양계용에너지 사료로서 고구마의 이용에 관한 연구 제1보 옥수수대치사료로서 고구마 펠릿트의 급여수준 = Studies on the Utilization of Sweet Potato as a Poultry Feed 1 . Substitution Level of Pelleted Sweet Potato for Corn in Growing Chick Ration

다국어 초록 (Multilingual Abstract)

The feeding value and maximum available level of sweet potato as a substitute for corn in the chick diets, which was formed in either all-mash or pellet, were studied. Thirty day-old female chicks of Stareross 288 were alloted into 12 lots fed on either mash or pellet with sweet potato to the level up to 30% of chick diets. All the experimental diets were formulated to contain iso-calorie and iso-protein. For the feeding periods of 0 to 7 weeks, 8 to 14 weeks and 0 to 14 weeks, the body wt. gain, feed intake, feed conversion and feed economy were observed and the efficiency of nutrients utilization of different diets was also examined at the end of feeding period. The results obtained were as follows: 1. The body weight gain of chicks were found significantly more in pelleted diet than in all-mash diet for the feeding periods of 0 to 7 weeks and 0 to 14 weeks. However, the body wt. gain was not significantly different between the substitute levels of sweet potato for any feeding period. For the period of 0 to 7 weeks the chicks fed pelleted diet with 30% sweet potato got significantly more body wt. gain than the chicks fed all-mash diet without sweet potato. 2. The feed intake of chicks were found significantly more in pelleted diet than in all-mash diet for the feeding period of 0 to 7 weeks and 0 to 14 weeks. However, the feed intake of chicks was not significantly different between the levels of sweet potato of the diets. Feed conversion of chicks fed pelleted diet was similar to that of chicks fed all-mash diet. The feed conversion of chicks fed all-mash or pelleted diet containing 30% sweet potato was worse than that of chicks fed all-mash diet without sweet potato. 3. The chicks fed all-mash or pelleted diet with the different substitute levels of sweet potato for corn were similar in the efficiency of nutrient utilization, which was determined at the end of feeding period, such as dry matter, crude protein, crude fat, crude fiber and nitrogen-free extracts of the diet. 4. The feed cost required for 1㎏ body wt. gain of the chicks fed pelleted diet was similar to that of the chicks fed all-mash diet. The diets containing the higher levels of sweet potato was found a slightly more expensive for 1㎏. body wt. groin of chicks. From the above results, it is concluded that the substitute of sweet potato for corn up to 25% in pelleted diet is more profitable, comparing with all-mash diet containing 60% corn only, if the sweet potato meal were home-produced.