The Growth Performance, Nutrient Digestibility And Quality Of Fillets Of Red Tilapia Fed Various Dietary Palm Oil Sources
| dc.contributor.author | Salim Bahurmiz, Osan Maroof | |
| dc.date.accessioned | 2016-10-13T08:26:12Z | |
| dc.date.available | 2016-10-13T08:26:12Z | |
| dc.date.issued | 2006-09 | |
| dc.description.abstract | Two related experiments were conducted. For Experiment 1, a 20-week feeding trial was carried out to investigate the influence of three palm oil products as the principal dietary lipid source on the fish performance, proximate composition, tissues fatty acid composition and nutrient digestibility of red hybrid tilapia (Oreochromis sp.) from stocking to marketable size. Four isonitrogenous (30% crude protein) and isoenergetic (16.50 kJg-1 ) practical diets were formulated with 8% of fish oil (FO), crude palm oil (CPO), palm fatty acid distillates (PFAD) or refined, bleached and deodorized palm olein (RBDPO), respectively. Each diet was fed to triplicate groups of 30 fish. Results showed that the source of added lipid did not significantly influence (P>O.OS) growth performance, feed utilization, biological indices, hematological parameters and production yield of tilapia. There was no significant difference in fillet proximate composition, except that fish fed the PFAD diet had lower lipid content. The deposition of fatty acids in fish tissues was generally influenced by the fatty acids concentration in the diets. Fillet fatty acid profiles of tilapia fed palm oil-based diets had significantly higher levels of saturated fatty acids, but lower contents of polyunsaturated fatty acid (PUFA) compared to the fish fed the FO diet. The concentration of n-3 highly unsaturated fatty acids (HUFA) such as EPA and DHA was markedly higher in fillets of fish fed with the FO diet compared with those fed the other diets. Apparent digestibility coefficients of the four dietary lipids were generally high. However, the three palm-origin oils showed significantly lower digestibility values compared to the fish oil. The dietary lipids did not significantly affect digestibilities of dry matter and protein. Inclusion of dietary palm-origin oils led to a decrease in digestibility coefficients of saturated fatty acids, and to a very slight reduction in digestibility of xix unsaturates. In all treatments, the apparent digestibilities of both total n-3 and n-6 PUFA were the highest, followed by monoenes, while the lowest were the saturates. In Experiment 2, post-harvest qualities of fresh and frozen fillets of tilapia grown on diets supplemented with the various sources of lipid were investigated. Results showed that the source of added lipid did not significantly influence the drip losses and texture of fresh fillet. However, oxidative stability of fillet lipids was significantly affected. Fillets of fish fed palm oil-based diets exhibited significantly lower levels of lipid oxidation than those of fish fed the FO diet. With the exception of fillet hardness, seven other sensory attributes did not differ significantly among treatments. During the 30-week frozen storage period, there was no significant effect of dietary lipid on post-thaw drip and fillet texture; nevertheless the both attributes were markedly affected by the storage time. By the end of the storage duration, fillets from all treatments became significantly harder. However, the significant effect of storage time on increasing the drip loss was observed only in fillets from the FO and RBDPO treatments. Frozen storage increased the level of lipid oxidation of all treatments, with clearly better oxidative stability achieved by fish fed the palm oil-based diets. Sensory attributes did not change much as frozen storage prolonged, but juiciness of fillets from fish fed the CPO diet decreased significantly with storage. The effect of dietary lipid on sensory qualities of frozen fillets was not obvious except for rancidity. The highc;st scores of the aftertaste rancidity were always given to frozen fillets from the FO group. Fillet nutritional qualities had no important changes over frozen storage, except that the percentage of total n-3 PUFA and individual n-3 and n-6 HUFA was found to decrease while the saturated, monounsaturated and n-6 PUFA tended to increase. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/2731 | |
| dc.subject | Biological Science | en_US |
| dc.subject | Palm Oil Sources | en_US |
| dc.title | The Growth Performance, Nutrient Digestibility And Quality Of Fillets Of Red Tilapia Fed Various Dietary Palm Oil Sources | en_US |
| dc.type | Thesis | en_US |
Files
License bundle
1 - 1 of 1
Loading...
- Name:
- license.txt
- Size:
- 1.71 KB
- Format:
- Item-specific license agreed upon to submission
- Description: