The difference in the daily pattern of ruminal temperature between pregnant and non-pregnant cows throughout pregnancy. The mean and standard deviation of ruminal temperature. The black line connected by the black round dot represents the average daily ruminal temperature in pregnant cows. The dashed line and solid line represent ± 2 standard deviation and average temperature in non-pregnant cows. Shaded black lines and dotted lines represent polynomial regression lines. The black diagonal line indicates when the FMD vaccine was administered. Thick horizontal black bars represent mean ruminal temperatures at four different periods: days 80 to 100 (I), days 145 to 165 (II), days 200 to 220 (III), and days 250 to 270 (IV). Means without a common letter represent significant differences (p < 0.05).