Utilization of Sodium Hydroxide Treated Cottonseed Hulls in Complete Diets In Vitro

Cottonseed hulls (CSH) were treated with NaOH @ 3,4,5 and 6 per cent (w/w) maintaining 40,50 and 60 per cent moisture at each treatment level. Bulk density of untreated CSH (200.64 kg/m³) improved significantly by 6 percent NaOH treatment only. NaOH treatment decreased NDF, ADF and hemi-cellulose (P<0.01) as well as ADL and silica (P>0.05) without affecting CP and cellulose contents of CSH. IVDMD of CSH improved (P<0.01) with an increase in NaOH level The effect of replacement of wheat straw of isocaloric complete diets (roughage: concentrate 60:40) containing 10,12, and 14 per cent CP with various levels of treated CSH (33,66 and 100%) on the physico-chemical characteristics and in vitro DM digestibility was evaluated. Experimental complete diets were further processed into flakes by passing through a mechanical oil cxpeller unit. Bulk density of CSH based complete diets increased with an increase in the level of CSH and it was further increased (P<0.01) by flaking process. CSH levels did not influence OM content of CSH based complete diets, however, difference in the OM content due to CP levels was significant (P<0.01). Cell wall constituents increased (P<0.01) with an increase in the level of CSH while flaking of these complete diets decreased (P<0.01) the cell wall constituents. IVDMD of CSH based complete diets were comparable with those based on WS, however, flaking of diets increased (P<0.01) the IVDMD. It was concluded that nutritional value of CSH can be improved by its NaOH treatment (5%NaOH at 50% moisture) and treated CSH can replace the wheat straw in the complete diets as a source of roughage. Flaking of such diet can increase the bull density (78%) as well as IVDMD.