Effects of feeding low fishmeal diets with increasing soybean meal levels on growth, gut histology and plasma biochemistry of sea bass

Abstract

The aquaculture industry depends upon the development of sustainable protein sources to replace fishmeal (FM) in aquafeeds and the products derived from soybeans are some of the most studied plant feedstuffs. A key area of investigation for continuing to improve modern aquafeeds includes the evaluation of varying proportions and combinations of plant ingredients to identify mixtures that are more efficiently utilized by the fish. This study investigated the effects of increasing soybean meal (SBM) by replacing a mix of plant ingredients in low FM (20%) diets on growth, blood biochemistry profile and gut histology on European sea bass. Five isonitrogenous and isolipidic experimental diets were formulated: four diets containing increasing SBM levels (0, 10, 20 and 30%; 0SBM, 10SBM, 20SBM and 30SBM, respectively) with a low content of FM (20%) and one control diet (0% SBM; 35% FM). Diets containing SBM brought to comparable performance and protein utilization, while 0SBM had negative impact on feed conversion rate and protein utilization. Blood parameters suggested an optimal nutritional status under all feeding treatments, even though slightly decreased values were reported at increasing dietary SBM. Histology examination did not show any changes indicative of soy-induced enteritis. We can conclude that for European sea bass: (i) different blends of plant protein did not affect feed intake despite the 20% FM dietary level; (ii) the inclusion of SBM maintains optimal growth and feed utilization in low FM diets; (iii) blood biochemistry profile showed a good nutritional status under all feeding regimes; (iv) no evidence of soy-induced enteritis was reported in any group fed low FM diets. For formulation of practical diets in on-growing of European sea bass, SBM up to 30% can be successfully incorporated into feeds containing low FM inclusion.

Effects of rearing density on growth, digestive conditions, welfare indicators and gut bacterial community of gilthead sea bream (Sparus aurata, L. 1758) fed different fishmeal and fish oil dietary levels

“…According to our findings, the gut bacterial community is dominated by Firmicutes (69.9-92.2%), followed by Actinobacteria and Proteobacteria. The dominance of Firmicutes we observed is in general agreement with the previous NGS-based survey of the gut bacterial community in sea bream and other marine or freshwater species fed similar aquafeed ingredients employed in the present study (FM, soy-derivates, corn glutens, wheat gluten and wheat meal) (Parma et al, 2016, Rimoldi et al, 2018a, 2018bParma et al, 2019). However, with a high inclusion level of dietary plant ingredients or functional additives in sea bream (Parma et al, 2016;Rimoldi et al, 2018a) or other marine fish species (Apper et al, 2016;Rimoldi et al, 2018b;Parma et al, 2019).…”

Substituting fishmeal with extruded soybean meal in diets did not affect the growth performance, hepatic enzyme activities, but hypoxia tolerance of Dolly Varden (Salvelinus malma) juveniles

“…Several effective methods were conducted to overcome the antinutritional effect of SBM in aquaculture, including deceasing its content in diets (Bonvini et al, ), or supplementation with methionine and phosphate (Kokou et al, ), phosphorus and magnesium (Imanpoor & Bagheri, ), glutamine and arginine (Gu et al, ), lysine and methionine (Jiang et al, ), hydrolysed feather meal (Zhang et al, ), exogenous enzyme complex (Ramos et al, ), mannan oligosaccharides (MOS) (Torrecillas et al, ) or lactoferrin (Ulloa et al, ) in diets with SBM. Scientists were also looking for other plant protein sources, such as cottonseed meal (CSM) (Lee, Dabrowski, Blom, Bai, & Stromberg, ), chickpeas meal (CPM) (Christodoulou et al, ), extruded canola seed‐pea (ECSP) (Bandegan et al, ), rubber seed meal (RSM) (Deng, Mai, Chen, Mi, & Zhang, ) or fermented Jatropha kernel meal (FJKM) (Phulia et al, ) to partially or totally replace SBM in aquafeeds.…”

Integrative Transcriptomic and microRNAomic Profiling Reveals Immune Mechanism for the Resilience to Soybean Meal Stress in Fish Gut and Liver

“…Other reports suggest that there was no sign of recovery even in a low dosage (10%) of SBM feeding in salmon (Uran et al, 2009 ). However, in European sea bass ( Dicentrarchus labrax ), an omnivorous fish, SBM of up to 30% can be successfully incorporated into feeds containing low FM inclusion (Bonvini et al, 2018 ). In common carp ( Cyprinus carpio L .…”