Calorimetric Studies on Energy Metabolism by the Laying White Leghorn Hen

호흡대사장치를 이용한 산란계의 기초대사, 유특 및 생산시 에너지대사 측정시험

The Calorimetric experiment was made firstly to measure the difference in energy metabolisms of laying hens among their three different laying periods, secondly to estimate the energy requirements of the layers on their respective laying periods. The laying period was divided into three chronological periods of 25-40, 41-55, and 56-69 weeks old of laying hens, which are refered to as period I, II, and III respectively. 1) The fasting heat production (FHP) of laying hen on the three laying periods were 81.5 Kcal/kg$\^$0.75/ for period I, 72.3 Kcal/kg$\^$0.75/ for perod II, and 97.5 Kcal/kg$\^$0.75/ for perod III. The marked increase in FHP was found in period m, while there was a small difference in FHP between period I and II. The present study have observed among the birds in period in the high degree of plumage defectiveness, and this condition of bird might have accounted for the increase in FHP. 2) The regression equation between ME intake and energy retention (ER) were calculated, and the equations indicated that, for the period I, II, and III, the ME requirements for maintenance (MEm) were 123, 111, and 131 Kcal/kg$\^$0.75/ respectively, and that the Net Availabilities of Metabolizable energy (NAME) were 76, 79, and 74 percent respectively. For the whole laying period measured, MEm was 119 Kcal/kg$\^$0.75/ and NAME was 79 percent. There was a tendancy of higher MEm, and lower NAME during Period III, comparing with period I and II.

닭의 산란기를 I기(25-40 주령), II기(41-55주령), III기(56-69주령)의 3기로 구분하고 각 산란기에서의 에너지대사를 측정하여 얻은 결과는 다음과 같다. 1. 산란계의 절식시 열생산량(FHP)은 대사체중당 산란 I기 81.5Kcal, IIrl 76.1Kcal, IIIrl 97.5Kcal였다. 즉 FHP는 산란기에 의하여 변화하고 특히 III기의 FHP가 높게 나타났다. 이 현상은 III기에 공시계의 우모가 손상 또는 탈락하여 열손실을 크게 한 때문으로 생각된다. 2. 호흡시험에 있어서 사료 ME섭취량과 에너지 축적량(ER)과의 회귀식에서 구한 유지를 위한 ME 요구량(MEm)은 산란I, II, III기에 있어서 각각 대사체중당 123Kcal, 111Kcal, 131Kcal 였으며, 전기간 평균 119Kcal였다. 또 생산을 위한 ME의 정미이용효율(NAME)을 산란I기 76%, II기 79%, III기 74%, 전 기간 평균에선 79%였다. 즉 산란 III기는 I기 또는 II기에 비하하여 MEm가 높고 NAME가 낮은 성적을 보이고 있다.