Body Lipid Content Research Articles

Lipid-lowering and antioxidant properties of probiotic Bifidobacterium animalis MSMC83 in rats on a high-fat diet.

Hyperlipidaemia, the abnormally high concentration of lipids such as cholesterol in the body, has a series of deleterious effects on health that are least in part are due to increased inflammation and oxidative stress. Probiotics are living microorganisms that possess the efficacy to improve health. Among the many effects that have been ascribed to probiotics is the potential to lower the body lipid content. Here, we used a rat model of induced hyperlipidaemia to assess the lipid-lowering and antioxidant properties of the probiotic strain Bifidobacterium animalis MSMC83 as well as its impact on intestinal barrier immunity and the intestinal microbiota. Oral probiotic intake led to a reduction of body weight, fasting blood glucose, and lipid levels, and increased expression of cholesterol-7α-hydroxylase and antioxidant enzymes. Additionally, B. animalis MSMC83 decreased the levels of liver enzymes and pro-inflammatory cytokines, leading to reduced hepatic steatosis. Furthermore, it re-established intestinal barrier integrity as shown by restoration of the tight junction protein zonula occludens-1 amount and reduced pathogen-induced inflammation in the intestinal epithelium as shown by readjusted expression of toll-like receptors (TLRs). Moreover B. animalis MSMC83 contributed to the maintenance of a balanced, diverse microbiome. Thus, our results indicate that B. animalis MSMC83 alleviates risk factors associated with hyperlipidaemia, suggesting its use as a probiotic to counter the effects associated with unhealthy diets.

Dietary lecithin attenuates adverse effects of high fat diet on growth performance, lipid metabolism, endoplasmic reticulum stress and antioxidant capacity in the intestine of largemouth bass (Micropterus salmoides)

This study was conducted to investigate the effects of dietary lipid and lecithin levels on growth performance, lipid metabolism, endoplasmic reticulum stress and antioxidant capacity in intestinal tissues of largemouth bass (Micropterus salmoides). Five experimental diets include the control (10.67 % lipid, normal dietary lipid without extra lecithin addition), 1.0 g/kg lecithin diet with normal dietary lipid level (Lec diet, 10.94 % lipid), high fat diet without extra lecithin addition (HFD, 18.65 % lipid), and HFD supplemented with 1.0 g/kg and 2.0 g/kg lecithin (HFD + Lec1 and HFD + Lec2 diets, respectively). Largemouth bass (initial body weight: 5.39 ± 0.04 g/fish) were fed five diets for 10 weeks. Dietary lecithin alleviated the growth retardation and intestinal damage induced by HFD. HFD-induced increase of whole body and intestinal crude lipid contents and decline of intestinal poly-unsaturated fatty acids content were also alleviated by dietary lecithin addition. Dietary lecithin alleviated the increase of TG content, activities of lipogenic enzymes (G6PD, 6PGD, ME, ICDH and FAS), mRNA expression of lipogenic genes (g6pd, 6pgd, fas, accα, dgat1, dgat2 and srebp1) and protein expression of Srebp1, and downregulation of mRNA expression of lipolytic gene cpt1) and protein expression of Pparα induced by HFD. Lecithin addition mitigated the up-regulation of mRNA expression of lipid absorption genes (fabp2, fatp4, sr-1b and npc1l1), and the down-regulation of mRNA expression of chylomicron assembly- and secretion-relevant genes (mttp and acat2) and proteins (Mttp, Apob and Sar1b), chylomicron components (TG, phosphatidylcholine and apolipoprotein) and MTTP activity induced by HFD. Compared with HFD, HFD + Lec1 diet significantly decreased the mRNA expression of endoplasmic reticulum (ER) stress genes (grp94, grp78, calr, chop, ire1α and xbp1) and Grp78 protein expression. Compared with HFD, the activities of antioxidant enzymes (CAT, T-SOD and GPx) and mRNA expression of genes (sod1, cat, gpx1 and nrf2) were significantly increased but MDA content and keap1 mRNA expression were significantly decreased in HFD supplemented with 1.0 g/kg and 2.0 g/kg lecithin. These results indicated that dietary lecithin supplementation increased growth rate, improved lipid metabolism, relieved ER stress, and enhanced antioxidant capacity, thereby alleviating negative effects of HFD on the function and health of intestinal tract of largemouth bass. Statement of relevanceOur results found that dietary addition of lecithin has obvious merits in alleviating negative effects of HFD on the intestinal function and health, which provided good basis for lecithin addition in aquafeeds.

Transcriptome-Guided Characterization of the Environmental Toxicity of Metformin: Disruption of Energy Homeostasis and Inhibition of Embryonic Development of Zebrafish at Environmentally Relevant Concentrations.

Metformin has been widely detected in aquatic ecosystems, yet the knowledge of its impact on aquatic organisms, particularly at environmentally relevant concentrations, remains limited. In the present study, we characterized the developmental toxicity of metformin in zebrafish, utilizing a transcriptome-guided toxicological assessment framework. Transcriptomic analysis conducted at metformin concentrations within the μg/L range revealed significant disruptions in biological processes associated with nucleotide, hydrocarbon, and amino acid metabolism, suggesting a significant disturbance in energy homeostasis. This observation was corroborated by energy-targeted metabolomic analysis, wherein a considerable number of metabolites involved in purine metabolism, pyrimidine metabolism, and the citrate cycle displayed significant alterations. Notably, most intermediates in the citrate cycle such as acetyl-CoA exhibited remarkable decreases. Additionally, our study identified significant impediments in zebrafish embryonic development, including decreased yolk extension progress, spontaneous contraction and body length, and increased yolk sac area and yolk/while body lipid content ratio, at metformin concentrations as low as 0.12 μg/L. Furthermore, the disruption of energy homeostasis by metformin was observed to persist into adulthood even after a prolonged recovery period. The present findings highlighted the disruptive effects of metformin on energy homeostasis and embryonic development in teleost at environmentally relevant concentrations, thereby prompting a reevaluation of its environmental risk to nontarget aquatic organisms.

Growth performance, fatty acid profile, antioxidant capacity, liver and gut histopathology in Asian seabass (Lates calcarifer) fed various levels of oxidized fish oil and vitamin E

A 60-day research was carried out to investigate interactive effects of dietary oxidized fish oil (OXFO) and vitamin E (Vit E) interaction effects on the growth, body composition and health indices in Asian seabass juveniles (Lates calcarifer, 21.9 ± 0.1 g). Fresh fish oil (FFO) and two levels of OXFO (50 and 100 % dietary inclusion level) along with three levels of Vit E (125, 250 and 500 mg) were used to design a 3 × 3 factorial research trial. Accordingly, nine experimental diets were formulated, including FFO+125 (FFO + 125 mg Vit E), FFO+250 (FFO + 250 mg Vit E), FFO+500 (FFO + 500 mg Vit E), 50 %OXFO+125 (blends (1:1) of FFO + OXFO +125 mg Vit E), 50 %OXFO+250 (blends (1:1) of FFO + OXFO +250 mg Vit E), 50 %OXFO+500 (blends (1:1) of FFO + OXFO +500 mg Vit E), 100 %OXFO+125 (OXFO +125 mg Vit E), 100 %OXFO+250 (OXFO +250 mg Vit E) and 100 %OXFO+500 (OXFO +500 mg Vit E). Four hundred five L. calcarifer juveniles were stocked into twenty-seven 300-L circular tanks (15 fish/tank), in a flow through system. The greatest and least final weights were recorded in fish fed 50 %OXFO+250 and 100 %OXFO+125 diets (129.4 vs. 114.8 g final weight) diets, respectively. Whole body lipid content in fish fed FFO+125 increased compared to the other treatments. Fish oil oxidation significantly reduced Vit E concentration in the liver, meanwhile supplementing diet with 500 mg Vit E enhanced Vit E contents of the liver and muscle (P < 0.05). Eicosapentaenoic acid and long chain polyunsaturated fatty acids (LC-PUFA) contents of fillet increased with increasing dietary OXFO content to 50 %, and supplementing diet with 250 mg Vit E enhanced LC-PUFA content of fillet. Hepatic catalase, superoxide dismutase and glutathione peroxidase activities reduced by supplementing diets with Vit E. Sever pathological alterations occurred in liver and gut of L. calcarifer by dietary inclusion of OXFO or high Vit E concentration (500 mg). In summary, supplementing OXFO containing diets with moderate levels of Vit E (250 mg) could improve growth performance and feed utilization by ameliorating oxidative stress indices, improving antioxidant capacity, and increasing body LC-PUFA content in L. calcarifer.

Physicochemical and stability analysis of mung bean protein hydrolysates with lipid peroxidation inhibition

This study investigated mung bean protein hydrolysates (MBPH) produced using neutral protease, examining their physicochemical properties, stability, and lipid peroxidation inhibition capabilities. The research revealed that MBPH molecular weight ranged from 17 to 26 kDa and perform various functions, including catalytic, nutrient storage, and binding. Stability assessments showed that MBPH are stable at 45 °C and pH of 7.5 but are light-sensitive and unstable in solution or when combined with sugars. Additionally, increased concentrations of digestive enzymes reduce MBPH stability. Antioxidant tests in vitro and in Caenorhabditis elegans confirmed MBPH's ability to neutralizing radicals, enhance antioxidant enzyme activities, and reduce lipid peroxidation, thereby protecting against oxidative damage. Furthermore, in vivo experiments showed that MBPH extend the lifespan of worms and reduced their body lipid content, indicating potential benefits in mitigating cholesterol-related damage. This research demonstrates the potential of MBPH in inhibiting lipid peroxidation.

Larval diet impacts black soldier fly (Diptera: Stratiomyidae) thermal tolerance and preference.

Thermal tolerance and preference are key parameters impacting agricultural production systems. In this study, the impact of larval diet on black soldier fly thermal tolerance and preference across life-stages and sexes was examined. Larvae were fed either a low-protein high-carbohydrate synthetic diet (i.e., P7C35), a high-protein low-carbohydrate synthetic diet (i.e., P35C7), or the Gainesville diet (i.e., C) as a control and reference. Our results demonstrate that the impacts of larval diet on black soldier fly thermal tolerance and preference could be stage and sex specific. The mean heat knockdown temperatures (HKT) ranged between 46.6 and 47.9 °C. Synthetic diets resulted in greater HKT and the difference decreased form larvae (e.g., ∼1 °C) to adults (e.g., ∼0.2 °C). The mean chill-coma recovery time (CCRT) ranged between 8.3 and 21.6 min. Not much differences were detected between diets, but CCRT became longer from larvae to adults. The mean thermal preference ranged between 13.6 and 29.5 °C. Larvae fed synthetic diets preferred much lower temperatures than the control diet. A bimodal distribution was observed for adults regardless of sex. Differences on body mass, lipid, and protein contents were detected among diets; however, more research should be done before any conclusions can be linked to their thermal traits. These findings highlight the importance of considering the ingredients and nutritional makeup of larval diets when optimizing temperature management protocols for mass production of black soldier flies. Conversely, specific diets can be developed to promote survival under extreme rearing temperatures.

Host and pathogen factors that influence variability of Mycobacterium tuberculosis lipid body content in sputum from patients with tuberculosis: an observational study

High proportions of Mycobacterium tuberculosis cells in sputum containing triacylglycerol-rich lipid bodies have been shown to be associated with treatment failure or relapse following antituberculous chemotherapy. Although lipid body determination is a potential biomarker for supporting clinical trial and treatment decisions, factors influencing variability in sputum frequencies of lipid body-positive (%LB+) M tuberculosis in patients are unknown. We aimed to test our hypothesis that exposure to host-generated NO and M tuberculosis strains are factors associated with differences in sputum %LB+. In this observational study, we determined %LB+ frequencies before treatment by microscopy in patients with smear-positive tuberculosis from two separate prospective observational study settings (Gondar, Ethiopia, recruited between May 1, 2010, and April 30, 2011, and Fajara, The Gambia, who provided sputum samples before treatment between May 5, 2010, and Dec 22, 2011). In Ethiopia, fractional exhaled nitric oxide (FeNO) was measured as a biomarker of host NO, and M tuberculosis strain differences were determined by spoligotyping. Treatment response was assessed by percentage weight change after 7 months. In The Gambia, treatment responses were assessed as change in BMI and radiographic burden of disease after 6 months. Sputum Mtuberculosis isolates were studied invitro for their %LB+ and triacylglycerol synthase 1 (tgs1) mRNA responses to NO exposure. Propidium iodide staining was used as a measure of NO strain toxicity. Correlation between invitro %LB+ frequencies following NO exposure and those of the same strain in sputum was examined with linear regression and Dunnett's multiple comparison test. In Ethiopia, 73 patients who were smear positive for pulmonary tuberculosis were recruited (43 [59%] were male and 30 [41%] were female). Of these, the %LB+ in the sputum of 59 patients showed linear correlation with log10 FeNO (r2=0·28; p<0·0001) and an association with strain spoligotype was suggested. Seven Mtuberculosis strains from The Gambia showed different dose-responses to NO invitro, demonstrated by changing lipid body content, tgs1 transcription, and bacterial toxicity. In sputum %LB+ frequencies correlated with invitro %LB+ responses to NO of the corresponding isolate. In a subset of 34 patients across both cohorts, higher sputum %LB+ frequencies before treatment were associated with weaker responses to treatment than lower sputum %LB+ frequencies. M tuberculosis strain and exposure to host-generated NO are associated with sputum %LB+. Our results support the use of M tuberculosis strain-dependent sputum %LB+ as a predictive biomarker of treatment response. The Medical Research Council, the University of Leicester, and the University of Gondar.

Zinc nutrition at first feeding imprints a programming effect on growth and hepatic lipid metabolism in juvenile rainbow trout

The objective of this study was to determine whether supplementation with deficient zinc (Zn) or/and excess copper (Cu) in the first-feeding diet of rainbow trout fry influenced the growth and physiological regulation of juvenile fish subjected to similar challenge feeds again. The feeding trial lasted for 24 weeks and had three phases. In phase I, rainbow trout fry was treated with one of four different plant-based feeds containing or exempting Zn or Cu supplementation (coded Zn-Cu-, Zn+Cu-, Zn-Cu+, Zn+Cu+) for 6 weeks. Thereafter, all groups were fed a common commercial feed for the next 12 weeks (phase II). In phase III, all groups were fed with the “challenge diet” for another 6 weeks which was the basal diet (Zn-Cu-) except that the vegetable oils were replaced by fish oil. The results demonstrated that fish fed a Zn+ diet at first feeding increased larval growth (phase-I), but it had no effect on growth at the end of phase II when fed commercial feeds. In phase III, when re-introduced to a Zn- challenge diet, the feed intake and growth of juveniles with Zn+ history significantly increased, with reduced feed efficiency. Fish growth was neither influenced by dietary Cu levels or by the dietary Cu history in any of the growth phases, but dietary Cu excess (Cu+) reduced body lipid and energy content in fry. In phase I, lower whole-body Zn concentration was observed in the fry of Zn- group compared to Zn+, while the contrary was observed in the juvenile fish as affected by dietary Zn history (phase III). In addition, Zn- dietary history showed increased levels of PUFA and higher mRNA expression of fatty acid biosynthesis genes in the liver. To conclude, early-stage dietary Zn+ history improved growth of juvenile rainbow trout, while dietary Zn- history exhibited signs of improved fatty acid biosynthesis capacity in the liver.

Physical traits and fitness of cold-induced lethargic Diachasmimorpha longicaudata (Hymenoptera: Braconidae) adults

ABSTRACT The chilled adult technique is a suitable strategy for the mass-release of insects for the area-wide management of insect pests. Chilling may have undesirable effects on the released insects. The relationship between physical traits and the effects of cold-induced lethargy on the fitness of Diachasmimorpha longicaudata has not been fully explored. In the present study, we evaluated the relationship between weight, size, and water and lipid content in D. longicaudata subjected to cold-induced lethargy at 9, 6, and 3°C, and the effects of cold induction on the survival, flight ability, and fecundity of parasitoid adults. During gradual chilling from 15°C to 3°C over a 45 min period, we observed that most wasps became lethargic at 9°C. The tibias of wasps that became lethargic at 3°C were larger than those of parasitoids that became lethargic at 9 and 6°C. Body water and lipid contents were higher in lethargic females chilled at 3°C, but no differences were observed in males. Lethargic males experienced reduced flight ability compared with the control, whereas fecundity was reduced only in lethargic females that had been exposed to 3°C. The survival rate was lower in both sexes. Our results suggest that greater body size and higher water and lipid contents delay the onset of cold-induced lethargy, but do not prevent negative effects on survival, fecundity, and flight ability in D. longicaudata. This study will help the advancement of parasitoid-release field programmes that use the chilled adult technique.

The effect of fishmeal replacement with organic acid fermented black soldier fly (Hermetia illucens) larvae meal on growth, nutrient utilization, metabolic enzyme activity, antioxidant status and immunity in Pangasius (Pangasianodon hypophthalmus)

Black soldier fly (Hermetia illucens) larvae meal is emerging as an alternative protein source and good substitute of fishmeal (FM). In an 8-week feeding trial, three hundred pangasius (Pangasianodon hypophthalmus,7.44 ± 0.01 g) fingerlings were randomly allocated over five treatments in triplicate tanks and fed five isoprotein (CP, 35%) and isolipidic (CL, 10%) diets formulated by replacing 0% (FBSFL0), 25% (FBSFL25), 50% (FBSFL50), 75% (FBSFL75) and 100% (FBSFL100) FM with organic acid (formic acid) fermented black soldier fly larvae meal (FBSFL). The inclusion of FBSFL did not affect growth, feed conversion ratio, nutrients utilization and survival rate of pangasius even when FM was completely replaced. The pangasius body protein content increased significantly (P < 0.05) with increasing FBSFL level in the diets while, body lipid content was unaffected (P > 0.05). The haematological indices were not (P > 0.05) affected with the FBSFL inclusion levels. Significantly (P < 0.05) higher and alike protease activity was recorded in FBSFL50, FBSFL75, and FBSFL100 groups. However, activity of amylase and lipase were similar among treatments. The liver antioxidant enzymes (SOD, catalase, and GST) did not show significant (P > 0.05) difference among the treatments. However, pangasius fed with FBSFL75 and FBSFL100 showed significantly higher and similar total antioxidant capacity (T-AOC). The FBSFL in the diet of pangasius did not affect the liver metabolic enzyme (MDH, G-6-PDH and GDH) activities. Relative gene expression of growth hormone (GH1) did not substantially differ among the groups (P < 0.05). No differences were observed in the immune gene expressions of complement (C3) and interleukin-1β (IL-1β) but the expression level of transferrin was up-regulated significantly (P < 0.05) in FBSFL25 group. No damage was observed in hepatic tissues in histomorphometry examination due to the inclusion of FBSFL. The study concludes that formic acid fermented BSFL can be employed as a complete substitute for FM in the pangasius diet, offering additional health benefits without any adverse effects.

Evaluation of the potential growth and body composition of the Cobb 700 genotype

ABSTRACT 1. The potential growth of the chemical and physical components of males and females of the Cobb 700 strain was measured from hatch to 15 weeks of age. 2. A four-phase ad libitum feeding programme was used to feed 200 chicks of each sex. All birds were weighed weekly. Ten birds per sex were sampled at 0, 7, 14, 28, 42, 56, 70, 84 and 105 d of age. They were weighed before and after plucking to determine the weight of feathers. Physical parts were measured on defeathered birds, whereafter these components were combined, minced, freeze dried to measure water content, and then analysed for protein, lipid and ash content. 3. Mature body weights of males and females averaged 8.38 and 6.94 kg, respectively, mature body protein weights averaged 1.48 and 1.19 kg and mature body lipid contents averaged 1.08 and 1.54 kg, respectively. 4. Rates of maturing of the empty feather-free body weights of males and females averaged 0.0417 and 0.0402/d, respectively. All chemical and physical components within a sex, other than feathers, had the same rate of maturing. The rate of maturing of feathers, calculated by iteration, in males was lower than in females (0.0324 vs. 0.0357/d) and the mature weight was higher (435 vs. 372 g). 5. The ratios of the chemical components to feather-free body protein at maturity for males and females were, for water, 3.80 and 3.34; for lipid, 0.73 and 1.29; and for ash, 0.13 and 0.19, respectively. Separate equations were required for males and females to describe the allometric relationship between lipid and protein in the feather-free body. 6. Mature body weights of broilers in this trial were considerably higher than those measured using the same protocol 28 years ago, whereas rates of maturing have remained the same.

Target for lipid-to-carbohydrate intake minimizes cost of growth.

Many theoretical treatments of foraging use energy as currency, with carbohydrates and lipids considered interchangeable as energy sources. However, herbivores must often synthesize lipids from carbohydrates since they are in short supply in plants, theoretically increasing the cost of growth. We tested whether a generalist insect herbivore (Locusta migratoria) can improve its growth efficiency by consuming lipids, and whether these locusts have a preferred caloric intake ratio of carbohydrate to lipid (C : L). Locusts fed pairs of isocaloric, isoprotein diets differing in C and L consistently selected a 2C : 1L target. Locusts reared on isocaloric, isoprotein 3C : 0L diets attained similar final body masses and lipid contents to locusts fed the 2C : 1L diet, but they ate more and had a ~12% higher metabolic rate, indicating an energetic cost for lipogenesis. These results demonstrate that some animals can selectively regulate carbohydrate-to-lipid intake and that consumption of dietary lipids can improve growth efficiency.

Comparison of Body Characteristics, Carotenoid Composition, and Nutritional Quality of Chinese Mitten Crab (Eriocheir sinensis) with Different Hepatopancreas Redness.

In this study, we investigated the body characteristics, carotenoid composition, and nutritional quality of Eriocheir sinensis with different hepatopancreas redness (a*). We distributed the crabs into two groups based on the hepatopancreas a* values and compared their body characteristics, chroma, carotenoid composition, and protein, lipid, total sugar, amino acid, and fatty acid content via paired t-test. The results revealed that the relationships between hepatopancreas a* values and crab quality are sex specific. In female crabs, the differences in nutritional characteristics were evident mainly in the hepatopancreases and ovaries. In the redder hepatopancreases, the content of zeaxanthin and β-carotene increased, and the levels of C22:6n3 and C20:5n3 decreased (p < 0.05). In the ovaries, the content of astaxanthin, canthaxanthin, β-carotene, umami, and sweet amino acids were lower in the redder hepatopancreas crabs (p < 0.05). In male crabs, there were positive relationships between hepatopancreas a* and amino acid and fatty acid content. The content of leucine, arginine, and total umami amino acids in muscles and of unsaturated fatty acids and n-6 polyunsaturated fatty acids in hepatopancreases and testicles increased with increasing hepatopancreas a* values (p < 0.05). Therefore, the redder the hepatopancreas, the higher the nutritional quality of male crabs.

Hypolipidemicand Anti-Obesity Effect of Anserine on Mice Orally Administered with High-Fat Diet via Regulating SREBP-1, NLRP3, and UCP-1.

To investigate the efficacy of anserine on antiobesity, C57BL/6 mice are orally administered with a high-fat diet (HFD) and different doses of anserine (60, 120, and 240mg/kg/day) for 16 weeks. Body weight, lipid, and epididymal fat content in mice are measured, and their liver damage is observed. The results display that the body weight, epididymal fat content, and low-density lipoprotein cholesterol (LDL-C) content in anserine groups are decreased by 4.36-18.71%, 7.57-35.12%, and 24.32-44.40%, respectively. To further investigate the antiobesity mechanism of anserine, the expression of SREBP-1, NLRP3, NF-κB p65 (p65), and p-NF-κB p65 (p-p65) proteins in the liver and peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1-α) and UCP-1 proteins in brown adipose tissue (BAT) is analyzed by Western blot. Results show that anserine can significantly decrease the expression of the NLRP3, p65, p-p65, and the SREBP-1 proteins and increase the expression of the PGC1-α and UCP-1 proteins. This study demonstrates that anserine lowered blood lipids and prevented obesity; its antiobesity mechanism may be related to the activation of brown fat by inflammation.

The response of turkeys to dietary balanced protein during two periods of growth

ABSTRACT 1. Two experiments were conducted to measure the response of growing turkeys to dietary protein content. In the first, 960 sexed British United Turkey (BUT 6) poults were used to measure the response to balanced protein from 3 to 6 weeks of age. In the second, 1440 sexed BUT and Hybrid Converter poults were raised from 14 to 17 weeks. 2. In both experiments, six levels of dietary protein were fed, with feed intake, body and feather weight gain and changes in body composition measured. The levels of protein chosen ranged from 0.53 to 1.2 of the Aviagen requirements for growing turkeys. 3. In the first experiment, six poults were sampled from each sex at the start of the experiment for carcass analysis, and four were sampled from each strain and sex in the second. At the end of each experiment, eight poults from each treatment were sampled. Body composition analyses were made on individual defeathered birds. 4. Weight gain increased linearly with protein intake in the early period and exponentially in the later period. In both periods, feed intake decreased as protein content reduced. 5. In the early period, body lipid content increased from 20.2 to 41.5 g/kg body weight, as dietary protein content decreased, but there was no change in the later period. Efficiency of utilisation of dietary protein declined linearly with an increase in dietary protein content, from 0.87 to 0.46 g/g in the first, and from 0.43 to 0.27 g/g in the later period. 6. The inability of the growing turkey to increase feed intake on marginally limiting feeds may have been due to a genetic constraints to store excess energy consumed as body lipid, resulting in the observed decrease in feed intake as dietary protein content is reduced.

Effects of Dietary Bile Acids on Growth Performance, Lipid Deposition, and Intestinal Health of Rice Field Eel (Monopterus albus) Fed with High-Lipid Diets.

The purpose of this trial was to study the positive effects of bile acids (BAs) on growth performance and intestinal health of rice field eel fed with high-lipid diets (HLDs). Rice field eels (initial weight 17.00 ± 0.10 g) were divided into four groups, each group containing four repetitions and feeding with different isonitrogenous diet: control diet containing 7% lipid content, HLDs containing the lipid content increased to 13%, HLDs supplementing with 0.025% BAs and 0.05% BAs, respectively. After 8 weeks, compared control group, the fish fed HLDs had no significant effect on weight gain rate and specific growth rate (P > 0.05), but increased the lipid deposition in tissues and intestinal lipase activity, and damaged to intestinal oxidative stress, inflammatory response, physical barrier, and structural integrity (P < 0.05). Dietary BAs significantly increased weight gain rate and specific growth rate in fish fed with HL diets (P < 0.05) and reduced feed conversation rate (P < 0.05). Further, the eels fed with BAs reduced the total lipid content in liver, muscle, and whole body (P < 0.05). Dietary BAs decreased the activity of intestinal lipase (P < 0.05). Meanwhile, BAs supplemented in HLDs improved intestinal antioxidant capacity through increasing the activities of T-SOD (total superoxide dismutase), GSH-PX (glutathione peroxidase), CAT (catalase), T-AOC (total antioxidant capacity), whereas reducing MDA (malondialdehyde) content (P < 0.05). Moreover, dietary BAs regulated the mRNA expression related to inflammatory response, oxidative stress, and physical barrier in intestine, such as tnf-α, il-8, tlr-8, il-10, nrf2, keap1, claudin12, and claudin15 (P < 0.05). Dietary BAs supplementation also enhanced the intestinal structural integrity characterized by increased fold height and lamina propria width (P < 0.05). This study showed that dietary BAs supplemented in HLDs (13% lipid) could increase the growth performance of rice field eel, reduce lipid deposition in tissues and whole body, and enhance intestinal health.

Insights into the interaction between stocking density and feeding rate in fish Megalobrama ambylcephala based on growth performance, innate immunity, antioxidant activity, and the GH-IGF1 axis

The interaction between stocking density and feeding rate was investigated in juvenile blunt snout bream (Megalobrama ambylcephala) (11.94 ± 0.04 g) based on growth performance and health status. A 2 × 4 factorial design was adopted, containing two stocking densities (10 and 20 fish/m3) and four feeding rates (3%, 4%, 5% and 6% body weight/day). After the 12-weeks feeding trial, high stocking density (20 fish/m3) significantly (P < 0.05) reduced weight gain rate (WGR), feed intake (FI), protein efficiency ratio (PER), nitrogen and energy retention efficiency (NRE and ERE), plasma immunoglobulin M (IgM) level, plasma lysozyme (LZM), myeloperoxidase (MPO) and alkaline phosphatase (AKP) activities, as well as hepatic superoxide dismutase (SOD) and catalase (CAT) activities, while the opposite was observed in feed conversion rate (FCR), condition factor (CF) and plasma complement 4 (C4) level. The highest feeding rate (6%) significantly (P < 0.05) increased WGR, FI, FCR, CF, the intraperitoneal fat ratio and the protein expression of growth hormone receptor, but significantly (P < 0.001) decreased PER, NRE and ERE. Moderate feeding rates (4%–5%) significantly (P < 0.05) increased body lipid and energy contents, the activities of SOD, CAT, glutathione peroxidase, LZM, MPO, AKP and acid phosphatase, the levels of complement 3 and 4 (C3 and C4), and the transcriptions and protein levels of growth hormone and insulin-like growth factor 1, while the opposite was noted in the malondialdehyde content. Furthermore, an interactive effect between stocking density and feeding rate was also noted in WGR, FI, plasma ACP, AKP and MPO activities, and liver malondialdehyde content. In summary, stocking density and feeding rate interactively affect the growth performance and health status of blunt snout bream. The optimum feeding rate of this species increased when cultured under high-density conditions.

Liver Transcriptome Profiling Identifies Key Genes Related to Lipid Metabolism in Yili Geese.

The Yili goose is the only indigenous goose breed that originates from Anser anser in China, known for its adaptability, strong flying ability, and tender meat with a low body lipid content. The liver plays a crucial role in lipid and glucose metabolism, including the intake, secretion, transportation, and storage of fatty acids (FAs). In this study, RNA-sequencing (RNA-seq) technology was performed to analyze the liver differentially expressed genes of Yili geese and their hybrid geese to investigate differences in liver lipid and glucose metabolism. A total of 452 differentially expressed genes (Q-value < 0.05) were identified. Notably, in KEGG enrichment analysis, four pathways (Q-value < 0.05) were enriched to be associated with lipid and glucose metabolism, including the metabolic pathway, PI3K-Akt signaling pathway, glycolysis/gluconeogenesis, and steroid biosynthesis. This study provides insights into potential candidate genes and metabolic pathways that affect the liver lipid metabolism of Yili goose. These findings provide a better understanding of animal liver lipid deposition and metabolism.

The optimal feeding regime for large yellow croaker Larimichthys crocea, with an emphasis on obviating raw fish diet in commercial farming

Commercial farming of large yellow croaker Larimichthys crocea still relies on raw fish diet. The present study assessed the possibility to replace raw fish diet with a formulated diet containing 490 g/kg crude protein by optimizing feed and feeding management. In experiment I, fish weighing 10.8 g were fed with the formulated diet at either five frequencies (FF13, 1/3 meal/d; FF12, 1/2 meal/d; FF11, 1 meal/d; FF21, 2 meal/d; FF31, 3 meal/d) or at 1 meal/d but different times (FF11, at 6:00; FF11A, at 18:00), respectively. In experiment II, fish were fed at 2 meal/d with the formulated diet (FF21) or a quality raw fish diet (RF21). The final body weight (FBW), weight gain, feed intake and body lipid content, fish in/out ratio (FIFO) and waste outputs (nitrogen, phosphorus and carbon) were higher, whereas the nutrient and energy retention efficiencies (NRE, nitrogen; PRE, phosphorus; CRE, carbon; ERE, energy) were lower, in FF21 and FF31 than in FF13, FF12 and FF11. No significant differences were detected in FBW and weight gain either between FF21 and FF31 or between FF13, FF12 and FF11. The feed conversion ratio (FCR) and feed cost were higher in FF31 than in FF13, FF12 and FF11. The activities of superoxide dismutase (SOD) and catalase (CAT) in plasm, activities of glutathione peroxidase (GSH-PX) and CAT in liver, and malondialdehyde (MDA) content in plasm and liver were higher in FF31 than in FF11. No significant differences were detected in FBW, weight gain, NRE, PRE, CRE, ERE, body composition, feed cost, FIFO-, waste outputs, activities of antioxidant enzymes and MDA content in plasm and liver between FF11 and FF11A despite FF11A had higher feed intake and FCR compared with FF11. The FBW, weight gain, feed intake, FCR, body lipid content, feed cost, FIFO, waste outputs, activities of SOD and GSH-PX in liver, plasm CAT activity, and MDA content in plasm and liver were higher, whereas the survival, NRE, PRE and ERE were lower, in RF21 than in FF21. Our study indicates that 2 meal/d is the optimal feeding frequency for large yellow croaker, and completely replacing raw fish diet with the formulated diet in commercial farming benefits to increase fish survival and yield and to reduce feed cost, FIFO, waste outputs and body lipid deposition.

Effect of alpha-ketoglutarate supplementation on growth, antioxidant capacity, gene expression and amino acid profile in Nile tilapia (Oreochromis niloticus) under varying protein diets

Protein is the most expensive component in aquafeed and emphasis is given to reduce dietary protein levels without compromising growth. Alpha ketoglutarate (AKG) promotes protein synthesis in fish and improves growth. The present experiment was conducted to investigate the effect of AKG with different dietary protein levels on growth, nutrient utilisation, antioxidant status and immunity in Nile tilapia (Oreochromis niloticus). Five diets were prepared with different levels of protein such as 20 (P20A), 25 (P25A), 30 (P30A) and 35 % (P35A) with 1 % AKG and 35 % protein without AKG (P35C). Nile tilapia fingerlings (300) were randomly stocked in fifteen 150 L capacity FRP tanks with 20 fingerlings (9.91 ± 0.06 g) in each. The fish were then fed with experimental diets twice daily for 60 days. The fish fed with P30A had significantly (P < 0.05) higher growth performance and nutrient utilisation. However, there was no significant (P > 0.05) difference in final body weight and weight gain of tilapia fed with P35C and P25Adiets. The feed conversion ratio (FCR) was significantly higher (P < 0.05) in P20A group and other groups showed alike (P > 0.05) FCR value. The whole body protein and lipid contents of final fish were significantly (P < 0.05) higher in P30A and P25A, respectively. The P25A, P30A and P35A showed increased (P < 0.05) activities of superoxide dismutase (SOD) and catalase (CAT). The activity of metabolic enzymes were also higher in higher protein levels with AKG (P30A and P35A). The expression level of growth gene insulin like growth factor 1 (IGF-1) was significantly up-regulated (P < 0.05) in the P30A. In addition, the relative expression levels of the pro-inflammatory factors tumour necrosis factor (TNF-α) were significantly (P < 0.05) lower in P30A, P25A, and P20A. Total amino acid profile of fish was higher in P35C group. In summary, the optimal choice for enhancing growth and health in Nile tilapia appears to be a diet comprising 30 % protein and 1 % AKG. However, diet of 25 % CP with AKG showed equivalent result in terms growth that of 35 % CP level without AKG. Hence, 25 % protein with 1 % AKG can effectively fulfil protein requirement in tilapia.