Using Azadirachta indica protein hydrolysate as a plant protein in Nile tilapia (Oreochromis niloticus) diet: Effects on the growth, economic efficiency, antioxidant-immune response and resistance to Streptococcus agalactiae.

A feeding trial for 90 days was conducted on Nile tilapia (Oreochromis niloticus) (average weight: 25.50 ± 0.05 g) to evaluate the effect of dietary inclusion of Azadirachta indica seed protein hydrolysate (AIPH). The evaluation included the impact on the growth metrics, economic efficiency, antioxidant potential, hemato-biochemical indices, immune response, and histological architectures. A total of 250 fish were randomly distributed in five treatments (n = 50) and received diets included with five levels of AIPH (%): 0 (control diet, AIPH0), 2 (AIPH2), 4 (AIPH4), 6 (AIPH6) or 8 (AIPH8), where AIPH partially replace fish meal by 0, 8.7%, 17.4%, 26.1%, and 34.8%, respectively. After the feeding trial, a pathogenic bacterium (Streptococcus agalactiae, 1.5 × 108 CFU/mL) was intraperitoneally injected into the fish and the survival rate was recorded. The results elucidated that AIPH-included diets significantly (p < 0.05) enhanced the growth indices (final body weight, total feed intake, total body weight gain, and specific growth rate) and intestinal morpho-metrics (villous width, length, muscular coat thickness, and goblet cells count) in comparison to the control diet, with the AIPH8 diet recording the highest values. Dietary AIPH inclusion significantly improved (p < 0.05) the economic efficacy indicated by reduced feed cost/kg gain and increased performance index. The fish fed on the AIPH diets had noticeably significantly higher (p < 0.05) protein profile variables (total proteins and globulin) and antioxidant capabilities (superoxide dismutase and total antioxidant capacity) than the AIPH0 group. The dietary inclusion of AIPH significantly (p < 0.05) boosted the haematological parameters (haemoglobin, packed cell volume %, and counts of red blood cells and white blood cells) and immune indices (serum bactericidal activity %, antiprotease activity, and immunoglobulin M level) in a concentration-dependent manner. The blood glucose and malondialdehyde levels were significantly (p < 0.05) lowered by dietary AIPH (2%-8%). The albumin level and hepatorenal functioning parameters (aspartate aminotransferase, alanine aminotransferase, and creatinine) were not significantly (p > 0.05) altered by AIPH diets. Additionally, AIPH diets did not adversely alter the histology of the hepatic, renal or splenic tissues with moderately activated melano-macrophage centres. The mortality rate among S. agalactiae-infected fish declined as dietary AIPH levels rose, where the highest survival rate (86.67%) was found in the AIPH8 group (p < 0.05). Based on the broken line regression model, our study suggests using dietary AIPH at the optimal level of 6%. Overall, dietary AIPH inclusion enhanced the growth rate, economic efficiency, health status, and resistance of Nile tilapia to the S. agalactiae challenge. These beneficial impacts can help the aquaculture sector to be more sustainable.

Supplementation of different zinc sources to low-CP diets and its effect on performance, carcass traits, liver and kidney functions, immunological, and antioxidant parameters of quail chicks.

The present study was performed to evaluate the influence of low crude protein (CP) levels, zinc sources (organic as zinc methionine-Zn-Met and inorganic as zinc oxide-ZnO) and their interactions on growth performance, carcass traits, and blood components of growing Japanese quail. A total of 450 one-wk-old Japanese quail with the same body weights were randomly distributed into 9 groups of 50 birds. The 9-diet treatments comprised 3 levels of CP (20, 22, and 24%) and 3 Zn source (0 g of Zn/kg diet, 0.1 g ZnO/kg diet, and 0.1 g Zn-Met/kg diet). The results obtained from this study showed that there were no significant differences among the groups, except for differences in body weight (BW) and body weight gain (BWG) at 3 to 5 - and 1 to 5 wk of age for quail supplemented with 24% and 20% CP. All the studied biochemical parameters were significantly influenced by different levels of CP and Zn, except urea and creatinine, which were affected by CP levels only. In conclusion, dietary protein level for growing Japanese quails could be reduced to 20% without negative effects on their performance, carcass traits, and blood metabolites.

Astragalus membranaceus polysaccharides modulate growth, hemato-biochemical indices, hepatic antioxidants, and expression of HSP70 and apoptosis-related genes in Oreochromis niloticus exposed to sub-lethal thallium toxicity.

A 60-day experiment was performed to assess the efficacy of dietary Astragalus membranaceus polysaccharides (ASP) in attenuation of sub-lethal thallium (Tl) toxicity in Nile tilapia. Six experimental groups (in triplicates) were designed where a fish group was raised in clean water and fed basal diet and served as control (CONT), two groups were fed the basal diet supplemented with 0.15% and 0.30% ASP (ASPL and ASPH), Tl-intoxicated group exposed to 1/10 of 96-h LC50 (= 41.9 µg/L), and two other groups were fed 0.15% and 0.30% ASP and concomitantly exposed to 41.9 µg Tl/L (ASPL-Tl and ASPH-Tl). At the end of the experiment, fish behavioral responses, clinical signs, survivability, growth, whole-body composition, intestinal digestive enzymes, serum biochemical parameters, hepatic antioxidative biomarkers, and transcription of stress and apoptosis genes were assessed. Results showed that the whole-body composition, intestinal α-amylase and protease enzymes, serum AST and blood urea levels, and hepatic GSH were not significantly different among groups (P > 0.05). The Tl-intoxicated fish group was off food, had darkened skin, showed restlessness and hyperexcitability, and high mortalities. FBW, WG, SGR and FI were significantly decreased alongside increase FCR in the Tl-exposed group. Tl exposure caused significant increases (P < 0.05) in intestinal lipase enzyme and serum indices such as ALT, creatinine, total cholesterol, triglycerides, glucose, and cortisol levels. Moreover, a significant decreases in hepatic CAT and SOD enzyme activities and significant increases in hepatic MDA contents were also noticed (P < 0.05). Furthermore, Tl exposure induced significant upregulation of hepatic HSP70 and apoptosis-related genes (p53 and caspase 3). Interestingly, dietary supplementation with ASP in ASPL-Tl and ASPH-Tl groups modulated the parameters mentioned above but still not reached the CONT values. Altogether, this study suggests that ASP could be beneficial in the modulation of sub-lethal Tl toxicity effects in Nile tilapia. Additionally, we can conclude that using natural feed supplements such as ASP in aquafeed might be necessary for maintaining the overall health performances of Nile tilapia.

Melamine and curcumin enriched diets modulate the haemato-immune response, growth performance, oxidative stress, disease resistance, and cytokine production in oreochromis niloticus.

Currently, feed adulteration and contamination with melamine (MEL) are considered one of the serious issues in the aquatic industry. With the limited studies of MEL exposure alone in fish, its adverse impacts on fish cannot be evaluated well. Accordingly, this study aimed to investigate the effects of MEL containing diets on the immune response, disease resistance to Aeromonas hydrophila, growth performance, chemical composition, immune-related genes expression, and histopathology of both spleen and head kidneys. Also, the efficacy of curcumin (CUR) dietary supplementation to alleviate MEL negative impacts were evaluated. A total of 180 apparently healthy Oreochromis niloticus (O. niloticus) were divided into four groups with three replicates fed the basal diet only, basal diet fortified with 200 mg/kg CUR, basal diet containing 1 % MEL, or a basal diet containing CUR + MEL. The results displayed that MEL significantly reduced growth performance indices and body crude lipid contents. Anemic, leukopenic, lymphocytopenic, heterocytopenic, esonipenic, hypoproteinemic and hypoalbuminic conditions were apparent. Moreover, depleted immune and antioxidant indicators including lysozyme activity, nitric oxide, immunoglobulin M, complement 3, glutathione peroxidase, and superoxide dismutase enzyme activity were recorded. Also, MEL reduced the disease resistance of O. niloticus to bacterial infection. Furthermore, MEL induced downregulation of mRNA levels of interleukin 1ß and tumor necrosis factor α in the spleen together with obvious pathological perturbations in both spleen and head kidneys. The CUR addition resulted in a significant enhancement in most indices. These results may conclude that MEL could alter both innate and adaptive immune responses via the negative transcriptional effect on immune-related genes together with the oxidative damage of the immune organs. Furthermore, CUR dietary supplements could be advantageous for mitigating MEL negative impacts, thus offering a favorable aquafeed additive for O. niloticus.

Ameliorative effect of ginseng extract on phthalate and bisphenol A reprotoxicity during pregnancy in rats.

Phthalates (such as DEHP) and bisphenol A (BPA) are widely used chemicals in plastics manufacturing and exert public health concerns as endocrine disrupters. This study was designed to investigate the deleterious effect of DEHP and BPA on endocrine profile of pregnant female rats and the combined treatment with ginseng extract (Panax ginseng). Seventy-two pregnant rats were divided into six groups (control, ginseng, DEHP, BPA, Gin + DEHP, and Gin + BPA), 12 females per each group. The drugs were supplemented from pregnancy day 0 until day 20. Determination of serum sex hormones (testosterone, progesterone, and estradiol) were determined on days 4, 10, and 20 of pregnancy. mRNA transcripts of STAR, HSD17B3, CYP17, AKT1, and PTEN were relatively quantified against ACTB in the ovary and placenta of days 10 and 20 pregnant females by relative quantitative polymerase-chain reaction (RQ-PCR). DEHP and BPA significantly decreased the endocrine profile of testosterone, progesterone, and estradiol of days 10 and 20 of pregnant females. Combined administration of these chemicals along with ginseng extracts has returned the hormones to normal levels when compared with the control group. The ovarian and placental CYP17 and HSD17B3 mRNA transcripts showed variable expression pattern in both tissues and they were significantly affected by DEHP and BPA administration, concomitantly correlating to STAR, AKT1, PTEN, progesterone, and testosterone levels on pregnancy days 10 and 20. The results confirm the reprotoxicity of DEHP and BPA as endocrine disruptors and indicate that ginseng could be used to alleviate the toxic effects of these chemicals.