Dairy Cattle Nutrition Division, National Dairy Research Institute, Karnal-132001, India,
Online published on 20 January, 2012.
Wheat straw was treated with urine 1 : 0, 2 :1 and 1: 1 (A, B and C respectively) and ensiled in cemented silos for one month. Percent CP and hemicellulose content increased significantly (P < 0.01) from 2.9 ± 0.23 and 13.25 in untreated straw (A) to 4.98 ± 0.16 and 23.43 (B), 7.31 ± 0.40 and 24.90 (C), in urine treated straw. While NDF, ADF and cellulose contents decreased (P < 0.01) due to treatment effect, the constituents like EE and NFE did not show any such effect.
The results of experiment on 9 Karan-Fries cattle divided into 3 equal groups fed on the 3 respective diets did not reveal any differences in DMI due to urine treatment of straw. Urine treatment had no effect on the digestibilities of CP, CF, NDF and ADF. While the cellulose digestibility decreased (P < 0.05) from 67.61 per cent (A) to 57.93 per cent (C), there was significant increase (P < 0.01) in the digestibilities of hemi-cellulose from 18.48 per cent (A) to 44.72 per cent (C) and lignin from 13.18 per cent (A) to 38.41 per cent (C). The nutritive value of urine treated straw calculated by difference method was 1.36 ± 0.09 per cent and 2.98 ± 0.20 per cent DCP(P < 0.05) and 46,59 ±1.71 and 48.31 ± 0.32 per cent TDN (P > 0.05) for the treatments B and C respectively. The N-balanees (g/d) increased significantly (P < 0.01) from 5.68 ± 1.98 (A) to 24.87 ± 0.95 (C). Ca and P balances were also higher (P < 0.05) in the urine treated straw fed groups.
Volatile fatty acid production rates estimated by single isotope infusion technique using C-14 showed a significant (P < 0.05) increase from 11.06 ± 1.40 moles/day in group A to 24.51 ± 3.87 moles/day in group C. The A ; P ratio also decreased (P < 0.01) from 2.46 in group A to 1.99 in group C due to the increase in propionic acid production indicating thereby an advantageous shift in the rumen fermentation pattern on feeding urine treated wheat straw.
