토종닭의 품종, 산란 연령 및 온․습도 지수가 산란율에 미치는 영향

Abstract

This study analyzed the effects of temperature, humidity, Temperature-Humidity Index (THI), and breed on the laying rate of four Korean Indigenous Chicken breeds. The research data included 3,738 chickens collected from Gyeongsang National University Farm from 2022 to 2024. The chicken breeds studied were Korean Rhode Island Red, Korean White Leghorn, Korean Brown Cornish, and Korean Native Chicken. Laying rates were measured from 18 to 65 weeks, and weather data from Jinju, South Korea, were utilized to assess external conditions. Regression and mixed model analyses were conducted using SAS 9.4. The THI analysis revealed that the highest laying rate (35.84±20.57%) occurred within the 40∼49 range, while the lowest laying rate (25.93±20.61%) was observed in the 80∼89 range. Age analysis showed higher laying rates at 30∼39 weeks (37.07±19.66%) and 40 weeks and above (37.86±19.62%). By breed, the Korean Rhode Island Red exhibited the highest laying rate (54.13±12.23%), whereas the Korean Brown Cornish showed the lowest laying rate (10.24±9.58%). According to the GLM analysis, humidity along with the daily temperature Range significantly affected the laying rate, and temperature itself also acted as an important factor. The interaction analysis among THI, age, and breed showed that all factors and their interactions had significant effects on the laying rate. This study suggests that maintaining THI within the 40∼49 range is crucial for optimizing the laying rate of Korean Indigenous Chickens and emphasizes the need for breed-specific environmental management. These results provide scientific evidence for efficient management and productivity enhancement of Korean Indigenous Chicken production, contributing to sustainable livestock development.