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Breeding and Genetics

We have been developing our genetic material Spring Tilpia, since 1988.

Spring Genetics’ base population had undergone 13 cycles of selection for harvest weight prior to its introduction to Miami. The base population at Spring Genetics was derived from a selective breeding program in Nicaragua, with three generations of selection primarily focused on growth rate and fillet yield (Gjerde et al., 2012). The program conducted in Nicaragua was designed and supervised by Akvaforsk Genetics Center, Norway. The material used in Nicaragua originated from a Vietnamese family-based breeding program started in 1999 that had been genetically improved for growth in freshwater earthen ponds for four cycles of selection. This Vietnamese material originated from the fifth generation of the Genetically Improved Farmed Tilapia (GIFT) breeding project conducted in the Philippines (Bentsen et al., 2012) and local Vietnamese strains. The collaborative GIFT research project was started in the Philippines in 1989 as a complete diallel cross experiment carried out with eight strains of Nile tilapia from Africa and Asia (Bentsen et al., 1998).

Program Structure

A large number of individual families are produced at the breeding nucleus
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Family Porduction Incubation Area

In order to effectively select for multiple traits, a large number of individual families are produced at the breeding nucleus and extensively performance tested for assessment of their genetic merit. Families are produced in separate rearing units from which a representative

Sample of breeding candidates and test fish are tagged and tested. Full-sib families are produced by natural single-pair mating of selected male and female breeders placed in separate tanks/hapas. A nested mating design where one male is mated to two females allows the production of paternal half-sib groups. The families are kept in separate units (incubators, nursery, growth to tagging tanks) until individual fish can be physically tagged. Once fish reach 8-10 grams all fish are individually tagged with Passive Integrated Transponder (PIT) tags to keep track of the pedigree. After tagging, representative samples of fish from all full-sib families are communally tested for the target traits.

A total of 592 families, distributed across four generations, have been produced and tested by Spring Genetics to date (Table 1). Fish have undergone three generations of selection for growth in Miami. Breeders from the first two generations were selected solely for growth performance, while for the third generation breeders were also selected based on resistance to S. iniae.

In June 2017 another generation of selected nucleus families was produced at Spring Genetics, based on growth, general survival and resistance to S. inea and S. agalactiae.

Table 1. Families produced so far in Spring Genetics

Generation

(selected base pop.)

Year fam. prod.

2012

2013

2014

2015

Period family production

April-May

June

June

June

# families produced

142

144

162

144

# fish tagged

13737

 11095

 18761

 15664

traits evaluated

growth

growth

growth

growth

pond survival

pond survival

pond survival

pond survival

S. iniae

S. iniae

S. aga.

S. aga.

Typical Genetic Gain

Genetic gain typically in the range of 8 - 15% per generation.

Competence Base

Breeding Program Designed and Supervised by Akvaforsk Genetics

Spring Genetics breeding program is designed and supervised by Akvaforsk Genetics (AFGC), a leading provider of genetic improvement services to aquaculture industries worldwide. AFGC has extensive experience and from more than 20 large scale selection programs covering 15 species of fish and shrimp across Europe, Asia and the Americas. AFGC conducts all relevant data analyses and genetic evaluations for Spring Genetics and also hosts the central SQL database containing all essential data for the breeding program. AFGC is instrumental for development and implementation of next generation molecular and genomic tools for increased gains.


Dissemination

Our Material is Distributed in many countries

Genetically improved Spring Genetics material is distributed to large producers and affiliated multiplication hatcheries in key markets in Latin America. These multipliers regularly receives new batches of breeders from selected lines produced at the breeding nucleus, rear them until sexual maturation and use them as commercial breeders to supply their regional markets.


Gene Editing

The Crispr technology gives the geneticists a new set of very powerful tools, but when is it safe and ready to use in Tilapia?

Selective breeding relies on genetic variation caused by natural mutations. Gene Editing (GE) using enzyme complexes such as CRISPR-Cas9 and TALENS that edit the DNA sequence can be used to make precise targeted changes in the genomes of plants and animals. Such mutations would occur naturally in populations of plants and animals, but at a very low level. This GE technology gives geneticists a new set of very powerful tools to improve efficiency, health and welfare.

Benchmark considers GE to be a separate technology to transgenesis (moving genes between species) which was used in defining Genetic Modification (GM). Regulators consider GE to be genetic modification because the resulting alterations occur by non-natural methods. Benchmark anticipates that authorities will develop a constructive, regulatory system that permits development and production of GE animals with improved health and welfare.

Benchmark Genetics does not use transgenesis or GM in its products.

Benchmark’s overall focus is on sustainable breeding and to operate as an ethical and responsible company. The company sees GE as a tool for breeding livestock with improved health, animal welfare and performance, and will research applications that do not constitute a risk to the genetic integrity of the individual, population or environment. Research in functional genomics, where Benchmark already is positioned in the forefront in the aquaculture industry, will identify genes that affect health and welfare as targets for GE.

Acting responsibly, as the guardians of our animals, we will develop strains capable of high performance in modern production systems. We will implement GE technology where it proves to be socially and legally acceptable and when it can be shown to improve the efficiency, health and welfare of our animals.

Please read more in our Gene Editing Position Statement

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