This thesis focuses on the uses of local feed resources as protein roughage sources in urea-treated rice straw based -diets for swamp buffalo. There were two experiments conducted and the results were as follows; in the first experiment, three crops as protein sources (cassava, Phaseolus calcaratus and sweet potato) were studied to determine the effects on yields and chemical composition(harvesting at 3 months after planting). A Randomized complete block design (RCBD) with 4 treatments and 4 replications was conducted to investigate the effect of different intercropping and foliage yield at 3 months of growth. The treatments were: T1= Cassava without intercropping as control treatment (4CF), T2 = Cassava intercropped with two rows of Phaseolus calcaratus (4CF+2PC), T3 = Cassava intercropped with two rows of sweet potato (Ipomoea batatas (L.) Lam), (4CF+2SP) and T4 = Cassava intercropped with one row of Phaseolus calcaratus and one row of sweet potato (4CF+1PC+1SP).
The results showed that yield of cassava foliage were significantly highest for 4CF+2SP (2.6 tons/ha DM) (P<0.05) as compared with other treatments while 4CF, 4CF+2PC and 4CF+1PC1SP were similar (1.9-2.1 tons/ha DM). The chemical compositions (DM, CP, ash, NDF, ADF, CT, and HCN) of cassava foliage (hay) were not significantly different among treatments.
In the second experiment, 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 with 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). Buffaloes in control treatment were fed with 100% 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 and were fed on ad libitum basis.
The experiment revealed that dry matter intake (2.4 % BW) was higher (p< 0.05) in buffalo fed on UTS+CH than in other diet 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) and rumen microorganisms, except for 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 with 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 tended to be lower while 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 resources treatments had no effect on nutrient digestibility except for CP and was higher (p<0.05) in buffalo fed 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. Under the prevailing swamp buffalo production for small-holder farmers, development of on-farm feed, based on local resources should be highly recommended in order to improve rumen ecology and subsequent productivity.