Test Diets Research Articles

Effects of supplementing coated methionine in a high plant-protein diet on growth, antioxidant capacity, digestive enzymes activity and expression of TOR signaling pathway associated genes in gibel carp, Carassius auratus gibelio.

This study explored the impacts of supplementation of different levels of coated methionine (Met) in a high-plant protein diet on growth, blood biochemistry, antioxidant capacity, digestive enzymes activity and expression of genes related to TOR signaling pathway in gibel carp (Carassius auratus gibeilo). A high-plant protein diet was formulated and used as a basal diet and supplemented with five different levels of coated Met at 0.15, 0.30, 0.45, 0.60 and 0.75%, corresponding to final analyzed Met levels of 0.34, 0.49, 0.64, 0.76, 0.92 and 1.06%. Three replicate groups of fish (initial mean weight, 11.37 ± 0.02g) (20 fish per replicate) were fed the test diets over a 10-week feeding period. The results indicated that with the increase of coated Met level, the final weight, weight gain (WG) and specific growth rate initially boosted and then suppressed, peaking at 0.76% Met level (P< 0.05). Increasing dietary Met level led to significantly increased muscle crude protein content (P< 0.05) and reduced serum alanine aminotransferase activity (P< 0.05). Using appropriate dietary Met level led to reduced malondialdehyde concentration in hepatopancreas (P< 0.05), improved superoxide dismutase activity (P< 0.05), and enhanced intestinal amylase and protease activities (P< 0.05). The expression levels of genes associated with muscle protein synthesis such as insulin-like growth factor-1, protein kinase B, target of rapamycin and eukaryotic initiation factor 4E binding protein-1 mRNA were significantly regulated, peaking at Met level of 0.76% (P< 0.05). In conclusion, supplementing optimal level of coated Met improved on fish growth, antioxidant capacity, and the expression of TOR pathway related genes in muscle. The optimal dietary Met level was determined to be 0.71% of the diet based on quadratic regression analysis of WG.

Dietary nano-Selenium supplementation improves growth performance, nutrient digestibility and hematology in Cirrhinus mrigala fingerlings

The following investigation was carried out to determine the effects of Selenium nanoparticles (Se NPs) on the growth rates, nutrient digestibility, and hematology of Cirrhinus mrigala fingerlings fed sunflower meal as basal diet. The experiment included seven test diets with varying Se levels (0, 0.5, 1, 1.5, 2, 2.5, and 3 mg/kg) based on Se NPs supplementation. Chromic oxide, an inert maker, was also added. Fingerlings were fed at a rate of 5% of their body weight. The test meal of 1 mg/kg Se NPs resulted in the highest weight gain (12.31 g) and the lowest feed conversion ratio (1.58). Best hematological indices (RBCs 2.84 106 mm−3, WBCs 7.79 103 mm−3, PLT 66, Hb 8.5 g/100 ml, PCV 25% and MCV 190 fl) and maximum nutrient absorption (crude protein 72%, ether extract 73% and gross energy 67%) were also observed in the case of 1 mg/kg supplementation of Se NPs. Hematology studies indicated that when fish were fed 0.5 mg/kg Se NPs, their levels began to rise. Maximum results were achieved with feed containing 1 mg/kg of Se NPs, but when the concentration increased above 1 mg/kg, the values began to decline. Instead, nutrient digestibility began to increase when the concentration of Se NPs increased to 1 mg/kg and abruptly started to decline with a further increase in Se NPs. The results demonstrated that a sunflower meal-based diet supplemented with Se NPs (1 mg/kg) increased the growth performance, nutritional digestibility, and hematology of C. mrigala fingerlings.

Improving Yellow Mealworm (Tenebrio molitor) Utilization with Sodium Butyrate in Nile Tilapia Diets: Effects on Growth Performance, Intestinal Histology, Antioxidative Response, and Blood Biomarkers

Yellow mealworm (Tenebrio molitor) meal was introduced to aquafeed as a suitable protein source to replace fish meal (FM) and soybean meal and, thereby, consistent aquaculture production. However, mealworms should be added at adequate levels due to the presence of antinutritional factors such as chitin. Consequently, sodium butyrate (SB) is suggested to improve feed quality and ensure aquatic animals’ productivity and welfare. In this study, parallel with the protein source (T. molitor meal or FM), dietary supplementation of SB (1 g/kg) is involved as a factor in the 2 × 2 factorial study. The first and the second diets were formulated using FM as a protein source with or without SB, while the third and fourth diets were prepared by replacing FM with T. molitor meal with or without SB supplementation. After 60 days, fish fed with FM or T. molitor and SB showed improved final body weight and weight gain, while those fed with T. molitor without SB had a reduced protein efficiency ratio. Histological analysis revealed that dietary SB improved intestinal histological features by increasing the height and branching of intestinal villi and immune cell infiltration near intestinal crypts in Nile tilapia-fed FM or T. molitor. Furthermore, fish-fed FM or T. molitor and SB had higher Hb, red blood cells, PCV, total protein, and globulin levels than fish-fed respective test diets without SB supplementation. Dietary SB addition to FM or T. molitor-based diets also significantly enhanced blood lysozyme and phagocytic activities, catalase, superoxide dismutase, glutathione peroxidase, and reduced MDA levels. Our results demonstrate that T. molitor meal can replace FM without compromising Nile tilapia’s growth performance and health status. Additionally, SB supplementation improved T. molitor meal utilization by Nile tilapia, thereby significantly enhancing the growth, digestion capacity, intestinal histological features, and antioxidative and immune responses. Consequently, dietary T. molitor meal reduces the reliance on FM and improves the sustainability and efficiency of Nile tilapia production.

Digestibility of Cockroach (Periplaneta americana) Insect Meal Diet By African Catfish (Clarias gariepinus) Juvenile and Its Effects on growth Performance

The use of Cockroach (Periplaneta americana) meal was studied to ascertain its digestibility and effect on growth performance of Clarias gariepinus. A 40% protein basal and test diets using fish and cockroach meal respectively with inert biomarker at 70:30% were fed for 42 days to Clarias gariepinus of average weight 29.22±0.18g. Catfish response to diets in terms of growth parameters revealed the following for reference diet fed and basal diet fed fish: weight gain (52.59g vs. 36.31g); specific growth rate (2.46%/g/day vs. 1.91%/g/day); feed conversion ratio (1.71 vs. 2.13); and percentage weight gain (181.44% vs. 123.35%). Apparent digestibility values of test diet were higher significantly (P&lt;0.05) than basal diet. Digestibility coefficient in reference diet fish and basal diet fish showed that: protein (88.48% vs 87.01%); dry matter (87.35% vs. 86.82%); energy (86.88% vs. 85.48%); and fat (39.67% vs. 27.75%). African catfish responded positively to CIM diet with improved growth performance up to 30% inclusion level. Apparent digestibility of the CIM diet was superior to the fishmeal reference diet.

Nutrient and Energy Apparent Digestibility of Protein-Based Feed Ingredients and Effect of the Dietary Factors on Growth Performance and Feed Utilization of Sobaity Seabream, Sparidentex hasta.

Two separate feeding trials were undertaken to benchmark a series of commercial diets and determine the nutrient and energy apparent digestibility coefficients of a variety of protein-based feed ingredients when fed to sobaity seabream, Sparidentex hasta. In Experiment 1, triplicate groups of fish (initial body weight: 330.5 ± 2.6 g) were fed with one of three locally available diets containing crude protein (CP) levels ranging from 44 to 46% of dry matter (DM), each with ~12% crude fat. Fish grew at around 3.2 g day-1 with a specific growth rate (SGR) of 0.7% day-1. Both the feed conversion ratio (FCR) and protein efficiency ratio (PER) were significantly better in fish fed diets, which contained the highest (46.4%) crude protein level. Overall, the data from these preliminary studies suggest that the best performance by sobaity seabream was obtained with a diet containing 46% crude protein, 20 MJ/kg, and a protein-to-energy ratio of 23 mg/kJ. In Experiment 2, fish with an initial body weight of 319 ± 7 g were held in 11 tanks and fed reference (D1) and test diets (D2-D11) for 7 days before fecal collection. This process was repeated twice in a blocking arrangement to generate three replicates. Each of the ten test diets contained 30% of a test ingredient, with the remaining 70% proportionally identical to the D1 diet. Diet apparent digestibility coefficients (ADCs) were measured, and the diet ADCs were then used to derive the protein and energy ADCs for the individual test ingredients. Ingredient protein ADC ranged between 75.5 and 93.9%, while ingredient energy ADC ranged between 66.8 and 81.2%.

The Potential of Fish Protein Hydrolysate Supplementation in Nile Tilapia Diets: Effects on Growth and Health Performance, Disease Resistance, and Farm Economic Analysis.

Fish protein hydrolysate (FPH) has shown immense potential as a dietary protein supplement and immunostimulant in aquaculture, especially in Nile tilapia production. Four isoproteic diets (30% crude protein) were prepared by including FPH at varying percentages (0%, 0.5%, 1%, and 2%). Nile tilapia fed with FPH diets for 90 days, and their growth performance, feed utilization, blood biochemistry, liver and gut morphology, and resistance against Streptococcus iniae were investigated. The findings revealed that diets physical attributes such as pellet durability index and water stability were remarkably (p < 0.05) varied between experimental diet groups. Furthermore, the test diets were more palatable when FPH was included at 1% and 2%. Fish that were fed with a 2% FPH-treated diet had significantly (p < 0.05) greater growth indices than other treatments. Additionally, their feed utilization was significantly (p < 0.05) improved. The experimental diets and intestinal total bacteria count (TBC) exhibited a rising trend with FPH levels, where the 2% FPH-treated diet recorded the highest TBC. Neutrophil (109/L), lymphocyte (109/L), eosinophil (109/L), and red blood cell(1012/L) counts were significantly (p < 0.05) higher in the 2% FPH-treated group, while the white blood cell (109/L), and basophil (109/L) counts were not influenced by the FPH inclusion. Moreover, the FPH-treated groups displayed lower creatinine, bilirubin, and urea levels than the control. The histological examination demonstrated that themid-intestine of 2% FPH-fed Nile tilapia had an unbroken epithelial wall, more villi with frequent distribution of goblet cells, wider tunica muscularis, and stronger stratum compactum bonding than other treatments. Additionally, this group exhibited more nuclei and erythrocytes and less vacuolar cytoplasm in liver than their counterparts. Nile tilapia that were given a diet containing 2% FPH had significantly (p < 0.05) higher resistance (83.33%) to S. iniae during the bacterial challenge test. A significant (p < 0.05) enhancement in farm economic efficiency was observed in the higher inclusion of FPH in diets. In summary, 2% FPH supplementation in Nile tilapia diets improved their growth performance, feed utilization, health status, disease resistance, and farm economic efficiency.

Impact of feeding biochar sources in rohu (Labeo rohita): Evaluating the growth, nutrient absorption, carcass composition, haematology and mineral status.

Biochar, an organic carbonaceous matter, is a unique feed additive that is now being used in aquaculture industry to formulate a cost-effective and eco-friendly diet. This experiment (in door) was conducted over course of 90 days to determine the most effective form of biochar, produced from various sources, for supplementation in Moringa oleifera seed meal-based diet. These sources were: farmyard manure biochar, parthenium biochar (PB), vegetable waste biochar, poultry waste biochar (PWB) and corncob waste biochar, added at 2 g/kg concentration to determine the effect of supplementation on the growth indices, nutrient absorption, carcass composition, haematology and mineral status of Labeo rohita (rohu) fingerlings. The research design consisted of six test diets with three replications (6 × 3) of each. Total of 270 fingerlings (6.30 ± 0.020 g) were fed at 5% body weight and 15 of them were kept in separate steel tanks. The results indicated that PWB was most effective in improving weight gain (285.58 ± 4.54%) and feed conversion ratio (1.060 ± 0.040) compared to control diet and other test diets. The same type of biochar (PWB) produced the best results for nutrient digestibility, that is, crude protein, crude fat and gross energy and carcass composition. In terms of haematology and mineral status, PWB showed the best results. In conclusion, it was found that PWB significantly enhanced (p < 0.05) L. rohita fingerling's growth, carcass composition, nutrient digestibility, haematological parameters (red blood cells, white blood cells, platelets and haemoglobin) and mineral composition (Ca, Na, P, Mg, Fe, Mn, Zn, K and Cu) whereas PB negatively affected all parameters. It is anticipated that the potential use of biochar will increase in aquaculture industry, as research on its incorporation in fish feeds is still limited.

Design and conduct of a randomized controlled feeding trial in a residential setting with mitigation for COVID-19

BackgroundEvaluating effects of different macronutrient diets in randomized trials requires well defined infrastructure and rigorous methods to ensure intervention fidelity and adherence. MethodsThis controlled feeding study comprised two phases. During a Run-in phase (14–15 weeks), study participants (18–50 years, BMI, ≥27 kg/m2) consumed a very-low-carbohydrate (VLC) diet, with home delivery of prepared meals, at an energy level to promote 15 ± 3% weight loss. During a Residential phase (13 weeks), participants resided at a conference center. They received a eucaloric VLC diet for three weeks and then were randomized to isocaloric test diets for 10 weeks: VLC (5% energy from carbohydrate, 77% from fat), high-carbohydrate (HC)-Starch (57%, 25%; including 20% energy from refined grains), or HC-Sugar (57%, 25%; including 20% sugar). Outcomes included measures of body composition and energy expenditure, chronic disease risk factors, and variables pertaining to physiological mechanisms. Six cores provided infrastructure for implementing standardized protocols: Recruitment, Diet and Meal Production, Participant Support, Assessments, Regulatory Affairs and Data Management, and Statistics. The first participants were enrolled in May 2018. Participants residing at the conference center at the start of the COVID-19 pandemic completed the study, with each core implementing mitigation plans. ResultsBefore early shutdown, 77 participants were randomized, and 70 completed the trial (65% of planned completion). Process measures indicated integrity to protocols for weighing menu items, within narrow tolerance limits, and participant adherence, assessed by direct observation and continuous glucose monitoring. ConclusionAvailable data will inform future research, albeit with less statistical power than originally planned.

Investigation of the suitability of 3 insect meals as protein sources for rainbow trout (Oncorhynchus mykiss).

An in vivo trial was conducted to determine the apparent digestibility coefficients (ADCs) of insect meals for rainbow trout, Oncorhynchus mykiss. Rainbow trout (approximately 370 g ± 23 g, mean ± SD initial weight) were stocked 25 per tank into 400-liter tanks. Fish were fed a reference diet, or 1 of 5 test diets created by blending the reference diet in a 70:30 ratio (dry-weight basis) with menhaden fish meal (MFM), 2 house cricket (Acheta domesticus) meals (cricket A and cricket B), Galleria mellonella meal, and yellow mealworm (Tenebrio molitor) meal. Diets were assigned to 3 replicate tanks of fish and fed twice daily for 14 days prior to fecal collection. Ingredients, diets, and fecal matter were analyzed in duplicate for proximate, mineral, and amino acid composition. House cricket meals were 67.3% and 69.0% protein (CP) and 16.6% and 17.1% lipid (CL), for house cricket A and B, respectively. Yellow mealworm meal contained 56.5% CP and 27.7% CL, and G. mellonella larvae meal contained 32.5% CP and 54.2% CL. Protein ADCs were 78.9 for G. mellonella larvae meal, 78.0 for yellow mealworm meal, and 76.5 for house cricket A and not different from the MFM protein ADC of 76.6, while house cricket B protein ADC was 65.8 and was significantly lower than the MFM protein ADC (F = 7.39; df = 4,14; P = 0.0049). Together, these nutritional values suggest house crickets, and yellow mealworms show promise as alternative protein sources in salmonid feeds, with the potential of G. mellonella as an alternative lipid source.

Evaluation of taurine and carnitine concentrations in whole blood, plasma, skeletal muscle and cardiac muscle in dogs.

Little is known about how plasma and whole blood taurine and plasma carnitine correlate to concentrations in skeletal and cardiac muscle and the effects of diet in dogs. The purpose of this study was to evaluate the correlation among plasma, skeletal and cardiac muscle carnitine and taurine and whole blood taurine and determine the effect of diet. The study protocol was approved by the Pet Food Solutions Institutional Animal Care and Use Committee. Thirty-three mixed-breed hounds and 32 beagles were evaluated at Day 0 then removed from their baseline diet and randomized to a test diet: high animal protein, grain-inclusive (HA-GI), low animal protein, grain-free (LA-GF), low animal protein, grain-inclusive (LA-GI), or high animal protein, grain-free (HA-GF). Blood was drawn every 30 days and endomyocardial (mixed breeds only) and skeletal muscle biopsies were collected at Days 0 and 180. The correlations between plasma and whole blood taurine, or plasma carnitine and skeletal and cardiac muscle concentrations were weak (p < 0.01-0.05). Mixed-breed hounds had increased (p = 0.029) whole blood taurine compared to beagles. Plasma taurine was lower with diet HA-GF, (p = 0.009) however, all diets had increased taurine from Day 0 and were, on average within the laboratory reference range. Dogs fed the HA-GI diet had increased cardiac muscle carnitine esters (p = 0.014). Increased carnitine esters were also appreciated in cardiac muscle in all diets from Day 0 to 180 (p = 0.0001). On Day 180 mixed-breed hounds had increased skeletal total carnitine (p < 0.001) compared to all time points and breeds. This study observed no correlation between plasma, whole blood, skeletal and cardiac muscle taurine concentrations but noted some effects between time, breed and diet.

Insoluble fibre and enzyme supplementation in mash or pellets diets on growth performance, apparent ileal digestibility and intestinal morphology of broiler chickens fed barley containing diets.

Enzyme supplementation and the inclusion of fibre in the barley-based diets have been some of the alternatives proposed to improve productivity in the absence of growth promoters. This study was performed to investigate the effect of adding sunflower hulls (SFH), a multi-enzyme carbohydrate, and feed forms (mash and pellet) on performance and some physiological parameters in broiler chickens fed barley containing diets. Treatments were two feed forms (mash vs. pelleted), and four diets consisted of a barley-based diet (control, CTL) or test diets which contained either SFH at 30g/kg, enzyme (ENZ; 0.2g/kg) or combination of SFH and enzyme (SFH+ENZ). The results showed that average daily feed intake and average daily gain were significantly increased in chickens that were fed ENZ (p<0.05). The highest digestibility of ether extract (EE) was observed in the treatment containing SFH and SFH+ENZ (p<0.05). The highest population of Lactobacillus spp. was observed in the treatment containing SFH (p<0.05). The villus height and villus height to crypt depth ratios of duodenum and jejunum were significantly higher (p<0.05) in broilers fed pellet diets compared to the mash. It can be concluded that pellet diets reduce digesta viscosity and harmful microorganisms (Escherichia coli), increase growth performance, and improve intestinal morphology in barley-based diets. Moreover, SFH and ENZ had favourable effects on EE digestibility and caecal microbial population of broilers fed with barley containing diets.

Evaluation of palmatine as an immunostimulant in diet for genetically improved farmed tilapia (GIFT, Oreochromis niloticus)

Palmatine as a medicinal herbs extract has strong bacteriostatic ability and is a promising source of antibacterial additive. The objective of this study was to assess the feasibility of palmatine as an antibiotic alternative in diet for genetically improved farmed tilapia (GIFT, Oreochromis niloticus). Four experimental diets were formulated with 0, 200, 400, and 800 mg/kg palmatine. Tilapia with consistent size (initial body weight 3.43 ± 0.02 g) were fed the test diets twice daily for ten weeks. Dietary palmatine inclusion regardless of levels unaffected the growth performance and feed efficiency (P > 0.05). However, dietary 200–800 mg/kg palmatine inclusion reduced the levels of total cholesterol and low-density lipoprotein cholesterol as well as the ratios of low-density/high-density lipoprotein cholesterol and aspartate/alanine aminotransferase in serum (P < 0.05), but generally improved the antioxidant-related enzymes activities in intestine, plasma and liver, the immunoglobulin M, complement 3, and complement 4 contents and lysozyme activity in plasma, and the phagocytic activity of macrophages in head kidney. Bacterial challenge test demonstrated that dietary supplementation with 200–800 mg/kg palmatine enhanced the resistance of tilapia to Aeromonas hydrophila, and the relative percentage survival was the highest in fish fed diet with 400 mg/kg palmatine. In conclusion, dietary palmatine supplementation enhanced the antioxidant and innate immune responses as well as the resistance against A. hydrophila without compromising growth performance of tilapia, and the suitable inclusion level of palmatine was 400 mg/kg of diet for tilapia.

Effects of Carica papaya peel meal-based diets on rabbit bucks' spermiogram and reaction time.

The study aimed to evaluate the effects of Carica papaya peel meal-based diet on spermiogram and reaction time in rabbit bucks. Ripe pawpaw fruits were harvested during the dry season. The peels were carefully removed from the pulp and sun-dried for a week. Afterward, they were ground and included in the test diets as pawpaw peel meal (PPM) at inclusion rates of 0%, 15%, and 30%. Rabbit bucks (n = 15) were randomly separated into three groups of five bucks and labeled as groups A, B, and C. Group A, the control group (0%), was fed the basal protein diet (BD), group B (PPM 15) was given a PPM-based diet (15%), while C (PPM 30) was given diet composed of PPM (30%). Semen samples were collected and evaluated fortnightly for 14weeks. The reaction time and mean ejaculate volume were lower (P < 0.05) in the treatment groups than in the control. Sperm motility and concentration decreased significantly (P < 0.05) across the groups from week 4 to the end of the experiment. Bucks fed PPM 15%, and PPM 30% had significantly (P < 0.05) higher percentages of dead sperm cells and total spermatozoa abnormalities. The control had (86%) normal spermatozoa morphology while those of PPM 15% and PPM 30% were (61%) and (52%), respectively. PPM 30% had the highest abnormal spermatozoa (47%) compared to PPM 15% (38%) and control (13%). The findings indicate that pawpaw peels up to 15% and 30% in the diet have a negative effect on spermiogram.

Determining the effects of Candida utilis-fermented pea starch vs. unfermented pea starch, alone or in whole diets, on palatability and glycemic response in dogs and cats.

Current research suggests yeast fermentation has the potential to improve palatability of pea-based diets for both cats and dogs. However, to be useful, fermentation should not compromise other healthy attributes of peas such as a low glycemic response. Fermentation of uncooked pea starch with Candida utilis (ATCC 9950) appeared to increase crude protein, crude fiber content, inorganic compounds (phosphorus and iron) and phenols. Whole diets were designed with fermented and unfermented pea starch to assess palatability, food intake, and glycemic responses in unacclimated, mixed sex Beagle dogs and mixed breed cats (n = 8 and n = 7, respectively). For palatability testing, a control diet was formulated with 30% corn starch as well as test diets with 30% inclusion of fermented or unfermented pea starch (all lab-made), then compared to a commercial diet containing pea starch (Legacy/Horizon). Fermentation had little effect on rapidly digestible starch either in uncooked starch form or when incorporated into whole diets, but did decrease resistant starch by 15% and increase slowly digestible starch by 20%. Palatability tests using either two choices or four choices at a time revealed a significant preference for the fermented pea starch diet (p < 0.01) in both species. For the glycemic responses, a total of four different pea products were included: unfermented pea starch, fermented pea starch, and 30% inclusion of unfermented and fermented pea starch in whole formulated diets. There were no significant changes in glycemic responses with the fermented pea diet compared to the unfermented diet, demonstrating that healthful low glycemic properties of pea starch were retained after C. utilis fermentation. Overall, C. utilis-fermentation technique was successfully adapted to pea starch where it resulted in increased palatability and food intake in dogs and cats, with potential to positively contribute to overall health benefits for both species.

Dietary calcifediol reduces mesenteric adiposity to the benefit of carcass growth independently of circulating vitamin D hormone in juvenile Atlantic salmon

Dietary vitamin D is required by cultivated fish for optimal growth, feed utilisation and bone health. The in vivo conversion of cholecalciferol (D3) to active vitamin D hormone (1,25-OH-D3) may be impaired in farm-raised fish fed modern feed formulations. Requiring fewer metabolic steps for its conversion, the use of dietary calcifediol (25-OH-D3) may mitigate against deficits in vitamin D metabolism.A 90-day experimental feeding trial was undertaken in juvenile (23 g) Atlantic salmon (Salmo salar) to test the efficacy of 25-OH-D3 added to a standard diet containing recommended levels of D3 (5640 IU). Test diets contained 100, 200 or 400 μg/kg added 25-OH-D3 against a no additive control diet. Effects on zootechnical performance, indices of adiposity, bone mineralisation, and circulating vitamin D metabolites were tested.Dietary 25-OH-D3 significantly reduced feed conversion ratio (FCR) and resulted in numerical increases in growth performance. 25-OH-D3 also significantly reduced mesenteric adiposity with concurrent increases in carcass weight. Levels of calcium, phosphorous, magnesium, zinc and manganese were not modulated in the vertebrae of fish receiving 25-OH-D3. Circulating 25-OH-D3 remained below detection limits and 1,25-OH-D3 was not significantly modulated by the dietary manipulations.The significant reduction of mesenteric adiposity to the benefit of carcass weight shows that dietary 25-OH-D3 improves the utilisation of lipids. The vitamin D requirement for bone mineralisation was met by the basal diet. Segmented regression estimates a dietary 25-OH-D3 supplementation of 143 to 180 μg/kg for improved feed conversion and reduced mesenteric adiposity. The lack of correlation between circulating vitamin D hormone and mesenteric adiposity indicates that lipid metabolism is regulated by localised tissue activation of vitamin D, rather than the endocrine functions of circulating 1,25-OH-D3.

Efficacy of nutritional selenium nanoparticles on growth performance, immune response, antioxidant capacity, expression of growth and immune-related genes, and post-stress recovery in juvenile Sobaity seabream (Sparidentex hasta)

This study evaluated the impacts of nano-Se on the growth, immunity, antioxidant capacity, physiological parameters, gene expression, and stress resistance of fingerling Sobaity seabream (Sparidentex hasta). The fish with an average weight of 21.5 ± 0.1 g were divided into four treatment groups in triplicates that received one of the test diets supplemented with varying levels of nano-Se: 0 (control), 0.5 (Se-0.5), 1 (Se-1), and 2 (Se-2) mg/Kg for 60 days. The results showed that final weight, weight gain rate, specific growth rate, feed intake, and feed conversion ratio improved with significant linear and quadratic trends (P < 0.05) in response to nano-Se-supplemented diets, and the best values were measured in the Se-2 group. Superoxide dismutase activity level remained unaffected among the four groups (P > 0.05). Catalase activity increased in nano-Se-supplemented groups, with the highest level measured in fish fed the Se-0.5 diet. Glutathione peroxidase activity levels were not significantly different between the control and nano-Se groups, but the lowest malondialdehyde concentration was detected in the Se-2 group. Nano-Se had no marked effect on total plasma Ig levels; however, the highest lysozyme activity and alternative complement activity (ACH50) were observed in the Se-0.5 and Se-2 groups, respectively. No significant differences (P > 0.05) were observed in plasma total protein, albumin, globulin, triglyceride, and thyroid hormone (T3 and T4) contents among the groups. However, the lowest cholesterol and low-density lipoprotein values and the highest high-density lipoprotein concentration were measured in the Se-2 group. The Se-0.5 and Se-1 groups exhibited significantly lower levels of aspartate aminotransferase activity, and the lowest alkaline phosphatase activity level was detected in the Se-1 group. The expression level of insulin-like growth factor I gene in all nano-Se-fed groups was significantly higher than the control. Also, the expression of interleukin-1β and lysozyme genes was significantly upregulated in nano-Se-supplemented groups, with the highest values in the Se-2 group. Following acute crowding stress, plasma cortisol and lactate levels at all post-stress time intervals were not significantly different among the experimental groups. Fish fed the Se-0.5 and Se-2 diets tended to have lower plasma glucose concentrations than other groups. In conclusion, dietary nano-Se at 2 mg/kg is recommended to promote growth performance and enhance antioxidant and immune parameters in Sobaity juveniles.

Black soldier fly (Hermetia illucens) larvae meal improves quail growth performance.

The aim of the present study was to determine the nutritional value of black soldier fly (BSF) larvae meal for quail (experiment I) and the dose-response effects of BSF levels on growth performance, relative organ weight, and body composition of growing quails (experiment II). In experiment I, 100 35-day-old quail were distributed in a completely randomized design, with two treatments (reference and test diet) and 10 replicates. The experimental period consisted of 5days of adaptation, followed by 5days of total excreta collection. The experimental feed consisted of a reference diet and a test diet formulated with 850g/kg reference diet and 150g/kg BSF. In experiment II, 1000 1-day-old quail were distributed in a completely randomized design, with five dietary levels of BSF (0, 25, 50, 75, and 100g/kg). At 42days of age, birds were slaughtered, and the relative organ weight and body composition were determined. Apparent metabolizable energy values corrected for nitrogen retention of BSF meal were 13.8MJ/kg. Across the starter (1-14days) and overall period (1-42days), increasing BSF levels had a quadratic effect on body weight and body weight gain. Feed conversion ratio was quadratically affected during the starter phase and linearly reduced over the overall period. Additionally, the BSF levels linearly decreased the small intestine's relative weight at 42days and had a quadratic effect on the rate of protein deposition. We concluded that the inclusion of 100g/kg BSF meal improves feed conversion ratio for growing quail.

The effects of dietary organic selenium on growth, body composition and hematological parameters of common Carp (Cyprinus carpio) reared in recirculating aquaculture system.

A feeding trial was conducted to examine the effects of different levels of dietary organic selenium (Se) on the growth, body composition, and hematological indices of common carp. Se element was supplemented to the basal diet at the rates of 0.0, 0.5, 1 and 2 mgkg-1. Fish were randomly stocked at a rate of 25 fish into 500L tanks in the Recirculating Aquaculture System (RAS) system for 10 weeks. Weight gain, final body weight, and specific growth rate were significantly higher (p<0.05) in fish fed 0.5 mgkg-1 followed by 1 and 2 mgkg-1 treatment diets fish. The lowest growth rate values were detected in fish-fed basal diets. Feed consumption of fish fed Se was not significantly different (p>0.05), also the survival rate was similar among the treatment groups. Whole-body composition showed that fish fed 1 mgkg-1 had significantly higher (p<0.05) body moisture and protein as dry weight basis. The highest fiber content was in fish fed 2 mgkg-1, but ash was significantly higher in fish fed only 0.5 mgkg-1 and fat remained unaffected. Whole-body Se concentrations were significantly (p<0.05) increased with increasing Se levels in test diets. the red blood cells and hemoglobin were significantly higher (p<0.05) in fish fed only 0.5mgkg-1 and the basal diet. The white blood cells increased in fish fed the basal and 2 mgkg-1 diet, but the lymphocyte percentage was increased (p<0.05) in fish fed basal and 0.5 mgkg-1. The study concludes that dietary Se has an overall positive effect on common carp. Growth performance, protein content in fish body, selenium deposition and some hematological parameters were observed in fish fed dietary organic selenium specifically in fish fed 0.5 and 1 mgkg-1. Therefore, inclusion of Se in the diet from 0.5 to 1 mgkg-1 would be an optimal level for common carp feed.

Comparative Study on the Effects of Four Plant Protein Sources on the Liver and Intestinal Health of Largemouth Bass, Micropterus salmoides.

The effects of plant protein sources (PPSs) on the health of the liver and intestine of the largemouth bass, Micropterus salmoides, were compared to verify the potential damaging effects of dietary fiber (DF). A diet containing 55% fish meal (FM) was used as the control. The test diets contained 25% soybean meal (SBM), rapeseed meal (RSM), cottonseed meal, or peanut meal, and the FM content was decreased to 30%. The protein and lipid contents of these five diets were balanced by casein and oil. Fish were raised for 8 weeks. The fish fed the diet containing PPS showed a trend of decreasing growth and apparent digestibility coefficients. The contents of total bile acid, lipid, and collagen in the liver were increased, and the mRNA expression levels of genes encoding inflammatory factors and enzymes involved in de novo fatty acid synthesis and bile acid synthesis were upregulated. Both the lipid and collagen contents in the liver were positively correlated with the DF content in the diet significantly. Morphology and histology showed reduced liver size, hepatic steatosis, and fibrosis in fish fed diets containing PPS. The lowest hepatosomatic index was observed in fish fed the SBM diet, and the most severe damage was observed in fish fed the RSM diet. No obvious histological abnormalities were observed in the hindgut. The bile acid profile in the liver could be used to distinguish the types of PPS very well by Fisher discriminant analysis. These results indicated that 25% of each of the four PPSs in the diet exceeded the tolerance range of largemouth bass and caused liver damage, which might be mediated by bile acid. DF in PPS might be an important agent contributing to liver damage.

Evaluation of in vitro and in vivo digestibility of potential feed ingredients for juvenile Yellowtail Snapper

AbstractObjectiveThe carnivorous Yellowtail Snapper Ocyurus chrysurus has the potential for production in aquaculture. However, there is a lack of studies investigating the digestibility of ingredients needed to formulate balanced diets for this species.MethodsThe in vitro protein digestibility of fish meal (FM), poultry by‐product meal (PBM), poultry meal (PM), protiblend, canola meal (CM), soybean meal, and wheat gluten was evaluated using the pH‐stat technique. The in vivo digestibility was determined by formulating test diets with a 70:30 ratio of the reference diet and the test ingredients.ResultIn terms of in vitro digestibility, FM, PBM, and PM exhibited the highest degree of hydrolysis (DH). Conversely, PBM displayed the lowest apparent digestibility coefficient of protein (ADCprotein) in the in vivo digestibility test. Meanwhile, FM, PM, and CM demonstrated higher values of protein digestibility. Beta regression between ADCprotein and the DH and ash content of the ingredients resulted in a high correlation (R2 = 0.94).ConclusionThe results of the present study indicate that Yellowtail Snapper efficiently digested and absorbed FM, PM, and CM ingredients, which contain a lower content of ash.