
1.73d |
3.13a |
2.09cd |
1.99cd |
2.93ab |
0.12 |
0.001 |
IVGP |
|
|
|
|
|
|
|
B |
87b |
121a |
88b |
90b |
119a |
5.3 |
0.001 |
C |
0.0036c |
0.0236a |
0.008bc |
0.0113bc |
0.014abc |
0.002 |
0.001 |
Lag time |
2.10b |
0.50b |
2.00b |
4.63a |
2.43b |
0.44 |
0.001 |
Keywords: Rabbits, Cecal fermentation, In vitro gas production