Vle CONG. INTERN. REPROD. ANIM. INSEM. ARTIF., PARIS, 1968, VOL. Il

Progress in the Artificial Insemination
of Sheep with Frozen Semen.

A.F. Fraser, MVSc, MRCVS,
Royal (Dicks School of Veterinary Studies,
Edinburgh, Scotland.

This work was carried out with
the aid of a grant from the
Agricultural Research Council.

Introduction

It has become widely recognised in the last
decade that the artificial insemination of sheep
using frozen semen is not usually associated with
satisfactory fertility rates. Various reports
(First et al, 1961; Kalev and Venko, 1961) indicate
that although results are variable, they do not
consistently reach a satistactory level by any of
the methods as yet reported.

Studies on the artificial insemination of
sheep using trozen semen were begun in the
Royal (Dick) School of Veterinary Studies, Bdinburgh
in 1964, This research is still in progress and
this paper is an interim report.

Methods

The initial studies were concerned with the
adoption of the most satistfactory method of freezing
to obtain highest recovery rates of motile
spermatozoa, Subsequent work has been concerned
with the refinement ot techniques of semen collection,
insemination and ewe management.

Results and Observations
(a) TFreezing.

The early freezing methods were similar to that
which had been successfully developed for the goat
(Fraser, 1962). Semen was diluted in various media

at dilution rates of L : 10 in glass ampoules.
Recovery rates in every case were very unsatisfactory.

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