Relationship of temperature and humidity to conception rate of Holstein cows in Hawaii.

摘要: Abstract Weather data and breeding records for a Holstein herd of 1300 cows in Hawaii were evaluated to determine effects climate on reproductive performance. The dairy is coastal near latitude 21°N. Average maximum temperature, relative humidity, resulting temperature-humidity index the warmest month year 31 C, 44%, 79. minimum temperature attending values same period 20 C, 96%, 68. From late April November, conception rates correlated negatively with average each day estrous cycle beginning 11 days prior breeding. Slopes regression lines differed, suggesting varying sensitivity rate heat stress different cycle. 2nd was most closely rate. Conception declined from 66% 35% as increased 68 78. Only had significant partial correlation coefficient when 1st breeding, following others held constant.