Desenvolvimento dos tecidos entérico, hepático e muscular de juvenis de pacu (Piaractus mesopotamicus, Holmberg 1887) e dourado (Salminus brasiliensis, Cuvier 1816) alimentados com dieta contendo colostro bovino liofilizado

Abstract

Enteric, liver and muscle tissues development of pacu (Piaractus mesopotamicus, Holmberg 1887) and dourado (Salminus brasiliensis, Cuvier 1816) juveniles fed diet containing lyophilized bovine colostrum The supply of lyophilized bovine colostrum (LBC), alternative protein source, has been evaluated as an innovative ingredient in fish nutrition. The milk secretion influence was studied on enteric, liver and muscle tissues development of pacu (Piaractus mesopotamicus) and dourado (Salminus brasiliensis), using analysis of serum IGF-I concentration, morphological structure study and enzyme activity in intestine, as well as the responses of cellular indicators in enteric, liver and muscle tissues. Juveniles of pacu (8.5 ± 0.7g; 7.7 ± 0.3cm) and dourado (13.3 ± 0.9g; 10.8 ± 0.3cm) were distributed in a completely randomized design in a factorial scheme 3x2, constituting of three diets with LBC inclusion (0, 10 or 20%) and two experimental periods (30 or 60 days). The performance indicators in pacu, interaction between diet and period was observed to weight gain (WG) and feed conversion rate (FCR) (P<0.05). GP values in 10 and 20% LBC did not differ from the values of 0% LBC, indicating that the diets were adequate and met the nutritional needs of the juveniles. Higher FCR was found with 10% LBC at 60 days. IGF-I concentration did not differ between diets in both species, but was higher in dourado at 60 days (P<0.05). The pacu and dourado intestinal epithelium histomorphometry, was not altered by the LBC supply, however, there were differences between intestinal segments. The enzyme activity of aminopeptidase N was higher in pacu fed 10% and 20% of LBC (P<0.05); the activity of peptidases and disaccharidases was lower at 60 days; except for aminopeptidase A which showed high activity in this period. In the dourado, was difference only to aminopeptidase A, which was lower at 60 days (P<0.05). Regarding the indicators of cellular activity, in intestine of pacu, total protein (TP)/RNA ratio was lower at 30 days. In liver of dourado, there was interaction between diet and period for DNA, being higher in fish fed 20% LBC, at 60 days. In muscle of pacu, TP/RNA was higher with 10% LBC; RNA, TP/DNA and RNA/DNA ratio lower at 60 d, while TP and DNA/RNA ratio increased during the same period. In muscle of dourado, RNA and RNA/DNA were lower at 60 days and, TP/RNA higher in the same period (P<0.05). Considering the aspects studied to evaluate the effects of bovine colostrum for juvenile pacu and dourado, it was observed that were kept unchanged the plasticity and enzymes activity in intestinal epithelium and cellular activity in enteric, liver and muscle tissues. This condition suggests the possibility of using this milk secretion in nutrition of fish studied.

The digestive tube of Piaractus brachypomus: gross morphology, histology/histochemistry of the mucosal layer and the effects of parasitism by Neoechinorhynchus sp.

“…Reite () reported that rodlet cells seemed to be recruited when helminths affected epithelial tissue in four teleost families (Salmonidae, Cyprinidae, Gadidae, and Labridae). In relation to Serrasalmidae, Nordi () suggested that rodlet cells were present in the intestinal epithelium of P. mesopotamicus juveniles based on the structure, size, and location of these cell types. Mori () identified rodlet cells in the intestine of C. macropomum , possibly related to an immune response, and concluded that species that present this type of cell might respond more quickly to sanitary challenges observed in fish farming.…”

Digestive tube of an herbivorous fish (Rhytiodus microlepis) from the Amazonian floodplain lakes: A morphological and histochemical study

“…In the intestinal mucosa of R. microlepis, we found two mucous cell types that reacted positively to the histochemical methods used, the goblet cells and rodlet cells. These cells are reported in the intestine of some families of teleosts such as Salmonidae, Cyprinidae, Gadidae, Labridae, Serrasalmidae (Nordi, 2015;De Oliveira et al, 2019) and omnivorous anostomids (Albrecht et al, 2001). Gut mucin glycoproteins are synthesised and secreted by goblet cells; however, according to Deplancke and Gaskins (2001), the regulatory networks that mediate goblet cell responses to intestinal injuries are poorly defined.…”