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Matching Livestock Systems with Available Resources |
MEKARN Regional Conference 2007 |
Four, rumen-fistulated growing
male Thai native swamp buffaloes averaging 330±30
kg in liveweight were fed with urea-treated rice straw based diet and 0.2% body
weight (BW) of concentrate diet, in a 4x4 Latin square design to
determine rumen ecology, microbial protein synthesis and digestibility of
different sources of supplemental roughages: cassava hay (CH),
Phaseolus calcaratus (PH) and sweet potato vine hay (SH). Control
buffaloes were fed with100% urea-treated rice straw (UTS) as a basal
roughage diet and with 0.2% body weight of concentrate twice daily throughout
the study. Supplementation with 50% of the following roughages from
CH (UTS+CH), PH (UTS+PH) or SH (UTS+SH) to the basal diets were made. All feeds
were fed on ad libitum basis.
The experiment revealed that dry matter intake (2.4 % BW) was higher (p< 0.05) in buffalo fed UTS+CH than other treatments (2.2, 2.3 and 2.2. % BW, for Control, UTS+PH and UTS+SH, respectively). Roughage treatments had no effect on rumen pH, temperature, rumen concentration of VFAs, acetic acid and butyric acid (C2), in exception of protozoal population. Ruminal ammonia-nitrogen and blood-urea nitrogen concentrations were affected (p < 0.05) by sources of supplemental roughages being significantly higher in control than in other treatments. There was a higher concentration (p<0.05) of C3 in the rumen at 4 h post-feeding of buffalo fed on UTS+PH and thus lowering C2 to C3 ratio than in other treatments, however mean values of C3 concentration and C2 to C3 ratio were not significantly different among treatments. Rumen protozoal population had a decreasing trend in UTS+CH, UTS+PH and was significantly reduced in UTS+SH as compared to control groups. Nitrogen supply, efficiency of rumen microbial protein synthesis and P/E ratio were highest (p<0.05) in roughage treatment of UTS+CH than in other treatments. Supplemental feed resource treatments had no effect on nutrient digestibilities except for CP and was higher (p<0.05) in buffalo fed on UTS+CH than in other treatments.
It is concluded that supplementation of cassava hay at 50% of total roughage was beneficial to buffalo fed on urea-treated rice straw based diet which improved ammonia-nitrogen utilization in the rumen, nitrogen supply, efficiency of rumen microbial protein synthesis and thus, resulting in remarkable P/E ratio.