Owing to cheap and abundant availability of rice polishing in Pakistan, researchers are attempting to enhance its inclusion level in poultry ratio. It also compares well with cereal grains in chemical composition. But the prevalence of rancidity due to high fat and other toxic factors limiting its use in poultry. Hence rice polishing was subjected to extrusion cooking for stabilizing the fat and improving its quality. The extrusion cooking of rice polishing was done at National Feed Mill, Sheikhupura.

Present experiment was conducted to observe the comparative effect of Raw and stabilized rice polishing on the performance of broiler chicks. Seven experimental rations (Starter and Finisher) were prepared designated as A, B, C, D, E, F and 0. All rations were isocaloric and isonitrogenous. Starter and Finisher ration "A" was kept as control containing no rice polishing. In rations B, C, and D raw rice polishing was used at levels 20, 25 and 30% respectively while in rations E, F and 0 stabilized rice polishing was used at the same levels. Starter rations were fed for 28 days and finisher ration from 29 days to 42 days.

Two hundred and ten (210), one day old broiler chicks were randomly divided into 7-groups having thirty chicks in each groups and which were further sub-divided into three replicates comprising ten chicks in each.

Results of present study indicated that maximum weight gain was observed in birds fed on ration "E" whereas second best was observed in chicks fed on ration "B". The birds fad on rations E, F and 0 (extruded rice polishing) gained better weight than those fed on rations B, C and D (raw rice polishing) at same levels and of control ration.

Best feed utilization per unit gain was observed in chicks fed on ration "E" and it began to decline as level of rice polishing (raw and extruded) raised to 30%. Overall feed efficiency of birds fed on rations containing (extruded rice polishing) was better than those fed on ration containing raw rice polishing and at the same levels.

During the whole experimental period, 4% mortality was observed In birds fed on different rations. This was due to heat stress .e. due to high ambient temperature (June, July months). The average dressing percentage was 55.20, 56.00, 54.5, 54.40, 54.77, 56.07 and 54.34 respectively. A non-significant difference was observed regarding dressing percentage. The average pancrease weight also showed a non-significant difference among treatments. However, a slight increase in pancrease weight was observed in birds fed on rations containing raw rice polishing. This might be due to secretion of bile (Lipase Enzyme). With respect of cost per kg live weight gain, the rations containing extruded rice polishing were observed slightly economical as compared to ration containing raw rice polishing.

RECOMMENDATIONS

As extrusion processing holds great promise as a mean to improve efficiency of nutrient utilization, it is therefore recommended that the use of extruded feedstuff, especially for non-traditional, feed ingredients should be promoted in poultry ration. The level of extruded rice polishing can be raised safely upto 25%.