Utilization of septage-raised tilapia (Oreochromis niloticus) as feed for snakehead (Channa striata) | |
| Author | Kamtorn Kaewpaitoon |
| Call Number | AIT Diss. no.AE-92-02 |
| Subject(s) | Channicthyidae Snakehead Fishes |
| Note | A dissertation submitted in the partial fulfillment of the requirement for the degree of Doctor of Technical Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. AE-92-02 |
| Abstract | Utilization of septage-raised Nile tilapia (oreochromis niloticus) either live or processed to replace traditional minced marine trash fish feed for high market value carnivorous fish, snakehead (Channa striata) was tested. A series of four experiments were conducted in cages suspended in an earthen pond on the AIT campus. Experiment 1 was designed to determine the prefered—size of tilapia as forage fish for snakehead of different size classes. Experiment 2 was designed to determine the feeding rate of snakehead of different size classes fed with live prefered—size tilapia as determined in Experiment 1. Experiment 3 was designed to compare growth, feed conversion ratio (FCR) and yield of snakehead fed with four diets: live prefered—size tilapia, tilapia meal, minced fresh tilapia and minced marine trash fish. Experiment 4 was a repeat of Experiment 3 with an additional assessment of the effects of supplementation by vitamin and mineral premix in diets containing or without soy bean oil on growth, FCR and yield of snakehead fed minced fresh tilapia diet formulated as in Experiment 3. Snakehead of l0—50 cm in total length exhibited a preference for the smallest size tilapia when tilapia of approximately 1.0, 1.5, 2.0 and 2.5 cm in body height were offered as prey. Mean feeding rate of snakehead of 10-35 cm in total length which grew well on live tilapia fingerlings ranged from 1.2 to 8.3 X of body weight/day. Feeding rate of snakehead of 35-50 cm in total length ranged from 0.4 to 0.6 Z of body weight/day which was insufficient to meet their daily nutritional requirements as indicated by weight loss over the 15 day period. It was postulated that feeding suppression may have resulted from stress caused by disturbance during feed monitoring. In Experiment 3, snakehead fed with live tilapia fingerlings showed significantly better growth performance, FCR, survival rate and yield than fish fed processed diets. Impairment of growth, high mortality and infection with chronic tuberculosis were observed in snakehead fed processed diets. It was postulated that diet rancidity due to improper storage conditions may have resulted in stress and increased susceptibility to diseases of the experimental snakehead. In Experiment 4, growth performance, survival rate and yield of snakehead fed minced fresh tilapia supplemented with vitamin and mineral premix with or without soy bean oil were comparable to those of snakehead fed frozen and fresh chopped tilapia diets although growth was higher with live tilapia fingerlings. It was postulated that the better growth performance of snakehead fed live tilapia fingerlings than those of snakehead fed other diets was due to the highly predaceous feeding habit of the snakehead. Yields of snakehead fed live tilapia fingerlings, chopped tilapia and minced fresh tilapia supplemented with vitamin and mineral premix with or without oil diets were in general comparable to those of commercial snakehead farms which utilized traditional trash fish diet. However, FCR's of snakehead fed minced fresh tilapia supplemented with vitamin and mineral premix with or without oil diets were higher than those of snakehead fed traditional trash fish diet and ranged from 4.1 to 5.2:1 (dry weight feed: wet weight gain or 12.0 to l5.1:l wet weight feed: wet weight gain basis). Replacing the traditional marine trash fish diet with minced fresh tilapia diet was probably not economically feasible. Only snakehead fed live tilapia fingerlings and chopped fresh tilapia, with FCR’s of 1.0:1 and 1.511 (dry weight feed: wet weight gain or 4.8:1 6.3:1 wet weight feeder wet weight gain basis) respectively, were in comparable to FCR of snakehead fed the traditional trash fish diet. A preliminary study on the relationship between growth and stocking density of swim—up tilapia fry nursed in septage—fed earthen ponds showed an inverse relationship between growth and stofiking density. Growth rate of swim—up tilapia fry stocked at 100 fry/m was faster than at 200 and 300 fry/m2 but low survival rates occurred at all stocking densities. The highest survival rate, 49.2 Z, and highest extrapolated net yield of 5.7 tonnes/ha/yr were obtained at 200 fry/m . A financial analysis compared hypothetical septage—fed tilapia pond systems, a grow—out system to produce chopped fresh tilapia and a nursing system to produce tilapia fingerlings for use as feed for snakehead. Although no system was financially feasible, with all options having a negative profit. However, when considered as a septage treatment system, the septage treatment cost of the grow—out system was approximately five times lower than that of the Bangkok Metropolétan Administration's activated sludge method. A subsidy of 35.69 Baht/m of septage treated ($ 1.43) for the septage—fed tilapia grow—out pond system would result in a profit if the repayment period was extended from 10 years to 15 or 20 years. |
| Year | 1992 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. AE-92-02 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Edwardsm Peter; |
| Examination Committee(s) | Lin, C. Kwai;Yakupitiyage, Amaratne;Chongrak Polprasert;Wee, Kok Leong; |
| Scholarship Donor(s) | Government of Australia; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1992 |