Abstract

Wheat straw (WS), barley straw (BS), sorghum stover (SS), and maize stover (MS) were subjected to different times of ensiling and urea treatment levels in order to identify the most effective ensiling time and urea treatment level to attain preferable nutritional aptitude. Both straws and stovers were treated with 0.40 and 0.50 g concentration levels of urea solution dissolved in 0.8 L of water and sealed plastic sheet for one to four weeks. Accordingly, to the general observation at the time of opening, there was no mold growth, appeared golden brown in color, and had soft consistency with a strong ammonia smell ensuring the effectiveness of the treatment. The chemical analyses and IVDMD were done at HRCL. The results showed that the urea level had a no-significant effect on all chemical compositions and IVDMD for all urea-treated straws and stovers. Therefore, treatment with 40 g urea may be more economical. On the other hand, negative and significant (P<0.001) correlations existed between IVDMD and fiber fractions for all treatments. While other quality parameters, IVDMD and CP, were strongly correlated (r=0.90) (P<0.01) for WS and BS. The results also revealed that the treatment duration on both straws and stovers should be 28 days.

Key words: Treatment, ensiling time, chemical analysis, digestibility, crop residues.