Average THI during the hot season (75.5) was higher (P<0.001) than that in cold (64.2) season. The percentage of days that THI was above 72 during the hot JNJ-7777120 was 87%. This indicates that there was an environmental heat stress on the cows during which the THIs were above the threshold of 72. Regardless of treatment, the relationship between the maximum temperature, THI and P/AI are shown in Fig. 2. In the hot months of June to September when the THI was greater than 72, P/AI were lower (P<0.05) than those recorded in the remaining months.
Fig. 2. The effect of THI and maximum temperature on pregnancies per AI (P/AI) during the experimental period.Figure optionsDownload full-size imageDownload high-quality image (107 K)Download as PowerPoint slide
3.5. Effect of parity by season interaction
Parity by season interaction did not have an arterioles effect on pregnancy loss or P/AI on days 33 and 48. Pregnancy loss was significantly lower (P<0.05) for primiparous and multiparous cows during cold (6.3% and 23.6% respectively) than in hot months (40.9% and 56.6% respectively).
Fig. 2. The effect of THI and maximum temperature on pregnancies per AI (P/AI) during the experimental period.Figure optionsDownload full-size imageDownload high-quality image (107 K)Download as PowerPoint slide
3.5. Effect of parity by season interaction
Parity by season interaction did not have an arterioles effect on pregnancy loss or P/AI on days 33 and 48. Pregnancy loss was significantly lower (P<0.05) for primiparous and multiparous cows during cold (6.3% and 23.6% respectively) than in hot months (40.9% and 56.6% respectively).