Alkaline phosphatase activity in serum of guinea fowl bearing bone tumours induced by osteopetrosis virus strain PTS‐56

Effects of Fishmeal Substitution with Mealworm Meals (Tenebrio molitor and Alphitobius diaperinus) on the Growth, Physiobiochemical Response, Digesta Microbiome, and Immune Genes Expression of Atlantic Salmon (Salmo salar)

A 12-week growth trial was conducted to assess the effects of mealworm meals, as a substitution for fishmeal, on the growth, physiobiochemical responses, digesta microbiome, and immune-related genes expression of Atlantic salmon (Salmo salar). Twenty Atlantic salmon parr (38.5 ± 0.1 g, initial weight) were stocked into each of 16 tanks in a recirculating aquaculture system. A fishmeal-based diet (100% FM) was used as the control treatment and was compared with three test diets where: (1) fishmeal was partially (50%) replaced with defatted mealworm meal, Tenebrio molitor (50% DMM), (2) fishmeal was fully replaced with defatted mealworm meal (100% DMM), and (3) fishmeal was partially replaced with whole lesser mealworm meal, Alphitobius diaperinus (50% WMM). All substitutions were done on a crude protein basis. Each of the four experimental diets was evaluated in quadruplicate tanks as part of randomized design. The results indicated that Atlantic salmon showed high survival (greater or equal to 98.8%), and no significant difference in final growth, feed efficiency, feces stability and condition indices. Hepatosomatic index was lower in fish fed 100% DMM and 50% WMM when compared to fish fed the control diet (100% FM). Whole-body proximate and amino acid compositions were not statistically different between treatments, while essential fatty acids, including linolenic, eicosapentaenoic acid, and homo-a-linolenic, were lower in fish fed 100% DMM. Plasma parameters (total protein, alanine aminotransferase, alkaline phosphatase, and total iron-binding capacity), hepatic peroxide, and antioxidant enzymes were not significantly affected by dietary substitutions, whereas plasma immunoglobulin M showed significantly higher levels in fish fed 50% DMM and 100% DMM when compared to fish fed the control diet (100% FM). The inclusion of mealworm meals significantly impacted the overall microbiome composition but not the richness and evenness of the salmon digesta microbiomes compared to control. The most common genus in all treatments was Pseudomonas, which has been previously shown to have both commensal and pathogenic members. The relative expressions of growth (IGF-I) and protein synthesis (TIPRL) were not significantly different between the treatments, whereas immunoglobulin genes (IgM, IgD, and IgT) were significantly upregulated in fish fed the DMM diets when compared to fish fed the control diet. Overall, this study suggests that the mealworm meals tested could be suitable alternatives to fishmeal in the diet of Atlantic salmon.

The effects of fish meal substitution by clam meal on the growth and health of Florida pompano (Trachinotus carolinus)

A 12-week feeding trial was conducted to evaluate the effects of fish meal (FM) substitution by clam meal (CM, at 10%, 20% and 30% of the diet) on the growth, feed utilization, hepatic antioxidant enzymes, plasma parameters, fatty acid and amino acid composition, and gut microbiome of juvenile Florida pompano, Trachinotus carolinus. The results indicated that: (1) juveniles fed 10% and 20% CM had a significantly higher final weight than the group fed the control (0% CM); and the control group also showed significantly lower weight gain, feed intake, protein retention value, whole-body crude protein and total amino acids composition, but higher hepatosomatic index and whole-body crude fat; (2) hepatic peroxide content and superoxide dismutase activity were not significantly affected by the substitution of CM, but it did affect glutathione peroxidase activity, with higher levels found in fish fed 30% CM compared to 0% and 10% CM; (3) plasma total protein, alkaline phosphatase, alanine aminotransferase, and immunoglobulin M showed no significant differences among the treatments; (4) there were no significant differences among treatments in terms of fatty acids composition and microbial diversity. Overall, this study concluded that CM has comparable benefit in the diet of Florida pompano as FM does.

Effects of Schizochytrium and micro-minerals on immune, antioxidant, inflammatory and lipid-metabolism status of Micropterus salmoides fed high- and low-fishmeal diets

A 12-week factorial experiment was conducted to investigate the interactive effects of dietary algal meal (Schizochytrium sp., AM) and micro-minerals (MM, either organic [OM] or inorganic [IM]) on the immune and antioxidant status, and the expression of hepatic genes involved in the regulation of antioxidants, inflammatory cytokines, lipid metabolism, and organ growth of largemouth bass (LMB; Micropterus salmoides) fed high-and low-fishmeal (FM) diets. For this purpose, two sets of six iso-nitrogenous (42% crude protein) and iso-lipidic (12% lipid) diets, such as high (35%) and low (10%) FM diets were formulated. Within each FM level, AM was used to replace 50% or 100% of fish oil (FO), or without AM (FO control) and supplemented with either OM or IM (Fe, Zn, Mn, Cu, and Se). Diets were fed to juvenile LMB (initial weight, 25.87 ± 0.08 g) to near satiation twice daily. The results indicated that FO replacement by dietary AM did not change the levels of most biochemical (ALB, AMY, TP and GLOB), antioxidants (SOD, GPx and GSH), and immune (IgM and lysozyme) parameters in LMB, except ALP and CAT. MM affected only hepatic GSH, with lower values in fish fed the OM diets. FM influenced the levels of ALP, AMY, GLOB, IgM, and MDA (P < 0.05). A three-way interactive effect (P = 0.016) was found on IgM only, with lower levels in fish fed diet 12 (low-FM, AM100, OM). Subsequently, the relative expressions of hepatic antioxidants (Cu/Zn-SOD and GPx-4), inflammatory cytokines (TNF-α and TGF-β1), lipid metabolism (FASN and CYP7A1), and organ growth (IGF-I) related genes were affected by the dietary treatments, with interactions being present in Cu/Zn-SOD, TNF-α, TGF-β1, FASN and IGF-I. Overall, dietary AM could be used as an alternative to FO in low-FM diets without compromising the health of LMB, especially when it is supplemented with MM.

Changes in alkaline phosphatase isoenzyme activity in tissues and plasma of Atlantic salmon (Salmo salar) before and during smoltification and gonadal maturation

Changes in tissue and plasma isoenzymes of alkaline phosphatase (ALP) were qualitatively and quantitatively determined for male and female Atlantic salmon parr, silvery parr, smolt, immature grilse, prespawning grilse and postspawning grilse using cellulose acetate electrophoresis, densitometry and spectrophotometry. Tissue ALP isoenzymes were isolated from intestine, kidney, bone, liver, and gonad and compared to plasma isoenzymes. Parr plasma displayed three isoenzymes from bone and liver (slow and fast). During smoltification, ALP activity increased in tissue extracts from liver, gonad, and kidney of males and females. Total plasma ALP activity also increased and was due to slow and fast liver isoenzymes. During ovarian development, total ALP plasma activity increased in females and was due mostly to liver isoenzymes and an incompletely identified isoenzyme or isoenzyme mixture (band 2). However, in males total ALP plasma activity did not increase during maturation and no band 2 was evident. In male and female maturing adult grilse, bone ALP activity declined and the isoenzyme band evident in parr plasma could not be detected. ALP activity declined in the plasma of postspawning males and females. In females this was due partly to the total clearance of band 2 from the plasma, together with lowered levels of liver isoenzymes. Treatment of postspawned grilse in February and March with triiodothyronine and thyroxine elevated plasma thyroid hormone levels and increased plasma ALP levels. In conclusion, plasma ALP isoenzyme activities change with physiological state, and knowledge of the conditions governing these changes is important when using these enzymes as a diagnostic tool.