Department of Animal Science, Punjab Agricultural University, Ludhiana-141 004, India
*Present address : Departmentof Animal Nutrition & Forages, Punjab Agricultural Universitv Ludhiana 141004. India
Online published on 5 January, 2012.
Urea and roughly ground wheat straw (WS) were mixed in the rations of 1:6, 1:5, 1:4 andl:3andthe moisture content raised to 70% with 0.75N sulphuric acid or water and the mixtures were either autoclaved at 7 kg/cm2 pressure for Ih or kept as such. The contents were dried at 50 C for 72h in a hot air oven and sealed dry. The loss of N during processing increased non-linearly with the increasing proportion of urea, and ranged between 24 to 30% for acidified and autoclaved (T1) and 19 to 26% for non-acidified and autoclaved (T2) complexes. 23 to 28% N of the acidified non-autoclaved control (T3) and 12 to 20% N of the non-acidified non-autoclaved control (T4) was also lost during the drying process alone. It was also observed that 5.27, 6.79, 8.22 and 9.66% of the finished complexes in T1, 50.7, 53.8 52.7 and 55.9% with urea : WS rationof 1:6 1:5 1:4 and 1:3 respectively was in the bound urease resistant form. 10 to 14% N of T3 control and 0.5 to 1.0% of T4 control also became urease resistant during the drying process. There was considerable hydrolysis of the fibrous fractions during acidic hydrolysis (T1) resulting in rise in the ADL value The DM digesti-bilitv of T1 increased by 20 to 30 units above that of WS whereas it improved by 2 to 3 units in T2 and 15 to 20 units in T3 The bound N of the T1 complex was 43 49 57 and 64% degradable in the rumen (in sacco) and that of the T2 contort ranged between 3 to 8% only Abomasal fluid did not alter the nature of the bound N significantly The results indicated that monosaccharides released by the acidic autoclaving improved the binding of urea considerably and bound N of such urea-straw products was about 50% degradable and the rest was espected to escape into the faeces
