injections of penicillin-streptomycin solution tfor three days follow-
ing surgery. No post-surgical semen was processed until all traces
of inflammatory exudate had disappeared from the ejaculate,

Semen was extended in Tris-yolk buffer (8) to contain 25 x 10
live spermatozoa per ml,, packaged in one ml, glass ampoules,
equilibrated for three hours and frozen in a programmed temperature
controlled alcohol bath, Inseminations were performed on first
service cows by commercial breeding co-operatives and the 60/90 day
non return rates calculated,

RESULTS AND DISCUSSION, All animals mounted teasers one or two days
after surgery and ejaculates were collected from three bulls at this
time, One other animal continued to mount and perform ejaculatory
motions without producing any semen for five weeks but eventually
regained the ability to ejaculate, Traces of inflammatory exudate
were visible in semen for five weeks following surgery. The opera-
tion did not appear to cause any permanent detrimental effect to the
bulls! general physical condition or ability to produce and ejacu-
late semen,

Rectal palpation, biochemical analysis of seminal plasma before
and after surgery and a necropsy specimen from one of the bulls
indicated that a small amount of seminal vesicular tissue remained
following this operation (9). An alternative technique utilizing
the same approach but involving complete dissection and removal of
the seminal vesicle with an electrocautery apparatus, working through
an illuminated speculum, is being investigated, If complete removal
of the seminal vesicle was required, this second technique would
probably be more satisfactory.

TABLE I

60/90 DAY NON RETURN RATE FOR FROZEN BULL SEMEN
PROCESSED BEFORE AND AFTER SEMINAL VESICULECTOMY

-

Pre-Surgical Post-Surgical
Bull A 69,0% (213) 74517 (201)
Bull B 7353% (210 67 .8% (152)
. s T e . T ST S S
Mean 71.5% =07

—

Each N,R, % for individual bulls are means of
four ejaculates, Total number of first services
is in brackets,

1260