Processing
semen
AI Fresh Semen Diluent
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Introduction |
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Beltsville Thawing Solution (BTS) is
the diluent commonly utilised. This is sufficient for semen stability /
viability for at least 96 hours at an ambient temperature of 17°C. The cost of this diluent and its ease of
manufacture make is economically and ergonomically attractive |
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Composition of BTS: to make 1 litre of
diluent D
glucose
37.15 g Tri-sodium
citrate 6.00 g ETDA
disodium salt 1.25 g Sodium
hydrogen carbonate 1.25 g Potassium
chloride
0.75 g |
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50 g packets of diluent are typically ready made with gentamycin added at 50 mg per litre strength. However to comply with EU directive the
additional antibiotics must be added to be equivalent to penicillin,
streptomycin, lincomycin and spectinomycin. |
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Storage of diluent powder |
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The diluent powder should be stored below
25•C in a dry room. The
packets must not be damaged. Once
opened store container or extended diluent at 4°C. |
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Preparation |
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1 |
Calculate amount of distilled water
that will be required. For example a 50
g packet of diluent is made up into 1 litre containers |
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2 |
The diluent must not be made more than
24 hours in advance of usage. Antibiotic deterioration is a potential
problem if diluent is made too early, 25% of gentamycin
has deteriorated in extended diluent by 72 hours at room temperature |
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3 |
The diluent powder must be white and
free flowing. If any diluent powder has clumps, is damp
or yellow or the package is torn, check the storage facilities and if correct
return the package to the manufacturer |
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4 |
Obtain the required semen diluent
container ie Sembag |
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5 |
At the commencement of
each semen processing day the diluent is heated to 30°C for a minimum
period of two hours, this helps to stabilise the diluent and ensure adequate
mixing. A microwave could be utilised |
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6 |
Ensure that the diluent has no
particulate matter visible present before use |
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8 |
Weigh the semen
diluent container with added powder and tare the scale (Zero) |
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9 |
Add cold distilled
water to the semen bag container.
Ideally add the required amount using a weigh scale. Do not be more than 10 g (10 ml) out.
Note using a weigh scale is more accurate than using a 2 litre
measuring cylinder. Ensure that you flush around the entrance
area to the semen diluent container to ensure all the diluent powder is mixed
into the distilled water. |
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10 |
With large
studs the use of a calibrated siphon system (often computer controlled)
greatly simplifies this stage. |
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11 |
Fix the spout
to the semen diluent container |
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12 |
Mix the powder
into the distilled water by gently shaking 5 times |
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13 |
The diluent is
then warmed to 35C for 2 hours to ensure that the chemicals thoroughly
mix. If the diluent is not intended for
immediate use store the prepared diluent at 4C (refrigerated). A microwave could be used warm the diluent |
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14 |
At the
commencement of each semen processing day the diluent is heated to 35 to a
minimum period of 2 hours, this helps to stabilise the diluent and ensure
adequate mixing |
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15 |
Ensure that the
diluent has no particulate matter visible present before use |
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16 |
In order to
speed up the warming period a microwave may be utilised. It will be necessary to experiment with the
semen diluent container and normal water to get the settings correct. Warm the diluent to 30C and finish off with
the water bath. An example
using a watt microwave set on high |