Effect of different levels of poultry waste or mulberry leaves with or without formic acid or molasses on napier Grass silage quality
Abstract
This study was done to determine the effect of poultry waste (PW) or Mulberry leaves
(ML) with or without formic acid or molasses on Napier grass (NG) silage quality.
Napier grass from an already established field was clear cut and weeded at Upper Kabete
Campus field station farm University of Nairobi. The Napier was harvested after 8 weeks
regrowth, wilted for 24 hours under the sun and chopped using a motorized chaff cutter to
2.5 em length.
The Napier grass was weighed and mixed with appropriate amount of PW or ML at 0, 15
and 30% (w/w). To the mixture was added either formic acid at 0, 0.5 and 1% (v/w) or
molasses at 0, 2 and 4% (w/w). The mixed material was ensiled in air tight polythene
bags of 500 gauges, 18 x 12 inches and stored for 30 days. At opening the silos DM, OM,
pH, CP, IVDMD, NH3-N, NDF, ADF, ADL and in vitro gas production were determined.
Results from this study indicate that, inclusion ofPW in NG silage resulted in an increase
in the pH (P<0.05) from 5.4 to 6.4. When molasses or formic acid was added to the
mixture, the pH was lowered at 15 % PW to 4.6 at 1% formic acid and 4.5 at 4%
molasses, but not at 30%. Addition of PW to NG silages increased (P<0.05) the CP
content, but the increase was not linear 15% having higher value than 30%. Addition of
either molasses or formic acid to NG silage alone resulted in increased CP while there
were no changes with inclusion of PW. Addition of PW resulted in increased (P<0.05)
ammonia nitrogen levels from 241-.676g kg" with 30% PW. Additions of molasses or
formic acid to the mixture reduced the ammonia-N value but were higher (347- 532 g kg-
I) at 4% molasses and lower (198-214 g kg') at 1% formic acid than the control.
Ammonia nitrogen content was higher with addition of molasses than formic acid. PW
inclusion in NG silages at 30% resulted in decreased (P<0.05) ME.
Inclusion of ML to NG silage resulted in linear increase in DM content from (211 to 254
g kg") and decreased (P<0.05) pH. Molasses addition to the mixtures resulted in higher
reduction in pH (5.4 to 3.8) compared to formic acid (5.4 to 4.6). Addition of ML
esulted in a linear increase in CP content from 88.4 to 130 g kg" with formic acid (0-
1%), 88.4-127 g kgiwith molasses (0-4%). NDF and ADF decreased with increasing
levels of ML.
IVDMD increased with increasing PW (6l.5% to 66. 3%) or ML (6l.5-74%) and with
addition of formic acid (6l.5 to73.0%) or molasses (6l.5 to 73.5%) to the mixtures but
the interactions were not significant. Treatments with molasses had higher values than
with formic acid
Inclusion of PW in NG silage increased pH, NH3-N, CP and IVDMD but the ME
decreased. Addition of both formic acid and molasses reduced the pH and NH3-N
content. Inclusion of ML decreased pH, NH3-N, NDF and ADF but increased DM, CP,
IVDMD and ME. Use ofML at 30% with 0.5% formic acid or 2% molasses would be the
best combination in improving the nutrient quality of Napier grass silage.
Citation
Master of science (animal nutrition option)Publisher
Department of animal production