OPTIMIZATION OF TREATMENT CONDITIONS OF WHEAT-STRAW WITH LIME - EFFECT OF CONCENTRATION, MOISTURE-CONTENT AND TREATMENT TIME ON CHEMICAL-COMPOSITION AND IN-VITRO DIGESTIBILITY

Chopped wheat straw (0.5-1.5 cm) was treated with different levels of lime (2-5% w/w), moisture (40-60%) and treatment time (1-3 weeks). Tre ated samples were kept in a laboratory at about 35 degrees C in a 4x3x 3 factorial arrangement, to study the effect of different factors on c hemical composition and in vitro organic matter digestibity (IVOMD). R esults showed that lime treatment appears to be effective in solubilis ing the cell wall constituents (CWC) and increasing the IVOMD signific antly (P<0.01). Neutral detergent fibre (NDF) and hemicellulose (HC) c ontents decreased significantly (P<0.01) due to the lime treatment; an d the respective decrease were to the extent of 5.40 and 16.00% in com parison to untreated wheat straw. Similarly, acid detergent lignin (AD L) was solubilised to the extent of 46.70% by lime treatment. IVOMD in creased (P<0.01) with increasing concentration of lime and the maximum value (59.71%) was noticed at 5% lime concentration. The other factor s like moisture content, reaction time and their interactions also sho wed significant effect on the enhanced solubilization of CWC. Lime (5% ) with 60% moisture for three weeks reaction period was an appropriate condition for the maximum response of treatment in wheat straw under laboratory conditions. (C) 1998 Elsevier Science B.V.