Dietary Arthrospira platensis improves systemic antioxidant potential and changes plasma lipids without affecting related hepatic metabolic pathways in post-weaned piglets

Impact of high Spirulina diet, extruded or supplemented with enzymes, on blood cells, systemic metabolites, and hepatic lipid and mineral profiles of broiler chickens

The impact of 15% dietary inclusion of Spirulina (Arthrospira platensis) in broiler chickens was explored, focusing on blood cellular components, systemic metabolites and hepatic lipid and mineral composition. From days 14 to 35 of age, 120 broiler chickens were divided and allocated into four dietary treatments: a standard corn and soybean meal-based diet (control), a 15% Spirulina diet, a 15% extruded Spirulina diet, and a 15% Spirulina diet super-dosed with an enzyme blend (0.20% porcine pancreatin plus 0.01% lysozyme). The haematological analysis revealed no significant deviations (p > 0.05) in blood cell counts across treatments, suggesting that high Spirulina inclusion maintains haematological balance. The systemic metabolic assessment indicated an enhanced antioxidant capacity in birds on Spirulina diets (p < 0.001), pointing toward a potential reduction in oxidative stress. However, the study noted a detrimental impact on growth performance metrics, such as final body weight and feed conversion ratio (both p < 0.001), in the Spirulina-fed treatments, with the super-dosed enzyme blend supplementation failing to alleviate these effects but with extrusion mitigating them. Regarding hepatic composition, birds on extruded Spirulina and enzyme-supplemented diets showed a notable increase in n-3 fatty acids (EPA, DPA, DHA) (p < 0.001), leading to an improved n-6/n-3 PUFA ratio (p < 0.001). Despite this positive shift, a reduction in total hepatic lipids (p = 0.003) was observed without a significant change in cholesterol levels. Our findings underscore the need for further exploration into the optimal inclusion levels, processing methods and potential enzymatic enhancements of Spirulina in broiler diets. Ultimately, this research aims to strike a balance between promoting health benefits and maintaining optimal growth performance in poultry nutrition.

Dietary Ulva lactuca and CAZyme supplementation improve serum biochemical profile and hepatic composition of weaned piglets

Ulva lactuca is a seaweed with antinutritional cell wall for monogastrics. Carbohydrate-Active enZymes (CAZymes) supplementation can potentially cause its disruption. This study evaluates four diets: Ctrl-control diet; UL-control + 7% U. lactuca (wild caught, powdered form); ULR-UL + 0.005% Rovabio^® Excel AP; ULU-UL + 0.01% ulvan lyase on piglets' haematologic and serologic profiles, hepatic lipids and minerals. White blood cells and lymphocytes reached the highest values in piglets fed UL compared to control, and to control and ULR; respectively (P < 0.05). IgG levels were boosted by seaweed incorporation compared to control (P = 0.015). The glycaemic homeostasis was assured by the seaweed inclusion. Dietary seaweed decreased serum lipids (P < 0.001), with the exception of ULU, due to HDL-cholesterol increase (P < 0.001). Cortisol was decreased in ULR and ULU (P < 0.001). No systemic inflammation was observed (P > 0.05). While hepatic n-3 PUFA increased in piglets fed with seaweed diets due to increment of beneficial 22:5n-3 and 22:6n-3 fatty acids (P < 0.05), the opposite occurred for n-6 PUFA, PUFA/SFA and n-6/n-3 ratios (P < 0.05). Hepatic pigments were unchanged (P > 0.05). ULR reduced α-tocopherol levels (P = 0.036) and increased serum potassium levels (P < 0.001) compared to control. Seaweed contributed to overcome piglets' weaning stress, with some benefits of including CAZyme supplementation.

Effect of dietary Spirulina (Arthrospira platensis) on the intestinal function of post-weaned piglet: An approach combining proteomics, metabolomics and histological studies

The effect of dietary Spirulina (Arthrospira platensis) and CAZyme supplementation was assessed on the gut of weaned piglets, using an integrated NMR-metabolomics approach combined with Tandem Mass Tag labelled proteomics. Thirty weaned male piglets were assigned to one of the three following diets (n = 10): cereal and soybean meal basal diet (Control), basal diet with 10% Spirulina inclusion (SP) and SP diet supplemented with 0.01% lysozyme (SP + L). The experiment lasted 4 weeks and, upon slaughter, small intestine samples were collected for histological, metabolomic and proteomic analysis. No significant differences were found for the histology and metabolomics analysis between the three experimental groups. Lactate, glutamate, glycine and myo-inositol were the most abundant metabolites. Proteomics results showed 1502 proteins identified in the intestine tissue. A total of 23, 78, 27 differentially abundant proteins were detected respectively for the SP vs. Control, SP + L vs. Control and SP + L vs. SP comparisons. The incorporation of Spirulina and supplementation of lysozyme in the piglet's diets is associated to intestinal proteomic changes. These include increased protein synthesis and abundance of contractile apparatus proteins, related with increased nutrient availability, which has beneficial (increased glucose uptake) and detrimental (increased digesta viscosity) metabolic effects. SIGNIFICANCE: The use of conventional feedstuffs becomes increasingly prohibitive due to its environmental toll. To increase the sustainability of the livestock sector, novel feedstuffs such as microalgae need to be considered. However, its recalcitrant cell wall has antinutritional effects that can inhibit high dietary inclusion levels. The supplementation with CAZymes is a possible solution to this issue. The small intestine is a central piece in monogastric digestion and of particular importance for the weaned piglet. Studying the effect of dietary Spirulina and CAZyme supplementation on its histomorphology, metabolome and proteome allows studying relevant physiological adaptations to these diets.

Antioxidant and Antimicrobial Activity of Algal and Cyanobacterial Extracts: An In Vitro Study

Algae and cyanobacteria, other than their nutritional value, possess different beneficial properties, including antioxidant and antimicrobial ones. Therefore, they can be considered functional ingredients in animal feed and natural substitutes for antibiotics. The aim of this study was to evaluate the antioxidant and antimicrobial capacity against porcine O138 E. coli of Ascophyllum nodosum, Chlorella vulgaris, Lithotamnium calcareum, Schizochytrium spp. as algal species and Arthrospira platensis as cyanobacteria. The antioxidant capacity was determined by ABTS Radical Cation Decolorization Assay testing at three different concentrations (100%; 75%; 50%). The growth inhibition effect of the extracts at concentrations of 25%, 12.5%, 6%, 3% and 1.5% against porcine O138 E. coli was genetically characterized by PCR to detect the presence of major virulence factors; this was evaluated by following the microdilution bacterial growth method. The ABTS assay disclosed that Ascophyllum nodosum was the compound with the major antioxidant properties (57.75 ± 1.44 percentage of inhibition; p < 0.0001). All the extracts tested showed growth inhibition activity at a concentration of 25%. Among all extracts, A. nodosum was the most effective, showing a significant growth inhibition of E. coli; in particular, the log10 cells/mL of E. coli used as a control resulted in a significantly higher concentration of 25% and 12.5% after 4 h (8.45 ± 0.036 and 7.22 ± 0.025 log10 cells/mL, respectively; p < 0.005). This also suggests a dose-dependent relationship between the inhibitory activity and the concentration. Also, a synergistic effect was observed on antioxidant activity for the combination of Ascophyllum nodosum and Lithotamnium calcareum (p < 0.0001). Moreover, to determine if this combination could affect the viability of the IPEC-J2 cells under the normal or stress condition, the viability and membrane integrity were tested, disclosing that the combination mitigated the oxidative stress experimentally induced by increasing the cell viability. In conclusion, the results obtained highlight that the bioactive compounds of algal species are able to exert antioxidant capacity and modulate O138 E. coli growth. Also, the combination of Ascophyllum nodosum and Lithotamnium calcareum species can enhance their bioactivity, making them a promising functional feed additive and a suitable alternative to antibiotics.