This study included a total of (93) Freizian cows. Animals were classified into three groups (pregnant animals, animals sufferring from ovarian inactivity and animals sufferring from persistent corpus luteum. The results showed that the highest milk geild was given by animals with persistent corpus luteum, while the lowest yeild was given by the group sufferred from ovarian inactivity.
The results showed also that there was a negative correlation between milk yeild and conception rate.