THE EFFECT OF TEMPERATURE HUMIDITY INDEX (THI) ON EGG PRODUCTION IN PRADU-HANGDUM CHAING MAI HIGH EGG PRODUCTION STRAIN CHICKENS

The purpose of this research was to study the effects of climate changes on egg production under Chiang Mai Livestock Research and Breeding Center in Chiang Mai Province. This study was conducted from 300 Pradu-Hangdum Chiang Mai high Egg Production strain chickens. The data record collected from April 2019 until March 2020. The study indicated that, the weather was hot and humid. The temperature ranged from 22.28-31.23?C and humidity range were 46.70-81.80%. The highest temperature in May (31.12?C) and April (31.23?C) the lowest temperature in December (22.28?C). Daily temperature and humidity data from meteorological measurements in Chiang Mai were recorded daily over the duration of the trial period were used to calculate the temperature humidity index (THI). The THI group for effect on egg production composition was set to 4 groups (THI1 is THI ? 70, THI2 is ? 74 THI > 70, THI3 is ? 78 THI >74 and THI4 is THI > 78). The highest THI values (THI 4) effect on age at first egg (AFE), THI4 (144.59 day) was lower than THI1 (161.40 day), THI2 (158.22 d) and THI3 (156.17 d). AFE in summer season was lower than raining season. The correlation between TEP270 and average egg at 1 mouth (AEM) traits were found the highest correlation (0.90). Moreover, the correlation between weight at first egg (HWFE) and age at first egg (AFE) was 0.38, it meaning that HWFE resulting in AFE faster.