APPARATUS FOR PERFORMING SCROTAL CIRCUMFERENCE MEASUREMENT ON BULLS

APPAREIL POUR MESURER LA CIRCONFERENCE DU SCROTUM CHEZ LES TAUREAUX

English Abstract

ABSTRACT OF THE DISCLOSURE
An apparatus for performing scrotal circumference
measurement on bulls consisting of a casing having an interior
cavity, an exterior surface with a concave portion and an
opening in the casing providing access to the interior cavity.
A graduated flexible tape is coiled within the interior cavity
of the casing. The graduated flexible tape extends through
the opening and has an end secured to the exterior surface of
the casing adjacent the concave portion such that the tape and
the concave portion define a circular opening to accommodate
a scrotal circumference. The graduations on the tape assign
a value to the concave portion thereby providing an accurate
circumferential measurement. A spring is positioned within the
interior cavity of the casing providing a biasing force of
between 1.26 and 2.26 kilograms of tension to draw the tape
into the interior cavity of the casing.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An apparatus for performing scrotal circumference
measurement on bulls, comprising:
a. a casing having an interior cavity, an exterior
surface with a concave portion and an opening in the casing
providing access to the interior cavity;
b. a graduated flexible tape coiled within the interior
cavity of the casing, the graduated flexible tape extending
through the opening and having an end secured to the exterior
surface of the casing adjacent the concave portion such that
the tape and the concave portion define a circular opening to
accommodate a scrotal circumference, and the graduations on the
tape assign a value to the concave portion thereby providing
an accurate circumferential measurement; and
c. biasing means positioned within the interior cavity
of the casing providing a biasing force of between 1.26 and
2.26 kilograms of tension to draw the tape into the interior
cavity of the casing.
2. The apparatus for performing scrotal circumference
measurement on bulls as defined in Claim 1, the biasing means
providing a biasing force of 1.76 kilograms of tension.
3. The apparatus for performing scrotal circumference
measurement on bulls as defined in Claim 1, having locking
means to lock the tape to the casing whereby a circular opening
of a predetermined size is maintained until the locking means
is released whereupon the biasing means draws the tape tightly
around the scrotal circumference.

7
4. An apparatus for performing scrotal circumference
measurement on bulls, comprising:
a. a casing having an interior cavity, an exterior
surface with a concave portion and an opening in the casing
providing access to the interior cavity;
b. a graduated flexible tape coiled within the interior
cavity of the casing, the graduated flexible tape extending
through the opening and having an end secured to the exterior
surface of the casing adjacent the concave portion such that
the tape and the concave portion define a circular opening to
accommodate a scrotal circumference, and the graduations on the
tape assign a value to the concave portion thereby providing
an accurate circumferential measurement;
c. biasing means in the form of a spring positioned
within the interior cavity of the casing providing a biasing
force of 1.76 kilograms of tension to draw the tape into the
interior cavity of the casing; and
d. locking means in the form of a manually activated
slidable wedge to lock the tape against a shoulder within the
interior cavity of the casing whereby a circular opening of a
predetermined size is maintained until the locking means is
released whereupon the biasing means draws the tape tightly
around the scrotal circumference.

Description

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The present invention relates to an apparatus for
performing scrotal circumference measurement on bulls.
5 BACKGROUND OF THE INVENTION
An important factor in cattle breeding is fertility.
Fertility manifests itself in sperm count and semen quality.
It is a highly heritable trait. Unless the cattle are selected
on the basis of their fertility genetic degeneration of the
cattle herd is the inevitable result. Determinations of
fertility have focused on bulls, for it is difficult to
determine the fertility of cows. It has been established,
however, that a bull of above average fertility will have
female progeny of above average fertility.
It has been determined that there is a correlation in
bulls between testicular weight and ~perm production. Sperm
production is recognized as being a factor in fertility. There
is a correlation between scrotal circumference measurement and
weight. As it is not practical to weigh the scrotum of a live
bull, efforts to determine fertility have focused upon scrotal
measurement. Experts have conducted studies to determine a
range of scrotal circumference of bulls according to age and
breed. From these ranges they have been able to determine
average scrotal circumference and set minimum recommended
scrotal circumference in order to avoid genetic degeneration
relating to fertility. One such study, a cooperative effort
between the Agriculture Canada Research Station at Lethbridge,
Alberta and the Western College of Veterinary Medicine at the
University of Saskatchewan, is documented in an article by G.H.
Coulter, R.~. Mapletoft, and W.F. Cates entitled "Scrotal
Circumference of Two Year Old Bulls of Several Beef Breeds"
which appeared in March 1987 issue Volume 27 No. 3 of
Theriogenology.
The measurements and their significance is predicated upon
measuring the scrotum with a measuring tape while applying
"moderate resistance". It is recognized that care must be
taken not to cause trauma to the bull's testes as such trauma

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results in inflammation which has a detrimental effect on the
sperm producing capability of the bull. Depending upon the
severity of the trauma such inflammation can effect fertility
for weeks or months. On the other hand, if insufficient
tension is applied the result gives an inaccurate and
misleading indication as to fertility. For example, in the
above mentioned article the scrotal circumference for yearling
Aberdeen Angus bulls varies between 24.5 and ~0.0 centimetres
with a mean of 33.9. Bulls with a scrotal circumference below
32 centimetres were not recommended as breeding bulls. An
error in measurement of one or more centimetres can have
dramatic effects on a breeding program.
Major sales of cattle breeding stock are implementing
minimum scrotal measurements as a prerequisite for accepting
bulls. It has been discovered, however, that there are only
a very few experts in the field who can perform consistent and
repeatable manual scrotal circumference measurements. Farmers
are relying upon inaccurate scrotal measurements when entering
cattle sales. Often they pay entry fees and travel great
distances to such sales only to discover that their bulls do
not meet the minimum scrotal measurement requirements.
Apparatus exist for performing diverse types of
circumferential measurement. The most closely analogous
apparatus is United States Patent 2,129,582 which issued to
Johansson in 1938. This Patent discloses a spring biased tape
forming a loop. This type of apparatus is not usable for
scrotal measurement without modifications for a number o~
reasons. One fundamental reason is that the spring tension
used in such measuring devices does not approach the "moderate
resistance" recommended for scrotal circumference measurement.
It is a matter of a great deal of experimentation and study to
determine what tension can be equated to "moderate resistance"
applied manually by a cattle expert.

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SUM~ARY OF THE INVENTION
What is required is an apparatus for performing scrotal
circumference measurements which will provide consistent and
repeatable results without regard to the skill of the user.
According to the present invention there is provided an
apparatus for performing scrotal circumference measurement on
bulls which is comprised of a casing having an interior cavity,
an exterior surface with a concave portion and an opening in
the casing providing access to the interior cavity. A
graduat~d flexible tape is coiled within the interior cavity
of the casing. The graduated flexible tape extends through
the opening and has an end secured to the exterior surface of
the casing adjacent the concave portion such that the tape and
the concave portion define a circular opening to accommodate
a scrotal circumference. The graduations on the tape assign
a value to the concave portion thereby providing an accurate
circumferential measurement. Biasing means are positioned
within the interior cavity of the casing providing a biasing
force of between 1.26 and 2.26 kilograms of tension to draw the
tape into the interior cavity of the casing.
With the apparatus as described, scrotal measurement can
be performed consistently and with repeatability. It is
preferred that the biasing force provide 1.76 kilograms of
tension as this is generally felt to be optimum for scrotal
circumference measurement.
Although ~eneficial results may be obtained through the
use of the apparatus as described, it must be appreciated that
there are difficulties inherent in measuring the scrotum of a
bull. Bulls are powerful animals, and the scrotum is one of
the more sensitive areas of the bull. It is preferred that the
measurement be performed with one hand, leaving the other hand
free to handle the bull's scrotum to assist in proper
placement. E~en more beneficial results may, therefore, be
obtained when the apparatus has locking means to lock the tape

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to the casing. This enables a circular ope~ing of a
predetermined size to be maintained while the tape i8 properly
positioned around the circumference of the scrotum. The
locking means is then released enabling the biasing means to
draw the tape tightly around the scrotal circumference.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more
apparent from the following description in which reference is
made to the appended drawings, wherein:
FIGURE 1 iS a longitudinal section view of an apparatus
constructed in accordance with the teachings of the present
invention.
15 DETAILED DESCRIPTION OF T~IE PREFERRED EMBODIMENT
The preferred embodiment, an apparatus for performing
scrotal circumference measurement on bulls generally identified
by reference numeral 10, will now be described with reference
to FIGURE 1.
The primary components of apparatus 10 consist of a casing
12 and a graduated flexible tape 14. Casing 12 has an interior
s:avity 16 and an exterior surface 18. Exterior surface 18 has
a concave portion 200 An opening 22 extends through casing 12
25 providing access to interior cavity 16. Tape 14 is coiled
within interior cavity 16 of casing 12. Tape 14 extends
through opening 22 and has an end 24 secured to exterior
surface 18 of casing 12 adjacent concave portion 20. Tape 14
and concave portion 20 define an expandable circular opening,
generally identified by reference numeral 26, which is intended
to accommodate a scrotal circumference. It must be noted that
the graduations (not shown) on tape 14 assign a value to
concave portion 20 thereby providing an accurate
circum~erential measurement. In the illustrated embodiment,
this is done by extending tape 14 across concave portion 20 and
fixing tape 14 to concave portion 20 by means of a plate 28
secured by rotatable fasteners (not shown). Biasing means are

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provided in the ~orm of a spring 30 positioned within interior
cavity 16 of casing 12. Spring 30 provides a biasing force
which draws tape 14 into interior cavity 16 of casing 12. It
is important to note that the biasing force provided by spring
30 must be within a range of 1.26 kilograms to 2.26 kilograms
of tension. After extensive study 1.76 kilograms of tension
is considered the optimum. Locking means are provided in the
form of a slidable wedge 32 manually activated by means of
switch 34~ Slidable wedge 32 locks tape 14 against a shoulder
36 within interior cavity 16 of casing 12.
The use and operation of scrotal measurement apparatus 10
will now be described with reference to FIGURE 1. The user
draws tape 14 from interior cavity 16 of casing 12 until a
circular opening 26 of a size larger that the scrotal
circumference being measured is obtained. Tape 14 is then
locked in position by means of switch 34 which presses slidable
wedge 32 against shoulder 36 to maintain circular opening 26
at its predetermined size. The user then uses one hand to
manipulate the scrotum of the bull, and the other hand to slide
tape 14 over the scrotum. Once tape 14 is correctly positioned
switch 34 is then used to release tape 14. Once tape 14 is
released, spring 30 draws tape 14 tightly around the scrotal
circumference.
It will be apparent to one skilled in the art that
modifications may be made to the illustrated embodiment without
departing from the spirit and scope of the invention as defined
by the claims.

Representative Drawing