초록
국내에서 사육되는 유색육용계 성장에 적합한 에너지와 단백질 수준을 구명하여 사료 급여 체계 확립에 필요한 기초자료를 제공하고자 두 차례의 사양 실험을 수행하였다. 공시동물은 유색육용계 1일령 암, 수컷 1,404수를 사용하였고, 펜당 26수씩 배치하였다. 사료내 에너지 수준은 사육전기 5주간 3,000, 3,100 kg/kcal이며, 단백질 함량은 $0{\sim}2$주에 20, 21, 22%를 급여하였으며, $3{\sim}5$주에 18, 19, 20, 21, 22%로 처리하였다. 조사 항목은 체중, 사료 섭취량을 측정하여 생산성을 계산하였으며, 실험 종료시 혈액을 채취하여 분석하였다. 실험 1 : $0{\sim}2$주간 사료 ME 함량 차이에 따른 생산 능력은 처리구간에 차이가 없으며 CP 함량 차이에 기인한 증체량과 사료 섭취량도 차이가 없었지만 사료 요구율은 CP 21, 22% 처리구에서 CP 20% 처리구에 비하여 통계적으로 개선되었다(P<0.05). 실험 개시후 $3{\sim}5$주간에 사료 ME 3,100 kcal/kg 처리구에서 ME 3,000 kcal/kg 처리구에 비하여 사료 요구율은 개선되었다(P<0.05). 이 기간에 사료내 CP 22% 처리구는 낮은 수준의 처리구보다 증체량이 유의하게 증가하였고(P<0.05) 사료 요구율은 CP가 높은 수준의 사료를 급여시에 낮은 수준의 CP 처리구에 비하여 개선되었지만 사료 섭취량은 처리구간에 차이가 없었다(P<0.05). 이 기간에 증체량과 사료 요구율은 ME와 CP간 상호 작용하였다(P<0.05). 전 실험기간 5주간에 사료 요구율은 ME 3,100 kcal/kg 처리구에서 ME 3,000 kcal/kg 처리구보다 개선되었으며, CP (20)18% 처리구는 다른 처리구에 비하여 높게 나타났다(P<0.05). 증폐량은 CP (22)22% 처리구에서 CP (21)21%, (20)18% 처리구보다 증가하였으며, ME와 CP간에 상호 작용은 증체량과 사료 요구율에서 나타났다(P<0.05). 혈중 알부민, 총콜레스레롤 함량은 ME 3,100 kcal/kg 처리구에서 ME 3,000 kcal/kg 처리구보다 증가하였지만 중성지방은 감소되었다(P<0.05). 한편 총콜레스테롤은 CP (22)21 처리구에서 CP (22)20, (20)18% 처리구에 비하여 증가하였다(P<0.05). 시험 2 : $0{\sim}2$주간 증체량은 ME 3,000 kcal/kg 처리구에 비하여 ME 3,100 kcal/kg 처리구에서 높게 나타났으며, CP 22% 처리구에서 CP 20% 처리구보다 유의하게 개선되었으며, CP과 ME는 상호 작용을 보였다(P<0.05). 사료 요구율은 CP 21, 22% 처리구에서 CP 20% 처리구보다 개선되었으나(P<0.05), $3{\sim}5$주 및 전체 사육 기간에 처리구간에 생산성은 차이가 없었다. 혈액 성상도 처리구간에 차이를 나타내지 않지만 ME와 CP 처리구간 총콜레스테롤 함량에 대한 상호 작용은 <.0001 수준에서 인정되었다. 따라서 교잡육용계 생리에 적합한 사료내 단백질 수준은 $0{\sim}2$주령에 22% 또는 그 이상의 수준으로 급여하고, $3{\sim}5$주의 단백질 수준은 21, 20% 수준으로 급여가 생산성의 극대화에 효과적일 것으로 생각되며, 사료내 에너지는 부분적으로 처리구간에 생산에 차이를 보였지만 일관성이 없었으므로 에너지 수준을 세분화하여 급여하는 추후의 시험이 필요할 것으로 사료된다.
To acquire essentially necessary basic data to establish feeding system by verifying appropriate dietary energy and protein level for the growth of commercial slow growing broiler chicks within the country, two experiments were conducted for 5 weeks. One day old, 1,404 male and female broiler chicks were used for the experiments, and 26 chicks were placed at each pen. The energy level of feed was maintained about 3,000 or 3,100 kg/kcal for whole breeding period of 5 weeks, and protein content was adjusted about 20, 21, and 22% during the first two weeks and the content was adjusted to 18, 19, 20, 21, and 22% from the 3 to 5 weeks old of the experiment. The categories of body weight and feed intake amount were monitored to calculate the productivity and blood sampling was conducted for the analysis at the end of each experiment. Experiment 1:Although the productivity by the ME content difference during $0{\sim}2$ weeks did not have significant difference and the body weight increase by the difference of CP content and feed intake amount did not have much difference, the feed requirement rate was statistically improved in CP 21 and 22% treatment groups compared to the CP 20% group (P<0.05). The feed ME 3,100 kcal/kg treated group during $3{\sim}5$ weeks after starting the experiment revealed to show improved feed requirement rate (P<0.05). Within the period of experiment, the CP 22% treated group resulted to show significant body weight increase compared to the groups treated with low levels of CP (P<0.05) and the feed requirement rate was improved in high CP treated group compared to low CP treated groups, but the feed intake amount did not show significant difference between treated groups. During the experiment period, the body weight increase and feed requirement rate revealed to interact between ME and CP (P<0.05). During the whole experiment period of the 5 weeks, the feed requirement rate was improved in ME 3,100 kcal/kg treated group than the groups treated with ME 3,000 kcal/kg, and the CP (20) 18% treatment groups resulted to show higher values than other treatment groups (P<0.05). Body weight increase was high in CP (22) 22% treated groups than those of CP (21) 21% and (20) 18% treated groups, and the interaction between ME and CP was found at body weight increase and feed requirement rate (P<0.05). Although blood albumin and total cholesterol levels were elevated in ME 3,100 kcal/kg treated group than ME 3,000 kcal/kg treated group, but neutral fat content was reduced (P<0.05). On the other hand, the total cholesterol content was increased in CP (22) 21% treated group than CP (22) 20% and CP (20) 18% treated groups (P<0.05). Experiment 2: The body weight increase in 0-2 weeks was higher in ME 3,100 kcal/kg treated group than ME 3,000 kcal/kg treated group, and it was highly improved in CP 22% treated group than CP 20% treated group by showing the interaction between CP and ME (P<0.05). The significant improvement of feed requirement rate was observed in CP 21% and 22% treated groups compared to CP 20% treated group (P<0.05). The productivity between the growth period from 3 to 5 weeks of age and whole growth period resulted to show no significant difference. Although no difference was observed in blood composition between treated groups, the interaction of ME and CP on cholesterol content was accepted at the range of P<0.05). Therefore, it is considered that the appropriate dietary protein level within feed for the physiology of growing broiler chicks was 22% or more for the first two weeks and protein level of 21% or 20% from 3 to 5 weeks old for the maximization of productivity. Even if the energy level within feed had some partial effects on the productivity, but did not show consistency. So, further experiments needto be conducted by differentiating the energy level.
