The general objective of this study was to obtain background information needed
for the development of a breeding program for the commercial production of Pacific
salmonids. The data consisted of preharvest (end of freshwater rearing and after 9 and 22
months of saltwater rearing) and harvest (29 months of saltwater rearing) weight and
length measurements from chinook (Oncorhynchus tshawytscha) and harvest weight and
length measurements (approximately 17 months of saltwater rearing) of coho (Q.
kisutch). The work entailed estimation of genetic parameters for the traits measured as
well as the development of methodology for the genetic analysis of data collected under
actual fish farming conditions. The statistical model used for the analyses was the animal
model that incorporated the additive genetic relationships among animals and, depending
on the analysis, the dominance genetic or full-sib family effects.
The heritabilities of preharvest weight and length measurements in chinook
ranged from 0.24 to 0.39. Heritabilities for harvest weight and length in chinook,
measured after 29 months of saltwater rearing were 0.27 and 0.29, respectively. In coho,
the heritabilities of the harvest weight and length were 0.38 and 0.51.
The dominance genetic effects associated with a full-sib family could be separated
from the conmion environmental effect of family tank only in preharvest weight and
length measurements in the chinook. For these traits, dominance genetic variance,
expressed as a ratio of the phenotypic variance, ranged from 0.08 to 0.26. For all other
traits of the chinook and coho, the common environmental effect associated with full-sib
family was confounded with the nonadditive genetic effects. The variance associated
with the full-sib family effect, as a fraction of the phenotypic variance, ranged from 0.05
to 0.07.
Selection on BLUP of breeding value was simulated with levels of the common
environmental effect associated with full-sib family of 0.0, 0.075 and 0.15. In the absence of a common environmental effect, selection on BLUP of breeding value resulted
in 8-14% greater response after 9 generations than phenotypic selection. In the presence
of the effect, selection on BLUP of breeding value resulted in 0.7% to 5% greater
response than selection on phenotype.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/8813 |
| Date | 05 1900 |
| Creators | Winkelman, Anne |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Relation | UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/] |
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