Analyses on the Status of Eggshell Breakage in the Step of Egg Conveyer System of the Laying Hen House

산란계사의 계란 이송단계에 따른 파란발생 실태분석

Broken eggs not only cause the economic loss in the egg producing industry, but also may not be good for the consumer's health. In order to identify the causes of eggshell breakage in laying hen houses, analyses on the status of eggshell breakage in the step of egg conveyer system of the laying hen house were conducted. The survey of eggshell breakage rate was implemented by four different stages egg conveying system. In the results, the breakage rate showed 4.7% in the egg collection belt, 2.5% in the egg elevator, 1.7% in the egg grading system and 0.9% in the egg conveyor belt. In particular, to Hy-line Brown variety, as the hens' raising week old increased, the breakage rate of eggshell increased while the strength of eggshell decreased. In the regression analysis between the breakage rate of eggshell and the strength of eggshell, the coefficient of determination ($R^2$) by the test of significance was computed as 0.7, therefore the changes of the strength of eggshell affects the breakage rate of eggshell. However, between the strength of eggshell and thickness of egg shell, and between the strength of eggshell and strain of eggshell, there was no significant difference detected in the regression analysis.

1. 조사농장의 산란율은 하이라인, 이사브라운 모두 $85{\sim}93%$ 수준 이였으며, 농가자체 파란율은 하이라인 $1.5{\sim}2.2%$, 이사브라운 $1{\sim}1.4%$이었다. 2. 계란 이송단계별 파란발생비율은 집란벨트 4.7%> 엘리베이터 2.5%> 선란기 1.7%> 컨베이어 0.9% 순 이었다. 3. 집란벨트에서 엘리베이터로 이송 중 계란이송가이드를 설치할 경우 약 1%의 파란경감 효과가 있는 것으로 나타났다. 4. 하이라인 브라운은 주령이 높아지면서 파란율은 높아지고, 파각력은 낮아지는 것으로 나타났으며, 회귀계수 분석 유의성은 $R^2=0.7$로 파각력의 변화가 파란율에 영향을 미치는 것으로 분석되었다. 5. 이사브라운에서는 환우 전에 비하여 환우 후 파각력이 높아진 것으로 나타났다. 6. 난각 두께와 파각력, 그리고 접촉 후 파각변위와 파각력과의 관계에서 이들 함수의 변수간에 회귀관계는 유의성이 나타나지 않았다.