Effect of Oviposition Time on Egg Qualities in Laying Hen

산란계에 있어서 방란시간이 란질에 미치는 영향

This study was carried out to investigate the effects of age of hen and oviposition time on egg weight, egg shell quality and e88 shape index in White Leghorn laying hens. The data were collected from 150 laying hens for about 4 months from September 1, 1986 to January 6, 1987. The results obtained from this study were summarized as follows; The percentage of the eggs produced before noon was decreased and that of the eggs produced after noon was increased as the hen gets older. Egg weight was increased rapidly to 270 days of age but after 270 days of age the rate of egg weight increase was slowly downed. The egg shell thickness became thinner and egg shell breaking strength was reduced and egg shape index was increased as the hen gets older. The egg weight was decreased as the oviposition time was proceeded and the regression coefficients of egg weight on oviposition time were -0.6788--0.4170, which means that the egg weight was decreased 0.4170-0.6788g per one hour delay of oviposition time. Egg shell thickness was increased 0. 0.00377-0.00643mm and egg shell breaking strength improved 0.0287-0.034kg/$\textrm{cm}^2$ per one hour delay of oviposition time. But it seems that there was no relationship between the oviposition time and the egg shape index.

본 연구는 백색레그흔 산란계에 있어서 초산후 일령의 1일중 방란시간의 경과가 란중, 란각질, 란형계수에 미치는 영향을 구명하기 위하여 1986년 9월 1일부터 1987년 1월 6일까지 약 4개월간에 걸쳐 산란계 150수를 가지고 시험을 실시한 결과, 초산후 일령이 경과함에 따라 방란비율이 오전중에는 감소했고 오후에는 증가했다. 란중은 270일령까지는 증가속도가 빨랐으나 그 이후에는 둔화되었다. 란각두께는 일령이 경과함에 따라 얇아졌고 란각강도도 일령이 경과됨에 따라 저하되었으며 란형계수는 커졌다. 1일중 방란시간이 늦어짐에 따라 란중은 점차 가벼워졌으며 발란시간에 대한 란중의 회귀계수는 -0.6788--0.4170로 방란시간이 1시간 늦어짐에 따라 란중은 0.4170-0.6788g이 가벼워졌다. 란각두께는 방란시간이 1시간 늦어짐에 따라 0.00377-0.00643mm씩 두꺼워졌으며 란각강도는 방란시간이 1시간 늦어짐에 따라 0.0287-0.0349kg/$\textrm{cm}^2$씩 향상되었다. 그러나 란형계수는 방란시간과 서로 상호관계가 없는 것으로 사료된다.