Two experiments were conducted to find the influence of age, season and raising condition on abdominal fat deposit in broiler chickens. In experiment 1, the relationship between age and abdominal fat deposit was studied. Twelve hundred birds were fed with regular commercial rations and placed in 2-tier colony cages in insulated windowless type house. One hundred and sixty birds were killed at 49-82 days of age and the weight of abdominal fat doposit was measured. The results revealed that the

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... tio of abdominal fat deposit expressed as a percent of dressed weight rose as their age increased. A remarkable rise in the ratio was noted on and after 65 days of age in female. At 82 days of age, the ratio in female was 4.33% as against 2.57% in male. In experiment 2, the relationship between raising condition and abdominal fat deposit was investigated. Eighty hundred birds were raised on floor and in colony cages in insulated windowless type house, and also on floor in open type house. The birds were raised in each of the four seasons: spring, summer, autumn and winter. At 72 days of age, 60 birds each from the three experimental groups were killed. The results showed the highest ratio of abdominal fat deposit in the chickens raised on floor in windowless type house, followed by those raised on floor in open type house and then those in colony cages in windowless type house. The ratio of abdominal fat deposit tended to be higher in chickens raised on floor in windowless type house in summer. (Japan. Poultry Sci., 16,[155][156][157][158][159] 1979)