초록
To investigate the response of egg production to the artificial light to induce early egg laying. and the changes of egg weight and egg shape during the egg laying cycle, 30 Korean ring-necked pullets and their 1,284 eggs layed under artificial light control were used in this study. The first egg was ohserved at the age of 31 wk, after 4 wk of stimulating light(16 hour light: 8 hour dark). Egg production rate during seven 2-wk periods from the begining of the first egg was 43.7% and a clear peak egg production(61.7%) was shown at the 4th 2-wk period. The effects of egg production period and pullet on the egg weight, egg length, egg width and egg shape index(width/length) were significant(P<0.01). In the egg production cycle. egg weight, egg length and egg width increased steadly with time. but the value of egg shape index increased up to the 3rd 2-wk period and then decreased. Repeatabilities from intraclass correlation for the egg weight, egg length. egg width and egg shape index were 0.61. 0.53, 0.49 and 0.48, respectively.
