Conservation of napier grass as silage by small holder dairy farmers in Tanzania
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Date
1996
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Journal ISSN
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Publisher
Sokoine University of Agriculture
Abstract
A 23 factorial experiment was conducted to investigate the best method of conserving
napier grass as silage under small scale dairy fanners situation. Four irealinenis
(methods) were imposed on the forage before it was ensiled in either earth pits or
concrete silos, namely; T1 - 5cm chopped grass with 3% molasses. T2 - 5cm chopped
grass without molasses, T3 - unchopped grass with 3% molasses and T4 - unchopped
grass without molasses. The silage was sampled after 3 months, and analyzed for
percentage DM losses, chemical composition, fermentation and sensoric qualities, fn
vitro DM and OM digestibilities and DM degradability. The rate of silage intake in
gDM/ minute was determined using six dairy heifers. Additionally, cost of producing
the silage under each method were estimated in Tsh./kgDM of useftil silage.
Both chopped and 3% molasses treated napier silage showed lower (P < 0.01 and P <
0.05, respectively) percentage DM losses as compared to unchopped and nnmolasscd
silage. However, the DM losses did not differ significantly between the silo designs
used. Chopped silage had more (P < 0.001 and P < 0.01) CP and WSC contents than
unchopped silage. Also addition of 3% molasses significantly increased (P < 0.01 and
P < 0.001) the CP and WSC composition of napier silage. The CP content however.
was more resei-ved in napier silage produced in the earth pits than the concrete silos.
The preservative quality of napier silage was highly (P< 0.001) improved by chopping
and/ or addition of 3% molasses at ensiling. Lower pH (3.99 vs 4.64). NH3 - N (4.03 vs
6-37) and butyric acid concentration (2.6 vs 7.5 gkg'1 DM) and higher content of hiciic
acid (37.3 vs 14.2 gkg'1 DM) and acetic acid (38.5 vs 21.8 gkg 1 DM) were observed in
chopped than unchopped silage. Lower pH, NH3 - N and butyric acid(4 21 vs 4.43.
4.09 vs 6.31% and 3.8 vs 6.4 gkg'1 DM, respectively) were also observed in molasses
treated compared to untreated silage, while lactic and acetic acid concentrations were
significantly higher (36.8 vs 14.7 gkg'1 DM and 40.3 vs 20.1 gkg' DM, respectively).
Additionally the sensoric scores were significantly (P< 0.001) better for chopped and/
or molasses treated napier silage. The condition which was more observed on silage
made in the earth pit silos.
Chopped silage had significantly higher (P < 0.001 and P < 0.01) In vitro DM and OM
digestibility and In sacco DM degradability than unchopped sihige. Also rnolassed
silage showed significantly higher (P < 0.001) In vitro DM and OM digestibility.
There was a significant (P< 0.01 and P< 0.001) improvement in rate of silage intake
when tlie animals were fed on pre - chopped and/ or molasses treated napier silage.
however minor differences were observed for the silage made in either type of the silo.
Economically, chopping and addition of molasses at ensiling produced napier silage at
a least cost especially from the earth pit silos compared with other ensiling methods.
It is concluded that, pre - chopping and addition of at least 3% molasses to napier grass
at ensiling produced good quality silage. Also the technique can be more economical
and technically feasible in short terms when plastic sheet covered earth pit silos are
used rather than the concrete silos which have higher initial construction costs.
Description
Masters Theses
Keywords
Napier grass, Silage conversation, Small holder farmers, Tanzania