Dietary Fat Level Research Articles

Short-term changes in dietary fat levels and starch sources affect weight management, glucose and lipid metabolism, and gut microbiota in adult cats.

A 2 × 2 factorial randomized design was utilized to investigate the effects of fat level (8% or 16% fat on a fed basis) and starch source (pea starch or corn starch) on body weight, glycolipid metabolism, hematology, and fecal microbiota in cats. The study lasted for 28 d and included a low fat and pea starch diet (LFPS), a high fat and pea starch diet, a low fat and corn starch diet, and a high fat and corn starch diet. In this study, hematological analysis showed that all cats were healthy. The apparent total tract digestibility of gross energy, crude protein, and crude fat was above 85% in the four diets. After 28 d, cats fed the high fat diets (HF) gained an average of 50 g more than those fed the low fat diets (LF). The hematological results showed that the HF diets increased the body inflammation in cats, while the LFPS group improved the glucolipid metabolism. The levels of glucose and insulin were lower in cats fed the LF diets than those in cats fed the HF diets (P < 0.05). Meanwhile, compared with the LF, the concentrations of total cholesterol, triglyceride, and high-density lipoprotein cholesterol in serum were greater in the cats fed the HF diets (P < 0.05). Additionally, both fat level and starch source influenced the fecal microbiota, with the relative abundance of beneficial bacteria, such as Blautia being significantly greater in the LFPS group than in the other three groups (P < 0.05). Reducing energy density and using pea starch in foods are both valuable design additions to aid in the management of weight control and improve gut health in cats. This study highlights the importance of fat level and starch in weight management in cats.

Quantifying the Contributions of Environmental Factors to Prostate Cancer and Detecting Risk-Related Diet Metrics and Racial Disparities.

The relevance of nongenetic factors to prostate cancer (PCa) has been elusive. We aimed to quantify the contributions of environmental factors to PCa and identify risk-related diet metrics and relevant racial disparities. We performed a unique analysis of the Diet History Questionnaire data of 41 830 European Americans (EAs) and 1282 African Americans (AAs) in the PLCO project. The independent variables in the regression models consisted of age at trial entry, race, family history of prostate cancer (PCa-fh), diabetes history, body mass index (BMI), lifestyle (smoking and coffee consumption), marital status, and a specific nutrient/food factor (X). P < .05 and a 95% confidence interval excluding zero were adopted as the criteria for determining a significant difference (effect). We established a priority ranking among PCa risk-related genetic and environmental factors according to the deviances explained by them in the multivariate Cox-PH regression analysis: age > PCa-fh > diabetes ⩾ race > lifestyle ⩾marital-status ⩾BMI > X. We confirmed previous studies showing that (1) high protein and saturated fat levels in diet were related to increased PCa risk, (2) high-level supplementary selenium intake was harmful rather than beneficial for preventing PCa, and (3) supplementary vitamin B6 was beneficial for preventing benign PCa. We obtained the following novel findings: high-level organ meat intake was an independent predictor for increased aggressive PCa risk; supplementary iron, copper and magnesium increased benign PCa risk; and the AA diet was "healthy" in terms of the relatively lower protein and fat levels and was "unhealthy" in that it more commonly contained organ meat. In conclusion, we established a priority ranking among the contributing factors for PCa and identified several risk-related diet metrics and the racial disparities. Our findings suggested some new approaches to prevent PCa such as restriction of organ meat intake and supplementary microminerals.

Glycemic Index of a High Protein and High Fiber Oral Nutritional Supplement Vidaslim®

Background: Food products with a low Glycemic index (GI) help control blood glucose levels and may also help reduce body weight. The risk of obesity-related chronic diseases increases with the consumption of refined carbohydrate-rich or a diet with high GI food choices. Vidaslim®, an Oral Nutrition Supplement was formulated by Signutra Inc, with a high protein blend (whey, soy, and casein), dietary Fiber (polydextrose), and several phytonutrients with an attempt to reduce body weight. Aim: To determine the GI of the Vidaslim® in fifteen overweight / obese people aged between 20 and 45 years. Methodology: The study participants consumed the test food, Vidaslim® containing 25 g of available carbohydrate. Participants underwent 3 days of reference food (glucose) testing and 1 day of test food with 2 days of wash-out period. In between capillary blood glucose was measured after overnight fasting at 0, 15, 30, 45, 60, 90, and 120 min after consuming the reference and test food in a random order. The GI was assessed using a validated protocol by FAO and ISO (2010). Following this, the glycemic load (GL) of Vidaslim® was also calculated. Results: Out of 15 participants who completed the study, 3 were removed as statistical outliers (GI &gt; mean ± 2SD), and hence the data was presented for the remaining 12 participants. The mean age of the participants was 28.1±5.4 years, and body mass index (BMI) was 27.2±2.7 kg/m2. Vidaslim® had a low GI value of 21±3.6 (Mean+SD). The GI value was not influenced by age, sex, dietary total calories, protein, fat, carbohydrates, dietary Fiber, and physical activity levels. The Glycemic Load (GL) of Vidaslim® was 4.86 (low GL). Conclusion: The oral nutritional supplement, Vidaslim®, has a low GI and GL value, and hence, could be a suitable healthy supplement for those with obesity and diabetes.

Machine Learning Models for Data-Driven Prediction of Diabetes by Lifestyle Type.

The prevalence of diabetes has been increasing in recent years, and previous research has found that machine-learning models are good diabetes prediction tools. The purpose of this study was to compare the efficacy of five different machine-learning models for diabetes prediction using lifestyle data from the National Health and Nutrition Examination Survey (NHANES) database. The 1999-2020 NHANES database yielded data on 17,833 individuals data based on demographic characteristics and lifestyle-related variables. To screen training data for machine models, the Akaike Information Criterion (AIC) forward propagation algorithm was utilized. For predicting diabetes, five machine-learning models (CATBoost, XGBoost, Random Forest (RF), Logistic Regression (LR), and Support Vector Machine (SVM)) were developed. Model performance was evaluated using accuracy, sensitivity, specificity, precision, F1 score, and receiver operating characteristic (ROC) curve. Among the five machine-learning models, the dietary intake levels of energy, carbohydrate, and fat, contributed the most to the prediction of diabetes patients. In terms of model performance, CATBoost ranks higher than RF, LG, XGBoost, and SVM. The best-performing machine-learning model among the five is CATBoost, which achieves an accuracy of 82.1% and an AUC of 0.83. Machine-learning models based on NHANES data can assist medical institutions in identifying diabetes patients.

Growth, carcass, digestive enzymes, intestinal microbiota and economics in growing Egyptian geese as affected by dietary fiber and fat levels

The present study aimed to investigate the effect of dietary crude fiber and fat levels on growth, carcass, digestive enzymes, intestinal microbiota and economics in growing Egyptian geese. A total number of 150 Egyptian goslings, 4 weeks old, with nearly the same body weights were randomly distributed in to six groups in a 3 × 2 factorial arrangement included. Three levels of fiber (8, 10, and 12%) and two levels of fat (5 and 6%) were used. Results showed that the highest (p = 0.029) body weight (BW) value was found in the experimental group fed 8% fiber diet compared to the other groups. The same trend was observed with increasing the dietary fat level from 5 to 6%. The best feed conversion ratio was associated with feeding geese on the lowest fat level (5%) comparing with the highest one (6%). The highest values (p ˂ 0.05 or 0.01) of the cecal length and weight were recorded in birds fed the high-fiber diet (12%) compared to the other levels. Increasing the level of dietary fat positively affected the concentrations of lipase enzymes. Feeding geese on the high-fiber diet (12%) accompanied with the highest (p ˂ 0.01) counts of beneficial lactic acid bacteria and the lowest (p ˂ 0.01) counts of E. coli and Salmonella compared to the other fiber levels. From an economic point of view, the diet contained 12% crude fiber and 5% crude fat was more suitable for the geese kept from 4 to 12 wks of age without any adverse effects on growth performance.

Effects of high fat in the diet on growth, antioxidant, immunity and fat deposition of Macrobrachium rosenbergii post-larvae

Lipids are essential nutrients for organisms, and high-fat feeds for shrimp may cause oxidative stress. This study evaluated the effects of feeding high fat in the diet on the growth, antioxidant, immunity, and liver fat accumulation of Macrobrachium rosenbergii post-larvae. Five groups with an initial body weight of 0.0084 ± 0.001 g were fed five isonitrogenous and isoenergetic diets (47.01% crude protein and 18.40 kJ/g gross energy) containing 8%, 10%, 12%, 14% and 16% (named L8, L10, L12, L14 and L16) lipid for 8 weeks, respectively. The results showed that the weight gain rate (WGR) and specific growth rate (SGR) of L8 group were significantly higher than those of L10, L12, L14 and L16 group (P < 0.05), and the feed coefficient (FCR) of L8 group was significantly lower than that of other groups (P < 0.05). With the increase of dietary fat level, the content of MDA and the activity of SOD increased significantly, and the activities of T-AOC and CAT decreased significantly (P < 0.05). H&E staining clearly revealed the occurrence of hepatocyte swelling, hepatocyte vacuolization and nucleus displacement to the peripheral cell vacuolization in the L16 group, and hepatic lipid accumulation was further observed in the L14 and L16 group by Oil red O staining. In addition, high-fat diet significantly upregulated the expression of Dorsal, Relish and IκBα mRNA, and also upregulated the expression of fat synthesis-related genes FAS, ACC, DGAT and fat transport-related gene FABP (P < 0.05), and significantly downregulated the expression of fat metabolism-related genes AMPK and CPT-1 (P < 0.05) compared to that of the L8 group. In conclusion, this study showed that feeding a high-fat diet could induce oxidative stress, inhibit growth performance, alter antioxidant capacity, cause hepatic fat deposition and affect the immune system of M. rosenbergii post-larvae.

The risk assessment of high-fat diet in farmed fish and its mitigation approaches: A review.

In the era of intensification of fish farms, the high-fat diet (HFD) has been applied to promote growth and productivity, provide additional energyand substitute partial protein in fish feeds. Certainly, HFD within specific concentrations was found to be beneficial in boosting fish performance throughout a short-term feeding. However, excessive dietary fat levels displayed vast undesirable impacts on growth, feed efficiency, liver function, antioxidant capacityand immune functionand finally reduced the economic revenue of cultured fish. Moreover, studies have shown that fish diets containing a high level of fats resultedin increasing lipid accumulation, stimulated endoplasmic reticulum stress andsuppressed autophagy in fish liver. Investigations showed that HFD could impair the intestinal barrier of fish via triggering inflammation, metabolic disorders, oxidative stress and microbiota imbalance. Several approaches have been widely used for reducing the undesirable influences of HFD in fish. Dietary manipulation could mitigate the adverse impacts triggered by HFD, and boost growth and productivity via reducing blood lipids profile, attenuating oxidative stress andhepatic lipid depositionand improving mitochondrial activity, immune function and antioxidant activity in fish. As well, dietary feed additives have been shown to decrease hepatic lipogenesis and modulate the inflammatory response in fish. Based on the literature, previous studies indicated that phytochemicals could reduce apoptosis and enhance the immunity of fish fed with HFD. Thus, the present review will explore the potential hazards of HFD on fish species. It will also provide light on the possibility of employing some safe feed additives to mitigate HFD risks in farmed fish.

Chemosensing of fat digestion by the expression pattern of GPR40, GPR120, CD36 and enteroendocrine profile in sheep

Gastrointestinal tract (GIT) epithelial cells detect nutrients in the lumen via G-protein coupled receptors (GPRs) located in the gut epithelial cells especially in enteroendocrine cells. Dietary free fatty acids (FFA) are the major energy source and also acts as signalling molecules for FFA receptors. Long chain fatty acids (LCFA) activate LCFA receptors, GPR40/FFAR1 and GPR120/FFAR4 which trigger intracellular signalling and release gut hormones or modifies gene expression that facilitate fat digestion and absorption. However, there is a paucity of information on chemosensing of nutrients and digestion in ruminants. Hence, present study was aimed to evaluate chemosensing of fat digestion and absorption by the expression pattern of GPR40, GPR120, chylomicron forming genes, fatty acid translocase (CD36/FAT), microsomal triglyceride transfer protein (MTTP) and apolipoprotein B (APOB) in the various segments of GIT in sheep supplemented with calcium salts of long chain fatty acids (CSLCFAs) along with the secretory patterns of gut peptides cholecystokinin (CCK) and peptide tyrosine tyrosine (PYY). The study was carried out for a period 60 days with eighteen adult ewes of 8–12 months of age and they were divided into three groups with six animals each as group-I, group-II and group-III. All the experimental animals were stall fed with a basal diet and maintained as per animal husbandry standards. Group-II and group-III were supplemented additionally with 3% and 5% CSLCFAs, respectively on dry matter intake. The results from the study indicated that the supplementation of CSLCFAs upregulated (P < 0.05) the relative mRNA expression of GPR40 and GPR120 in the various segments of GIT of sheep in correspondence to level of dietary fat. Abundance of mRNA expression of CD36, MTTP and APOB increased (P < 0.05) in the GIT of sheep in accordance to quantity of LCFAs in the diet where these genes facilitate fatty acid uptake. Feeding of CSLCFAs enhanced (P < 0.05) pre-feeding level of CCK from day 15 onwards, whereas, post-feeding CCK and PYY increased in all the experimental sheep. However, the increase was higher (P < 0.05) in sheep supplemented with CSLCFAs by 10.80 ± 1.45% and 14.25 ± 1.17%, respectively in comparison to group-I. The comprehensive results of the study concluded that feeding of additional CSLCFAs upregulated the expression of GPR40, GPR120, CD36, and chemosensing of LCFAs by these genes triggered the signalling transduction that enhanced CCK and PYY levels to facilitate fat digestion and absorption in accordance with quantity of dietary fat. This was further evident from the significant upregulation of MTTP and APOB in the various segments of GIT supported the high content of dietary fat at cellular fat metabolism in the gut that regulates the fatty acid uptake.

Abstract 2178: Diet-modulated SCAP-SREBP signaling is essential for acinar cell differentiation, pancreatic morphogenesis, and pancreatic adiposity

Abstract High levels of dietary fats are associated with pancreatitis, diabetes, and pancreatic cancer. Sterol regulatory element binding protein Cleavage-Activating Protein (SCAP) is an essential intermediate in lipid-regulated activation of Sterol Regulatory Element Binding Protein (SREBP) transcription factors, which induce expression of genes regulating lipid homeostasis. We previously demonstrated that the elevated SREBP1 arising from inhibition of the cholesterol biosynthetic pathway in mice genetically predisposed to pancreatic cancer additionally transcribed genes that induced epithelial-mesenchymal transition, promoting basal rather than glandular cancer. To further evaluate SCAP and SREBP function in the pancreas, we developed a new mouse model with selective pancreatic knockout of the Scapf/f gene under the control of the Pdx1-Cre promoter (ScapΔpanc mice). Although size of the pancreas in ScapΔpanc neonates was unaffected, and number of islets was normal, there was a reduced number of acinar cells, and some evidence of disorganized tissue structure. Preliminary histopatholgical assessment of pancreatic tissue of ScapΔpanc neonates indicated no acinar cell apoptosis, and unimpaired acinar proliferation, suggesting loss of Scap may cause a differentiation defect. Further supporting this idea, siRNA depletion of Scap in the rat AR42J acinar cell line resulted in loss of markers of mature acinar cell identity. ScapΔpanc pancreata underwent progressive and selective loss of acinar cells as mice aged, with three-month old mice having large areas of acinar cell loss, and mislocalization of ductal cells. Coupled with this loss was a large increase in pancreatic adipocytes and mesenchymal cells, resulting in a highly disorganized tissue morphology accompanied by signs of inflammation. These phenotypes were exacerbated in mice maintained on high fat or high carbohydrate diet. Together, these results imply that SCAP and SREBP signaling in the pancreas plays an important role in mediating dietary modulation of pancreatic development, acinar cell homeostasis, and restraint of pancreatic adiposity. Intrapancreatic fat, associated with obesity and chronic pancreatitis, is a known risk factor for pancreatic cancer, and SCAP polymorphisms have been to interact with diet in regulating obesity and blood pressure in humans; we propose SCAP-SREBP signaling in the pancreas may mediate dietary promotion of pancreatic cancer risk. Citation Format: Anna C. Lilly, Aizhan Surumbayeva, Theodore Nguyen, Igor Astsaturov, Erica A. Golemis. Diet-modulated SCAP-SREBP signaling is essential for acinar cell differentiation, pancreatic morphogenesis, and pancreatic adiposity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2178.

Effects of Pantothenic Acid on Growth Performance, Oxidative Stress, and Lipid Content in High-Fat-Fed Megalobrama amblycephala

This study was to elucidate the effects of dietary pantothenic acid (PA) on growth, lipid metabolism, and antioxidant status in juvenile blunt snout bream Megalobrama amblycephala. Fish were fed with four experimental diets containing two lipid levels (5% and 11%) and two PA supplementation levels (24 mg kg-1 and 240 mg kg-1) for eight weeks. The results showed that diets containing 11% lipid significantly increased condition factor, mesenteric fat index, triacylglycerol (TG), and cholesterol (TCH) in the liver as well as total lipid content and TCH in the muscle ( P &lt; 0.05 ), but significantly decreased specific growth rate and whole-body protein ( P &lt; 0.05 ). As the dietary lipid level increased, hepatic antioxidant enzyme activities were significantly increased ( P &lt; 0.05 ) as well as malondialdehyde content ( P &lt; 0.05 ). Besides, cytosolic cytochrome c concentration was also significantly ( P &lt; 0.05 ) increased, while mitochondrial protein, cytochrome c, and Na+-K+-ATPase activities were significantly decreased ( P &lt; 0.05 ). There were no significant changes on growth performance and body composition of PA supplementation. Then, significantly negative ( P &lt; 0.05 ) interactions were observed between dietary lipid and PA supplementation on EPA, DHA, and EPA + DHA content of the muscle. Saturated fatty acid (SFA) and polyunsaturated fatty acid (PUFA) contents in the liver were significantly increased ( P &lt; 0.05 ) with dietary lipid level increased, while liver monounsaturated fatty acid (MUFA) was significantly decreased ( P &lt; 0.05 ). Muscle SFA, DHA, and EPA + DHA contents were significantly decreased ( P &lt; 0.05 ) when dietary fat level increased. Meanwhile, EPA, DHA, and EPA + DHA content was significantly decreased ( P &lt; 0.05 ) with dietary high PA supplementation. On the whole, a high PA supplementation level of 240 mg kg-1 could alleviate lipid content accumulated and oxidative damage induced by a high-fat diet.

Increased Variation in Body Weight and Food Intake Is Related to Increased Dietary Fat but Not Increased Carbohydrate or Protein in Mice.

A variety of inbred mouse strains have been used for research in metabolic disorders. Despite being inbred, they display large inter-individual variability for many traits like food intake and body weight. However, the relationship between dietary macronutrients and inter-individual variation in body weight and food intake of different mouse strains is still unclear. We investigated the association between macronutrient content of the diet and variations in food intake, body composition, and glucose tolerance by exposing five different mouse strains (C57BL/6, BALB/c, C3H, DBA/2, and FVB) to 24 different diets with variable protein, fat, and carbohydrate contents. We found only increasing dietary fat, but not protein or carbohydrate had a significant association (positive) with variation in both food intake and body weight. The highest variation in both body weight and food intake occurred with 50% dietary fat. However, there were no significant relationships between the variation in fat and lean mass with dietary protein, fat, or carbohydrate levels. In addition, none of the dietary macronutrients had significant impacts on the variation in glucose tolerance ability in C57BL/6 mice. In conclusion, the variations in food intake and body weight changes increased with the elevation of dietary fat levels.

Effect of dietary modulation of fiber and fat level on liver and kidney functions, lipid profile, antioxidant and immune parameters in growing Egyptian geese

Determining the optimal requirements from dietary fiber and fat for Egyptian geese is a matter of great concern regarding health, production and growth. Therefore, the current study estimated the effects of different dietary fiber and fat levels on functions of liver and kidney, lipid profile, immunity and antioxidant measurements of the growing Egyptian geese. 150 Egyptian goslings (4 weeks old), with almost the same body weights were randomly allocated into 6 groups (25 goslings/group). All groups were subdivided into five replicates, each replicate contains five geese. Liver and kidney functions, immunity and antioxidant parameters were not significantly affected the different studied levels of fiber and fat or by their interaction. Various levels of fiber significantly affected total cholesterol, triglycerides, LDL-cholesterol and VLDL-cholesterol in a concentration-dependent manner and the lowest the lipid profile values were obtained at 12%. In conclusion, the present findings show that use of dietary fiber up to 12% and 5% dietary fat showed no detrimental effects on the immune status and general health of geese and resulted in the preferable lipid profile. This experiment provides a base for further study about the optimal requirements from dietary fiber and fat for the growing Egyptian geese.

Growth and Fatty Acid Composition of Black Soldier Fly Hermetia illucens (Diptera: Stratiomyidae) Larvae Are Influenced by Dietary Fat Sources and Levels.

Simple SummaryThe black soldier fly Hermetia illucens is a potentially promising feed or food source due to its valuable nutritional composition. However, its fat content and fatty acid composition significantly vary with the rearing substrates, making it a flexible resource in fat quantity and quality. Recent research has attempted to manipulate the fat content and fatty acid composition of the insect with modulated feed formulation. Nevertheless, the results of most investigations are not comparable, since the rearing substrates used are various organic wastes with complex substrates. Therefore, it is necessary to perform a quantitative and accurate assessment of dietary fat on larval yield and fatty acid composition. In this study, the influence of two supplemental levels of six dietary fat sources on growth and nutrient composition was evaluated, especially fatty acid composition of black solider fly Hermetia illucens larvae. Additionally, the relationships between dietary fat and larval growth and fatty acid composition were quantitatively determined. Our work deepens the understanding of the fat/fatty acid needs of this insect and therefore enlightens the purposive culture of insects for appropriate fat supply.A 16-day rearing trial was performed to investigate the influence of two supplemental levels (5% and 10%) of six dietary fat sources (linseed oil, peanut oil, coconut oil, soybean oil, lard oil and fish oil) on the growth, development and nutrient composition of black solider fly larvae. Our results demonstrated that the pre-pupa rate of larvae was linearly influenced by dietary C18:0, C18:3n-3 and C18:2n-6 content (pre-pupa rate = 0.927 × C18:0 content + 0.301 × C18:3n-3 content-0.258 × C18:2n-6 content p < 0.001)), while final body weight was linearly influenced by that of C16:0 (final body weight = 0.758 × C16:0 content, p = 0.004). Larval nutrient composition was significantly affected by dietary fat sources and levels, with crude protein, fat and ash content of larvae varying between 52.0 and 57.5, 15.0 and 23.8, and 5.6 and 7.2% dry matter. A higher level of C12:0 (17.4–28.5%), C14:0 (3.9–8.0%) and C16:1n-9 (1.3–4.3%) was determined in larvae fed the diets containing little of them. In comparison, C16:0, C18:1n-9, C18:2n-6 and C18:3n-3 proportions in larvae were linearly related with those in diets, with the slope of the linear equations varying from 0.39 to 0.60. It can be concluded that sufficient C16:0, C18:0 and C18:3n-3 supply is beneficial for larvae growth. Larvae could produce and retain C12:0, C14:0, and C16:1n-9 in vivo, but C16:0, C18:1n-9, C18:2n-6 and C18:3n-3 could only be partly incorporated from diets and the process may be enhanced by a higher amount of dietary fat. Based on the above observation, an accurately calculated amount of black soldier fly larvae could be formulated into aquafeed as the main source of saturated fatty acids and partial source of mono-unsaturated and poly-unsaturated fatty acids to save fish oil.

Different dietary combinations of high/low starch and fat with or without bile acid supplementation on growth, liver histopathology, gene expression and fatty acid composition of largemouth bass, Micropterus salmoides

High dietary levels of fat and/or starch can lower the growth and cause extensive liver inflammation that is linked to mortalities in largemouth bass, Micropterus salmoides. However, bile acids (BA) may mitigate these adverse effects. In a 2 × 2 × 2 factorial feeding trial, M. salmoides juveniles were fed different combinations of dietary high (HF), low fat (LF), high (HS) or low starch (LS) levels with or without BA supplementations at 1% for 8 weeks. A total of 8 isonitrogenous diets were formulated to include, HF/LS, HF/HS, LF/HS, LF/LS, HF/LS-BA, HF/HS-BA, LF/HS-BA and LF/LS-BA. Survival, growth performance, feeding efficiency, whole-body proximate composition, muscle/liver fatty acid composition, hepatic expression of growth regulator (GH/IGF1 axis), lipid metabolism (fatty acid synthase ‘FASN’ and cholesterol 7 alpha-hydroxylase ‘CYP7A1’) and antioxidant capacity (superoxide dismutase ‘SOD’) genes as well as liver histopathology were assessed. Results showed that among diets without BA, there was no significant effect on growth or feeding efficiency, but when BA was included this led to more variable effects including significantly higher weight gain in the LF/HS-BA group compared to all others fed BA. The HF, HS or their combination led to extensive hepatic inflammation, but BA appeared to partially mitigate this in the LF/HS group (i.e. LF/HS-BA). No abnormal liver histopathology was observed in the LF/LS and LF/LS-BA treatments. Muscle 22:6n-3 was significantly higher in the HF/LS and HF/HS-BA groups compared to those fed the HF/HS or LF/LS diets. Dietary fat had a significant effect on the moisture, crude lipid, and caloric content of M. salmoides. Hepatic expression of IGF-I and CYP7A1 were differentially modulated under different treatments. Overall, these results show that BA can alleviate some liver inflammation caused by high dietary starch; however the LF/LS diets led to a better balance between growth performance and liver health.

High-Fat-Diet-Induced Oxidative Stress in Giant Freshwater Prawn (Macrobrachium rosenbergii) via NF-κB/NO Signal Pathway and the Amelioration of Vitamin E.

Lipids work as essential energy sources for organisms. However, prawns fed on high-fat diets suffer from oxidative stress, whose potential mechanisms are poorly understood. The present study aimed to explore the regulation mechanism of oxidative stress induced by high fat and the amelioration by vitamin E (VE) of oxidative stress. Macrobrachium rosenbergii were fed with two dietary fat levels (LF 9% and HF 13%) and two VE levels (200 mg/kg and 600 mg/kg) for 8 weeks. The results showed that the HF diet decreased the growth performance, survival rate and antioxidant capacity of M. rosenbergii, as well as inducing hypertrophied lipid droplets, lipophagy and apoptosis. A total of 600 mg/kg of VE in the HF diet alleviated the negative effects induced by HF. In addition, the HF diet suppressed the expression of toll-dorsal and imd-relish signal pathways. After the relish and dorsal pathways were knocked down, the downstream iNOS and NO levels decreased and the MDA level increased. The results indicated that M. rosenbergii fed with a high-fat diet could cause oxidative damage. Its molecular mechanism may be attributed to the fact that high fat suppresses the NF-κB/NO signaling pathway mediating pro-oxidant and antioxidant targets for regulation of oxidative stress. Dietary VE in an HF diet alleviated hepatopancreas oxidative stress and apoptosis.

Effects of different dietary fat levels and sources on diet digestibility, fattening performance and meat quality of Holstein young bulls when substituted for dietary barley grain

ABSTRACT The aim of the present study was to investigate the effects of substituting dietary barley grain by different sources and levels of fat on performance and meat quality of Holstein young bulls. Twenty-eight Holstein male calves, 274 ± 32 kg initial body weight, were used in a completely randomised design with a 2 × 2 factorial treatment arrangement for 100 d (with 10 d of adaptation). Seven animals were randomly allocated per treatment. Four dietary treatments were tested, which included: (1) diet supplemented with saturated fat (Energizer® RP10) at low level (diet with high barley and starch content), (2) diet supplemented with saturated fat at high level (diet with low barley and starch content), (3) diet supplemented with unsaturated fat (Persiafat) at low level (diet with high barley and starch content) and (4) diet supplemented with unsaturated fat at high level (diet with low barley and starch content). The dry matter intake, average daily gain, feed conversion ratio and carcass traits were not affected by supplemental fat sources and levels. Total tract digestibility of acid detergent fibre was improved after inclusion of both rumen-protected fat sources while other nutrient digestibilities were not affected by the fat sources or levels. In conclusion, partial replacing of dietary starch with fat supplements has not negative effects on calves’ performance and digestibility of neutral detergent fibre.

Increasing levels of microalga supplementation in diet on

Context In recent years, microalgae have been used in the diet to improve the quality of animal products due to their oil content and quality, but determining the optimum dose is very important to prevent some fermentation and economic losses in animal production. Aims The study investigated the effects of microalga (DHA-gold) supplementation in the diet at different levels in in vitro ruminal biohydrogenation and fermentation. Methods The treatments were control (no additional oil, forage:concentrate ratio 60:40 on a dry-matter (DM) basis) or the addition of 1%, 2%, and 3% of microalga in the diet on a DM basis. Four rumen-cannulated goats were used as donors for the in vitro experiment. The treatments were incubated using a batch culture technique, and the fatty acid profile and fermentation parameters were determined after 0, 3, 6, 12, and 24 h. Key results Total conjugated linoleic acids (CLA), cis-9, trans-11 CLA and trans-11 C18:1 fatty acids increased with supplementation of microalgae. The 24-h biohydrogenation rate of unsaturated fatty acids varied between 61% and 98%. In addition, the highest CLA content was obtained from the 3% algae group. Biohydrogenation of C18:3, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) fatty acids was decreased with the 2% microalga supplementation. The microalga supplementation had no effect on ruminal pH, ruminal acetate, propionate, and butyrate proportions, or the acetate:propionate ratio. Conclusion Under the current in vitro study conditions, 2% microalga supplementation to diet increased the ruminal biohydrogenation intermediate products, such as total CLA and trans-11 C18:1 fatty acid and decreased the ruminal biohydrogenation ratio of n-3 fatty acids (C18:3, EPA, and DHA). Implications Increasing the bioactive and beneficial fatty acids (e.g. CLAs) that are absorbed in the rumen by ruminants and then transferred to animal products (meat, milk) is important. From the results of this in vitro study, dietary microalga increased the ruminal CLA, C18:3, EPA, and DHA concentrations. However, dietary fat level should be evaluated in terms of improving an animal’s performance (growth rate, digestibility, milk yield, carcass, and milk quality).

Effect of Type and Dietary Fat Content on Rabbit Growing Performance and Nutrient Retention from 34 to 63 Days Old.

Simple SummaryAn increase in the fat content of the diet increases the dietary energy concentration, and consequently, the growth and feed efficiency of the animals. The fatty acids (FA) profile of the fat source can also affect animal body composition. The purpose of this study was to test the effect of some fat sources added at different levels in growing rabbit feed. In this study, it was observed that the increment of dietary fat improved nitrogen efficiency utilization and reduced nitrogen excretion; the fat source also affected animal performance and mortality rate.The study was carried out on individually and collectively housed growing rabbits from 34 to 63 days of age. Two experiments were conducted using three fat sources: Soybean oil (SBO), Soya Lecithin Oil (SLO), and Lard (L; Exp. 1), and SBO, Fish Oil (FO), and Palm kernel Oil (PKO; Exp. 2), added at two inclusion levels (1.5 and 4.0%). In both trials, 180 rabbits were housed in individual cages and additional 600 rabbits in collective cages from day 34 to 63. Animals fed with 4% dietary fat showed lower Daily Feed Intake (DFI) and Feed Conversion Ratio (FCR) than those fed with 1.5%, except in the individually housed animals in Exp. 1. In the collective housed group in Exp. 1, DFI was a 4.8% higher in animals fed with diets containing lard than those fed with SBO (p = 0.036). Lard inclusion also tended to reduce mortality (p = 0.067) by 60% and 25% compared with SBO and SLO diets, respectively. Mortality was the highest with the higher level of soya lecithin (14% vs. 1%, p < 0.01). A similar mortality rate was observed in the lowest level of SBO. In the grouped-housed animals in Exp. 2, a decrease of DFI (−12.4%), Bodyweight (BW) at 63 d (−4.8%), and Daily Weight Gain (DWG) (−7.8%) were observed with the inclusion of fish oil (p < 0.01) compared to other fat sources. Fish oil also tended to increase (p = 0.078) mortality (13.2%) compared with palm kernel oil (6.45%); similar results were found when animals were individually housed. The overall efficiency of N retention (NRE) increased with the highest level of fat in Exp. 1 (34.9 vs. 37.8%; p < 0.0001). It can be concluded that lard and palm kernel oil are alternative sources of fat due to the reduction of mortality. The inclusion of fish oil impaired animal productivity and increased mortality. An increment of the dietary fat level improved FCR and overall protein retention efficiency.

Impact of graded maternal dietary fat content on offspring susceptibility to high-fat diet in mice.

Maternal high-fat diet (HFD) increases offspring obesity, yet the impacts of different levels of maternal dietary fat have seldom been addressed. In mice, the impact of graded maternal dietary fat on offspring adiposity and offspring's later susceptibility to HFD were assessed. Lactating mice were fed diets with graded fat content from 8.3% to 66.6%. One male and one female pup from each litter were weaned onto a low-fat diet for 15 weeks. HFD (41.7%) was then introduced to half of the offspring for 12 weeks. Offspring body weight and adiposity were positively related to maternal dietary fat content and were higher when mothers were exposed to HFD. The maternal diet effect was nonlinear and sex dependent. A maternal dietary fat of 41.7% and above exaggerated the offspring body weight gain in males but was not significant in females. Maternal 8.3% fat and 25% fat diets led to the highest daily energy expenditure and respiratory exchange ratio in offspring. Offspring fed a low-fat diet had higher daily energy expenditure and respiratory exchange ratio than those fed an HFD. Increasing maternal dietary fat during lactation, and HFD in later life, had significant and interacting impacts on offspring obesity. Maternal diet had a bigger impact on male offspring. The effects of maternal dietary fat content were nonlinear.

Effect of dietary carbohydrate and fat supplementation on the yield and chemical composition of fillet and the location of fat deposition in striped catfish (Pangasius hypophthalmus), African catfish (Clarias gariepinus) and snakehead (Channa striata)

This study compared three different fish species, striped catfish (Pangasius hypophthalmus), African catfish (Clarias gariepinus) and snakehead (Channa striata), regarding the effect of dietary macronutrient composition on: 1. the fillet yield and the fillet chemical composition; 2. the location of fat deposition within the body (fillet, liver, viscera or rest fraction). The selected species were studied for the development of net energy formulas, in three different studies. The design of these studies and especially the diet formulation were similar. Diets were formulated according to a 2 × 2 factorial design: with or without extra carbohydrates supplementation; and with or without extra fat supplementation. Fillet yield of striped catfish (P. hypophthalmus), African catfish (C. gariepinus) and snakehead (C. striata) was not affected by the dietary macronutrient composition. Fillet fat and protein contents were changed by the dietary macronutrient composition. In all compartments (liver, viscera, fillet and the rest fraction), both dietary fat and dietary carbohydrates levels increased the fat content. The response to dietary carbohydrates in snakehead, a lowering of fillet fat content, is opposite to the response in both catfish species. The distribution of the total amount of body fat over the different compartments, was not influenced by dietary carbohydrates level, but did depend on dietary fat level. Dietary fat supplementation led to relatively more fat in viscera and fillet but less fat was stored in the rest fraction. In striped catfish (P. hypophthalmus), African catfish (C. gariepinus) and snakehead (C. striata), most of the body fat is stored in the rest fraction (head, skin, subcutaneous fat, scales, bones and air bladders).