Abstract:
Three experiments were conducted to determine the performance of small
ruminants fed crop residue supplemented with tree leaves and shrubs.
Experiment 1 was undertaken to determine the chemical composition of eight browse
species harvested during the dry and wet seasons of Ghana. Also, the chemical
compositions of untreated rice straw (RS), sodium hydroxide treated rice straw (STS) and
urea ammoniated rice straw (UTS) were determined. Samples were analyzed for Dry
matter, Crude protein, Neutral detergent fibre, Cellulose, Lignin, Ash and in vitro dry
matter digestibility.
The mean DM value of the dry season browse species (38.9%) was significantly
higher (p< 0.05) than that of the wet season species (33 .0%). The mean CP value for the
dry season species (17.9%) was however not significantly different (p> 0.05) from that of
the wet season species (15.0%). Similarly, there were no differences (p> 0.05) between
the other parameters. Crude protein ranged from 12.9% in Khaya to 21.9% in Milletia for
the dry season samples and 11.8% in Khaya to 17.1% in Ritchiea for the wet season \
samples. The IVDMD (75.1 and 80%)was highest in Securinega virosa for dry and wet
season samples respectively and lowest in Milletia (40.7 and 41.1%) for dry and wet
season samples respectively.
Experiment 2 compared the effects of ammoniation and browse supplementation
on rumen metabolites and rumen degradation in sheep. With the exception of Delonix and
Milletia, all the browse species had dry matter degradability (DMD) values above 60%
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while UTS had a value of 55%. The N degradation characteristics gave a range of
83.5% for the browse species, 47.3 and 60.9% for STS and UTS respectively
There were no difference between the mean pH levels and peak ammonia nitrogen
levels for animals on STS supplemented with browse and those on UTS.
The feeding value of STS supplemented with browse was compared with that of
UTS in Experiment 3. Parameters investigated included dry matter intake, liveweight
changes and nutrient digestibility.
Although the DMI of UTS (433.8g/d) was higher than that for STS with browse,
which ranged between 339 to 392.5g/d, the liveweight changes and nutrient digestibilities
showed no significant differences (p> 0.05).
Straw treated with NaOH and supplemented with browse can help maintain the
weights and provide some amount of growth in small ruminants during the dry season.
