| dc.contributor.author | Uraiwan, Supattra. | en_US |
| dc.date.accessioned | 2014-10-21T12:34:45Z | |
| dc.date.available | 1990 | |
| dc.date.issued | 1990 | en_US |
| dc.identifier.other | AAINN64553 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55220 | |
| dc.description | The Nile tilapia (Oreochromis niloticus) has been cultivated in Thailand since 1966. It is now one of the most economically important freshwater species for various types of aquaculture throughout the country. However, broodstock management guidelines for proper selective breeding procedures to improve production in tilapia culture have not been established. The present study aims to establish selection procedures for improvement of growth rate in tilapia culture, and to provide genetic information (realized heritability and selection response) for developing broodstock management guidelines. Two selection experiments were conducted from 1984 to 1989. (1) Within-family selection which is a procedure that appears to be suitable for tilapia culture in Thailand. (2) Indirect selection or age-at-maturity selection which is designed to elucidate the relationship between age at maturation and growth rate of tilapia. After three and four generations of selection in two selection experiments, growth rate of progenies of selected and unselected lines was compared in various aquaculture systems: aquaria, tanks, cages, concrete ponds and earthen ponds in private farms and a government fishery station. The principal conclusions are: (1) within-family selection for growth can improve growth rate of tilapia, and the genotype-environment interaction of growth may be significant enough to be considered if the improved strain is to be distributed to farms, (2) selection for age-at-maturity resulted in genetic changes in growth rate. A positive correlation between growth rate of all ages and early maturation was found. Selection for early maturing fish can provide an increase in growth rate. The results of these two experiments will be used in broodstock management guidelines for tilapia in Thailand. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1990. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Agriculture, Animal Culture and Nutrition. | en_US |
| dc.subject | Agriculture, Fisheries and Aquaculture. | en_US |
| dc.title | Artificial selection on growth and age at maturation of tilapia (Oreochromis niloticus Linn.) in Thailand. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
