Dietary Lipid Levels Affect the Growth Performance, Lipid Deposition, and Antioxidative Capacity of Juvenile Scaleless Carp, Gymnocypris przewalskii, on the Qinghai‐Tibetan Plateau

Abstract

A 56‐d growth trial was conducted to evaluate the growth performance, lipid deposition, and antioxidative capacity of juvenile scaleless carp, Gymnocypris przewalskii, on Qinghai‐Tibetan Plateau. One‐year‐old juveniles (initial weight: 15.99 ± 0.02 g) were fed practical diets with different lipid levels of 4, 5.5, 7, 8.5, and 10%, respectively. Results showed that the best specific growth rate (SGR), feed conversion rate, and total antioxidative capacity (T‐AOC) in hepatopancreas were observed in fish fed the diet with 7% lipid level. Fish fed with high lipid diets (8.5 and 10%) had significantly higher condition factor and viscerosomatic index as well as lipid in muscle, intestine, mesenteric fat tissue, and whole body. Highest level of hepatopancreas lipase and lipoprotein lipases activities as well as malondialdehyde content and the lowest level of feed intake and T‐AOC content in hepatopancreas and intestine were also observed in fish fed with high lipid diets (8.5 and 10%) (P < 0.05). In conclusion, based on SGR and hepatopancreas T‐AOC content, dietary lipid requirement of juvenile G. przewalskii was estimated to be 7.35 and 7.39%, respectively.

Crude Lipid Levels in Semi-Purified Diets for Zebrafish

“…Therefore, a lower dietary lipid concentration may be necessary to meet the energy requirements for growth when zebrafish are fed until apparent satiety. Moreover, the results obtained in this study align with those obtained for other species in the Cyprinidae family, such as grass carp (Ctenopharyngodon idella) [27,28] , catla (Catla catla) with 8% CL [29] and scaleless carp Gymnocypris przewalskii with 7.35% CL [21]. Conversely, crucian carp (Carassius auratus var.…”

“…Additionally, fish fed 4.87 and 13.94% CL showing intermediary ingestion of feed between unsupplemented and supplemented lipid diets. Meng et al [21] also observed a significant difference in feed intake when scaleless carp were fed diets with the lowest (4% CL) and highest (10% CL) lipid levels. However, similar feed intake (P>0.05) was reported by the same authors for fish fed 5.5, 7.0, and 8.5% crude lipid in the diet.…”

“…The level of dietary lipid in commercially available diets for zebrafish range from 11% to 19% [8,10]. This is higher than optimum lipid level recommended to several other cyprinid species [17,18,21,22], as well previous study with D. rerio [23]. However, considering the current knowledge of zebrafish nutrition, develop standard diets based on ingredients with high nutritional value and safety is recommended.…”

Dietary nano-selenium alleviated intestinal damage of juvenile grass carp (Ctenopharyngodon idella) induced by high-fat diet: Insight from intestinal morphology, tight junction, inflammation, anti-oxidization and intestinal microbiota

“…A previous study found that the growth reaction increased with the increase of dietary lipid level until the optimal demand level was reached, and after that it decreased as the lipid level in the diet increased ( Meng et al., 2018 ). In the present study, HFD significantly decreased the SGR and the SR of juvenile grass carp and increased the FCR compared with the regular diet, indicating the adverse effects of excessive fat intake.…”

“…The indicators for evaluating a healthy intestine include goblet cell count, intestinal villus height (VH), villus width (VW) and so on ( Kuebutornye et al., 2020 ). Many studies have reported that HFD decreased the health status of the intestine ( Ding et al., 2010 ; Meng et al., 2018 ). The present study also observed that the intestine of juvenile grass carp fed with HFD showed structural disorder and a decrease in VH and VW, which might consequently result in the increase of the FCR.…”