Comparative Approach of the de novo Fatty Acid Synthesis (Lipogenesis) between Ruminant and Non Ruminant Mammalian Species: From Biochemical Level to the Main Regulatory Lipogenic Genes

Development of fatty liver disease model using high cholesterol and low choline diet in white leghorn chickens

Nonalcoholic fatty liver disease (NAFLD), which shows similar symptoms as fatty liver hemorrhage syndrome (FLHS) in chickens, is the most common cause of chronic liver disease and cancer in humans. NAFLD patients and FLHS in chickens have demonstrated severe liver disorders when infected by emerging strains of human hepatitis E virus (HEV) and avian HEV, respectively. We sought to develop a fatty liver disease chicken model by altering the diet of 3-week-old white leghorn chickens. The high cholesterol, and low choline (HCLC) diet included 7.6% fat with additional 2% cholesterol and 800 mg/kg choline in comparison to 5.3% fat, and 1,300 mg/kg choline in the regular diet. Our diet induced fatty liver avian model successfully recapitulates the clinical features seen during NAFLD in humans and FLHS in chickens, including hyperlipidemia and hepatic steatosis, as indicated by significantly higher serum triglycerides, serum cholesterol, liver triglycerides, cholesterol, and fatty acids. By developing this chicken model, we expect to provide a platform to explore the role of lipids in the liver pathology linked with viral infections and contribute to the development of prophylactic interventions.

Hericium erinaceus polysaccharides ameliorate nonalcoholic fatty liver disease via gut microbiota and tryptophan metabolism regulation in an aged laying hen model

Polysaccharides extracted from Hericium erinaceus (HEP) exhibit hepatoprotective activity in the alleviation of non-alcoholic fatty liver disease (NAFLD); however, the mechanisms underlying whether and how HEP regulation of the gut microbiota to alleviate liver-associated metabolic disorders are not well understood. This study used an aged laying hen model to explore the mechanisms through which HEP alleviates NAFLD, with a focus on regulatory function of HEP in the gut microbiome. The results showed that HEP ameliorated hepatic damage and metabolic disorders by improving intestinal barrier function and shaping the gut microbiota and tryptophan metabolic profiles. HEP increased the abundance of Lactobacillus and certain tryptophan metabolites, including indole-3-carboxylic acid, kynurenic acid, and tryptamine in the cecum. These metabolites upregulated the expression of ZO-1 and Occludin by activating the AhR and restoring the intestinal barrier integrity. The increased intestinal barrier functions decreased LPS transferring from the intestine to the liver, inhibited hepatic LPS/TLR4/MyD88/NF-κB pathway activation, and reduced hepatic inflammatory response and apoptosis. Fecal microbiota transplantation experiments further confirmed that the hepatoprotective effect is likely mediated by HEP-altered gut microbiota and their metabolites. Overall, dietary HEP could ameliorate the hepatic damage and metabolic disorders of NAFLD through regulating the "gut-liver" axis.

Comparative lipidome study of maternal plasma, milk, and lamb plasma in sheep

Lipids play a critical role in neonate development and breastmilk is the newborn's major source of lipids. Milk lipids directly influence the neonate plasma lipid profile. The milk lipidome is dynamic, influenced by maternal factors and related to the maternal plasma lipidome. The close inter-relationship between the maternal plasma, milk and neonate plasma lipidomes is critical to understanding maternal-child health and nutrition. In this exploratory study, lipidomes of blood and breast milk from Suffolk sheep and matched lamb blood (n = 13), were profiled on day 34 post birth by untargeted mass spectrometry. Comparative multivariate analysis of the three matrices identified distinct differences in lipids and class of lipids amongst them. Paired analysis identified 346 differential lipids (DL) and 31 correlated lipids (CL) in maternal plasma and milk, 340 DL and 32 CL in lamb plasma and milk and 295 DL and 16 CL in maternal plasma and lamb plasma. Conversion of phosphatidic acid to phosphatidyl inositol was the most active pathway in lamb plasma compared to maternal plasma. This exploratory study illustrates the partitioning of lipids across maternal plasma, milk and lamb plasma and the dynamic relationship between them, reiterating the need to study these three matrices as one biological system.

Dietary supplementation of magnolol alleviates fatty liver hemorrhage syndrome in postpeak Xinhua laying hens via regulation of liver lipid metabolism

As a metabolic disease, fatty liver hemorrhagic syndrome (FLHS) has emerged as a major cause of noninfectious mortality in laying hens, resulting in substantial economic losses to the poultry industry. This study aimed to investigate the therapeutic effects of magnolol on FLHS in postpeak laying hen model, focusing on lipid metabolism, antioxidative capacity, and potential molecular mechanisms of action. We selected 150 Xinhua laying hens aged 50 wk and divided them into normal diet group (ND), high-fat diet group (HFD), 100 mg/kg magnolol group (MG100), 300 mg/kg magnolol group (MG300), 500 mg/kg magnolol group (MG500) on average. The experiment lasted for 6 wk, and liver samples were collected from the hens at the end of the experiment. The results demonstrated that the inclusion of magnolol in the diet had a significant impact on various factors. It led to a reduction in weight, an increase in egg production rate, a decrease in blood lipid levels, and an improvement in abnormal liver function, liver steatosis, and oxidative stress. These effects were particularly prominent in the MG500 group. The RNA-Seq analysis demonstrated that in the MG500 group, there was a down-regulation of genes associated with fatty acid synthesis (Acc, Fasn, Scd, Srebf1, Elovl6) compared to the HFD group. Moreover, genes related to fatty acid oxidation (CPT1A and PGC1α) were found to be up-regulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of these differentially expressed genes indicated their enrichment in the PPAR signaling pathway. These findings demonstrate that magnolol can mitigate FLHS by inhibiting fatty acid synthesis and promoting fatty acid oxidation. This discovery offers a novel approach for treating FLHS in laying hens, reducing the economic losses associate with FLHS.

Effect of monensin on milk production efficiency and milk composition in lactating dairy cows fed modern diets

Since the US Food and Drug Administration's approval of monensin in 2004, significant nutritional advances have been made to increase feed efficiency and milk fat production. Recent evidence suggests monensin's adverse effect on milk fat percentage may be absent when diets are formulated to address known diet-induced milk fat depression risk factors. Thus, study objectives were to evaluate effects of monensin level on dry matter intake (DMI), milk production and composition, and efficiency of high-producing cows fed diets formulated to optimize milk fat. Ninety-six lactating Holstein cows (36 primiparous, 60 multiparous; 106 ± 17 d in milk [DIM]) were balanced by parity, DIM, and milk production and were randomly assigned to 1 of 12 pens with 8 cows per pen. All cows received 11 g/t monensin for 5 wk after which pens received 1 of 4 dietary treatments (n = 3) formulated to provide 0 (CON), 11 (R11), 14.5 (R14.5), or 18 (R18) g/t monensin for 9 wk. The basal diet was 54% forage, 27% NDF, 29% starch, and 2.3% rumen unsaturated fatty acid load. Pen was the experimental unit and data were analyzed using the Fit Model Procedure of JMP. Effects of treatment, time, and treatment × time interaction were included as fixed effects and pen as a random effect. Least squares means were determined and linear and quadratic contrasts were tested. Dry matter intake tended to decrease linearly with increasing monensin dose. Milk yield, fat percentage, and protein percentage and yield were unaffected by treatment while fat yield was quadratically increased. Milk de novo and mixed fatty acid (FA) yields (g/d) increased quadratically with monensin whereas preformed FA linearly decreased during the experimental period. Energy-corrected milk (ECM) was quadratically increased by monensin. Milk urea nitrogen concentrations increased linearly with increasing monensin dose. Monensin linearly increased feed efficiency (ECM/DMI, 3.5% fat-corrected milk/DMI, and solids-corrected milk/DMI). Body weight gain did not differ between treatments. Estimated dietary energy tended to increase linearly with increasing monensin level. These data suggest monensin improves component-corrected milk production efficiency, estimated dietary energy, and does not negatively affect milk fat percentage or FA profile.

Comparative Lipidomics and Metabolomics Reveal the Underlying Mechanisms of Taurine in the Alleviation of Nonalcoholic Fatty Liver Disease Using the Aged Laying Hen Model

SCOPE

Aged laying hen is recently suggested as a more attractive animal model than rodent for studying nonalcoholic fatty liver disease (NAFLD) of humans. This study aims to reveal effects and metabolic regulation mechanisms of taurine alleviating NAFLD by using the aged laying hen model.

METHODS AND RESULTS

Liver histomorphology and biochemical indices show 0.02% taurine effectively alleviated fat deposition and liver damage. Comparative liver lipidomics and gene expressions analyses reveal taurine promoted lipolysis, fatty acids oxidation, lipids transport, and reduced oxidative stress in liver. Furthermore, comparative serum metabolomics screen six core metabolites negatively correlated with NAFLD, including linoleic acid, gamma-linolenic acid, pantothenate, L-methionine, 2-methylbutyroylcarnitine, L-carnitine; and two core metabolites positively correlated with NAFLD, including lysophosphatidylcholine (14:0/0:0) and lysophosphatidylcholine (16:0/0:0). Metabolic pathway analysis reveals taurine mainly regulated linoleic acid metabolism, cysteine and methionine metabolism, carnitine metabolism, pantothenic acid and coenzyme A biosynthesis metabolism, and glycerophospholipid metabolism to up-adjust levels of six negatively correlated metabolites and down-adjust two positively correlated metabolites for alleviating NAFLD of aged hens.

CONCLUSION

This study firstly reveals underlying metabolic mechanisms of taurine alleviating NAFLD using the aged hen model, thereby laying the foundation for taurine's application in the prevention of NAFLD in both human and poultry.

Inulin-enriched Megamonas funiformis ameliorates metabolic dysfunction-associated fatty liver disease by producing propionic acid

Accumulated evidence supports the beneficial role of inulin in alleviating metabolic dysfunction-associated fatty liver disease (MAFLD) by modulating gut microbiota. However, the underlying mechanisms are not fully understood. Here we used high-fat diet (HFD)-induced laying hen model of MAFLD to investigate the effect of inulin on ameliorating MAFLD and found that the inulin-enriched Megamonas genus was inversely correlated with hepatic steatosis-related parameters. Oral administration of a newly isolated commensal bacterium by culturomics, M. funiformis CML154, to HFD-fed hens and mice ameliorated MAFLD, changed liver gene expression profiles, and increased intestinal propionate concentration. Further evidence demonstrated that the anti-MAFLD effect of M. funiformis CML154 is attributed to propionate-mediated activation of the APN-AMPK-PPARα signaling pathway, thereby inhibiting fatty acid de novo synthesis and promoting β-oxidation. These findings establish the causal relationships among inulin, M. funiformis, and MAFLD, and suggest that M. funiformis CML154 is a probiotic candidate for preventative or therapeutic intervention of MAFLD.

Effect of pre- and postpartum supplementation of a pure glycerol product to dairy cows on feed intake, metabolic markers, and milk yield and components

The objective of this study was to quantify the effects of supplementing transition dairy cows with a low inclusion dry glycerol product in the pre- and postpartum periods on feed intake, metabolic markers, and milk yield and components. Multiparous Holstein dairy cows (n = 60) were enrolled in a 2-by-2 factorial design study. Starting 21 d before expected parturition, cows individually received a dry cow diet with (1) 250 g/d glycerol product supplementation [66% pure glycerol (United States Pharmacopeia grade); GLY], or (2) no supplementation (CON) mixed to their total mixed ration. After parturition, cows, again, were individually assigned to either GLY, or (2) no supplementation (CON) to their partial mixed ration for the first 21 d in milk (DIM). Cows were milked by an automated milking system and offered a target of 5.4 kg DM/d pellet (23% of target total dry matter intake, DMI) in the automated milking system and followed for 42 d into lactation. Blood samples were collected 6.3 ± 3.47 d before calving for all blood measures and 3, 7, 10, and 14 DIM for analysis of glucose and β-hydroxybutyrate, as well as 3 and 7 DIM for nonesterified fatty acids (NEFA) and haptoglobin. Initial dry cow body weight (BW), calf birth weight, previous 305-d milk, and month of parturition were used as covariates in the statistical model. Cows supplemented with GLY prepartum lost less BW and consumed more DMI pre- and postpartum, as well as had lower postpartum blood β-hydroxybutyrate and NEFA concentrations compared with those fed the CON treatment prepartum. Cows supplemented with GLY postpartum had lesser DMI in the first 42 DIM than cows fed CON postpartum, but also had reduced blood NEFA concentrations, odds of a high haptoglobin test, odds of a low blood glucose test, and lesser preformed fatty acid concentrations and yields in their milk. Cows supplemented glycerol both pre- and postpartum lost the least total BW from -21 to 21 DIM. No treatment effects were detected for milk yield; however, cows receiving GLY postpartum had lower milk fat. Overall, glycerol supplementation during the transition period, particularly during the 21 d before calving, was associated with markers of improved metabolic status.

Changes in the Lipid Metabolism of the Longissimus thoracis Muscle in Bulls When Using Different Feeding Strategies during the Growing and Finishing Phases

The objective was to evaluate the supplementation strategy's effect on beef cattle during the growing phase and two systems during the finishing phase. One hundred and twenty young bulls were randomly divided in a 2 × 2 factorial design to receive either mineral (ad libitum) or protein + energy (3 g/kg body weight (BW)/day) during the growing phase and pasture plus concentrate supplementation (20 g/kg BW/day) or feedlot (25:75% corn silage:concentrate) during the finishing phase. Feedlot-fed bulls had meat (Longissimus thoracis-LT) with a higher content of lipids and saturated and monounsaturated fatty acids and a greater upregulation of stearoyl-CoA desaturase and sterol regulatory element-binding protein-1c than animals that fed on pasture (p < 0.05). On the other hand, pasture-fed bulls had meat with a higher content of α-linoleic acid, linolenic acid, and n6 and a greater n6:n3 ratio compared to the feedlot-fed group (p < 0.05). In addition, meat from pasture-fed bulls during the finishing phase had 17.6% more isocitrate dehydrogenase enzyme concentration than the feedlot group (p = 0.02). Mineral-fed and pasture-finished bulls showed down-regulation of peroxisome proliferator-activated receptor gamma (p < 0.05), while the bulls fed protein + energy and finished in the feedlot had higher carnitine palmitoyltransferase 2 expression (p ≤ 0.013). In conclusion, mineral or protein + energy supplementation in the growing does not affect the fatty acid composition of intramuscular fat of LT muscle. In the finishing phase, feeding bulls in the feedlot upregulates the lipogenic genes and consequently improves the intramuscular fat content in the meat.

Probiotics Increase Intramuscular Fat and Improve the Composition of Fatty Acids in Sunit Sheep through the Adenosine 5'-Monophosphate-Activated Protein Kinase (AMPK) Signaling Pathway

This experiment aims to investigate the impact of probiotic feed on growth performance, carcass traits, plasma lipid biochemical parameters, intramuscular fat and triglyceride content, fatty acid composition, mRNA expression levels of genes related to lipid metabolism, and the activity of the enzyme in Sunit sheep. In this experiment, 12 of 96 randomly selected Sunit sheep were assigned to receive the basic diet or the basic diet supplemented with probiotics. The results showed that supplementation with probiotics significantly increased the loin eye area, and decreased plasma triglycerides and free fatty acids, increasing the content of intramuscular fat and triglycerides in the muscle and improving the composition of the fatty acids. The inclusion of probiotics in the diet reduced the expression of adenosine 5'-monophosphate-activated protein kinase alpha 2 (AMPKα2) mRNA and carnitine palmitoyltransferase 1B (CPT1B) mRNA, while increasing the expression of acetyl-CoA carboxylase alpha (ACCα) mRNA, sterol regulatory element-binding protein-1c (SREBP-1c) mRNA, fatty acid synthase mRNA, and stearoyl-CoA desaturase 1 mRNA. The results of this study indicate that supplementation with probiotics can regulate fat deposition and improves the composition of fatty acids in Sunit sheep through the signaling pathways AMPK-ACC-CPT1B and AMPK-SREBP-1c. This regulatory mechanism leads to an increase in intramuscular fat content, a restructuring of muscle composition of the fatty acids, and an enhancement of the nutritional value of meat. These findings contribute to a better understanding of the food science of animal resources and provide valuable references for the production of meat of higher nutritional value.

Mimicking Wagyu beef fat in cultured meat: Progress in edible bovine adipose tissue production with controllable fatty acid composition

Since the current process of livestock meat production has considerable effects on the global environment, leading to high emissions of greenhouse gases, cultured meat has recently attracted attention as a suitable alternative way to acquire animal proteins. However, while most published studies on cell-cultured meat have focused on muscle tissue culture, fat production which is an important component of the process has often been neglected from this technology, even though it can enhance the meat's final taste, aroma, tenderness, texture, and palatability. In this study, we focused on bovine muscle reconstruction by monitoring and optimizing the possible expansion rate of isolated primary bovine adipose stem cells and their adipogenesis differentiation to be fully edible for cultured meat application. After approximatively 100 days of serial passages, the bovine adipose-derived stem cells, isolated from muscle tissue, underwent 57 ​± ​5 doublings in the edible cell culture medium condition. This implies that by cultivating and amplifying them, a minimum of 2.9 ​× ​10²² ​cells can be obtained from around 10 ​g of fat. It was discovered that these cells retain their adipogenesis differentiation ability for at least 12 passages. Moreover, the final lipid composition could be controlled by adjusting the fatty acid composition of the culture medium during the differentiation process, resulting in organoleptic features similar to those of real fat from muscle. This was especially so for the cis isomer oleic acid percentage, an important part of high-grade Japanese Wagyu meat. These characteristics of the primary bovine adipose-derived stem cell proliferation and adipogenesis differentiation provide valuable insights for the in vitro production of meat alternatives.

Chitosan Oligosaccharides Alleviate Heat-Stress-Induced Lipid Metabolism Disorders by Suppressing the Oxidative Stress and Inflammatory Response in the Liver of Broilers

Heat stress has been reported to induce hepatic oxidative stress and alter lipid metabolism and fat deposition in broilers. Chitosan oligosaccharides (COSs), a natural oligosaccharide, has anti-oxidant, anti-inflammatory, and lipid-lowering effects. This study is conducted to evaluate dietary COS supplementation on hepatic anti-oxidant capacity, inflammatory response, and lipid metabolism in heat-stressed broilers. The results indicate that heat-stress-induced poor (p < 0.05) growth performance and higher (p < 0.05) abdominal adiposity are alleviated by COS supplementation. Heat stress increases (p < 0.05) serum AST and ATL activity, serum and liver MDA, TG, TC, and LDL-C levels, and the expression of hepatic IL-1β, IL-6, SREBP-1c, ACC, and FAS, while it decreases (p < 0.05) serum SOD and CAT activity, liver GSH-Px and SOD activity, and the expression of hepatic Nrf2, GPX1, IL-10, MTTP, PPARα, and CPT1. Nevertheless, COS supplementation decreases (p < 0.05) serum AST and ATL activity, serum and liver MDA, TG, TC, and LDL-C levels, and the expression of hepatic IL-1β, IL-6, SREBP-1c, ACC, and FAS, while it increases (p < 0.05) serum SOD and CAT activity, liver GSH-Px activity, and the expression of hepatic Nrf2, CAT, IL-10, LPL, MTTP, PPARα, and CPT1. In conclusion, COS could alleviate heat-stress-induced lipid metabolism disorders by enhancing hepatic anti-oxidant and anti-inflammatory capacity.

Effects and potential mechanism of dietary vitamin C supplementation on hepatic lipid metabolism in growing laying hens under chronic heat stress

The adverse effects of chronic heat stress (CHS)-induced fatty liver syndrome on laying hens during the egg-producing stages have been wildly documented. However, until nowadays, the CHS responses of growing laying hens as well as its alleviating effects of vitamin C are rarely reported. In this study, 12-wk-old laying hens were subjected to CHS at 36 °C for 10 h/d for 3 wk with or without dietary supplementation of 300 mg/kg vitamin C. Results showed that CHS significantly impaired the growth performances and the liver functions of birds, as characterized by reduced feed intake and body weight, increased hepatic lipid accumulation and serum concentrations of TG, ALT, and AST, as well as the abnormal expression patterns of the lipid metabolism-related genes. Vitamin C supplementation successfully mitigated the lipid accumulation, while showing no alleviating effect on the serum contents of ALT or AST, which are two key indicators of liver functions. Metabolomic analysis based on UPLC-Q-TOF/MS identified 173 differential metabolites from the HS and HSV group samples, and they are mainly enriched in the pathways related to the cellular components, vitamin and amino acid metabolism and energy substance metabolism. The results indicate that CHS-induced hepatic lipid deposition in growing laying hens is effectively alleviated by dietary supplementation of vitamin C, which is probably resulted from the alterations of hepatocellular metabolic patterns.

Hepatoprotective and antifibrotic effects of trans-chalcone against bile duct ligation-induced liver fibrosis in rats

Objectives

Several lines of research have shown that hepatic fibrosis is one of the leading causes of death worldwide. Trans-chalcone is a flavonoid precursor with anti-oxidant and anti-inflammatory effects. The present study was conducted to examine the antifibrotic properties of trans-chalcone on bile duct ligation (BDL)-induced liver cholestasis in rats.

Materials and Methods

Following the BDL operation, trans-chalcone at doses of 12, 24, and 50 mg/kg was administered orally once a day for 45 consecutive days. Serum levels of liver indices, including alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total and direct bilirubin, and lipid profile in addition to blood urea nitrogen (BUN) and creatinine, were measured. Additionally, catalase (CAT) and superoxide dismutase (SOD) activities were assessed in liver homogenates. Histopathological evaluations were performed using Masson trichrome (MT) and hematoxylin and eosin (H&E) staining.

Results

The elevated levels of liver enzymes, total and direct bilirubin, BUN, creatinine, cholesterol, triglyceride, and low-density lipoprotein (LDL) induced by BDL were significantly reduced following trans-chalcone administration; while serum level of high-density lipoprotein (HDL) increased. Besides, treatment with trans-chalcone elevated the activities of CAT and SOD in the liver tissues of the animals with BDL surgery. According to MT and H&E staining, BDL-induced histopathological changes, including infiltration of inflammatory cells, hepatocyte necrosis, ductal hyperplasia, and collagen deposition were ameliorated using trans-chalcone administration.

Conclusion

It can be concluded from the present study that trans-chalcone, possibly by its anti-oxidant and anti-inflammatory properties, may exert hepatoprotective and antifibrotic effects in BDL-induced liver fibrosis.

A simplified and defined serum-free medium for cultivating fat across species

Cultivated meat is a promising technology with the potential to mitigate the ethical and environmental issues associated with traditional meat. Fat plays a key role in the meat flavor; therefore, development of suitable adipogenic protocols for livestock is essential. The traditional adipogenic cocktail containing IBMX, dexamethasone, insulin and rosiglitazone is not food-compatible. Here, we demonstrate that of the four inducers only insulin and rosiglitazone are necessary in both serum-free (DMAD) and serum-containing media, with DMAD outperforming FBS. Two glucocorticoid receptor activators, progesterone and hydrocortisone, found in DMAD and FBS, affect differentiation homogeneity, without playing an essential role in activating adipogenic genes. Importantly, this protocol leads to mature adipocytes in 3D culture. This was demonstrated in both media types and in four species: ruminant and monogastric. We therefore propose a simplified one-step adipogenic protocol which, given the replacement of rosiglitazone by a food-compatible PPARγ agonist, is suitable for making cultivated fat.

Tumor necrosis factor alpha and palmitate simulate bovine fatty liver disease in vitro when using abattoir-derived primary bovine hepatocytes isolated by a novel nonperfusion method

Hepatic lipidosis (i.e., fatty liver) is a common periparturient disease in high-producing dairy cattle affecting nearly 50% of cows to some degree and costing an estimated 60 million dollars annually. Large animal studies are costly, labor intensive, and are not well suited to mechanistic studies. Traditionally, mechanistic studies employ in vitro methodologies, utilizing established cell lines or primary cell culture methods. However, with dairy cattle, established hepatic cell lines do not exist, and methods for primary cell culture studies typically involve complicated procedures that often utilize very young animals (typically bull calves). Several previously published papers have used abattoir-derived tissues as a source of primary cells; however, a simple method utilizing simple culture media has yet to be presented. In addition, we sought to develop a way to replicate the syndrome of fatty liver disease "in a dish" using adult cattle that should more closely represent the physiology of the periparturient dairy cow. Herein we present a non-perfusion-based method that results in robust growth and proliferation of abattoir-derived bovine hepatocytes that demonstrate lipid loading, elevated lactate dehydrogenase leakage, and cytotoxicity as demonstrated by elevated caspase 3/7 expression consistent with in vivo physiology of the periparturient dairy cow with fatty liver disease.

Essential Oils as a Dietary Additive for Small Ruminants: A Meta-Analysis on Performance, Rumen Parameters, Serum Metabolites, and Product Quality

There is an increasing pressure to identify natural feed additives that improve the productivity and health of livestock, without affecting the quality of derived products. The objective of this study was to evaluate the effects of dietary supplementation with essential oils (EOs) on productive performance, rumen parameters, serum metabolites, and quality of products (meat and milk) derived from small ruminants by means of a meta-analysis. Seventy-four peer-reviewed publications were included in the data set. Weighted mean differences (WMD) between the EOs treatments and the control treatment were used to assess the magnitude of effect. Dietary inclusion of EOs increased (p < 0.05) dry matter intake (WMD = 0.021 kg/d), dry matter digestibility (WMD = 14.11 g/kg of DM), daily weight gain (WMD = 0.008 kg/d), and feed conversion ratio (WMD = −0.111). The inclusion of EOs in small ruminants’ diets decreased (p < 0.05) ruminal ammonia nitrogen concentration (WMD = −0.310 mg/dL), total protozoa (WMD = −1.426 × 105/mL), methanogens (WMD = −0.60 × 107/mL), and enteric methane emissions (WMD = −3.93 L/d) and increased ruminal propionate concentration (WMD = 0.726 mol/100 mol, p < 0.001). The serum urea concentration was lower (WMD = −0.688 mg/dL; p = 0.009), but serum catalase (WMD = 0.204 ng/mL), superoxide dismutase (WMD = 0.037 ng/mL), and total antioxidant capacity (WMD = 0.749 U/mL) were higher (p < 0.05) in response to EOs supplementation. In meat, EOs supplementation decreased (p < 0.05) the cooking loss (WMD = −0.617 g/100 g), malondialdehyde content (WMD = −0.029 mg/kg of meat), yellowness (WMD = −0.316), and total viable bacterial count (WMD = −0.780 CFU/g of meat). There was higher (p < 0.05) milk production (WMD = 0.113 kg/d), feed efficiency (WMD = 0.039 kg/kg), protein (WMD = 0.059 g/100 g), and lactose content in the milk (WMD = 0.100 g/100 g), as well as lower somatic cell counts in milk (WMD = −0.910 × 103 cells/mL) in response to EOs supplementation. In conclusion, dietary supplementation with EOs improves productive performance as well as meat and milk quality of small ruminants. In addition, EOs improve antioxidant status in blood serum and rumen fermentation and decrease environmental impact.

Whole transcriptome RNA Sequencing Reveals the Global Molecular Responses and circRNA/lncRNA-miRNA-mRNA ceRNA Regulatory Network in Chicken Fat Deposition

Fat deposition is a vital factor affecting the economics of poultry production. Numerous studies on fat deposition have been done. However, the molecular regulatory mechanism is still unclear. In the present study, the whole-transcriptome RNA sequencing in abdominal fat, back skin, and liver both high- and low-abdominal fat groups was used to uncover the competitive endogenous RNA (ceRNA) regulation network related to chicken fat deposition. The results showed that differentially expressed (DE) genes in abdominal fat, back skin, liver were 1207(784 mRNAs, 330 lncRNAs, 41 circRNAs, 52 miRNAs), 860 (607 mRNAs, 166 lncRNAs, 26 circRNAs, 61 miRNAs), and 923 (501 mRNAs, 262 lncRNAs, 15 circRNAs, 145 miRNAs), respectively. The ceRNA regulatory network analysis indicated that the fatty acid metabolic process, monocarboxylic acid metabolic process, carboxylic acid metabolic process, glycerolipid metabolism, fatty acid metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling pathway took part in chicken fat deposition. Meanwhile, we scan the important genes, FADS2, HSD17B12, ELOVL5, AKR1E2, DGKQ, GPAM, PLIN2, which were regulated by gga-miR-460b-5p, gga-miR-199-5p, gga-miR-7470-3p, gga-miR-6595-5p, gga-miR-101-2-5p. While these miRNAs were competitive combined by lncRNAs including MSTRG.18043, MSTRG.7738, MSTRG.21310, MSTRG.19577, and circRNAs including novel_circ_PTPN2, novel_circ_CTNNA1, novel_circ_PTPRD. This finding provides new insights into the regulatory mechanism of mRNA, miRNA, lncRNA, and circRNA in chicken fat deposition.

Astragalus polysaccharide mitigates transport stress-induced hepatic metabolic stress via improving hepatic glucolipid metabolism in chicks

In the modern poultry industry, newly hatched chicks are unavoidably transported from the hatching to the rearing foster. Stress caused by multiple physical and psychological stressors during transportation is particularly harmful to the liver. Astragalus polysaccharide (APS) possesses multiple benefits against hepatic metabolic disorders. Given that transport stress could disturb hepatic glucolipid metabolism and the role of APS in metabolic regulation, we speculated that APS could antagonize transport stress-induced disorder of hepatic glucolipid metabolism. Firstly, newly hatched chicks were transported for 0, 2, 4, 8 h, respectively. Subsequently, to further investigated the effects of APS on transport stress-induced hepatic glucolipid metabolism disturbance, chicks were pretreated with water or APS and then subjected to transport treatment. Our study suggested that APS could relieve transport stress induced lipid deposition in liver. Meanwhile, transport stress also induced disturbances in glucose metabolism, reflected by augmented mRNA expression of key molecules in gluconeogenesis and glycogenolysis. Surprisingly, APS could simultaneously alleviate these alterations via PGC1α/SIRT1/AMPK pathway. Moreover, APS treatment regulated the level of PPARα and PPARγ, thereby alleviating transport stress-induced alterations of VLDL synthesis, cholesterol metabolism, lipid oxidation, synthesis and transport-related molecules. These findings indicated that APS could prevent the potential against transport stress-induced hepatic glucolipid metabolism disorders via PGC1α/ SIRT1/ AMPK/ PPARα/ PPARγ signaling system.

Genome-wide identification of fatty acid synthesis genes, fatty acid profiles, and life parameters in two freshwater water flea Daphnia magna strains

The freshwater water flea Daphnia magna is a planktonic animal belonging to the Cladocera. To evaluate differences between two D. magna strains (KIT and NIES) in terms of life parameters and fatty acid profiles, we examined several endpoints. In the D. magna KIT strain, the numbers of total and cumulative offspring were lower at 23 °C and higher at 14 °C than in the D. magna NIES strain. However, at 14 °C, the D. magna KIT strain showed an increased lifespan. Although the n-3/n-6 polyunsaturated fatty acids (PUFA) ratio was always decreased at a low temperature, the PUFA ratio in the KIT strain had a higher value on day 3 than the NIES strain, which gave it higher adaptability to low temperature. In addition, we identified the elongation of very long chain fatty acids (elovl) and fatty acid desaturase (fad) genes, which are involved in fatty acid biosynthesis pathways, in the genomes of both D. magna KIT and NIES. The Elovl and Fad genes in both D. magna strains were highly conserved, including tandem duplicated Elovl 1/7 genes. This study provides new information about the molecular basis for the difference in temperature sensitivity between two strains of D. magna.

Transcriptome study digs out BMP2 involved in adipogenesis in sheep tails

Background

Hu sheep and Tibetan sheep in China are characterized by fat tails and thin tails, respectively. Several transcriptomes have been conducted in different sheep breeds to identify the differentially expressed genes (DEGs) underlying this trait. However, these studies identified different DEGs in different sheep breeds.

Results

Hence, RNA sequencing was performed on Hu sheep and Tibetan sheep. We obtained a total of 45.57 and 43.82 million sequencing reads, respectively. Two libraries mapped reads from 36.93 and 38.55 million reads after alignment to the reference sequences. 2108 DEGs were identified, including 1247 downregulated and 861 upregulated DEGs. GO and KEGG analyses of all DEGs demonstrated that pathways were enriched in the regulation of lipolysis in adipocytes and terms related to the chemokine signalling pathway, lysosomes, and glycosaminoglycan degradation. Eight genes were selected for validation by RT–qPCR. In addition, the transfection of BMP2 overexpression into preadipocytes resulted in increased PPAR-γ expression and expression. BMP2 potentially induces adipogenesis through LOX in preadipocytes. The number of lipid drops in BMP2 overexpression detected by oil red O staining was also greater than that in the negative control.

Conclusion

In summary, these results showed that significant genes (BMP2, HOXA11, PPP1CC and LPIN1) are involved in the regulation of adipogenesis metabolism and suggested novel insights into metabolic molecules in sheep fat tails.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08657-8.

Fatty acid profile characterization in colostrum, transition milk, and mature milk of primi- and multiparous cows during the first week of lactation

The specific fatty acid (FA) profile of colostrum may indicate a biological requirement for neonatal calves. The objective of this study was to characterize the FA profile and yields in colostrum, transition milk, and mature milk in primiparous (PP) and multiparous (MP) cows. Colostrum was milked from 10 PP and 10 MP Holstein cows fed the same pre- and postpartum rations. Milkings (M) 2 to 5 and 12 were respectively termed transition and mature milk. Overall, short-chain FA (C4:0 and C6:0) were 61 and 50% lower in colostrum than mature milk, respectively. A parity by milking interaction was also present, with higher C4:0 for PP cows at M2 and for MP cows at M12. Additionally, higher concentrations of C6:0 were present for PP cows at M2 through M4 and for MP cows at M12. Palmitic (C16:0) and myristic (C14:0) acids were 38% and 19% higher in colostrum than mature milk, respectively. However, total saturated FA remained relatively stable. Branched-chain FA were 13% lower in colostrum than mature milk and higher in PP than MP cows throughout the milking period. The proportion of trans-monounsaturated FA (MUFA) was 72% higher in PP cows throughout the milking period, as well as 13% lower in colostrum than mature milk. In contrast, cis-MUFA and total MUFA were not affected by milking nor parity. Linoleic acid (LA) was 25% higher in colostrum than transition and mature milks, but α-linolenic acid (ALA) did not differ. Consequently, the ratio of LA to ALA was 29% higher in colostrum than mature milk and 33% higher in MP cows. Linoleic acid was also 15% higher in MP cows, whereas ALA was 15% higher in PP cows. Conjugated linoleic acid (CLA, cis-9,trans-11) was 2.7-fold higher in PP cows, and no differences between colostrum and mature milk were detected. Overall, polyunsaturated FA (PUFA) from the n-6 and n-3 series were over 40% higher in colostrum compared with transition and mature milk. Milking by parity interactions were present for arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and total n-3 PUFA, translating to higher proportions in PP cows in M1 to M3, whereas proportions remained relatively stable throughout the milking period in MP cows. Despite increasing milk yields throughout the subsequent milkings, higher yields of EPA, ARA, DPA, and DHA were present in colostrum than in mature milk. Greater proportions and yields of n-3 and n-6 FA in colostrum may translate to specific requirements for newborn calves. Differences were also observed between PP and MP cows and may reflect different nutrient requirements and partitioning.

Effects of in ovo feeding of t10,c12-conjugated linoleic acid on hepatic lipid metabolism and subcutaneous adipose tissue deposition in newly hatched broiler chicks

The purpose of this study was to investigate whether in ovo feeding of t10,c12-conjugated linoleic acid (CLA) could regulate hepatic lipid metabolism and decrease lipid accumulation in newly hatched chicks. Three hundred and sixty fertilely specific pathogen-free hatching eggs were selected and randomly divided into 6 groups. On embryonic day 11 of incubation (E11), 0, 1.5, 3.0, 4.5, 6.0, or 7.5 mg t10,c12-CLA were injected into the eggs. The results indicated that in ovo feeding of t10,c12-CLA significantly decreased the subcutaneous adipose tissue (SAT) mass and the relative SAT weight of newly hatched chicks in linear and quadratic manners (P < 0.05). In liver, the levels of triglycerides were reduced linearly and quadratically and total cholesterol were reduced quadratically as the dose of t10,c12-CLA increased (P < 0.05). Meanwhile, the hepatic carnitine palmitoyltransferase-1a (CPT1a) content and polyunsaturated fatty acid proportion were increased quadratically in t10,c12-CLA groups (P < 0.05), accompanied by the decrease of malondialdehyde level and the increase of glutathione peroxidase and total antioxidant capacity activities (P < 0.05). In addition, in ovo feeding of t10,c12-CLA decreased the mRNA expression levels of fatty acid synthase, acetyl-CoA carboxylase 1 in linear and quadratic manners (P < 0.05), and decreased the mRNA expression of adipose triacylglyceride lipase and stearoyl-CoA desaturase significantly in liver (P < 0.05), accompanied by upregulating the mRNA expression of CPT1a quadratically and AMP-activated protein kinase α linearly and quadratically (P < 0.05). In SAT, the mRNA expression of peroxisome proliferator-activated receptor γ (PPARγ) and sterol regulatory element-binding protein-1c were decreased linearly and quadratically (P < 0.05), and the expression of PPARα and CPT1a genes were increased linearly and quadratically as the dose of t10,c12-CLA increased (P < 0.05). In conclusion, our findings demonstrate that in ovo feeding of t10,c12-CLA alleviates lipid accumulation in newly hatched chicks by suppressing fatty acid synthesis and stimulating lipolysis in the liver and inhibiting adipocyte differentiation in subcutaneous adipose tissue.

Fatty acid profile characterization in colostrum, transition milk, and mature milk of primi- and multiparous cows during the first week of lactation

The specific fatty acid (FA) profile of colostrum may indicate a biological requirement for neonatal calves. The objective of this study was to characterize the FA profile and yields in colostrum, transition milk, and mature milk in primiparous (PP) and multiparous (MP) cows. Colostrum was milked from 10 PP and 10 MP Holstein cows fed the same pre- and postpartum rations. Milkings (M) 2 to 5 and 12 were respectively termed transition and mature milk. Overall, short-chain FA (C4:0 and C6:0) were 61 and 50% lower in colostrum than mature milk, respectively. A parity by milking interaction was also present, with higher C4:0 for PP cows at M2 and for MP cows at M12. Additionally, higher concentrations of C6:0 were present for PP cows at M2 through M4 and for MP cows at M12. Palmitic (C16:0) and myristic (C14:0) acids were 16% and 27% higher in colostrum than mature milk, respectively. However, total saturated FA remained relatively stable. Branched-chain FA were 13% lower in colostrum than mature milk and higher in PP than MP cows throughout the milking period. The proportion of trans-monounsaturated FA (MUFA) was 42% higher in PP cows throughout the milking period, as well as 15% lower in colostrum than mature milk. In contrast, cis-MUFA and total MUFA were not affected by milking nor parity. Linoleic acid (LA) was 13% higher in colostrum than transition and mature milks, but α-linolenic acid (ALA) did not differ. Consequently, the ratio of LA to ALA was 23% higher in colostrum than mature milk and 25% higher in MP cows. Linoleic acid was also 13% higher in MP cows, whereas ALA was 15% higher in PP cows. Conjugated linoleic acid (CLA, cis-9,trans-11) was 63% higher in PP cows, and no differences between colostrum and mature milk were detected. Overall, polyunsaturated FA (PUFA) from the n-6 and n-3 series were over 25% higher in colostrum compared with transition and mature milk. Milking by parity interactions were present for arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and total n-3 PUFA, translating to higher proportions in PP cows in M1 to M3, whereas proportions remained relatively stable throughout the milking period in MP cows. Despite increasing milk yields throughout the subsequent milkings, higher yields of EPA, ARA, DPA, and DHA were present in colostrum than in mature milk. Greater proportions and yields of n-3 and n-6 FA in colostrum may translate to specific requirements for newborn calves. Differences were also observed between PP and MP cows and may reflect different nutrient requirements and partitioning.

The Impact of Incretin-Based Medications on Lipid Metabolism

Pathophysiological pathways that are induced by chronic hyperglycemia negatively impact lipid metabolism. Thus, diabetes is commonly accompanied by varying degrees of dyslipidemia which is itself a major risk factor for further macro- and microvascular diabetes complications such as atherosclerosis and nephropathy. Therefore, normalizing lipid metabolism is an attractive goal for therapy in patients with diabetes. Incretin-based medications are a novel group of antidiabetic agents with potent hypoglycemic effects. While the impact of incretins on glucose metabolism is clear, recent evidence indicates their positive modulatory roles on various aspects of lipid metabolism. Therefore, incretins may offer additional beneficial effects beyond that of glucose normalization. In the current review, how these antidiabetic medications can regulate lipid homeostasis and the possible cellular pathways involved are discussed, incorporating related clinical evidence about incretin effects on lipid homeostasis.

Regulation of Key Genes for Milk Fat Synthesis in Ruminants

Milk fat is the most important and energy-rich substance in milk and plays an important role in the metabolism of nutrients during human growth and development. It is mainly used in the production of butter and yogurt. Milk fat not only affects the flavor and nutritional value of milk, but also is the main target trait of ruminant breeding. There are many key genes involve in ruminant milk fat synthesis, including ACSS2, FASN, ACACA, CD36, ACSL, SLC27A, FABP3, SCD, GPAM, AGPAT, LPIN, DGAT1, PLIN2, XDH, and BTN1A1. Taking the de novo synthesis of fatty acids (FA) and intaking of long-chain fatty acids (LCFA) in blood to the end of lipid droplet secretion as the mainline, this manuscript elucidates the complex regulation model of key genes in mammary epithelial cells (MECs) in ruminant milk fat synthesis, and constructs the whole regulatory network of milk fat synthesis, to provide valuable theoretical basis and research ideas for the study of milk fat regulation mechanism of ruminants.

Engineered whole cut meat-like tissue by the assembly of cell fibers using tendon-gel integrated bioprinting

With the current interest in cultured meat, mammalian cell-based meat has mostly been unstructured. There is thus still a high demand for artificial steak-like meat. We demonstrate in vitro construction of engineered steak-like tissue assembled of three types of bovine cell fibers (muscle, fat, and vessel). Because actual meat is an aligned assembly of the fibers connected to the tendon for the actions of contraction and relaxation, tendon-gel integrated bioprinting was developed to construct tendon-like gels. In this study, a total of 72 fibers comprising 42 muscles, 28 adipose tissues, and 2 blood capillaries were constructed by tendon-gel integrated bioprinting and manually assembled to fabricate steak-like meat with a diameter of 5 mm and a length of 10 mm inspired by a meat cut. The developed tendon-gel integrated bioprinting here could be a promising technology for the fabrication of the desired types of steak-like cultured meats.

Carcass characteristics and meat quality of lambs fed with cassava foliage hay and spineless cactus

The objective of this study was to evaluate the influence of the total or partial replacement of Tifton 85 hay (TH) by cassava foliage hay (CH) and/or spineless cactus (SC) on the carcass characteristics and meat quality of confined lambs. Thirty-five Dorper x Santa Inês crossbred lambs were used, with an initial average weight of 16.0 ± 1.9 kg, fed with five treatment diets: 70% TH, 70% CH, 35% TH + 35% CH, 35% TH + 35% SC, and 35% CH + 35% SC. After 90 days of confinement, the animals were slaughtered and the carcass and meat data were compared using the Tukey test at 5%. The partial replacement of TH by SC increased the cold carcass weight by 3.9 kg (p < .05). The proportion of fat (%) increased (p < .05) when TH was replaced by CH + SC. The intensity of red (a*) was lower (p < .05) in the meat of animals fed with CH or CH + SC. It is recommended to partially replace TH with SC, or to replace totally with CH in association with SC.

Unexpectedly high thermostability of an NADP-dependent malic enzyme from a psychrophilic bacterium, Shewanella livingstonensis Ac10

Psychrophilic enzymes are generally active at low temperatures, and their functions have attracted much interest in food processing, biochemical research, and chemical industry. However, their activities are usually lost above their growth temperature because of their flexible and unstable structure. Here, we unexpectedly found that a homodimeric NADP-dependent malic enzyme from a psychrophilic bacterium, Shewanella livingstonensis Ac10 (SL-ME) showed sufficient activity with 60°C treatment, similar to its counterpart from mesophilic Escherichia coli (MaeB). Consistently, SL-ME and MaeB irreversibly denatured at 71.9°C and 64.5°C, respectively. Therefore, SL-ME shows robust catalytic activity, which appears to be advantageous for its application in the bioconversion of NADP to NADPH, an essential ingredient for membrane phospholipid synthesis.

Molecular Regulation of Lipogenesis, Adipogenesis and Fat Deposition in Chicken

In the poultry industry, excessive fat deposition is considered an undesirable factor, affecting feed efficiency, meat production cost, meat quality, and consumer’s health. Efforts to reduce fat deposition in economically important animals, such as chicken, can be made through different strategies; including genetic selection, feeding strategies, housing, and environmental strategies, as well as hormone supplementation. Recent investigations at the molecular level have revealed the significant role of the transcriptional and post-transcriptional regulatory networks and their interaction on modulating fat metabolism in chickens. At the transcriptional level, different transcription factors are known to regulate the expression of lipogenic and adipogenic genes through various signaling pathways, affecting chicken fat metabolism. Alternatively, at the post-transcriptional level, the regulatory mechanism of microRNAs (miRNAs) on lipid metabolism and deposition has added a promising dimension to understand the structural and functional regulatory mechanism of lipid metabolism in chicken. Therefore, this review focuses on the progress made in unraveling the molecular function of genes, transcription factors, and more notably significant miRNAs responsible for regulating adipogenesis, lipogenesis, and fat deposition in chicken. Moreover, a better understanding of the molecular regulation of lipid metabolism will give researchers novel insights to use functional molecular markers, such as miRNAs, for selection against excessive fat deposition to improve chicken production efficiency and meat quality.

Supplementing conjugated linoleic acid (CLA) in breeder hens diet increased CLA incorporation in liver and alters hepatic lipid metabolism in chick offspring

This experiment was designed to investigate the effect of supplementing conjugated linoleic acid (CLA) in breeder hens diet on development and hepatic lipid metabolism of chick offspring. Hy-Line Brown breeder hens were allocated into two groups, supplemented with 0 (CT) or 0.5% CLA for 8 weeks. Offspring chicks were grouped according to the mother generation and fed for 7 days. CLA treatment had no significant influence on development, egg quality, and fertility of breeder hens, but darkened the egg yolks in shade and increased yolk sac mass compared to CT group. Addition of CLA resulted in increased body mass and liver mass, and decreased deposition of subcutaneous adipose tissue in chick offspring. The serum triglyceride (TG) and cholesterol (TC) levels of chick offspring were decreased in CLA group. CLA treatment increased the incorporation of both CLA isomers (c9t11 and t10c12) in liver of chick offspring, accompanied by the decreased hepatic TG levels, related to the significant reduction of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) enzyme activities and the increased of carnitine palmitoyltransferase-1 (CPT1) enzyme activity. Meanwhile, CLA treatment reduced the mRNA expression of genes related to fatty acid biosynthesis (FAS, ACC, and sterol regulatory element-binding protein-1c), and induced the expression of genes related to β-oxidative (CPT1, AMP-activated protein kinase, and peroxisome proliferator-activated receptor α) in chick offspring liver. In summary, the addition of CLA in breeder hens diet significantly increased incorporation of CLA in liver of chick offspring, which further regulate hepatic lipid metabolism.

A novel chicken model of fatty liver disease induced by high cholesterol and low choline diets

Fatty liver diseases, common metabolic diseases in chickens, can lead to a decrease in egg production and sudden death of chickens. To solve problems caused by the diseases, reliable chicken models of fatty liver disease are required. To generate chicken models of fatty liver, 7-week-old ISA female chickens were fed with a control diet (17% protein, 5.3% fat, and 1,300 mg/kg choline), a low protein and high fat diet (LPHF, 13% protein, 9.1% fat, and 1,300 mg/kg choline), a high cholesterol with low choline diet (CLC, 17% protein, 7.6% fat with additional 2% cholesterol, and 800 mg/kg choline), a low protein, high fat, high cholesterol, and low choline diet (LPHFCLC, 13% protein, 12.6% fat with additional 2% cholesterol, and 800 mg/kg choline) for 4 wk. Our data showed that the CLC and LPHFCLC diets induced hyperlipidemia. Histological examination and the content of hepatic lipids indicated that the CLC and LPHFCLC diets induced hepatic steatosis. Plasma dipeptidyl peptidase 4, a biomarker of fatty liver diseases in laying hens, increased in chickens fed with the CLC or LPHFCLC diets. Hepatic ballooning and immune infiltration were observed in these livers accompanied by elevated interleukin 1 beta and lipopolysaccharide induced tumor necrosis factor mRNAs suggesting that the CLC and LPHFCLC diets also caused steatohepatitis in these livers. These diets also induced hepatic steatosis in Plymouth Rock chickens. Thus, the CLC and LPHFCLC diets can be used to generate models for fatty liver diseases in different strains of chickens. In ISA chickens fed with the CLC diet, peroxisome proliferator-activated receptor γ, sterol regulatory element binding transcription factor 1, and fatty acid synthase mRNAs increased in the livers, suggesting that lipogenesis was enhanced by the CLC treatment. Our data show that treatment with CLC or LPHFCLC for 4 wk induces fatty liver disease in chickens. These diets can be utilized to rapidly generate chicken models for fatty liver research.

Alteration of fatty acid profile of milk in Holstein cows fed Bacillus coagulans as probiotic: a field study

BACKGROUND

Probiotics may improve milk quality and the general health status of animals.

AIMS

The effects of dietary Bacillus coagulans PRM101 on milk components, milk fatty acids (FA), and some health indicators of dairy cows were investigated.

METHODS

The probiotic was added to the feed of 12 Holstein cows (2 g/cow: 2 × 1011 CFU/cow) for 63 days compared to a control group fed on the basal ration (n=11). Milk and blood samples were taken on days 0, 21, 42, and 63.

RESULTS

The yields of milk and energy corrected milk (ECM; computed from milk weight and its fat and protein content) decreased linearly and similarly (P=0.60) in both groups. The treatment cows, however, showed quadratic increases in the weights of milk (P=0.03) and ECM (P=0.04) at d42 of the study. Energy corrected milk (d42, P<0.05) and crude protein content of milk (d42, P<0.05; d63, P<0.1) were higher in the cows receiving the probiotic. The proportions of heptadecanoic (C17:0; P=0.002) and linoleic (C18:2; P=0.077) acids in milk fat (g/100 g fat) were higher in the treatment cows on d63. Milk total antioxidant capacity (TAC), malondialdehyde (MDA), and similarly, amyloid A (AA) and haptoglobin (Hp) of milk and blood were not affected. Total antioxidant capacity and MDA were negatively correlated in the control group (r=-0.669, P=0.005). Heptadecanoic acid correlated negatively with milk MDA (r=-0.611, P=0.035) and positively (r=0.591, P=0.043) with serum Hp in the treatment cows.

CONCLUSION

Dietary B. coagulans PRM101 may improve the proportions of C17:0 and C18:2 FA in milk. Some improvements in milk protein and the health status of the cows may also be anticipated.

Radical Response: Effects of Heat Stress-Induced Oxidative Stress on Lipid Metabolism in the Avian Liver

Lipid metabolism in avian species places unique demands on the liver in comparison to most mammals. The avian liver synthesizes the vast majority of fatty acids that provide energy and support cell membrane synthesis throughout the bird. Egg production intensifies demands to the liver as hepatic lipids are needed to create the yolk. The enzymatic reactions that underlie de novo lipogenesis are energetically demanding and require a precise balance of vitamins and cofactors to proceed efficiently. External stressors such as overnutrition or nutrient deficiency can disrupt this balance and compromise the liver’s ability to support metabolic needs. Heat stress is an increasingly prevalent environmental factor that impairs lipid metabolism in the avian liver. The effects of heat stress-induced oxidative stress on hepatic lipid metabolism are of particular concern in modern commercial chickens due to the threat to global poultry production. Chickens are highly vulnerable to heat stress because of their limited capacity to dissipate heat, high metabolic activity, high internal body temperature, and narrow zone of thermal tolerance. Modern lines of both broiler (meat-type) and layer (egg-type) chickens are especially sensitive to heat stress because of the high rates of mitochondrial metabolism. While this oxidative metabolism supports growth and egg production, it also yields oxidative stress that can damage mitochondria, cellular membranes and proteins, making the birds more vulnerable to other stressors in the environment. Studies to date indicate that oxidative and heat stress interact to disrupt hepatic lipid metabolism and compromise performance and well-being in both broilers and layers. The purpose of this review is to summarize the impact of heat stress-induced oxidative stress on lipid metabolism in the avian liver. Recent advances that shed light on molecular mechanisms and potential nutritional/managerial strategies to counteract the negative effects of heat stress-induced oxidative stress to the avian liver are also integrated.

Low dietary inclusion of nutraceuticals from microalgae improves feed efficiency and modifies intermediary metabolisms in gilthead sea bream (Sparus aurata)

The aim of this work was to evaluate two functional feeds for the gilthead seabream, Sparus aurata, containing low inclusion of two microalgae-based products (LB-GREENboost, LB_Gb; and LB-GUThealth, LB_Gh). Fish (12–13 g) were fed for 13 weeks a control diet or one of the four diets supplemented with both products at 0.5% or 1%. LB_Gb and LB_Gh did not affect specific growth rate or survival, but increased feed efficiency by decreasing feed intake and enlarging the intestines. LB_Gb increased hepatosomatic index and reduced cortisol levels in plasma, while both products lowered plasma lactate. Extensive metabolite and metabolic enzyme profiling revealed that microalgae supplementations, especially 1% LB_Gh: (i) decrease plasma lactate and increase hepatic glycogen, (ii) reduce hepatic gluconeogenesis, (iii) enhance hepatic lipogenic activity and lipid secretion, (iv) led fish to double triglyceride content in muscle and to stimulate its lipid oxidative capacity, and (v) increase the content of monounsaturated fatty acids and the omega-3 alpha-linolenic acid in muscle. This study demonstrates that both microalgae-based products are suited to improve feed efficiency and orchestrate significant changes in the intermediary metabolism in gilthead seabream juveniles.

Impact of SNPs in ACACA, SCD1, and DGAT1 Genes on Fatty Acid Profile in Bovine Milk with Regard to Lactation Phases

Simple Summary

Fatty acids are an important component of milk fat. Because of their wide spectrum of effects on human health, it is important to better understand the regulation of their profile in milk. This study aims to analyzing the relation between selected genes with milk fatty acid content. As increased concentration of unhealthy fatty acids and lower concentration of healthy ones in less frequent homozygotes and a strong influence of the genes on fatty acids with 18 carbon atoms were observed, these findings could be useful in future dairy cattle selection aiming production of more healthy milk.

Abstract

Milk fat is a dietary source of fatty acids (FA), which can be health promoting or can increase risks of some diseases. FA profile composition depends on many factors, among them gene polymorphism. This study analyzed the relation between polymorphism of acetyl-CoA carboxylase α (ACACA), stearoyl-CoA desaturase 1 (SCD1), diacylglycerol acyltransferase 1 (DGAT1) genes with FA profile in milk from Polish Holstein-Friesian cattle and determined changes of FA percentage during lactation with regard to polymorphism. Milk samples were collected twice: during the first phase of lactation (<90 Days in milk; DIM) and at the end of lactation (>210 DIM). During the first milk collection, blood samples were taken to analyze three chosen single nucleotide polymorphisms (SNPs): AJ312201.1g.1488C > G SNP in ACACA gene, A293V SNP in SCD1 gene, and K232A SNP in DGAT1 gene. Increased concentration of FA that are less beneficial for human health and have lower concentration of healthy FA in homozygotes: GG in ACACA, VV in SCD1, and KK in DGAT1 were observed, as well as a strong influence of the analyzed genes on FA with 18C atoms was also found. Moreover, it was demonstrated that lactation phase significantly affected FA percentage in milk depending on the phenotype. These results may contribute their part to knowledge toward obtaining more beneficial milk composition.

Differentially expressed genes identified through RNA-seq with extreme values of principal components for beef fatty acid in Nelore cattle

The aim of this study was to identify differentially expressed genes (DEG) in the Longissimus thoracis muscle of Nelore cattle related to fatty acid (FA) profile through RNA sequencing and principal component analysis (PCA). Two groups of 10 animals each were selected containing PC1 and PC2 extreme DEG values (HIGH × LOW) for each FA group. The intramuscular fat (IMF) was compared between cluster groups by ANOVA, and only the sum of monounsaturated FA (MUFA) and ω3 showed significant differences (p < .05). Interestingly, the highest percentage (95%) of phenotypic variation explained by the sum of the first two PC was observed for ω3, which also displayed the lowest number of DEG (n = 1). The lowest percentage (59%) was observed for MUFA, which also revealed the largest number of DEG (n = 66). Since only MUFA and ω3 exhibited significant differences between cluster groups, we can conclude that the differences observed for the remaining groups are not due to the percentage of IMF. Several genes that have been previously associated with meat quality and FA traits were identified as DEG in this study. The functional analysis revealed one KEGG pathway and eight GO terms as significant (p < .05), in which we highlighted the purine metabolism, glycolytic process, adenosine triphosphate binding and bone development. These results strongly contribute to the knowledge of the biological mechanisms involved in meat FA profile of Nelore cattle.

Adipose Tissue Modification through Feeding Strategies and Their Implication on Adipogenesis and Adipose Tissue Metabolism in Ruminants

Dietary recommendations by health authorities have been advising of the importance of diminishing saturated fatty acids (SFA) consumption and replacing them by polyunsaturated fatty acids (PUFA), particularly omega-3. Therefore, there have been efforts to enhance food fatty acid profiles, helping them to meet human nutritional recommendations. Ruminant meat is the major dietary conjugated linoleic acid (CLA) source, but it also contains SFA at relatively high proportions, deriving from ruminal biohydrogenation of PUFA. Additionally, lipid metabolism in ruminants may differ from other species. Recent research has aimed to modify the fatty acid profile of meat, and other animal products. This review summarizes dietary strategies based on the n-3 PUFA supplementation of ruminant diets and their effects on meat fatty acid composition. Additionally, the role of n-3 PUFA in adipose tissue (AT) development and in the expression of key genes involved in adipogenesis and lipid metabolism is discussed. It has been demonstrated that linseed supplementation leads to an increase in α-linolenic acid (ALA) and eicosapentaenoic acid (EPA), but not in docosahexaenoic acid (DHA), whilst fish oil and algae increase DHA content. Dietary PUFA can alter AT adiposity and modulate lipid metabolism genes expression, although further research is required to clarify the underlying mechanism.

Folic acid perfusion administration reduced abdominal fat deposition in starter Arbor Acres broilers

With intensive selection for meat production in broilers, excessive fat accumulation is also accompanied and causes economic concerns. Folic acid was reported to be involved in lipid metabolism. The present study was conducted to investigate the role of folic acid in reducing abdominal fat deposition. A total of 105 one-day-old healthy Arbor Acres broilers were randomly distributed into 3 treatments, including the control (Con), saline-perfusion group (NS), and folic acid perfusion group (FA). The growth performance, biochemical characteristics in serum, and lipid metabolism in the liver and abdominal fat tissues were evaluated. Results have shown that folic acid significantly reduced abdominal fat percentage (P < 0.05) and had no effects on BW, ADFI, ADG, and FCR (P > 0.05). Serum triglycerides (TG), total cholesterol (TC), and alanine aminotransferase (ALT) levels were lower in FA group but albumin concentration was higher (P < 0.05). Hepatic ACC, SCD, ELOVL6, PI3K, LDLR, HMGCR, and ABCA1 mRNA abundance were all down-regulated in FA group (P < 0.05) when compared with the Con and NS groups, while CPT1 and PPARα were not affected. In addition, MTTP mRNA abundance was higher in the liver of birds subjected to folic acid (P < 0.05). There was no difference about TG deposition in the liver among all groups based on hematoxylin−eosin (HE) and Oil Red O staining. On the other hand, ELOVL6, PPARγ, IGF1, and TGFβ2 expression were notably decreased in the abdominal fat in FA group (P < 0.05). In conclusion, our data demonstrated that folic acid has reduced abdominal fat percentage by decreasing hepatic lipogenesis and suppressing adipocytes proliferation and differentiation. And the inhibiting effect of adipocytes might be mediated by IGF1 and TGFβ2 down-regulation.

Hepatic exosome-derived miR-130a-3p attenuates glucose intolerance via suppressing PHLPP2 gene in adipocyte

OBJECTIVE

Glucose and lipid metabolism disorders are a major risk factor for type II diabetes and cardiovascular diseases. Evidence has indicated that the interplay between the liver and adipose tissue is crucial in maintaining energy homeostasis. Recently, the interaction between two distant endocrine organs mainly focuses on the regulation of hormones and receptors. However, as a novel carrier in the inter-tissue communication, exosomes plays a role in liver-fat crosstalk, but its effects on glucose and lipid metabolisms are still unclear. In this study, we sought to investigate the effects of hepatic exosome-derived miR-130a-3p in the regulation of glucose/lipid metabolism in adipose tissues.

MEASURE

In vivo, we constructed generalized miR-130a-3p knockout (130KO) and overexpressed (130OE) mice. Wild type (WT), 130KO and 130OE mice (n = 10) were assigned to a randomized controlled trial and were fed diets with either 10% (standard diet, SD) or 60% (high-fat diet, HFD) of total calories from fat (lard). Next, hepatic exosomes were extracted from WT-SD, 130KO-SD and 130OE-SD mice (WT-EXO, KO-EXO, OE-EXO), and 130KO mice were injected with 100 mg hepatic exosomes of different sources via tail-vein (once every 48 h) for 28 days, fed with HFD. In vitro, 3T3-L1 cells were treated with miR-130a-3p mimics, inhibitor and hepatic exosomes. Growth performance and glucose and lipid metabolic profiles were examined.

RESULTS

After feeding with HFD, the weights of 130KO mice were markedly higher than WT mice. Over-expression of miR-130a-3p in 130OE mice and intravenous injection of 130OE-EXO in 130KO mice contributed to a positive correlation with the recovery of insulin resistance. In addition, miR-130a-3p mimics and 130OE-EXO treatment of 3T3-L1 cells exhibited decreasing generations of lipid droplets and increasing glucose uptake. Conversely, inhibition of miR-130a-3p in vitro and in vivo resulted in opposite phenotype changes. Furthermore, PHLPP2 was identified as a direct target of miR-130a-3p, and the hepatic exosome-derived miR-130a-3p could improve glucose intolerance via suppressing PHLPP2 to activate AKT-AS160-GLUT4 signaling pathway in adipocytes.

CONCLUSIONS

We demonstrated that hepatic exosome-derived miR-130a regulated energy metabolism in adipose tissues, and elucidated a new molecular mechanism that hepatic exosome-derived miR-130a-3p is a crucial participant in organismic energy homeostasis through mediating crosstalk between the liver and adipose tissues.

Developmental changes in hepatic lipid metabolism of chicks during the embryonic periods and the first week of posthatch

The liver is the main site of de novo lipogenesis in poultry, and hepatic lipid metabolism disorder will lead to excessive abdominal fat deposition or fatty liver disease, finally causing huge economic loss. The present study was conducted to investigate developmental changes in hepatic lipid metabolism of chicks from embryonic periods to the first week after hatching. Liver samples were collected from embryonic day 11 (E11) to the age of day 7 posthatch (D7) for lipid metabolism analysis. Hematoxylin–eosin and Oil Red O staining analysis showed that hepatic lipids increased gradually during embryonic period and declined posthatch; The sum of hepatic triglycerides and cholesterol reached the peak at E19 and D1 by ELISA analysis (P < 0.05). Acetyl-CoA carboxylase, fatty acid synthase, and acyl-CoA desaturase 1 mRNA expression in the liver were higher from E17 to D1 with the peak at E19 when compared with those at E13 and E15 (P < 0.05). Hepatic elongase of very long-chain fatty acids 6 and microsomal triglyceride transfer protein mRNA abundance were lower during embryonic periods but reached relative higher level after hatching (P < 0.05). On the contrary, hepatic carbohydrate response element binding protein (ChREBP), carnitine palmitoyltransferase 1, and peroxisome proliferators–activated receptor α expression were higher during embryonic periods but decreased posthatch (P < 0.05). The mRNA abundance of sterol-regulatory element binding protein 1c was the lowest at E13 and E15, then increased gradually from E17 to D1, while decreased from D3 to D7 little by little (P < 0.05). In summary, hepatic lipogenesis genes have different expression patterns during the embryonic periods and the first week of posthatch, which might be activated by ChREBP during embryonic periods; fatty acid oxidation was enhanced around the hatched day but declined posthatch. These findings will broaden the understanding of physiological characteristics and dynamic pattern about hepatic lipid metabolism in chicks.

High fructose-containing drinking water-induced steatohepatitis in rats is prevented by the nicotinamide-mediated modulation of redox homeostasis and NADPH-producing enzymes

An imbalance in the redox state, increased levels of lipid precursors and overactivation of de novo lipogenesis determine the development of fibrosis during nonalcoholic steatohepatitis (NASH). We evaluated the modulation of NADPH-producing enzymes associated with the antifibrotic, antioxidant and antilipemic effects of nicotinamide (NAM) in a model of NASH induced by excess fructose consumption. Male rats were provided drinking water containing 40% fructose for 16 weeks. During the last 12 weeks of fructose administration, water containing NAM was provided to some of the rats for 5 h/day. The biochemical profiles and the ghrelin, leptin, lipoperoxidation and TNF-α levels in serum and the glucose-6-phosphate dehydrogenase (G6PD), malic enzyme (ME) and NADP⁺-dependent isocitric dehydrogenase (IDP) levels, the reduced/oxidized glutathione (GSH/GSSG) and reduced/oxidized nicotinamide adenine dinucleotide (phosphate) (NAD(P)H/NAD(P)⁺) ratios, and the levels of various lipogenic and fibrotic markers in the liver were evaluated. The results showed that hepatic fibrosis induced by fructose consumption was associated with weight gain, hunger-satiety system dysregulation, hyperinsulinemia, dyslipidemia, lipoperoxidation and inflammation. Moreover, increased levels of hepatic G6PD and ME activity and expression, the NAD(P)H/NAD(P)⁺ ratios, and GSSG concentration and increased expression of lipogenic and fibrotic markers were detected, and these alterations were attenuated by NAM administration. Specifically, NAM diminished the activity and expression of G6PD and ME, and this effect was associated with a decrease in the NADPH/NADP⁺ ratios, increased GSH levels and decreased lipoperoxidation and inflammation, ameliorating fibrosis and NASH development. NAM reduces liver steatosis and fibrosis by regulating redox homeostasis through a G6PD- and ME-dependent mechanism.

The inclusion of spineless cactus in the diet of lambs increases fattening of the carcass

The objective of this study was to evaluate the effect of replacement maniçoba hay by spineless cactus on the performance, carcass characteristics, and meat quality of confined lambs. Thirty-two male lambs, with an average body weight of 20.8 ± 2.9 kg, were fed with different levels of spineless cactus in replacement for 0, 33, 66 or 100% of maniçoba hay (i.e. 0, 200, 400, 600 g kg^-1 of dietary DM). The replacement maniçoba hay by spineless cactus did not influence dry matter intake (g d^-1) and cold carcass weight (P > .05), but increased (P < .05) the carcass finishing fat but did not influence (P < .05) the physical characteristics of the lambs' meat. Lower values for odor, flavor and purchase intention of meat were observed with 66% of replacement. Therefore, replacement of 33% maniçoba hay by spineless cactus can be recommended as optimal level, because it improve the fattening of the carcass, without causing negative effects on performance or meat quality.

Profiling solute-carrier transporters in key metabolic tissues during the postpartum evolution of mammary epithelial cells from nonsecretory to secretory

Modifications in the abundance of solute-carrier (SLC) transcripts in tandem with adjustments in genes-associated with energy homeostasis during the postpartum transition of the mammary epithelial cells (MEC) from nonsecretory to secretory is pivotal for supporting milk synthesis. The goal of this study was to identify differentially expressed SLC genes across key metabolic tissues between late pregnancy and onset of lactation. Total RNA was isolated from the mammary, liver, and adipose tissues collected from rat dams on day 20 of pregnancy (P20) and day 1 of lactation (L1) and gene expression was measured with Rat 230 2.0 Affymetrix GeneChips. LIMMA was utilized to identify the differential gene expression patterns between P20 and L1 tissues. Transcripts engaged in conveying anions, cations, carboxylates, sugars, amino acids, metals, nucleosides, vitamins, and fatty acids were significantly increased (P < 0.05) in MEC during the P20 to L1 shift. Downregulated (P < 0.05) genes in the mammary during the physiological transition included GLUT8 and SLC45a3. In the liver, SLC genes encoding for anion, carbonyl, and nucleotide sugar transporters were upregulated (P < 0.05) at L1. while genes facilitating transportation of anions and hexose were increased (P < 0.05), from P20 to L1 in the adipose tissue. GLUT1 and GLUT4 in the liver, along with GLUT4 and SGLT2 in the adipose tissue, were repressed (P < 0.05) at L1. Our results illustrate that MEC exhibit dynamic molecular plasticity during the nonsecretory to secretory transition and increase biosynthetic capacity through a coordinated tissue specific SLC transcriptome modification to facilitate substrate transfer.

Interactions between the cecal microbiota and non-alcoholic steatohepatitis using laying hens as the model

Chronic liver disease has caused increasing numbers of deaths worldwide. Fatty liver hemorrhagic syndrome, one of the chronic liver diseases in laying hens, has great similarity to non-alcoholic fatty liver disease (NAFLD) in humans. It is characterized by the pathological accumulation of liver fat. Non-invasive techniques are needed for early identification of fibrosis. As primary de novo lipogenesis in the liver of chicken is similar to that of humans, mature chicken is an ideal animal model for the understanding of NAFLD. This study was aimed to evaluate the relationships between gut microbiota and natural chronic liver disease (i.e., non-alcoholic steatohepatitis [NASH] and fibrosis stages) in a well-characterized laying hen population. One hundred 20-wk-old Hy-Line Brown laying hens were used and fed with basal diets until 52 wk of age. At the end of the experiment, birds were killed for sampling blood, liver, and cecal contents, and then classified by liver histology measurement into different groups. We investigated microbial community structure of cecum using 16S rRNA gene sequencing. Subjects in stage 0 fibrosis without NASH were classified as low NAFLD (Group A), subjects in stage 1-2 fibrosis with mild to moderate NASH were defined as low NASH (Group B), and subjects in stage 3 fibrosis were defined as severe NASH (Group C). The abundance of Firmicutes was reduced in Groups B and C (P < 0.001), whereas opposite results were observed for the abundance of Bacteroidetes. Additionally, the families Bacteroidaceae, Ruminococcaceae Lachnospiraceae, and lactobacillae were significantly different between groups of differing fibrosis stages (P < 0.001), driven entirely by alterations of Bacteroides and lactobacillus and lachnospiraceae genera (P < 0.001), were observed. Results indicated that cecal dysbiosis was linked with the severity of fibrosis and NASH; importantly, increased levels of serum AST, alkaline phosphatase, and uric acid were accompanied with liver fibrosis and NASH severity. Collectively, these data highlight the role of gut-liver axis and associations between the gut microbiota and fibrosis and NASH severity.