PRESERVATION OF BULL SEMEN

Abstract

To date efforts on the part of research workers to preserve semen have not been too successful.In our laboratory recent studies indicate excellent results in preserving bull semen by the use of an egg yolk-buffer solution.The yolk is buffered at pH 6.7 with a phosphate buffer and the yolk-buffer-semen mixture stored in the refrigerator at a temperature of about 10".The buffer is prepared with ~/15 or ~/12 dibasic sodium phosphate and monobasic potassium phosphate.3 parts of fresh egg yolk and 2 to 3 parts of buffer are mixed and the pH of the mixture adjusted to 6.70 with NaBPOd.The semen is then mixed with from 1 to 4 volumes of the yolkbuffer solution.Samples are drawn from this mixture for insemination as occasion requires.Very active motility is preserved for 120 to 150 hours and there is still considerable movement at 300 hours or more.The motility results are supported by pregnancy records for periods up to 100 hours.It is believed that the spermatozoa thus environed can be used successfully up to 100 to 150 hours of age.This yolk-buffer solution diverges from the dilutor principle employed by other workers, since it is especially designed to meet the metabolic requirements of the sperm and is not primarily a semen dilutor, although it fulfils this requirement also.It appears to provide a pabulum in which the energy and catabolic requirements are met.