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.

1. Visual Inspection

   1. Are the eggs cool and moist?
   2. Is there ice in the upper tray?
   3. Did the eggs arrive on time?
   4. Is the shipping container damaged?
   5. Are there excessive numbers of dead eggs?
   
   

2. 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 during shipment.

3. Disinfection
   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 water

   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 thermometer.
• 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 temperature.
• Prepare a disinfecting solution as specified above.
• Submerge the eggs for 10 minutes. Gently stir the eggs once or twice.
• 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.