Comparison of effects of dietary‐specific fatty acids on growth and lipid metabolism in Nile tilapia

Abstract

The dominant fatty acids (FAs) in oils are often used to explain different nutritional effects of dietary oils in fish. However, the amounts of dominant FAs among oils are different, and the nutritional roles of these important FAs in fish have not been precisely compared at similar levels in feeding trials. In the present study, different amounts of palmitic acid were added to safflower oil (SO), olive oil (OO) and fish oil (FO) to obtain comparable amounts (about 550 g/kg of total FAs) of 18:2n‐6, 18:1n‐9 and 20:5n‐3 + 22:6n‐3 and subsequently fed to Nile tilapia (11.1 ± 0.01 g) for 8 weeks. The results showed similar growth among groups but FO group obtained lower fat deposition, serum ALT and AST activities, compared to OO. Lipogenesis‐related gene expressions were higher in OO group than FO group in liver, muscle and adipose tissue, but there were only few differences in these genes between SO and FO groups. Lipid catabolism genes in FO group were higher than OO and SO groups in adipose tissue, but not in muscle, and the significantly higher expressions of CPT1b and PPARα were only observed in liver. Overall, dietary 18:2n‐6, 20:5n‐3 and 22:6n‐3 were beneficial to normal growth and lipid metabolism, whereas high amount of 18:1n‐9 induced lipid deposition and liver damage in Nile tilapia.

Impact of Dietary Docosahexaenoic Acid : Eicosapentaenoic Acid Ratio on Growth, Fatty Acid Composition, Lipid Metabolism, and Antioxidant Status of Juvenile Hybrid Grouper (Brown‐marbled Grouper Epinephelus fuscoguttatus ♀ × Giant Grouper E. lanceolatus ♂)

“…Ingredients, diets, and muscle lipid extraction and fatty acid analyses were conducted as described by Liu et al (2019). Briefly, 50‐mg samples were homogenized in 0.37‐M KCl and vortexed in 4 mL of chloroform : methanol (2:1, volume : volume) for 4 h at 4°C.…”

“…From the remaining two fish, liver was sampled, snapfrozen in liquid nitrogen, and stored at −80°C for RNA extraction and enzyme activity analysis, and the muscle tissues were collected for composition and fatty acid analyses. Fatty acid analysis.-Ingredients, diets, and muscle lipid extraction and fatty acid analyses were conducted as described by Liu et al (2019). Briefly, 50-mg samples were homogenized in 0.37-M KCl and vortexed in 4 mL of chloroform : methanol (2:1, volume : volume) for 4 h at 4°C.…”

Growth performance, digestive and absorptive capacity of on‐growing grass carp ( Ctenopharyngodon idellus ) fed with graded level of dietary fibre from soybean hulls

“…(2016); Condition factor (CF) is calculated according to Liu et al. (2019). The ADC of dry matter, crude protein and crude fat are calculated according to Tian et al., (2012) as follows: PWG (%) = 100 × [final body weight (g) – initial body weight (g)]/initial body weight (g) SGR (% g/day) = 100 × [ln (final body weight, g) – ln (initial body weight, g)]/days FE (%) = 100 × [final body weight (g) – initial body weight (g)]/feed intake (g) HSI (%) = 100 × hepatopancreas weight (g)/final body weight (g) ISI (%) = 100 × wet intestine weight (g)/wet body weight (g) RGL (%) = 100 × intestine length (cm)/total body length (cm) CF (%) = 100 × final body weight (g)/total body length (cm) 3 ADC (%) = 100 × [1 – (AF/AI) × (NF/NI)], where AI is the Cr 2 O 3 content in the feed, AF is the Cr 2 O 3 content in the faeces, NI is the nutrient content in the feed, and NF is the nutrient content in the faeces. …”

“…The hepatosomatic index (HSI), intestine index (ISI) and relative gut length (RGL) are calculated according to Zeng et al (2016); Condition factor (CF) is calculated according to Liu et al (2019). The ADC of dry feed intake (g) HSI (%) = 100 × hepatopancreas weight (g)/final body weight (g) ISI (%) = 100 × wet intestine weight (g)/wet body weight (g) RGL (%) = 100 × intestine length (cm)/total body length (cm) CF (%) = 100 × final body weight (g)/total body length (cm) 3 Li et al (2012).…”

Crecimiento y supervivencia de Cryphiops caementarius en cocultivo con Oreochromis niloticus a diferentes densidades

“…En la misma especie de tilapia alimentada con una dieta con 30% de proteína, se produce mayor retención de proteínas y aminoácidos, los cuales mejoran el crecimiento (32). Así mismo, los ácidos grasos como el ácido linoleico, el eicosapentanoico y docosahexanoico, son beneficiosos para el crecimiento y el estado de salud (33).…”