여름철 산란계사 내 열환경인자 중 제어요소에 관한 연구 = Study on Control of Thermal Environmental Factors for Improvement of Productivity of Laying Hens in Summer

다국어 초록 (Multilingual Abstract)

This study carried out to determine control factors for the improvement of productivity oflaying hens suffering heat stress during hot weather. A total of 48,451 ISA Brown layers werehoused in a farm located in Gyeongsangnam-do, Republic of Korea. Five thermo-hydrometerloggers were installed inside the house to collect data of dry-bulb temperature and relativehumidity. The experiment continued for 81 days when the summer season begins from 19thJune to 7th September, 2018. This study analyzed the correlations among layers’ productionindex and daily average, highest, and lowest temperature; daily average, highest, and lowest relative humidity; and daily average, minimum, and maximum THI. The result indicated thatfeed consumption, hen-day egg production, egg weight, and FCR decreased as the daily average,highest and lowest dry-bulb temperature and THI rise (p<0.01). On the other hand, water intakeincreased as the daily average, highest and lowest dry-bulb temperature and THI rise (p<0.001).
The relative humidity was not considered to have direct correlations to the layers’ productionindex (p>0.05). However, it was noticeable that the mortality did not have significant relationswith daily average and highest temperature; THI; or daily average, highest and lowest relativehumidity while it was relevant to the daily lowest temperature and THI (p<0.05). In conclusion,to enhance the productivity of laying hens in a hot climate, it is recommended that dailyaverage, highest, and lowest dry-bulb temperature and THI are maintained as low as possible.
Especially, the daily lowest temperature is needed to lower to 20℃, which is the lowest criticaltemperature for layers.

국문 초록 (Abstract)

본 연구는 여름철 산란계의 더위 스트레스로 인한 생산성 저하에 영향을 미치는 열환경인자들 중 제어 요소를 결정하고 산란계의 생산성을 높일 수 있는 방안을 모색하기 위해 수행되었다. 경상남도에 위치한 산란계사에서 ISA Brown 품종의 산란계 48,451수를 공시하여 생산성 지표를 측정하였다. 또한산란계사 내부에 온습도로거를 설치하여 건구온도와 상대습도를 여름이 시작되는 6월 19일부터 9월7일까지 총 81일간 동안 측정하였다. 1일 평균온도, 1일 최고온도, 1일 최저온도, 1일 평균상대습도,1일 최고상대습도, 1일 최저상대습도, 1일 평균THI, 1일 최고THI 그리고 1일 최저THI와 산란계의 생산성 지표 간의 상관관계를 분석하였다. 분석한 결과에 의하면, 1일 평균, 최고, 최저의 건구온도와 THI가 상승할수록 사료섭취량, 헨데이 산란율, 난중과 FCR은 낮아졌다(p<0.01). 반면, 음수량은 1일 평균,최고, 최저의 건구온도와 THI가 상승할수록 증가하였다(p<0.001). 상대습도의 경우, 산란계의 생산성지표에 대해 직접적인 상관관계를 가지지 않는 것으로 판단된다(p>0.05). 특이점으로는 폐사율의 경우,1일 평균·최고 온도, THI와 1일 평균·최고·최저 상대습도와는 유의적인 상관관계를 가지지 않았지만, 1일 최저의 온도와 THI와는 상관관계를 갖는 것으로 분석되었다(p<0.05). 따라서, 여름철 산란계의생산성을 향상시키기 위해서는 산란계사 내의 1일 평균, 최고, 최저의 건구온도와 THI를 가능한 낮추는것이 필요하고, 특히 1일 최저온도를 산란계의 하한임계온도인 20℃에 근접하게 조성해주는 것이 유리할 것으로 판단된다.

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