Utilization of wheat straw in sheep: Using an applicable method of chemical treatment

Abstract

Utilization of wheat straw in sheep: Using an applicable method of chemical treatmentAs part of research on utilization of straw as a feedstuff for small ruminants, wheat straw (WS) was pretreated with a warmed solution (4%) of NaOH (sodium hydroxide) and then treated with SO2(sulphur dioxide) gases of different sulphur levels (0, 1, 2 and 4 percent, weight/weight of dry matter) for two periods of 1 and 2 smoking days. The chemical composition, and dry matter degradability (DMD) of the neutral detergent fibres (NDF), acid detergent fibres (ADF) and acid detergent lignin (ADL) in sheep rumen was determined, as was also the intake of the treated straw and the performance ofGhizlestrain lambs. To estimate rumen DMD, treated WS samples were immersed in the rumen for a 72 h incubation period using the nylon bag (in sacco) technique. The chemical composition of the treated WS was changed with either one of NaOH or NaOH+SO2prior to the rumen incubation, and the amounts of lignin, cellulose, hemicelluloses and silica significantly decreased specially in the SO2-smoked wheat straw. Dry and organic matter decreased non-significantly (P>0.05). The rumen DMD rate of the WS SO2-treated for a period of 48 hours did show higher values (P<0.01) compared to those smoked during 1 day.In saccodegradation also significantly decreased NDF, ADF and ADL. The best results were observed with WS SO2samples smoked to 4% level during 2 days, followed by 2% level with the same smoking period. Although, a higher intake of treated WS was calculated for those smoked by 2% SO2gas for a period of 1 d, the best performance was observed in lambs fed WS treated by NaOH+SO2for a period of 2 days. It is concluded that chemical treatment of wheat straw by NaOH (4%) solution and SO2(2%) gas smoking for a period of 2 days, can be used as an applicable method on a farm scale for better utilization of WS as a feedstuff for small ruminants such as sheep.