초록
Effects of conjugated linoleic acid(CLA), known as an effective anticarcinogen in several aminal models, on the egg production and egg weight of laying hens, and the weight gains of broilers were investigated. CLA was synthesized from corn oil by the alkaline isomerization method and purified by the low-temperature precipitation method. Diets for laying hens and for broilers were synthesized to meet the specification of their NRC standard rationals. Two separated experiments(Experiment I and II) were conducted for laying hens. in experiment I, 45 hens(300 days of age) were divided into 15 hens per treatment group; each hen was housed in wired cage located in a temperature and humidity-controlled house and adopted to the control diet. One week later, each group was subjected to one the four treatment groups for 5 weeks : control, 1.0% CLA, 2.5% CLA and 5.0% CLA diets. Diet and water were ad libitum. The condition of experiment II was the same as that of experiment I except for the addition of 5% corn oil diet and the extension of feeding period to 7 weeks. Egg production, egg weight and feed intake were recorded every week. Forty-five broilers(10day of age) were adopted to the control diet for a week and then switched to the treatment diets for 5 weeks : control, 1.0% CLA, 2.5% CLA, 5% CLA and 5% corn oil, Body weight and feed intake of broilers were measured every week. Diets supplemented with various amounts of CLA enhanced the egg production and increased the egg weight regardless laying hen's age(150 days or 300 days) as compared to control diet. The most effective diet for the egg production and egg weight of young hens(150 days of age) was found to be 1.0% CLA diet, but relatively higher CLA diet(2.5% CLA) was required for old hens (300 day of age) to obtain similar results as seen in younger hens. All hens treated with CLA ate greater amount of feed than control hens. Broilers treated with various amount of CLA ate less feed as compared to control ones, but the body weight gain was greater than the control broilers. These results indicate that CLA enhanced the egg production and agg weight of laying hens, and increased the body weight gain of broilers with less diet consumption.