Production performance, stress tolerance and intestinal integrity of sunshine bass fed increasing levels of soybean meal

Abstract

Soybean meal (SBM) is perhaps the most common fish meal (FM) alternative used in aquafeeds; however, SBM cannot fully replace FM in sunshine bass Morone chrysops × M. saxatilis feeds without impacting growth. Reduced production performance may be the result of subtle changes in morphology and/or physiological status. Accordingly, our objective was to assess growth, gastrointestinal integrity and stress tolerance of sunshine bass fed increasing amounts of SBM. Fish (approximately 14.5 g) were fed diets (14% lipid and 40% protein) containing increasing amounts of SBM at the expense of FM (30% FM, 20% FM, 15% FM, 10% FM, 5% FM and 0% FM) for 8 weeks. As expected, complete replacement of FM reduced growth. Although some signs of enteritis were noted, no significant differences in gut integrity were observed. Following 15-min low-water stress challenge, plasma glucose levels were elevated, particularly among fish fed increasing amounts of SBM. Cortisol response was similar, but statistical differences were not resolved for this parameter. Completely replacing FM in feeds for sunshine bass elicits overt reductions in growth. More subtle physiological changes may also result from FM replacement, including alterations in stress tolerance, and these may be important to consider in terms of the suitability of aquafeed formulations and optimal nutrition of sunshine bass.

Amending reduced fish‐meal feeds with marine lecithin, but not soy lecithin, improves the growth of juvenile cobia and may attenuate heightened responses to stress challenge

“…Success using fish meal–free feeds is rarely reported in cobia, and only in feeds containing relatively complex blends of ingredients and some animal‐derived proteins (Salze et al., 2010). In addition to the effects on production performance, marine protein replacement has been linked with reduced stress tolerance and increased handling mortality in other carnivorous taxa such as hybrid striped bass Morone chrysops × Morone saxatilis (Laporte and Trushenski, 2011; H.A. Lewis and J.T.…”

Impact of a plant-based diet on behavioural and physiological traits in sea bass (Dicentrarchus labrax)

“…Previous studies on sea bream showed that the replacement of dietary fish oil with vegetable oils (such as linseed oil, but not soybean oil) led to significantly higher plasma cortisol concentrations after acute stress , and significantly higher levels of cortisol release by the head kidney after adrenocorticotropic hormone (ACTH) stimulation (Ganga et al 2011). Similar results have also been shown in sunshine bass (Morone saxatilis) and cobia (Rachycentron canadum) fed reduced fish meal feeds (Laporte and Trushenski 2012;Trushenski et al 2013). The replacement of fish oil with vegetable oils devoid of LC-PUFA results in lower tissue concentrations of arachidonic acid, essential fatty acids and DHA (Ganga et al 2011).…”

Nutritional impacts on fish mucosa: dietary considerations

“…The distal intestines of cobia (Rachycentron canadum) (Romarheim et al, 2008), Egyptian sole (Solea aegyptiaca) (Bonaldo et al, 2006), and European seabass (Bonaldo et al, 2008) were completely unaffected by feeding soybean meal. Similarly, the intestinal integrity of hybrid striped bass (Morone chrysops x M. saxatilis) was largely unaffected by feeding soybean meal, soy protein concentrate, or soy protein isolate (Blaufuss and Trushenski, 2012;Laporte and Trushenski, 2012). Gilthead seabream exhibited only minor infiltration of leukocytes into the lamina propria of the distal intestine (Bonaldo et al, 2008).…”