Effects of dietary taurine amino acid on growth performance, mucosal and immune response, gene expression and antioxidant defence of asian seabass (Lates calcarifer).

BACKGROUND: The enhancement of fish immune system and growth performance throughout the administration of bio-friendly agents such as diet supplements (taurine) is considered a promising alternative in farmed aquatic species. MATERIALS AND METHODS: The present study was aimed to examine the effect of supplementation of dietary taurine (0, 5 g-TAU5 and 10 g-TAU10) in crystalline form (99% purity) in L. calcarifer juveniles, taking into account growth performance, general health indices and immune related-genes mRNA transcript abundance. RESULTS: The results confirmed that the supplementation of taurine enhances significantly all the growth parameters and a better flesh quality. While the blood biochemical and immunological factors didn't present any significant differences, the expression of growth-related genes showed that IGF-1 was almost 3 times higher in fishes fed diet Tau 5 and Tau 10 compared to the control group. CONCLUSIONS: Finally, it can be concluded that at the maximum dose tested (10 g) the treatment was effective for Asian seabass. In addition, Tau inclusion in an FM-based diet can increase the productivity parameters along with raising the antioxidant status.

Effect of Dietary Lactobacillus casei on Physiometabolic Responses and Liver Histopathology in Common Carp (Cyprinus carpio) After Exposure to Iron Oxide Nanoparticles.

A 60-day feeding trial was performed to assess the dietary effect of Lactobacillus casei as a probiotic supplement on some serum biochemical parameters and liver histopathology in common carp fry after exposure to iron oxide nanoparticles (IoNPs). Six treatments were prepared as follows: control (no IoNP exposure and no dietary probiotic), P6: 106 CFU/g probiotic diet, P7: 107 CFU/g probiotic diet, NPs: 0.15 mg/l IoNPs, NPs + P6: 0.15 mg/l IoNPs with 106 CFU/g probiotic diet, and NPs + P7: 0.15 mg/l IoNPs with 107 CFU/gprobiotic diet. Based on the results, serum aspartate aminotransferase and alanine aminotransferase levels were significantly increased in 0.15 mg/l IoNPs, P7, and NPs + P6 treatments compared to the control group. In addition, the examination of antioxidant enzymes showed a significant increase in the levels of cortisol and glutathione S-transferase as well as malondialdehyde level. IoNPs also caused significant histopathological changes in the fish liver during the experiment such as hyperemia in sinusoidal spaces, hepatocytes vacuolation and necrosis, pyknosis, and disruption of hepatic lobules and atrophy. Results revealed the protective effects of dietary L. casei to mitigate the adverse impacts of IoNPs on the physiological processes of common carp.

Effects of dietary supplementation of bovine lactoferrin on antioxidant status, immune response and disease resistance of yellowfin sea bream (Acanthopagrus latus) against Vibrio harveyi.

This study investigated the effect of the dietary supplementation of bovine lactoferrin (LF) on growth performance, hematological and immunological parameters, antioxidant enzymes activity and disease resistance against Vibrio harveyi in yellowfin sea bream (Acanthopagrus latus) fingerling. The fish with initial body weight 10 ±â€¯0.3 g were randomly distributed at 10 fish per each 250 L fiberglass tank, and fed with four experimental diets (a control basal diet and three supplemented diets with 400, 800 and 1200 mg LF kg-1 diet) for 8 weeks. The obtained results showed that fish fed with LF supplemented diets had significantly higher final body weight as compared to control diet (P < 0.05). There were no significant differences between LF-treatments and the control group in white blood cell counts, red blood cell counts, hemoglobin and hematocrit. Total protein and complement activity (ACH50) in the serum of yellowfin sea bream were enhanced with increasing the dietary LF supplementation level (P < 0.05). The mucus lysozyme activity in fish fed on 800 and 1200 mg LF kg-1 was significantly higher than those fed on 400 mg LF kg-1 and control fish (P < 0.05). None of the antioxidant enzymes (catalase, glutathione reductase, glutathione S-transferase) was affected by LF supplementation (P > 0.05). Fish fed with dietary LF had a significantly higher survival rate than those fed with the control diet after challenge with Vibrio harveyi (P < 0.05). These results revealed that diet supplementation in A. latus especially with 1200 mg LF kg-1 improve fish growth performance and immune parameters, as well as survival rate against Vibrio harveyi.