Physiological response,blood chemistry profile and mucus secretion of red sea bream (<Emphasis Type="Italic">Pagrus major</Emphasis>) fed diets supplemented with <Emphasis Type="Italic">Lactobacillus rhamnosus</Emphasis> under low salinity stress

Environmental stressors caused by inadequate aquaculture management strategies suppress the immune response of fish and make them more susceptible to diseases. Therefore, efforts have been made to relieve stress in fish by using various functional feed additives in the diet, including probiotics. The present work evaluates the effects of Lactobacillus rhamnosus (LR) on physiological stress response, blood chemistry and mucus secretion of red sea bream (Pagrus major) under low salinity stress. Fish were fed four diets supplemented with LR at [0 (LR0), 1 × 10² (LR1), 1 × 10⁴ (LR2) and 1 × 10⁶ (LR3) cells g^?1] for 56 days. Before stress, blood cortisol, urea nitrogen (BUN) and total bilirubin (T-BIL) showed no significant difference (P > 0.05), whereas plasma glucose and triglyceride (TG) of fish-fed LR2 and LR3 diets were significantly lower (P < 0.05) than those of the other groups. Plasma total cholesterol (T-CHO) of fish-fed LR3 diet was significantly (P < 0.05) lower than that of the other groups. Furthermore, total plasma protein, mucus myeloperoxidase activity and the amount of mucus secretion were significantly enhanced in LR-supplemented groups when compared with the control group (P < 0.05). After the application of the low salinity stress test, plasma cortisol, glucose, T-CHO and TG contents in all groups showed an increased trend significantly (P < 0.01) compared to the fish before the stress challenge. However, plasma total protein and the amount of secreted mucus showed a decreased trend in all groups. On the other hand, BUN, T-BIL and mucus myeloperoxidase activity showed no significant difference after exposure to the low salinity stress (P > 0.05). In addition, the fish that received LR-supplemented diets showed significantly higher tolerance against low salinity stress than the fish-fed LR-free diet (P < 0.05). The physiological status and the detected immune responses, including total plasma protein and mucus myeloperoxidase activity in red sea bream, will provide a more comprehensive outlook of the effects of probiotics to relieve stress in fish.     

Effect of high inclusion of rendered animal by‐product ingredients on growth,digestibility and economic performances in climbing perch Anabas testudineus

A 70‐day growth trail was conducted to investigate the effects of inclusion of high levels of meat and bone meal (MBM) and protein concentrate (PC) on growth, digestibility and economic performances of climbing perch, Anabas testudineus. Four isonitrogenous diets were formulated by lowering the level of dietary fishmeal protein at 0 (D₁, control), 70 (D₂), 85 (D₃) and 100% (D₄) with a mixture of MBM and PC protein (1:1). Triplicate groups of 300 fish (mean weight of 0.80 g) stocked in each 40 m² pond and fed the respective test diets. A digestibility trial was conducted after the growth trial in indoor glass aquarium. The result showed that growth parameters were significantly decreased (P < 0.05) with fishmeal replacement levels. However, significant differences were not found in feed conversion ratio and survival of fish. No difference was also found in protein efficiency ratio among D1, D2 and D3. Similar to growth parameters, total fish production was highest in D1, intermediate in D2 and D3; and lowest in D4. Apparent digestibility coefficients of dry matter, protein and lipid were highest (P < 0.05) in D1 and lowest in D4. The economic analysis revealed that the benefit cost ratio was ranked by D₃ (1.81), D₂ (1.71), D₁ (1.66) and D₄ (1.46) respectively. Upon considering the overall performances and unavailability of finite protein sources, it can be concluded that 70–85% fishmeal could be replaced with a mixture of MBM and PC (1:1) in practical diets for climbing perch.     

Replacement of squid and krill meal by snail meal (Buccinum striatissimum) in practical diets for juvenile of kuruma shrimp (Marsupenaeus japonicus)

A 60‐day feeding trial was conducted to investigate the effects of substituting squid and krill meal with marine snails (Buccinum striatissimum) into the diets of juvenile kuruma shrimps (Marsupenaeus japonicus). Five experimental diets were formulated to contain varying levels of snail meal at 0%, 25%, 50%, 75% and 100% (D1, D2, D3, D4 and D5, respectively) and fed to juvenile kuruma shrimps (initial mean weight 0.27 ± 0.02 g). The results showed that weight gain, feed intake and specific growth rate were improved significantly in D4 and D5 groups when compared with D1 group (p < 0.05). Significant differences were not detected in survival rate among all shrimps fed diets containing several levels of snail meal (p > 0.05). Crude protein content of shrimps fed the control diet was significantly lower than other treatments (p < 0.05). Lipid content in shrimps fed 50% snail meal were significantly higher than the control while cholesterol content in shrimps fed 100% snail meal were significantly decreased and polyunsaturated fatty acid contents were significantly increased in shrimps fed 75%–100% snail meal (p < 0.05). These results suggest that supplementing snail meal for complete replacement of squid and krill meal can be done to improve juvenile kuruma shrimps’ growth and reducing their cholesterol levels.     

Combination of serum phosphorylated neurofilament heavy subunit and hyperintensity of intramedullary T2W on magnetic resonance imaging provides better prognostic value of canine thoracolumbar intervertebral disc herniation

The aim of this study was to evaluate the prognostic value of concurrent measurement of serum phosphorylated neurofilament heavy subunit (pNF-H) concentration and intramedullary T2W hyperintensity in paraplegic to paraplegic dogs. Our hypothesis was that concurrent measurement of these would provide a more accurate prediction of functional outcome in dogs with thoracolumbar intervertebral disc herniation (IVDH). A prospective case-control clinical study was designed using 94 dogs with acute onset of thoracolumbar IVDH. The association of serum pNF-H concentration, T2W hyperintensity on sagittal MRI (T2H/L2), deep pain perception and surgical outcome were evaluated with logistic regression analysis after three months for all 94 surgically treated dogs. Sensitivity to predict non-ambulatory outcome was compared among pNF-H and T2H/L2 and combination of both. Logistic regression analysis indicated that serum pNF-H concentration and T2H/L2 were significantly correlated with surgical outcome (P<0.05); however, deep pain perception was not (P=0.41). The results of logistic regression analysis indicated that the odds ratios of unsuccessful long-term outcome were 2.6 for serum pNF-H concentration, 1.9 for T2H/L2 and 2.3 for deep pain sensation. The sensitivity and specificity to predict non-ambulatory outcome for using serum parameter pNF-H>2.6 ng/ml, using T2H/L2 value of>0.84 and using both serum pNF-H and T2H/L2, were 95% and 75.7%, 65% and 86.5%, and 90.0% and 97.5%, respectively. Therefore, combined measurements of serum pNF-H and T2H/L2 might be useful for predicting long-term outcome in dogs with thoracolumbar IVDH.     

Hypoxia inducible factor 1α expression and effects of its inhibitors in canine lymphoma

Hypoxic conditions in various cancers are believed to relate with their malignancy, and hypoxia inducible factor-1α (HIF-1α) has been shown to be a major regulator of the response to low oxygen. In this study, we examined HIF-1α expression in canine lymphoma using cell lines and clinical samples and found that these cells expressed HIF-1α. Moreover, the HIF-1α inhibitors, echinomycin, YC-1 and 2-methoxyestradiol, suppressed the proliferation of canine lymphoma cell lines. In a xenograft model using NOD/scid mice, echinomycin treatment resulted in a dose-dependent regression of the tumor. Our results suggest that HIF-1α contributes to the proliferation and/or survival of canine lymphoma cells. Therefore, HIF-1α inhibitors may be potential agents to treat canine lymphoma.     

Growth,nutrient utilization,oxidative condition,and element composition of juvenile red sea bream <Emphasis Type="Italic">Pagrus major</Emphasis> fed with fermented soybean meal and scallop by-product blend as fishmeal replacement

A feeding trial was conducted to evaluate the effect of fermented soybean meal and scallop by-product blend (3:2) (FP) on the performance of juvenile red sea bream. Five isocaloric diets were prepared by replacing 0% (FP0), 15% (FP15), 30% (FP30), 45% (FP45), and 60% (FP60) fishmeal (FM) protein with FP, respectively. Triplicate groups of fish (initial mean weight 2.83 g) were fed the test diets for 45 days in a flowthrough seawater system. The results demonstrated that growth rates of fish fed FP0, FP15, and FP30 were similar, and significantly higher (P < 0.05) than those of FP45 and FP60. Nutrient utilization was significantly lower in FP60, with no differences found among the other groups. Dietary heavy-metal contents were affected by inclusion of FP, impacting on whole-body heavy-metal contents. In terms of oxidative stress, fish fed the FP30 diet were in the best condition, since this fish group showed the least oxidative-stressed condition as well as the highest tolerance against oxidation. In conclusion, the approach of utilizing this fermented mixture is promising and it could replace at least 30% FM protein in red sea bream diet without negative effects on performance, body composition or health of fish.     

Effect of replacing fishmeal with canola meal on growth and nutrient utilization in kuruma shrimp Marsupenaeus japonicus (Bate)

A feeding trial was conducted to assess the nutritional values of canola meal as a substitute for fishmeal in diets for kuruma shrimp using five isocaloric diets (190 kJ kg^?1) prepared by replacing 0%, 10%, 20%, 30% and 40% of fishmeal protein with canola meal protein in CM0, CM10, CM20, CM30 and CM40 diets respectively. Triplicate groups of juveniles (0.19 g) were fed the respective diets for 60 days in tanks. At the end of trial, weight gain (%) and specific growth rate (% day^?1) were not significantly (P > 0.05) different among shrimp fed CM0, CM10 and CM20 diets. However, growth was significantly (P < 0.05) decreased in shrimp fed CM30 and CM40 diets. As with growth performance, feed intake, feed conversion ratio and protein efficiency ratio were also decreased (P < 0.05) in CM30 and CM40 groups. Whole body dry matter, methionine and proline were significantly decreased with canola meal substitution levels. In general, retention efficiency of protein and indispensible amino acids were decreased as canola meal increased in diets. It may be concluded that 20% fishmeal protein can be successfully replaced with canola meal, while supplementation of amino acids or blending with complementary proteins could facilitate higher fishmeal replacements in kuruma shrimp diets.     

Effects of dietary inactivated Pediococcus pentosaceus on growth performance,feed utilization and blood characteristics of red sea bream,Pagrus major juvenile

A feeding trial was carried out to determine effects of dietary supplements of inactivated Pediococcus pentosaceus (PP) on growth, feed utilization and blood characteristics of red sea bream. Five diets containing different concentrations [0 (PP0), 1.6 × 10¹⁰ (PPI), 1.6 × 10¹¹ (PPII), 1.6 × 10¹² (PPIII) and 3.2 × 10¹² (PPIV) cells g^?1] of PP were fed to fish for 56 days. At the end of the feeding trial, the obtained results revealed a significant increase (P < 0.05) in weight gain, specific growth rate and skin mucus secretion in all PP‐supplemented groups when compared with control group. Moreover, fish fed PPIII and PPIV diets resulted in significantly higher final body weight, feed efficiency ratio and bactericidal activity than those of fish fed PP0 diet (P < 0.05). Further, fish fed the PPIII diet also had a higher feed intake, protein efficiency retention, haematocrit, mucus lysozyme activity (LA), plasma and serum proteins than those of PP0 fed group (P < 0.05). Similarly, fish fed PPIV diet resulted in a significant increase in serum LA, peroxidase activity and tolerance against low‐salinity stress test (P < 0.05). Considering these promising results, we suggest that the supplementation of PP Prep improves growth and health conditions of Pagrus major.     

Antioxidant constituents in distillation residue of Awamori spirits

Constituents in a distillation residue of Awamori (millet spirits) and their antioxidant activity are investigated in this study. The supernatant of the distillation residue obtained by centrifugation was partitioned with n-hexane, chloroform, ethyl acetate, and n-butanol against water to afford the corresponding solubles. Among them, n-hexane and chloroform solubles showed higher antioxidant potency than l-ascorbic acid by the bleomycin-Fe method. In chloroform solubles, seven cyclic dipeptides were identified along with ethyl 2-pyrrolidione-5-carboxylate, tyrosol, and ethyl p-hydoroxyphenyllactate. Antioxidant activity of ethyl p-hydoroxyphenyllactate was 4.2 times that of l-ascorbic acid, whereas cyclic dipeptides showed activity 0.89-1.29 times as strong as that of l-ascorbic acid. On the other hand, scavenging effect of cyclic dipeptides against O(2)(-.) and OH(.) by using electron spin resonance was also investigated. In the results, cyclo(l-Ile-l-Pro) showed significantly strong inhibitory effect against OH(.) (95.4% at 2.5 x 10-3 M) and cyclo(l-Phe-l-Pro), cyclo(l-Pro-l-Val), and cyclo(l-Leu-l-Pro) inhibited OH(.) 64.9, 54.1, and 51.0%, respectively, whereas alpha-tocopherol showed 37.7% inhibition, though only a few cyclic dipeptides weakly inhibited O(2)(-.).