M. I. Anjum, I. H. Mirza, A. G. Khan and A. Azim

    Over a period of six weeks, 90 day-old broiler chicks were randomly allotted into two experimental groups comprising forty five chicks on each treatment. Two experimental rations containing 2% fresh soybean oil (3 mEqO₂/kg and acid value 2.52 mg/g of oil) and 2% oxidized soybean oil (50 mEqO₂/kg and acid value 7.26 mg/g of oil) were formulated for both starter (0-4 week) and finisher (5-6 week) phases. At the end of feeding trial, six chicks per treatment were slaughtered and meat and liver tissues were ground and stored at 4°C for thiobarbituric acid numbers. Weight gain and feed conversion ratio were significantly improved in chicks fed on diet containing fresh soybean oil (FSO) compared to the chicks fed diet containing oxidized soybean oil (OSO). Feed intake was non-significantly different between the two groups. Dressing percentage and organs weights of birds were found to be non-significant for both treatments. However, liver weight increased (P<0.05) in OSO group compared to FSO group. Higher (P<0.05) thiobarbituric acid numbers were found of liver of chicks fed OSO containing diet compared to FSO group, however, no difference was found in meat thiobarbituric acid number of both groups. This study suggested that addition of oxidized oil had negative effect on weight gain, feed conversion ratio, liver weight and liver thiobarbituric acid numbers.

Key words: Broiler chicks, oxidized soybean oil, growth, carcass quality.