Feed Utilization Research Articles

Effect of thymol on the efficiency of feed utilization and compensatory growth in severe feed-restricted lambs.

The present study aimed to evaluate the effect of thymol on growth performance and apparent total tract digestibility of nutrients in severely feed-restricted lambs. Twenty-one male Baluchi lambs were randomly blocked by live weight into three groups: control without feed restriction (CON), feed restricted (FR), and feed restricted plus thymol (FR + T). The lambs underwent a four-week feed restriction period followed by four weeks of realimentation. Thymol was administered daily to the FR + T group during the feed restriction period. Average daily gain (ADG), average daily feed intake, feed efficiency (FE), partial efficiency of maintenance (PEM), and residual feed intake (RFI) were measured as growth performance parameters. Results showed that the severe feed restriction had adverse effects on ADG and FE, but improved PEM (P < 0.05). The effects of thymol administration on ADG, FE, PEM, and apparent total tract digestibility were not significant (P > 0.05). However, the lambs that received thymol during the feed restriction period showed a negative RFI during realimentation (P < 0.05). Overall, these findings suggest that feed restriction as well as thymol may have the potential to improve efficiency of feed utilization in growing lambs. However, this positive effect is independent of the improvement in nutrient digestibility.

Comparison of Pediococcus pentosaceus YC64-fermented soybean meal and raw soybean meal in diets for Nile tilapia: Growth performance, feed utilization, and intestine health

Fermentation is a promising approach for improving the utilization of soybean meal (SM) by aquaculture fish, and the strain is the core of microbial fermentation processes. Herein, Pediococcus pentosaceus YC64, an autochthonous probiotic isolated from the intestine of Nile tilapia (Oreochromis niloticus), was applied to the fermentation of raw SM. In an eight-week feeding trial, tilapia juveniles were divided into two treatments fed on diets with 0 % (Control) and 100 % of SM protein replaced by fermented SM (FSM). Results showed that solid-state fermentation improved SM quality indicated by increased acid-soluble protein contents. Fish fed the FSM diet had significantly higher weight gain, feed efficiency, and protein efficiency compared to those fed the SM diet. Furthermore, whole-body protein content significantly increased in the FSM-fed fish, accompanied with the increased amino acid transport and reduced protein catabolism. Texture profile analysis indicated that fish fed the FSM diet had reduced muscle hardness compared with the control, which was associated with changes in collagen deposition and myofiber development. Moreover, feeding an FSM diet enhanced goblet cell proliferation and stimulated mucin secretion, ultimately leading to improved intestinal tight junctions and reduced inflammatory response. Besides, the FSM diet feeding altered intestinal microbiota community, characterized by increased abundance of Pediococcus. Overall, P. pentosaceus YC64 exhibits promise as a fermentation strain in the production of FSM. The FSM performed better than SM in improving the growth performance, feed utilization, and intestine health of Nile tilapia.

Potential Development Ability of Residual Zoites, a Second-Generation Meront, Inducing Long-Term Infection by the Mouse Eimerian Parasite, Eimeria krijgsmanni.

Coccidiosis caused by eimerian parasites results in lethal watery or bloody diarrhea in hosts, and markedly impairs the growth of and feed utilization by host animals. We previously investigated detailed the life cycle of Eimeria krijgsmanni as a mouse eimerian parasite. Only second-generation meronts, as an asexual stage, were morphologically detected in the epithelium of the host cecum for at least 8 weeks after infection, even though oocyst shedding finished approximately 3 weeks after infection. The presence of zoites was of interest because infection by eimerian parasites is considered to be self-limited after their patent period. To clarify the significance of residual second-generation meronts in E. krijgsmanni infection, we performed infection experiments using immunocompetent mice under artificial immunosuppression and congenital immunodeficient mice. The number of oocysts discharged and the duration of oocyst discharge both increased in immunosuppressed mice. In immunodeficient mice, numerous oocysts were shed over a markedly longer period, and oocyst discharge did not finish until 56 days after inoculation. The present results suggest that the second-generation meronts survived in the epithelial cells of the cecum after the patent period, thereby contributing to extended infection as an asexual stage. The results obtained on E. krijgsmanni indicate that infections by Eimeria spp. are not self-limited and potentially continue for a long period of time.

Manipulation impacts of jack mackerel meal in low fish meal diets on growth, feed availability, and biochemical composition of olive flounder (Paralichthys olivaceus) and economic analysis

AbstractManipulation effects of jack mackerel meal (JMM) in the low fish meal (FM) diets substituting 50% FM with meat meal (MM) on growth performance of olive flounder and economic analysis were determined. Seven experimental diets were created. The control (Con) diet contained 60% FM. In the other diets, 50% of the FM level used for the Con diet was substituted with MM, and then graded levels (0, 10, 20, 30, 40, and 50%) of JMM were included at the expense of FM, named the MJ0, MJ10, MJ20, MJ30, MJ40, and MJ50 diets, respectively. The experimental diets were distributed to triplicate groups of fish. A total of 525 fish was divided into 21 flow‐through tanks. Fish were hand‐fed to apparent satiation for 8 weeks. Weight gain, specific growth rate (SGR), and feed consumption of fish fed the Con diet were comparable with fish fed the MJ20, MJ30, MJ40, and MJ50 diets. Weight gain, SGR, and feed consumption of fish linearly improved with JMM inclusion levels in the low FM diets replacing 50% FM with MM. The strong correlation between isoleucine and lysine content among essential amino acids in the experimental diets versus weight gain, SGR, and feed consumption of olive flounder were observed. Dietary treatments did not influence feed utilization, chemical composition, and amino acid profiles of fish. Incorporated 20%–50% JMM as an effective feed attractant and enhancer in the low FM diets replacing 50% FM with MM achieved comparable weight gain, SGR, and feed consumption to fish fed a 60% FM‐based diet. Finally, the MJ50 diet led to the highest economic profit index (EPI) for farmers.

Growth of Bamboo Lobster (Panulirus versicolor; Latreille, 1804) Fed with Feed Made from Sosodek Fish Meal (Atherinomorus lacunosus)

Bamboo lobster (Panulirus versicolor) is a marine commodity with promising prospects for aquaculture development. Feed is a critical issue in the growth of P. versicolor, necessitating an effective, affordable solution that promotes optimal growth. This study aimed to examine the use of sosodek fish meal (A. lacunasus) as a nutrient source to enhance the growth of P. versicolor. Specimens of P. versicolor (weighing 79.97±38 g) were obtained from local fishermen in Togean District, Tojo Una-Una Regency, Central Sulawesi. The experiment tested the use of sosodek fish meal as a feed ingredient at different percentages: 0% (control), 10% (A), 20% (B), and 30% (C). The lobsters were kept in containers with 25 liters of seawater, with one lobster per container, and each treatment was replicated three times. Feed was given at 5% of body weight, three times daily. Body weight was measured every two weeks. Water quality was maintained within a range suitable for P. versicolor. The results indicated that weight gain and daily growth rates, from highest to lowest, were observed in treatment C (11.84 g and 0.49%/day), B (7.4 g and 0.21%/day), A (2.82 g and 0.09%/day), and control (2.38 g and 0.08%/day). Feed conversion ratios, from lowest to highest, were recorded as C (13.1), B (25.1), A (71.9), and control (64.0). Feed utilization efficiency, from highest to lowest, was seen in treatment C (10.28%), B (4.32%), A (1.85%), and control (1.72%). Survival rates for all treatments were 100%. The analysis showed that individual weight gain, daily growth rates, and feed utilization efficiency were significantly higher, and feed conversion ratios were lower in treatment C (30% sosodek fish meal) compared to other treatments (P&lt;0.05). Utilizing 30% sosodek fish meal as feed ingredient significantly enhances the growth of P. versicolor.

Vitamin D3 alleviates the damage caused by high-fat and maintains lipid metabolism homeostasis in hepatopancreas by promoting fatty acid β-oxidation of Portunus trituberculatus

The purpose of present study was to evaluate the effects of vitamin D3 supplementation in high-fat diet on growth performance, calcium and phosphorus in tissue, immunity and lipid metabolism, and to explore whether adding vitamin D3 to high-fat diet can alleviate the adverse effects of high-fat diet on swimming crab (Portunus trituberculatus). The three experimental diets were normal fat diet (NFD, 9.35 % fat, 45.53 % protein), high fat diet (HFD, 14.69 % fat, 44.93 % protein) and high fat diet supplemented with 0.47 mg/kg VD3 (HFD+VD), respectively. A total of 108 healthy swimming crabs with an initial body weight of 9.42±0.13 g were selected for an 8-week feeding trial. The results showed that crabs fed with HFD+VD diet exhibited significantly higher percent weight gain (PWG), specific growth rate (SGR), feed efficiency (FE) and molting rate (MR) compared to those fed with HFD diet (P < 0.05). It was observed from hepatopancreas crude lipid content, TG content and hepatopancreas sections that HFD caused hepatopancreatic cell damage and abnormal lipid accumulation (P < 0.05), however, there were no significant differences in hepatopancreas crude fat content, TG content and hepatopancreas section observation between HFD+VD group and NFD group (P > 0.05). Crabs fed HFD diets with or without VD3 significantly down-regulated the expression of genes related to fatty acid transport, such as fabp9 and lpr1 in hepatopancreas (P < 0.05), moreover, the expression of genes related to fatty acid β-oxidation (cpt2 and acox1) were significantly up-regulated and genes related to lipid synthesis (fas and 6pgd) were significantly down-regulated in the hepatopancreas of the crabs fed with HFD+VD diet compared to those fed with HFD diet (P < 0.05). In conclusion, the results of present study indicated that a high-fat diet can cause deformation and rupture of hepatopancreas cells through abnormal lipid accumulation, thereby causing associated inflammation, leading to large calcium and phosphorus deposits in hemolymph and muscle, however, high fat diet supplemented with vitamin VD3 mainly enhanced the β-oxidation of fatty acids, inhibited lipid synthesis, alleviated abnormal lipid accumulation, and thus maintained the balance of lipid metabolism in hepatopancreas cells and promoted growth performance and feed utilization for swimming crab.

Comparative growth, survival, and feed conversion factor of the F1 generation of two new strains of tilapia Oreochromis niloticus produced by mass selection

Growth, survival, and use of feed of the F1 generation of two new strains of tilapia Oreochromis niloticus (GenBank Strain Y = OK078792 to OK078796 and Strain A = OK078797 to OK078807) produced by mass selection was compared with a known fast-growing commercial strain in Mexico (GenBank Strain Q = OR744820 to OR744838), during a grow-out phase of 165 days. Genetic variability including observed (Ho) and expected (He) heterozygosity, inbreeding coefficient (Fis), and paired comparisons of strain fixation index (Fst) of the three strains were also compared, and an additional analysis of molecular variance (AMOVA) was performed. Twelve hapas of 8.2 m3 (four for each strain) were stocked at a density of 25 org m−3 of 4.58 ± 0.67 g, which were fed with 45 to 25% crude protein feed under a dynamic feeding scheme of 8 to 3% live weight. Growth was estimated by growth rates in weight and length, and by the weight-specific growth rate (SGR). The use of feed was estimated by the total feed consumption rate and the feed conversion factor (FCF). Results indicate no significant differences (P > 0.05) in growth parameters of the three strains, except in SGR which was significantly higher in the control strain (Q) (2.75% day−1) as compared with strains Y and A (2.51 and 2.59% day−1 respectively). The average final weight and size of the fish were 314.6 ± 11.8 g and 25.5 ± 0.4 cm respectively. No significant differences (P > 0.05) were found in survival and feed utilisation among strains, with average values of 96.4% survival, feed consumption of 3.91 g day−1, and FCF of 2.08. Results of genetic diversity indicate that there were no significant differences (P > 0.05) in Ho and He of the three strains, with average values of 0.310 and 0.280 respectively. Fis values were negative and similar for the three strains, with a mean value of −0.109 which indicates no consanguinity in their populations. Finally, the paired comparisons of Fst were significantly different (P < 0.001), showing relatively low values but different from 0 (Y vs. A = 0.025, A vs. Q = 0.041 and Y vs. Q = 0.055), indicating slight but significant population differentiation between strains. In conclusion, the performance and genetic variability of the F1 generation of the two new strains suggest that valuable broodstock is now available for mass production of fry, with similar performance as to one of the best strains of tilapia in Mexico.

Fermented aquatic weed meal (FAWM) as a protein source in Asian Catfish Clarias batrachus diets: Impacts on growth, blood chemistry profile, liver and gut morphology and economic efficiency

The global aquaculture industry is increasingly seeking sustainable alternatives to fishmeal (FM) due to its high price and shortfall in supply. In this context, fermented aquatic weed meal (FAWM) could emerge as a viable plant protein source for aquafeed. Four isoproteic diets [30 % crude protein (CP)] were formulated, incorporating 50 % total protein from FAWM comprising fermented Azolla diet (D1), Pistia diet (D2), and Eichhornia diet (D3). The control diet (D0) did not contain FAWM. At the end of the 90 days feeding trial, their growth performance, whole-body proximate composition, gut microbial load, haemato-biochemical indices, liver and gut health, and economic efficiency were determined. Fish fed with D0 had significantly (p < 0.05) improved growth performance and feed utilization compared to other treatment groups. Meanwhile, the fish supplemented with D1 diet exhibited significantly (p < 0.05) higher final weight (g), specific growth rate (%/day), weight gain (%), total biomass (g), and protein efficiency ratio among the FAWM dietary groups. The D1 group also demonstrated the significantly (p < 0.05) highest whole-body CP (64.27 ± 0.40 %) and lower crude lipid (8.24 ± 0.28 %) compared to other test diets. The total bacteria (TB) and lactic acid bacteria (LAB) in the fish gut were found to be significantly (p < 0.05) higher in D1 group. Furthermore, most of the hemato-biochemical indices of fish were significantly (p < 0.05) affected by FAWM inclusions, with few exceptions. The histological findings indicated that amongst the FAWM groups, D1 fish exhibited improved intestinal health. Nonetheless, the gut of the control fish demonstrated substantially (p < 0.05) lower villi width and crypt depth than other treatments. The D1 and D2 diet groups had significantly improved liver health. Moreover, FAWM inclusion enhanced economic efficiency by considerably reducing farm feed cost (US$/kg) and increasing return on investment (%). In summary, dietary inclusion of fermented Azolla pinnata (D1) protein at 50 % in aquafeed promoted feed utilization, growth, health, and farm economics of Asian catfish fingerlings compared to other FAWM diets.

Evaluation of dietary yeast derived mannan oligosaccharide for pacific whiteleg shrimp Penaeus vannamei: Effects on growth performance, immune response, hepatopancreas morphology and resilience to infection against Vibrio parahaemolyticus

With trends towards low fishmeal and higher plant ingredient-based diets for shrimp, there is consequently greater demand on feed additives to bolster the protein and nutrient profile quality for achieving more efficiency. Also, there is a need to enhance innate immunity and resilience to infection under intensive shrimp production scenarios. This investigation tested incremental levels 0, 0.2; 0.4; 0.6 and 0.8 % of a commercial yeast cell wall extract mainly comprising β-glucan and mannan oligosaccharides (MOS) (YM, YeaMOS, Angel Yeast, Yichang, Hubei, China) for post-larval shrimp Penaeus vannamei in isonitrogenous and iso-lipidic diets with proteinaceous plant ingredients amounting to 50 % contribution of the diet formulation. After 60 d, growth and feed utilization performance were not significantly affected in shrimp in terms of weight gain or FCR, but due to much higher survival, total biomass in groups of shrimps fed with dietary YM was higher compared to the control treatment. A sequential specific pathogen challenge test with Vibrio parahaemolyticus at final dose of 104 CFU mL−1 resulted in a marked improvement in survival against the control group with much enhancement at the inclusion level of 0.4 % YM (p<0.05). Before challenged, the total haemocyte count (THC) and the relative gene expression of Prophenoloxidase (ProPO) were higher in the group of shrimps fed with YM. Likewise, after infection, the amount of THC and ProPO remained better in the group of shrimps fed with YM. However, the 0.8 % YM treatment did not significantly differ from the control for phagocytic activity and index. The histomorphology condition of the hepatopancreas of shrimp before the infection for all treatments appears normal without significant numbers of hepatopancreatic tubules (T) and epithelial cell vacuoles (V). After pathogen challenge, all shrimp exhibited severe necrotic cell damage and massive sloughing of hepatopancreatic tubule epithelial cells into the lumen. Overall, giving YM as feed additives can improve the shrimp biomass and health, with the use of 0.4 % inclusion levels in practical diets for shrimp P. vannamei become the optimum dose to develop more efficient aquafeed production.

Dietary monosodium glutamate affects the growth and feed utilization of Eriocheir sinensis by regulating the appetite related genes expression

This study assessed the impacts of monosodium glutamate (MSG) on the growth performance, feed utilization, feed intake, and appetite regulation of Chinese mitten crab, Eriocheir sinensis. A total of 240 juvenile crabs (9.16 ± 0.21 g) were assigned to six experimental diets supplemented with MSG at 0 %, 0.20 %, 0.39 %, 0.59 %, 0.78 % and 0.98 %. The results demonstrated that 0.59 % MSG supplementation significantly enhanced the weight gain rate (WGR), specific growth rate (SGR), and feed utilization of juvenile E. sinensis by increasing feed intake (FI) (p < 0.05). Moreover, dietary moderate MSG improved the mid-intestine morphology, such as height of microvillus (HMV), width of microvillus (WMV), and thickness of muscularis (TM). The qRT-PCR analysis demonstrated that the mRNA expression levels of the appetite-stimulating neural signals agouti related protein (agrp) and ghrelin were increased significantly by dietary moderate MSG (p < 0.05). Conversely, the mRNA levels of protein kinase B (akt), target of rapamycin (tor) and 4E-binding protein (4e-bp), as well as appetite-suppressing neural signals pro-opiomelanocortin (pomc), corticotropin-releasing factor (crf) and peptide yy (pyy) were significantly down-regulated (p < 0.05). The two-slope broken-line regression analysis of SGR in relation to dietary MSG levels suggested that the optimum dietary MSG level for juvenile E. sinensis was 5.6 g/kg. Collectively, MSG may potentially stimulate or suppress the appetite regulation neural signals/hormones, thereby modulating the feeding behavior of E. sinensis.

Microplastics accumulation in gut and revealing their impacts on nutritional quality and health of freshwater carp, Catla catla

The widespread presence of microplastics (MPs) in aquatic ecosystems raises concerns about their potential harm to aquatic life, particularly fish, which are a vital source of protein for human consumption. It emphasizes the importance of examining their occurrence and impacts. The focus of this study was to find out deleterious effects of polylactic acid MPs (PLA-MPs) on the Catla catla fingerlings by observing their growth, body composition, digestibility, histopathology, blood health, and mineral analysis. Utilizing sunflower meal (SFM) as the basal diet, six test diets were formulated, incorporating distinct MP concentrations: control (no MPs), 0.5 %, 1 %, 1.5 %, 2 %, and 2.5 %. These test diets were tested in three replicates of 15 fingerlings per tank and fed at 5 % equivalent of their live wet body weight for 90 days. After exposure to 2.5 % MPs, C. catla, fingerlings showed a significant decline in growth rate and feed utilization. Increased FCR and decreased WG (g) were observed in 2.5 % PLA-MPs. As MP levels increased, nutrient digestibility and minerals content decreased. PLA-MPs increased body fat and moisture, but decreased protein and ash content. MP exposure leads to significant changes in hematological parameters, including decreased RBCs, Hb, PLT, PCV, and MCHC, and increased WBCs, MCH, and MCV. Furthermore, histopathological examination of the gut showed increased intestinal abnormalities at the 2.5 % PLA-MPs concentration. This study underscored the adverse effects of PLA-MP pollution on the overall health performance of C. catla fingerlings.

Dietary salt concentrations influence growth, nutrient utilization, and fatty acid profiles of turbot (Scophthalmus maximus) reared in brackish water.

Expansion of economically viable turbot (Scophthalmus maximus) aquaculture depends on access to brackish-cold ground water sources in various parts of the world. Since brackish water sources can adversely affect the physiology and zoo technical performance of fish due to the burden of osmoregulation, dietary salt inclusion can alleviate the negative impacts of low-saline waters in several aquaculture species. This study investigated the effects of increasing dietary salt levels on the growth, feed utilization, body composition, and tissue fatty acid composition of juvenile turbot (initial live weight 120.3 ± 0.03g/fish). Fish were fed five experimental diets supplemented with varying levels of sodium chloride (1.8-6.4%) or a control diet without salt. Each diet was tested in triplicate tanks for 9weeks. Results showed that increasing dietary salt intake negatively impacted turbot performance, with significant reductions in weight gain, specific growth rate, and feed conversion ratio. Dry matter and ash content in the whole body and filet increased quadratically with increasing salt levels, whereas gill moisture and protein content decreased linearly. Furthermore, the nitrogen, lipid, and energy utilization efficiencies decreased with their respective intake and gain levels. Dietary salt significantly influenced the fatty acid profiles of gill, liver, and filet tissues. In the gill, monounsaturated fatty acids (16:1n-7, ΣMUFA) and n-6 PUFA (20:2n-6) increased, whereas EPA and DHA decreased. Liver ΣSFA (16:0, 18:0) increased, and n-3 PUFA (18:3n-3, 20:5n-3) decreased with increasing dietary salt. Filet saturated fatty acids (14:0, 15:0, 17:0) and n-6 PUFA (20:2n-6, 20:4n-6) increased, while n-3 PUFA (18:3n-3, EPA) decreased with dietary salt. DHA levels in filets showed a quadratic increase. Overall, this study shows that increasing dietary salt negatively impacts turbot growth, feed utilization, and tissue fatty acid composition in brackish water, highlighting the need for further studies on salinity management strategies for turbot aquaculture.

Handheld Near-Infrared Spectroscopy for Undried Forage Quality Estimation.

This study investigates the efficacy of handheld Near-Infrared Spectroscopy (NIRS) devices for in-field estimation of forage quality using undried samples. The objective is to assess the precision and accuracy of multiple handheld NIRS instruments-NeoSpectra, TrinamiX, and AgroCares-when evaluating key forage quality metrics such as Crude Protein (CP), Neutral Detergent Fiber (aNDF), Acid Detergent Fiber (ADF), Acid Detergent Lignin (ADL), in vitro Total Digestibility (IVTD)and Neutral Detergent Fiber Digestibility (NDFD). Samples were collected from silage bunkers across 111 farms in New York State and scanned using different methods (static, moving, and turntable). The results demonstrate that dynamic scanning patterns (moving and turntable) enhance the predictive accuracy of the models compared to static scans. Fiber constituents (ADF, aNDF) and Crude Protein (CP) show higher robustness and minimal impact from water interference, maintaining similar R2 values as dried samples. Conversely, IVTD, NDFD, and ADL are adversely affected by water content, resulting in lower R2 values. This study underscores the importance of understanding the water effects on undried forage, as water's high absorption bands at 1400 and 1900 nm introduce significant spectral interference. Further investigation into the PLSR loading factors is necessary to mitigate these effects. The findings suggest that, while handheld NIRS devices hold promise for rapid, on-site forage quality assessment, careful consideration of scanning methodology is crucial for accurate prediction models. This research contributes valuable insights for optimizing the use of portable NIRS technology in forage analysis, enhancing feed utilization efficiency, and supporting sustainable dairy farming practices.

Evaluation of a carbohydrase (xylanase and glucanase) enzyme complex in diets for Florida pompano Trachinotus carolinus

AbstractFlorida pompano, Trachinotus carolinus, can be fed soy‐based, low‐animal protein diets. However, anti‐nutritional factors and carbohydrates limit digestibility. Dietary carbohydrase enzymes have been used to improve carbohydrate digestibility in several species and may be beneficial for Florida pompano. The present study was designed to evaluate the effects of using a carbohydrase enzyme complex (Natugrain® TS L, BASF Corporation, Ludwigshafen, Germany) composed of endo‐1,4‐ß‐xylanase and endo‐1,4‐ß‐glucanase (Xyl + Glu) on growth performance, feed utilization, and digestibility in diets fed to juvenile Florida pompano. A growth trial was conducted with iso‐nitrogenous (40%) and iso‐lipidic (8%) test diets containing 0, 0.015, 0.030, and 0.045% of Xyl + Glu. The trial was conducted in a recirculating system with 12, 1000‐L tanks. Twenty fish (mean weight: 23.34 g ± 1.49 g) were stocked into each tank in a randomized design. Growth results indicated that there were no significant differences (p &gt; 0.05) in growth and feed conversion; however, thermal growth coefficient displayed significant differences (p = 0.0499) between the 0.015 and 0.030% inclusion. All enzymatic treatments displayed significant differences (p = 0.029) in apparent digestibility of crude protein compared with the basal diet. Results indicate that Xyl + Glu enzyme complex can impact protein digestibility but did not significantly affect growth performance.

Evaluation of four novel non-grain protein sources completely replacing soybean meal on growth performance, serum biochemistry, amino acid transport and intestinal health of grass carp (Ctenopharyngodon idella) at different water temperatures

To investigate the effects of non-grain protein source and water temperature on growth and feed utilization differences of grass carp, the effects of different protein sources on the growth performance, serum biochemistry, digestive enzymes, amino acid transport and intestinal health of grass carp were studied at 24 °C, 28 °C and 32 °C. In this study, a total of 1350 grass carp (Ctenopharyngodon idella) (initial weight 5.00 ± 0.02 g) were selected, and Clostridium autoethanogenum protein (CAP), Tenebrio molitor meal (TMM), cottonseed protein concentrate (CPC) and Chlorella powder (CHP) were used as a single protein source to completely replace soybean meal for 56 days. The results showed that the final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR) and protein efficiency ratio (PER) of grass carp increased significantly with the increasing temperature (P < 0.001). The CHP and SBM groups showed no significant differences in FBW, WGR, SGR and PER (P > 0.05), which were higher than the CAP, TMM and CPC groups (P < 0.001). The alanine transaminase (ALT), aspartate aminotransferase (AST), total protein (TP) and triglyceride (TG) concentrations of grass carp at 32 °C were significantly lower than those at 24 °C and 28 °C (P < 0.001). The acid phosphatase (ACP) activity decreased significantly with the increase of temperature (P = 0.001). The amylase (AMS) activity of the TMM, CPC and CHP groups was significantly lower than that of the SBM and CAP groups (P < 0.001), and the ACP and lipase (LPS) activities in the TMM group were significantly lower than those in the SBM group (P < 0.001). In addition, the interaction between temperatures and protein sources significantly affected the gene expression levels of amino acid transport including solute carrier family 1 member 3 (SLC1A3), solute carrier family 7 member 1 (SLC7A1), solute carrier family 7 member 5 (SLC7A5), solute carrier family 15 member 1b (SLC15A1b), solute carrier family 7 member 7 (SLC7A7), target of rapamycin (TOR), 4E binding protein 1 (4E-BP1) and ribosomal protein S6 kinase 1 (S6K1), intestinal inflammatory including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-8 (IL-8), interleukin-10 (IL-10) and tight junction proteins (occludin, claudin1, claudin3, claudin7 and claudin11) (P ≤ 0.001). Collectively, our results indicated that CHP could be a potential protein source in the case of complete replacement of soybean meal in grass carp.

Protein-sparing effects of lipids in the diet of golden pompano (Trachinotus ovatus): evaluation of growth, feed utilization, and lipid metabolism.

To investigate the influences of dietary protein and lipid levels on the growth, feed utilization, morphometric parameters, body composition, serum biochemical parameters, and lipid metabolism of golden pompano (Trachinotus ovatus), nine test diets containing three protein levels (35%, 40%, and 45%) and three lipid levels (8%, 13%, and 18%) were designed in the present study. Each diet (named D1-D9) was randomly assigned to feed triplicate groups of golden pompano juvenile (initial weight ~ 70 g) for 50 days. The results showed that the dietary lipid levels positively correlated with weight gain, specific growth rate, and protein efficiency ratio (PER), suggesting that the high lipid diets (18%) can be efficiently utilized in this fish species. The dietary protein levels have no significant influences on the growth and feed utilization except for the PER. Increasing dietary protein levels resulted in a decrease in hepatosomatic index (HSI), viscerosomatic index (VSI), and intestinal somatic index (ISI), while the dietary lipid level did not have a significant impact on morphological indices except for ISI. The dietary protein and lipid levels had no significant influences on the contents of crude lipid, crude ash, and moisture of whole body, while the crude protein contents was significantly affected by the dietary protein levels. Serum biochemical indexes, including cholesterol (CHO), triglycerides (TG), high-density lipoprotein cholesterol (HDL), and low-density lipoprotein cholesterol (LDL), as well as HDL/LDL ratio were significantly affected by the dietary lipid levels, but not by the dietary protein levels. The expression levels of genes and their associated proteins involved in hepatic lipogenesis (Srebp-1c and Fas) and fatty acids β-oxidation (Pparα and Cpt-1) were up-regulated with increasing dietary lipid levels, while the former was up-regulated, and the latter was down-regulated with increasing dietary protein levels. Considering the present results in terms of growth performance, feed utilization, morphometric parameters, and lipid metabolism, the recommended dietary protein and lipid levels for golden pompano are 40% and 18%, respectively. The findings suggested that this species exhibits a significant protein-sparing effect on lipid utilization.

Effect of dietary supplementation of selenium-L-methionine on growth, antioxidant capacity and resistance to nitrite stress of spotted seabass (Lateolabrax maculatus) under two rearing water temperatures

A 10-week feeding trial, followed by 24-h nitrite stress, was performed to evaluate the effects of dietary selenium-L-methionine (Se-Met) on growth, Se accumulation, antioxidant capacity, transcripts of selenoproteins and histological changes of muscle as well as resistance to nitrite stress in spotted seabass (Lateolabrax maculatus) reared at optimal (27 °C) and high (33 °C) temperatures. Five experimental diets were formulated to contain 0, 0.9, 1.8, 3.5, and 7.0 mg Se-Met/kg. Each diet was fed to fish (2.60 ± 0.2 g) in two parallel treatments at 27 or 33 °C. The results showed that elevated temperature (33 °C) induced thermal stress in fish, and fish under thermal stress exhibited lower weight gain (WG) and hepatosomatic index (HSI) but a higher condition factor (CF) compared to those reared at 27 °C. However, the growth and feed utilisation were promoted in L. maculatus with 0.9 to 3.5 mg/kg Se-Met treatments. The protein and lipid content in the muscle increased with the dietary Se-Met level, and the total Se level in the whole body and muscle showed a linear increase with dietary Se-Met supplementation. Thermal stress changed the histology of the muscle, leading to raised levels of malondialdehyde (MDA), reduced antioxidant parameters in the serum and liver, and a decrease in the transcripts of selenoprotein genes in the muscle. Meanwhile, increased antioxidant capacity of serum and liver and up-regulated transcripts of selenoprotein of muscle were observed in L. maculatus reaching a maximum with 3.5 mg Se-Met/kg treatment. After 24 h of nitrite stress, thermal stress exacerbated oxidative damage caused by nitrite stress in L. maculatus. In contrast, dietary Se-Met enhanced the resistance to nitrite stress of L. maculatus fed with Se-Met enriched diets containing 0.9 to 1.8 mg Se-Met/kg. Based on the effects of dietary Se-Met on the growth, antioxidant capacity and resistance to nitrite stress of L. maculatus, this study suggests that the optimal range of Se-Met supplementation in L. maculatus diets is 1.80 to 2.39 mg Se-Met/kg of diet at 27 °C and 1.80 to 4.46 mg Se-Met/kg of diet at 33 °C.

Sustainable aquaculture practices in South Asia: a comparative analysis of feed formulation and utilization.

Sustainable aquaculture practices in South Asia: a comparative analysis of feed formulation and utilization.

The Effect of Coffee Grounds Extracts on The Nutrient Utilization and Growth Performance of Tilapia (Oreochromis niloticus)

The study examines the effects of supplementing coffee grounds to commercial feed on the growth, feed utilization and survival rates of Nile tilapia (Oreochromis niloticus). Given that feed quality and environmental conditions significantly impact fish productivity, the inclusion of coffee grounds, rich in antioxidants and potential immunostimulants, was hypothesized to enhance fish growth and health. The experiment, conducted over 45 days, involved five treatments with varying coffee ground concentrations (0%, 2%, 4%, 6%, and 8%) within a Completely Randomized Design (CRD). Each treatment was replicated three times, resulting in a total of 15 experimental units. Results indicated significant improvements in growth parameters, including absolute weight and length, relative growth, and specific growth rates, particularly at the 6% concentration. However, feed conversion ratio (FCR) and feed utilization efficiency (EPP) did not show significant differences. The study concludes that a 6% coffee ground concentration is optimal for promoting tilapia growth without adversely affecting feed efficiency.

The effects of using hydrolyzed feather meal, amino acids, and probiotics in the diet of juvenile rainbow trout on growth, digestibility, and expression of growth-related genes

The study investigated the effect of replacing fishmeal by varying levels of hydrolyzed feather meal (HFM) as well as dietary probiotic supplementation on growth performance, digestibility, histology, and gene expression of juvenile rainbow trout (Oncorhynchus mykiss). Five iso-nitrogenous (average of 50.60% crude protein), iso-energetic (average of 21.79 kJ/g), and iso-lipidic (average of 21.86% crude lipid) diets were formulated and fed to triplicate groups of juvenile rainbow trout weighing 29.65 ± 0.39 g (mean ± SD) for 75 days. Dietary treatments included one control (50% fishmeal) and four experimental diets, each containing 2 g/kg probiotics (Lactobacillus plantarum and Bacillus subtilis). The experimental diets included HFM30 (150 g/kg HFM, 9 g/kg lysine, and 4 g/kg methionine), HFM35 (175 g/kg HFM, 11 g/kg lysine, and 5 g/kg methionine), HFM40 (200 g/kg HFM, 13 g/kg lysine, and 6 g/kg methionine), and HFM45 (225 g/kg HFM, 15 g/kg lysine, and 7 g/kg methionine). Up to 40% replacement of fishmeal with HFM showed no significant difference compared to control group in growth performance (P > 0.05). Feed utilization of HFM45 was slightly lower than control and all the other experimental groups. There was no statistically significant difference in FCR value between HFM40 and control groups (P > 0.05). The apparent digestibility coefficients (ADCs) for protein and amino acids were very high in all groups (P < 0.05). Intestinal mucosa and sub‐mucosa layers of experimental fish showed general tissue integrity with no signs of tissue necrosis. For intestinal morphology, where 45% HFM replacement was applied, villus length to crypt depth (VL to CD) and villus surface area (SA) decreased by 46.01% and 44.44%, respectively, compared to the control group (P < 0.05). This situation shows that intestinal morphology can be damaged when the highest level (HFM45) of feather meal is used. Dietary HFM upregulated growth-related genes such as IGF-II, IGFBP-1b, IGFr1a, GDF9, and FGF2 and downregulated GHR-I and IGF-I. Overall, inclusion of HFM at 40% showed similar results to control group in juvenile rainbow trout feeding.