SELECTING
FOR
SUSTAINABILITY
presented by
Michael Bruce
Introduction
What is selective breeding and why so important?
What are the key elements of a selective breeding?
programme
When should it be used?
What are the Options?
Stories of Success?
Our work to date?
What is selective breeding and why so
important?
Allows the control of animal stocks and selection of
beneficial traits for industry
Beef - body conformation and yield
Dairy - milk yields and composition
Racehorses - speed & stamina
Avoids the most common mistake of too few breeders and
high incidence of relatedness in off-spring
Removes the reliance on unpredictable wild broodstock
When is it appropriate to begin?
Immediately
Essential part of opportunity assessment
Integral part to business planning and operation
Designed to evolve as your company grows and develops
to ensure sustainability financially, environmentally and
socially.
What are the key elements of selective
breeding?
Preliminary Goal
Develop a thorough understanding of target species
Genetic variation across geographical ranges
Information on performance characteristics
Knowledge of biology (specifically reproduction)
Knowledge of life history traits (e.g. survival)
Goal
to begin with appropriate levels of variability in founder
broodstock
Options
OPTION 1
Walkback selection – individual mass selection with use of
DNA markers to determine parentage and relatedness to avoid
js1
and control inbreeding.
Least cost option
OPTION 2
Combined family based selection – entails establishing
multiple crosses with known parents and evaluating families
as well as individuals.
Slide 6
js1
DNA markers we have are only for parentage analysis. They are not linked to prodcution traits or sex.
symondsje, 10/11/2010
Options
Walkback selection
Pros
Lower costs
Works well for a single trait with moderate to high heritability (e.g. growth)
Can have high selection intensity if selecting from commercial cages
Cons
Still need control of crosses during breeding season to ensure enough parents
are involved.
Inadvertent changes may reduce the number of parents contributing later on e.g.
grading.
Must use DNA markers to determine pedigree otherwise high risk of inbreeding
Less accurate than family breeding
Can only select for traits can measure on the live individual – no good for quality
or sexual maturation
Unknown unfavorable relationships between the selected trait and other
important traits could compromise performance – genetic changes are permanent
Options
Combined family-based selection
Pros
Works well for a multiple traits with moderate to high heritability (e.g. growth)
Higher degree of accuracy
Suitable for traits such as quality and sexual maturation
Cons
More expensive
Cost-benefit model
Cost-benefit analysis is needed to determine which of the selective
breeding options best fits a company’s business plan and provides the
best return on investment.
An Excel based model was developed that incorporates:
Broodstock numbers required for the different designs based on the
tonnage of production.
Cost of rearing varying numbers of broodstock based on the tonnage of
production.
Commercial production costs and economic values of the traits to be
selected.
Prediction of the response to selection for up to 3 traits and the net
present value and return on investment (ROI) for each type of programme
over a 20 year time period.
Selective breeding
benefits, family
versus walkback
selection
Scenario 1: No unfavourable
relationship with growth, varying
tonnage, gains over 20 years
Walkback = mass selection with
genotyping to control inbreeding,
minimal cost programme
Selective breeding
benefits, family
versus walkback
selection
Scenario 2: Unfavourable relationship with
growth (e.g. increase in incidence of early
maturation), varying tonnage, gains over 20
years
Atlantic salmon family-based
breeding, Norway
After six generations of selection:
Growth rate has increased relative to wild fish by 84%
(14% per generation).
Other traits selected:
age of sexual maturity
product quality
disease resistance
This improved stock has meant that productivity and profitability has
substantially increased worldwide.
Target Species - NIWA
Paua / Abalone
(Haliotis iris)
Hapuku / Groper
(Polyprion oxygeneios)
Yellowtail kingfish
(Seriola lalandi)
Target Species - NIWA
Current status: Hapuku and kingfish programmes
Hapuku – 43 families evaluated so far
Family mean breeding values (weight 10)
250
200
150
Growth – high to
moderate
heritability,
very encouraging
Breeding Value
100
50
0
‐50
‐100
‐150
‐200
Family
Target Species - NIWA
Paua selective breeding: Currently evaluating 100 families
Industry partner: OceaNZ Blue Ltd
NIWA’s broodstock programme
Uses a combination of breeding, genetics, nutrition and
husbandry to address an industry need to identify elite
broodstock and improve stock performance
Selective
breeding:
Elite
broodstock
.
Globally competitive
Hapuku, kingfish &
paua industries
Revenue through the
sale of cultured fish/shellfish
nationally & internationally.
World leaders
in broodstock
husbandry and
nutrition
Development of
NZ aquaculture
Conclusion
A selective breeding programme can be designed to
meet your business needs and can grow in size and
complexity as you business grows.
Selective breeding is a vital part of business planning
and early integration and adoption of selective
breeding will be one aspect that ensures that your
business is enduring, profitable, environmentally
responsible and therefore sustainable.