Effects of Stage of the Estrous Cycle and Exogenous Hormones upon the Volume and Composition of Oviduct Fluid in Ewes

Abstract

Protein, lactic acid and alkaline phosphatase activity were determined in oviduct fluid collected from ewes during various periods of natural and synchronized estrous cycles. Average values were: protein, 3.02 gm./100 ml.; lactic acid, 44.13 mg./100 ml. and alkaline phosphatase, 32.88 units of activity/ml, per hour. The progesterone-PMS treatment used to regulate estrus had no significant effect upon these constituents. Protein and lactic acid did not change significantly during the estrous cycle, but alkaline phosphatase activity was higher (P<.01) during estrus than during other periods of the cycle. A significant (P<.05) period-by-treatment interaction was obtained with protein. Only traces of reducing sugars, ranging from 0.0 to 1.03 mg./100 ml., were found in oviduct fluid, and concentration did not vary with hormone treatment or stage of estrous cycle. Oviduct fluid contained cellular debris, leucocytes and unidentified particles which ranged from 0.2 to 0.5 µ in diameter. Bacterial growth was not obtained when agar plates and broth cultures were inoculated with oviduct fluid. The presence of a cannula in the oviduct did not affect ovarian activity or length of estrous cycle. Observations on the volume of fluid secreted by the oviduct showed that the period of maximum secretion occurred on the first or second day after the onset of natural estrus, but was delayed until the third day when estrus was regulated with progesterone-PMS.