Alternative dietary protein sources for Atlantic salmon (Salmo salarL.) effect on intestinal microbiota, intestinal and liver histology and growth

Abstract

The present study has addressed the issue of dietary alterations on gut microbiota in fish by investigating modulation of the allochthonous and autochthonous bacterial gut community of Atlantic salmon following feeding with pea protein concentrate, soy protein concentrate, extracted sunflower, poultry by-product and feather meal. The results revealed that total allochthonous and total autochthonous bacteria isolated from the distal intestine (DI) were affected by dietary modulations. Total autochthonous bacteria in proximal intestine remained unaffected. Corynebacteriaceae dominated the allochthonous bacteria and Lactobacillaceae dominated the autochthonous bacteria community in proximal and DI indicating that the most abundant groups are not shifted by alternative proteins. Some variations were observed between the bacterial communities as result of dietary manipulations. Alternative protein sources resulted in no severe signs of enteritis. Vacuolization of the liver was unaffected by diet. Furthermore, addition of plant materials significantly affected production of acetic acid. Weight of pyloric-, proximal-and DI was influenced by diet, especially feather meal. Growth performance was significantly affected by inclusion of feather meal to the diet. In conclusion the results showed that pea protein concentrate and poultry by-products are suitable protein replacements for Atlantic salmon and that soy protein concentrate is a potential candidate.

Evaluation of the effect of commercially available plant and animal protein sources in diets for Atlantic salmon (Salmo salar L.): digestive and metabolic investigations

“…The decreased activity of C-LAP in the chyme also indicates that the plant ingredients investigated in this trial did not cause inflammation, which has been reported to be accompanied by increased cell turnover and sloughing (Bakke-McKellep et al 2007;Chikwati et al 2013b). The lack of inflammation was also confirmed by the histomorphological evaluation conducted and reported from this feeding trial (Hartviksen et al 2014). Some variable responses were observed by the different plant ingredients on intestinal function.…”

“…A compensatory feedback mechanism may be involved to mitigate the loss of function caused by the inflamed DI (see also Bakke-McKellep et al 2000;Krogdahl et al 2003;Chikwati et al 2013a). However, the more refined SPC, which removes most of the unfavorable ANFs and/or other components that cause inflammation (van den Ingh et al 1996;Francis et al 2001), has not been reported to cause overt inflammation in the DI in this (Hartviksen et al 2014) or previous studies (Olli et al 1994;Penn et al 2011). Thus, it is more likely that the reduced BBM-LAP activity in the DI was due to increased digestive and absorptive processes in the proximal part of the GI tract, as indicated by higher BBM-LAP in the PI and increased PI and MI weights (Hartviksen et al 2014), resulting in less substrate present in the DI chyme and thus a down-regulation in tissue enzyme activity.…”

“…The present study is the second report from this feeding trial. The previous study presented the dietary effects on intestinal microbiota populations, feed intake, growth, feed conversion ratio (FCR), and liver and GI organ indices and histomorphology (Hartviksen et al 2014). In brief, ESF significantly reduced cumulative feed intake and growth compared to the FM diet.…”

Microbial interactions in the fish gut

“…Chapter 3 2011; Turnbaugh et al, 2009b;Muegge et al, 2011;Delsuc et al, 2014) and fish Ingerslev et al, 2014;Meziti et al, 2012;Hartviksen et al, 2014). This is not the case in our study where the same feed was used in all treatments.…”

“…Peptostreptococcaceae is a family of obligate anaerobic bacteria (Ringø et al, 1995). In salmon, Peptostreptococcaceae was detected as a member of both the allochthonous and autochthonous microbiota regardless of the fish diet, indicating that Peptostreptococcaceae might be a natural part of the intestinal microbiota of this species (Hartviksen et al, 2014). The family has been also reported in the gut microbiota of yellow catfish and common carp (van Kessel et al, 2011).…”