19.06.2024
Author: Lucie Gavin-Plagne, PhD | Field Application Scientist at IMV Technologies
Fertility in salmonids is influenced by a variety of factors. For fertility optimization, it is always interesting to observe production at a high-level stage. The freezing step represents only one step within a global process to achieve high fertility rate: each step needs to be standardized, and each step has an impact on fertility.
Environmental conditions and broodstock management are the fundamental base of the gametes quality. Feed type, particularly fatty acids and vitamins, as well as the feed management (when and how?) and water quality play significant roles in regulating reproductive physiology and behavior. Photoperiod or light type and intensity, and the adequate maturation timing represent an important impact on the fertility.
Laboratory factors include type of sperm collection (gonad sperm with immature sperm versus stripped sperm) and risk of contamination, storage and transport conditions (temperature shock, osmolarity) as well as freezing standardization (vapours versus controlled-rate freezer).
Egg management has a pivotal role as the oocyte collection timing as well as homogeneity and quality within a female can impact the fertility outcome. The fertilization protocol as well as the incubator management after fertilization should not be taken lightly.
Factors of variations have also been reviewed by Gallego and Asturiano, 2018. Additionally to the factors already cited, hormonal induction is often used In captive populations, to manipulate reproduction, including the induction of neo-males for sex reversal or spawning induction.
Techniques for gamete collection and storage involve careful timing, and the use of anesthetics to ensure sperm viability and minimize stress. Understanding the breeding cycle, including seasonal changes, manipulation of sex-reversed females, and selecting optimal breeding stock based on age, is essential for effective management and conservation of salmonid populations.
At the end, the human factors have to be considered in the risk management. That is why a relevant Standard Operating Procedure (SOP) as well as checklists are essential to ensure high fertility at the end.
In order to tackle these challenges, IMV Technologies is proposing a complete range of standardized products and service offer to help you in implementing a cryolab. This offer includes an audit, especially a pre-sale audit to ensure that everything is ready for beginning a cryolab process. This audit is made by a technical expert, Lionel Goardon, who has more than 30 years of experience in a trout farm.
A complete handbook for each step from sperm collection to oocyte fertilization is part of the offer when you are using a cryolab.
Our Field Application team is dedicated to support our customers worldwide for any biological and process considerations. In aquaculture, we provide a personalized 1 to 3 years training and support to help you to manage the cryolab, ensure that the process is standardized and used in an optimal way, and give you all the clues to be autonomous in your daily work when freezing salmonid sperm!
