Receiving and Disinfecting Trout Eggs
The following is a step-by-step procedure for receiving eggs by
shipment. For more information, please refer to SRAC Publication 220 –
Handling Eggs and Fry.
- Are the eggs cool and moist?
- Is there ice in the upper tray?
- Did the eggs arrive on time?
- Is the shipping container damaged?
- Are there excessive numbers of dead eggs?
Tempering and Water Hardening
When receiving eggs from suppliers, the eggs should first be
tempered or brought to the same water temperature as the hatchery.
This should be done in an area to avoid possible contamination of
the hatchery and water supplies. Tempering accomplishes two
purposes. The first is to avoid temperature shock by bringing the
eggs gradually up to the hatchery water temperature. The second
reason for tempering is to allow the eggs to absorb water lost
Once the eggs are tempered, the next step is disinfection. Do
not disinfect eggs that are hatching. A 10 minute treatment
with 100 ppm iodine solution is recommended. Iodophor disinfectants
like Argentyne, Wescodyne, and Betadyne are commonly used. The
following amounts are recommended:
Argentyne and Betadyne (1% iodine)
38 ml (1.28 fl.ozs or 7.5 teaspoons) Argentyne or Betadyne per
gallon of water
Wescodyne (1.6% iodine)
23.7 ml (0.8 fl.ozs or 4.5 teaspoons) Wescodyne per gallon of
In water typical of western North Carolina, add 10g (2 level
teaspoons) of baking soda (sodium bicarbonate) per 5 gallons of
iodine solution to avoid pH shock during treatment. The baking soda
is used to buffer the solution when the pH is less than 6 and/or
the water is soft.
Tempering and Disinfection Procedure
- Open the egg shipping container.
- Measure the temperature of the eggs with a standard
- Prepare a container to hold the eggs during the tempering
procedure. Add an appropriate quantity of clean hatchery water to
submerge all the eggs. Adjust the water temperature with ice (if
necessary) to the temperature of the eggs.
- Gently remove the eggs from the shipping container and submerge
them in the tempering container.
- Gradually add hatchery water over 30 minutes to 1 hour until
the tempering container water and hatchery water are the same
- Prepare a disinfecting solution as specified above.
- Submerge the eggs for 10 minutes. Gently stir the eggs once or
- Remove the eggs from the disinfecting solution and place in
incubators or hatching trays.
The use of brand names in this publication does not imply
endorsement of the products or services named or criticism of
similar ones not mentioned.