Use of conventionally modified canola meal to improve utilization in nile tilapia and asian seabass diets | |
| Author | Pichet Plaipetch |
| Call Number | AIT Diss. no.AQ-12-02 |
| Subject(s) | Giant perch Sea basses Nile tilapia |
| Note | A dissertation submitted in partial fulfillment of the requirements for the Doctor of Philosophy in Aquaculture and Aquatic Resources Management |
| Publisher | Asian Institute of Technology |
| Abstract | This dissertation aimed to increase utilization of canola meal for both diets of Nile tilapia, Oreochromis niloticus and Asian sea bass, Lates calcarifer. Three conventional processing methods consisted of water extraction, yeast fermentation with Saccharomyces cerevisaie and integration method (water extraction followed by yeast fermentation) were used to improve nutritional quality of canola meal to attain this goal. The first study was to determine their effectiveness on changes of key anti-nutritional factors (ANFs) and nutrients of canola meal. The results showed that all the three methods completely removed glucosinolates (GLs), and reduced phytic acid, tannins and non-tannins by 5-18, 36-49 and 70-89%, respectively. These processing methods also increased meal crude protein (CP), crude fiber (CF) and minerals of P, Ca, Mg, Fe, Zn, Cu and Mn by 4-9, 7-9 and 4-35 %, respectively. In contrast, crude lipid (CL) and essential amino acids (EAAs) were reduced by 13-34 and 1-31 %, respectively. Based on criteria of removing ANFs and maintaining the valuable nutrients, among them yeast fermentation was the best method. In the second study, canola meals processed by all these three methods were subjected to digestibility tests of Nile tilapia and Asian sea bass. The results showed that digestibility coefficients of dry matter (DM), CP, CL and energy of canola meals in Nile tilapia were 66-75, 73-77, 76-92, and 73-81 %, respectively. Among them, yeast fermented meal maximized all the nutrient digestibility coefficients. Digestibility coefficients of DM, CP, CL, and energy of all the processed canola meals in Asian sea bass were 69-75, 74-79, 73-82 and 66-72 %, respectively. Among them, yeast fermented meal also maximized all the nutrient digestibility coefficients. In both fishes, canola meal processed by integration method provided all the lowest digestibility of the nutrients. Based on overall nutrient digestibility and concern of ANFs, canola meal processed by yeast fermentation was selected to test in growth trials of both species. The third study was to determine the effects of replacement of dietary soybean meal protein with yeast fermented canola meal for Nile tilapia. Three fish groups were fed twice a day to satiation for 60 days with each of five diets consisted of a soybean meal base (control) and four diets of replacing soybean protein with yeast fermented canola meal at ratios of 25, 50, 75 and 100 %. The results showed that an increased ratio of protein replacement, especially at 75 and 100 % levels significantly reduced protein efficiency ratio, nutrient digestibility, body deposition of CL, Ca, Mg, P and their retention in Nile tilapia. These seemed to be related to an increased dietary phytic acid. However, there were non-significant differences of growth, survival rate, feed intake and feed conversion ratio among the fish fed with the test diets. The fourth study was to determine the effects of replacement of dietary fishmeal protein with yeast fermented canola meal for Asian sea bass. Three fish groups were fed twice a day to satiation for 60 days with each of five diets consisted of a 35 % fishmeal base (control) and four diets of replacing fishmeal protein with yeast fermented canola meal at ratios of 25, 50, 75 and 100 %, respectively. The results showed that yeast fermented canola meal could be used to test only at 75 % level. Because fish rejected diet of replacing at ratio of 100 % and completely died within two weeks. Survivals of fish fed all the test diets showed non-significant differences. Diet of protein replacement at ratio of 75 % significantly reduced growth, protein efficiency ratio, nutrient digestibility, and retention of CP, Ca, Mg, P, and increased feed conversion ratio of fish compared with the lower levels. These also seemed to be related to an increased dietary phytic acid. This study also showed the potentiality of reducing dietary fishmeal for Asian sea bass to be below 10 %, as fish accepted and grew with a diet containing only 8.75 % dietary fishmeal. |
| Year | 2012 |
| 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 | Aquaculture and Aquatic Resources Management (AQ) |
| Chairperson(s) | Yakupitiyage, Amararatne |
| Examination Committee(s) | Gallardo, Wenresti G.;Anal, Anil K.;Silva, Sena De; |
| Scholarship Donor(s) | Ministry of Agriculture and Cooperatives Thailand (MOAC) |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2012 |