Tool Time
By Mel DeJarnette, Reproductive Specialist
Tim Allen will tell you that a quality repair job depends
on having the right parts and tools for the job. If you’re
like me however, your most frequently used tool is the hammer
(even for repairing electronics). If a hammer is not within
arm’s reach, a crescent or pipe wrench will suffice.
The consequences of improper use of common tools are not usually
serious. However, misuse of tools stored in an A.I. breeding kit
can have significant effects on reproductive performance in your herd. There are several variations of common A.I. breeding
tools. For the most part, one tool will perform as well as another
if properly used. Let’s discuss some of the differences in common breeding equipment.
A.I. GUNS
There are two types of breeding guns commonly available in the U.S.,
the French O-ring and the spiral gun. Both guns perform equally well,
however, each requires a different type of sheath.
The base of the O-ring gun has a raised metal flange. The proper sheath
for this gun has a small split at the base which allow the sheath to
slide over this flange. The O-ring then slides over the sheath and flange
to lock the assembly together.
The spiral type gun does not have a raised flange but is threaded at
the base. The proper sheath for this gun does not have a split. This
sheath is simply twisted or screwed into place.
When using a spiral gun, be careful not to "strip the threads" when
tightening the sheath. With the O-ring gun, be careful not to lose
the O-ring.
SHEATHES
Sheathes are manufactured with or without a plastic insert designed
to give a leak proof seal regardless of how square (within reason)
a straw is cut. For sheathes with the insert, the manufacturer recommends
cutting the straw at a slight angle so it will be easier to start into the insert. However, when using standard sheathes without inserts, a
square cut to the end of the straw is essential to obtain a proper seal.
Sheathes with inserts are available for both the O-ring and spiral type
insemination guns.
When used properly, no one gun or sheath has superiority over the other.
Thus, many A.I. organizations promote only one combination of A.I. gun
and sheath. If you purchase all your breeding supplies from only one source,
you may not have noticed the differences. If you buy supplies from multiple
sources, make sure the sheathes you buy are compatible with you’re A.I. gun.
Regardless of what type gun or sheath you use, always check the seal on
your loaded insemination gun by pushing the plunger until a small drop
of semen emerges from the sheath opening with no leakage inside. If something
isn’t right, this procedure will let you know.
STRAW CUTTING DEVICES
There are two devices recommended for cutting straws, a sharp pair of
stainless steel scissors or the Cito straw cutter.
The Cito cutter is a round plastic device with a small hole to insert
the straw. A hidden blade cuts exactly ¼" off the end of the straw.
The cut is always square and the straw will not be crimped.
The problem with Cito cutters is that they are seldom disassembled and
cleaned. Each time a straw is cut, drops of semen and extender contaminate
the concealed blade providing an excellent medium and location for bacterial
growth. Subsequent straws are then contaminated which may cause fertility
problems. The Cito cutter should be taken apart and cleaned after each days’ use.
Scissors take a fraction more time and patience to insure a square cut, but
the blades are easily cleaned between each use.
THAW BATHS
To thaw a unit of semen the only requirement of a thaw bath is that it
hold enough water to completely immerse the straw and that it maintain the
water at 95°F for the thawing period (45 seconds). A standard wide-mouth,
foam insulated thermos works nicely for this purpose. Although a glass lined,
vacuum insulated thermos would hold water temperature longer, these units are more expensive, less durable and have small openings making it difficult to retrieve straws.
When an extended holding time is required, as for large herds or for
synchronization projects, thermostatically controlled thaw baths are available.
These should be checked periodically with a glass thermometer to ensure the
thermostat is working properly. The problem with these units is that many are
used repeatedly for weeks or months without cleaning or changing the water.
Regardless of the thaw bath you use, the water should be dumped and the unit
cleaned and dried at the end of each day. If you wouldn’t drink the water in
you thaw bath, you probably shouldn’t thaw semen in it either.
THERMOMETERS
The glass mercury thermometer is the standard by which all thermometers should
be compared. However, the glass thermometer doesn’t fare well in durability
tests. Thus, the metal dial thermometer has become the industry standard.
More recently, a small, plastic card with a heat sensitive strip that illuminates
numbers corresponding to the temperature has been developed. Each type should
be checked against a standard mercury thermometer at least monthly.
BREEDING KITS
The main requirements for an A.I. kit are durability and easy cleaning. Most
kits are either hard plastic or stainless steel. Stainless steel is more durable,
but also more expensive. If a plastic box is used, the interior surface should
have a smooth finish for easy cleaning. Breeding kits should be thoroughly
cleaned and disinfected at least monthly.
Reproductive efficiency is the summation of many variables. Proper use and
maintenance of the tools in your A.I. breeding kit are essential for maximum fertility.
Home
Info Request Form
Copyright 1996-2001 Select Sires Inc. Last updated 25-Dec-2001.
Web Site Design by Point & Click Software, Inc.
|
