Dietary Different Replacement Levels of Fishmeal by Fish Silage Could Influence Growth of Litopenaeus vannamei by Regulating mTOR at Transcriptional Level

Abstract

Fish silage (FS) has been confirmed as a high-quality feed ingredient because of its balanced nutrition, low cost, and environmental friendliness. In the present study, we evaluated the performance of replacing fishmeal by FS in the diet of white shrimp, Litopenaeus vannamei. Five isonitrogenous (410 g kg −1) and isolipidic (75 g kg −1) diets were formulated with replacement of fishmeal by 0% (FM), 25% (FS25%), 50% (FS50%), 75% (FS75%), and 100% (FS100%) FS. After an 8-week trial, shrimps fed low FS diets (FM and FS25%) had significantly higher final weight (FW), weight gain (WG), and specific growth ratio (SGR) (P < 0.05). No significant differences were found in body composition and most antioxidant enzyme activities of all groups (P > 0.05). Compared to high FS groups (FS75% and FS100%), low FS replacement levels (0 and 25%) had enhanced trypsin activity. And trypsin transcriptional level presented a similar trend with trypsin activity. In terms of intestinal histopathology, no obvious histological damage was observed in the intestine of all groups. tor and s6k of low replacement level groups (FM and FS25%) were significantly upregulated (P < 0.05), which indicated activation of mammalian target of rapamycin (mTOR) signaling pathway in low FS groups at transcriptional level. The enhanced performances of growth and mTOR signaling pathway in low FS groups (FM and FS25%) provided us some insights into the regulation mechanism of nutrient signal on growth. Based on the above, dietary FS could influence the growth of shrimp by regulating mTOR at the transcriptional level, and FS is a potential substitute of fishmeal in shrimp feed.

Dietary DL‐methionyl‐DL‐methionine supplementation could improve growth performance under low fishmeal strategies by modulating TOR signalling pathway of Litopenaeus vannamei

“…Hepatopancreas in the crustacea play an essential role in nutrient absorption and metabolism, so it is important to understand whether the substitution level of fishmeal and changes of the dietary amino acids are linked with changes in the transcription of genes known to participate in protein absorption and metabolism. To date, limited data were reported about the relationship between the dietary amino acid supplementation and the TOR signalling pathway in shrimp and how fishmeal level affects TOR signalling pathway (Shao et al, 2020;Xie, Wei, Chen, et al, 2020). Also, TOR is appreciated to be a vital link between immune function and metabolism.…”

Evaluation of the Dietary Black Soldier Fly Larvae Meal (Hermetia illucens) on Growth Performance, Intestinal Health, and Disease Resistance to Vibrio parahaemolyticus of the Pacific White Shrimp (Litopenaeus vannamei)

“…However, the effect of dietary BSF on the intestinal health remains unknown. Excessive replacement of FM may lead to impaired nutritional sensitivity and metabolism (Xu et al, 2016;Shao et al, 2020). Besides, intestinal histology is directly related to the digestion and absorption of nutrients by the shrimp, thus affecting growth.…”

Seafood Waste Management Status in Bangladesh and Potential for Silage Production

“…Digestibility and growth studies have shown that fish silage is highly digestible and can be used to replace up to 75% of fishmeal in aqua-feeds [52]. For shrimp, Litopenaeus vannamei fed with 25% to 50% silage-based diets showed higher growth performance [51,114] and improved gut health [54]. Fish silage not only acts as a feed ingredient but also an essential feed additive [32].…”