Effects of dietary lipids on tissue fatty acids profile, growth and reproductive performance of female rice field eel (Monopterus albus)

Abstract

The effects of different lipids on tissue fatty acid profile and reproductive performance in female rice field eel were investigated in this study. Virgin female eels were fed with six diets containing different lipids (diets FO, LO, SO, PO and PL with fish oil, linseed oil, soybean oil, peanut oil and pork lard, respectively; diet APO with arachidonic acid and peanut oil). The results showed that there were positive correlations between the contents of 18:2n-6, 18:3n-3, arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the tissues of eels and those of the corresponding fatty acids in their diets. The specific growth rate of eels fed with diet PO was the lowest and significantly lower than that of FO and SO. Gonad of eels fed with diets PO and PL showed hypogonadism. The long chain polyunsaturated fatty acids (LC-PUFA) can be synthesized by eels, but the quantity was not enough to meet their reproduction requirement completely. The fatty acid desaturation, rather than elongation probably was one of the limiting factors. Addition of proper amount of ARA in diet was favorable to the increase of the hatching rate of fertilized eggs, while EPA and DHA in diet were beneficial to the increase of the survival rate of larva. Both n-3PUFA and a suitable n-6/n-3PUFA ratio were necessary for growth and reproduction of eels.

Effects of dietary vegetable oils on liver and gonad fatty acid metabolism and gonad maturation in gilthead seabream (Sparus aurata) males and females

“…Fernandez-Palacios et al (1995) recommended that broodstock diets for gilthead seabream should contain 16 g n-3 HUFA kg −1 for improved spawning performance, while Rodriguez et al (1997) found better egg quality from 18 g n-3 HUFA diet. Similar delayed gonad maturation due to insufficient dietary n-3 HUFA level was recently reported by Zhou et al (2010) for eels fed diets containing peanut oil or pork lard oil and developed hypogonadism, while those fed diets containing linseed or fish oil develop normal gonad structure. Based on our results, it is clear that in terms of the effect of VO diets on reproductive characteristics, and linked with the other factors determined, LO blend diet is considered to be better than SBO blend diet for gilthead seabream adults as further indicated from PCA figures.…”

Effects of partial replacement of fish meal with Spirulina platensis meal in practical diets on growth, survival, body composition, and reproductive performance of three-spot gourami (Trichopodus trichopterus) (Pallas, 1770)

“…Diets were made as pellets with appropriate diameters of 1.5-2 mm. The pellets were dried in an oven (Fan Azma Gostar, Model BM 55) at 60°C for 24 h, kept in separate, tightly capped bottles, and finally stored at -20°C until use (Sink and Lochmann 2008;Zhou et al 2011).…”

“…At the end of the experiment, individual females (n = 4) from every treatment was randomly killed and the contents of gonad and viscera were removed to assess the gonadosomatic index (GSI) and viscerosomatic index (VSI). The growth and reproductive indices were based on Sink and Lochmann (2008) and Zhou et al (2011) as follows:…”

Differential gene expression in small and large rainbow trout derived from two seasonal spawning groups

“…Extrinsic factors such as variation in circannual photoperiod [9], and changes in water temperature [10,11] have largely predictable effects on growth rates. Other factors are more complex and relate to interactions between extrinsic and intrinsic factors that regulate growth, such as individual responses to stress and disease [12], population density [13], social status [14], and feeding regime [15]. Variation in growth in response to these factors has a strong genetic basis as indicated by the detection of moderate to high heritability values [16-18] and chromosomal regions (quantitative trait loci, QTL) associated with variation in body size [19,20].…”