The amount of milk yield ol a sheep per day and lactation can oe determined by the milk yield controls. Milk yield controls are important in determining the amount of milk obtained during the lactation period, in ensuring data for increasing milk yield related to selection studies They are also important for being a criterion in milk sheep breed seleclion, in determining the animals with poor performance so as to make an accurate seleclion. In addition it will be possible, to feed the animals according to their real yield abilities and lo minimize the economic loses of yield by early diagnosing and treatment of mastitis as a result of regular controls in the flock.