The goal of these experiments was to ensile combinations of shrimp or crab waste
with perennial ryegrass straw and analyze it for silage quality and ruminal degradability.
The rapid deterioration of seafood wastes required initial preservation prior to ensiling
to minimize odor production and protein breakdown. Eight experiments were conducted
to preserve, ensile and test the ruminal degradability of shrimp and crab waste. The first
three experiments attempted to preserve crab waste with the addition of 0 to 15%
molasses for 14 days or shrimp waste with molasses at 0 to 25% for 6 or 21 days. In
all three experiments, the addition of molasses decreased crude protein, crude protein
loss, and pH, and improved odors. Although a lactic acid fermentation began, the high
pH and acetic and butyric acid concentrations indicate fermentation was not completed.
The crude protein loss and odor production warrants a quicker method of preservation.
In Experiments 4 and 5, shrimp or crab waste were combined with 6 levels of salt from
0 to 12.5% for 6 days. The addition of salt decreased crude protein percentage, crude
protein loss and all volatile fatty acid concentrations while increasing the pH and
improving the odors. The 7.5% salt-preserved shrimp and crab wastes had 29.9 and
30.7% crude protein, respectively.
Experiments 6 and 7 ensiled the salt-preserved shrimp and crab waste with grass
straw, molasses and an inoculant in 15 L mini-silos for 40 days. Shrimp waste was
combined at 37, 47 or 52% dry matter while crab waste was combined at 43, 46 or 52%
dry matter. Molasses at 0, 10, or 20% and an inoculant were added to both silages.
The 47% dry matter, 20% molasses non-inoculated shrimp silage had the following
analysis on a dry matter basis: crude protein, 16.1%, acid detergent fiber. 27.0%.
acetic acid, 1.37%. butyric acid, .01%, lactic acid, 7.17%, and a pH of 7.0 and a good
silage odor. The 46% dry matter, 10% molasses, inoculated crab silage had the
following analysis on a dry matter basis: crude protein. 21.1%, acid detergent fiber,
19.6%, acetic acid, 1.68, butyric acid, .00%, lactic acid, 2.86% and a questionable odor
score.
In Experiment 8, the ruminal degradability of shrimp and crab waste and shrimp
and crab silage were tested using two fistulated steers and sampled at nine time points
ranging from 0 to 96 hr.
Shrimp waste had a ruminally available DM%, CP%, ADF%, and %ADIN of
36.9, 43.0, 44.2, and 43.6% respectively. Crab waste had a ruminally available DM%,
CP%, ADF%, and %ADIN of 38.9, 53.3, 41.0, and 33.0% respectively. Ensiling the
shrimp and crab wastes improved the percentage of ruminally available DM and CP and
lowered the percentage of ruminally available ADF and ADIN. This indicates that
ensiling promotes the degradation of chitin and the release of nitrogen to the rumen.
Effective preservation of shrimp and crab waste with salt and then adequate fermentation
of the wastes with grass straw, molasses and inoculant has increased the ruminal
degradability of the wastes and led to successful transformation of the waste into a dairy
heifer feedstuff. / Graduation date: 1995
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/35279 |
| Date | 30 August 1994 |
| Creators | Evers, Dale J. |
| Contributors | Carroll, Diane J. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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