| dc.contributor.author | Xu, Xueliang. | en_US |
| dc.date.accessioned | 2014-10-21T12:36:13Z | |
| dc.date.available | 1994 | |
| dc.date.issued | 1994 | en_US |
| dc.identifier.other | AAINN93803 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55422 | |
| dc.description | Feeding trials on both juveniles and broodstock of the Chinese prawn, Penaeus chinensis were conducted using highly purified n-3 and n-6 fatty acids (18:2n-6, 18:3n-3, 20:4n-6 and 22:6n-3) as well as using various lipid sources. In the absence of n-3 or n-6 fatty acids, juvenile Chinese prawns suffered high mortality (96-100%). EFA-deficiency resulted in poor growth and very low total body lipid (0.0071% of body wt.). Body lipid levels were also extremely low when either 18:2n-6 or 18:3n-3 was fed as the sole dietary unsaturated fatty acid supplements; only a mixture of both 18:2n-6 and 18:3n-3 or longer chain highly unsaturated acids (20:4n-6 or 22:6n-3) added individually or in mixtures were effective in raising carcass lipid levels. | en_US |
| dc.description | Juvenile prawns fed diets containing a mixture of 18:2n-6 and 18:3n-3 had better weight gains than did those fed on either 18:3n-3 or 18:2n-6 alone. With respect to growth response, the long chain n-3 fatty acid 22:6n-3 had the greatest EFA value among these four n-3 and n-6 series fatty acids, whereas the EFA value of 20:4n-6 was between 18:3n-3 and 22:6n-3 for juvenile Chinese prawns. The results indicate that n-3 and n-6 fatty acids are essential for survival and normal growth of Chinese prawns and EFA values of the fatty acids in the diet of juvenile Chinese prawns increased in the order: 18:2n-6 $<$ 18:3n-3 $<$ 20:4n-6 $<$ 22:6n-3. | en_US |
| dc.description | Fatty acid analyses showed that juvenile prawns possess the ability to elongate dietary 18:2n-6 and 18:3n-3 to 20:2n-6 and 20:3n-3, respectively, however, no further desaturation of either n-3 or n-6 of 18 carbon fatty acids was observed, indicating that Chinese prawn juveniles may lack delta-6 desaturase. In its wild habitat most foods ingested by prawns are rich in longer chain n-3 HUFA. Therefore, the results confirm that long-chain n-3 and n-6 HUFA are essential in the diet of Chinese prawn. | en_US |
| dc.description | Different dietary lipid sources had a great effect on fecundity of broodstock as well as egg hatchability and egg fatty acid composition of Chinese prawn. The present data indicates that the fecundity and hatchability of prawn broodstocks are related to their dietary HUFA content; the highest correlation coefficients were found between 20:5n-3 and fecundity (r$\sp2$ = 0.844) and between 22:6n-3 and percentage hatch (r$\sp2$ = 0.852). Though other explanations of the results are possible, I hypothesize that 20:5n-3 may play a specific role in oogenesis (possibly in combination with 20:4n-6) and that 22:6n-3 plays a critical role in embryonic development leading to successful hatching of the Chinese prawn. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1994. | 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 | Essential fatty acid metabolism, juvenile requirements and reproductive performance of the Chinese prawn (Penaeus chinensis). | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
