The development of a technique for cannulating the rete testis permitted continuous collection of spermatozoa and fluid from the testis of conscious rams for up to 5 months (Voglmayr, Scott, Setchell & Waites, 1967; Voglmayr, 1970). When this technique was employed on bulls, the flow of rete testis fluid began to decline 4 to 5 days after surgery and ceased by Day 11 (Voglmayr, Larsen & White, 1970). Histological examination revealed that fibrous tissue had blocked the orifice of the catheter (J. K. Voglmayr, unpublished observations). Early cessation of flow was unusual in rams even if several attempts were required to insert the flexible catheter into the rete testis (J. K. Voglmayr, unpublished observations). This paper describes a modified
J. K. VOGLMAYR, J. F. KAVANAUGH, L. C. GRIEL Jr, and R. P. AMANN
G. J. Killian, D. A. Chapman, J. F. Kavanaugh, D. R. Deaver, and H. B. Wiggin
Summary. The oviducts of 4 cows were cannulated and oviduct fluid was collected daily from the exteriorized cannulas for a total of 5 oestrous cycles. Daily serum samples were assayed for oestradiol-17β and progesterone to monitor the oestrous cycle. Data for each cycle were compared for oviduct fluid collected during the non-luteal phase (serum progesterone ⩽ 1·5 ng/ml) and the luteal phase (serum progesterone > 1·5 ng/ml). During the non-luteal phase oviduct fluid volume was higher and the osmolality was lower than during the luteal phase. Total protein, cholesterol and phospholipid secreted daily was greater during the non-luteal phase. Cholesterol and protein concentrations were generally lower during the non-luteal phase, but phospholipid concentrations were generally higher. About 40% of the phospholipid in oviduct fluid was phosphatidylcholine and lysophosphatidylcholine, while phosphatidylinositol and lysophosphatidylinositol accounted for 20%. The ratio of 1-acyl-phospholipid to diacylphospholipid increased during the non-luteal phase. An increased cholesterol to phospholipid ratio, and a decreased cholesterol to protein ratio in oviduct fluid also were associated with the non-luteal phase. Changes in the lipid composition of oviduct fluid during the oestrous cycle may play a role in the preparation of gametes for fertilization.
Keywords: oviduct fluid; cow; phospholipid; cholesterol; protein