Department of Animal Nutrition & Forages, Punjab Agricultural University, Ludhiana - 141 004, India
Online published on 5 January, 2012.
Variable amounts of urea and chopped wheat straw (1:6,1:9 and 1:14) were moistened to 70 % moisture and ensiled in 31 capacity thermocol lontainers. These containers were sealed for 9d. The inside temperature on 9th day varied between 70-75° C. The control and ensiled mixtures were dried at low temperature (50° C) for 72 h. There was a loss of 15 to 25% DM during the whole process. The N loss was 70 to 75% of added urea N. The N content of wheat straw (0.5%) was increased to 1.72,1.33 and 1.11% with 1:6,1:9 and 1:14 mixtures of which 64, 51 and 44% was present as bound (jackbean urease resistant) N. Drying of ensiled mixtures (controls) also resulted in 27, 13 and 5% bound N. The cellulose content decreased, whereas, the ADF, NDF and CF content increased with ensiling. The in sacco rumen degradability of DM increased from 40% of that of untreated wheat straw to 65, 62 and 60% for ensiled, and 52, 50 and 48% for unenslled urea straw mixtures, respectively. The corresponding values for the degradation of bound N in the rumen were 61,54 and 50% for the ensiled mixtures and 33,26 and 20% for the unensiled mixtures. The in vitro abomasal digestion had unsignificant effect on the release of bound N as either urea or as NH. The defects in fermentation technology for the upgradation of lowgrade roughages have been discussed and remedy suggested for improvement.
