Dietary choline supplementation regulated lipid profiles of egg yolk, blood, and liver and improved hepatic redox status in laying hens

Reproductive characteristics and methods to improve reproductive performance in goose production: A systematic review

In the past two decades, the high demand of and significance of poultry meat have promoted the development of the goose industry. Despite the continuous expansion of the goose breeding scale and the generation of large economic benefits by the goose industry, low reproductive efficiency remains a barrier to limit vigorous development of the goose industry. Poor reproductive efficiency can be attributed to breeding seasonality, strong broody behavior, and poor semen quality. Based on the reproductive endocrine regulation mechanism of geese, an overview of past studies that have developed various methods to achieve a significant improvement in goose reproductive performance including physical facilities for artificial illumination control and dietary nutrition manipulation to improve breeder reproductivity, and artificial incubation equipment and technology for better hatchability. The most recent advances utilize immunoneutralization to regulate critical hormones involved in goose reproduction. This review provides new information for industry and academic studies of goose breeding.

Integrated metabolome and transcriptome analysis reveals key genes and pathways associated with egg yolk percentage in chicken

Yolk percentage is a critical index in the egg product industry, reflecting both nutritional value and economic benefits. To elucidate the underlying mechanisms that contribute to variations in egg yolk percentage, we performed integrated transcriptome and metabolome analyses on the liver, ovary, and magnum tissues of Rhode Island Red chickens with high and low yolk percentages. A total of 322 differentially expressed genes (DEGs) and 128 significantly differential metabolites (SDMs) (VIP>1, P < 0.05) were identified in the liver, whereas 419 DEGs and 215 SDMs were detected in the ovary, and 238 DEGs along with 47 SDMs were found in the magnum. In the liver, genes such as HMGCR, DHCR7, MSMO1, and CYP7A1 were linked to cholesterol metabolism, essential for steroid hormone synthesis and yolk formation, while ACACB, ACSL1, ACSL4, LPL, and SGPP2 were involved in fatty acid biosynthesis, a key process for supplying energy and structural components of the yolk. In the ovary, COL6A6, COMP, CHAD, ITGA7, THBS2, and TNC contributed to extracellular matrix-receptor interactions, which are fundamental for follicle development and oocyte maturation. In the magnum, UGT1A1, MAOB, and ALDH3B2 participated in drug metabolism-cytochrome P450 and amino acid metabolism, ensuring a proper environment for egg white formation and potentially influencing nutrient allocation to the yolk. Metabolic pathway enrichment revealed that steroid hormone biosynthesis, glycerophospholipid metabolism, and betaine metabolism were predominant in the liver; pyruvate, taurine, and hypotaurine metabolism in the ovary; and phenylalanine metabolism in the magnum. Moreover, integrated analysis highlighted key metabolites and genes potentially regulating yolk deposition, including 7,8-dihydroneopterin and Pg 38:4 in the liver (related to immune modulation and lipid metabolism, respectively), thalsimine in the ovary, as well as DL-glutamine in the magnum, all of which may be crucial for maintaining metabolic homeostasis and supporting egg formation. Collectively, these findings deepen our understanding of how distinct molecular and metabolic pathways in the liver, ovary, and magnum orchestrate yolk proportion and deposition. Such insights may advance future strategies to improve egg quality and productivity in poultry breeding programs.

Storage deterioration and detection of egg multi-scale structure: A review

This review summarized the processes and mechanisms of deterioration in different components of eggs during storage. The mechanisms linked to reduced glycosylation, structural decay, and ovomucin degradation during egg-white thinning were elucidated, along with the weakening of lysozyme-ovomucin interactions. The degradation and S-conformation transformation of ovalbumin were studied, and the potential application of solubility-viscosity theory in egg-white thinning was discussed. Furthermore, the metabolic pathways of glycerophospholipids and glycerolipids during lipid hydrolysis in egg yolk were scrutinized, and the mechanism of fatty acid auto-oxidation was concluded. The review also delineated the mechanism of cuticle thinning and the impact of preservation strategies on cuticle quality. The reproductive and adaptive strategies of dominant bacteria during egg spoilage were addressed, summarizing the microbial perspective. Lastly, methods for assessing egg freshness were reviewed, encompassing both traditional destructive testing methods and advanced photoelectric nondestructive testing techniques.

Effects of Milk Thistle Extract Supplementation on Performance, Egg Quality, and Liver Pathology of Laying Hens' Fed Diets Lacking Supplemental Choline Chloride

The current study evaluated the effects of milk thistle extract supplementation in laying hens' fed diets lacking choline chloride addition. A total of 60 Isa-brown laying hens were randomly allocated into T1: control diet, 0% extract supplementation; T2: control diet with 1% extract; T3: control diet with 2.5% extract; and T4: control diet with 4% extract. Egg quality parameters, yolk lipid oxidation, malondialdehyde (MDA) content, and fatty acid profile were assessed. Livers were examined grossly and histologically to evaluate hepatocellular lesions such as vacuolization (lipidosis), reticular stromal architecture, the amount of collagenous connective tissue, and vascular wall changes. Groups T3 and T4 showed darker yolks compared to both control group and T2 (p = 0.001) and redness of the egg yolk (p < 0.001). The MDA was lowest in T2 group which had improved gross appearance with lower degrees of hepatic vacuolization than other groups. Liver discoloration was milder in T3 (43.8%) compared to the T1 and T4 groups (18.8% and 12.5%, respectively, p = 0.013). Reticulin loss was correlated with the degree of hepatic vacuolization (r = 0.751, p < 0.001). Supplementation with MT extract in diets lacking choline chloride may influence certain egg quality indices and liver gross macroscopic lesions in laying hens.

Coated cysteamine and choline chloride could be potential feed additives to mitigate the harmful effects of fatty liver hemorrhagic syndrome in laying hens caused by high-energy low-protein diet

The research aimed to examine the impact of coated cysteamine (CS) and choline chloride (CC) on relieving the pathological effects of fatty liver hemorrhagic syndrome (FLHS) in laying hens. FLHS was induced by a high-energy low-protein (HELP) diet. Ninety laying hens were equally divided into 5 treatments with 6 replicates per treatment (3 hens/replicate). The control treatment (Cont) was fed a basal diet, while the remaining treatments were fed a HELP diet. Under the HELP dietary plan, 4 treatments were set by a 2 × 2 factorial design. Two levels of CS (CS-: 0.00 mg/kg CS; CS+: 100 mg/kg diet) and 2 levels of choline (CC-: 1,182 mg/kg; CC+: 4,124 mg/kg) were set and named CS-CC- (HELP), CS+CC-, CS-CC+ and CS+CC+. The liver of the CS-CC- (HELP) group became yellowish-brown and greasy, with hemorrhages and bleeding spots. Elevated (P < 0.05) plasma and hepatic ALT and AST and hepatic MDA levels, combined with reduced (P < 0.05) plasma and hepatic SOD and GSH-Px activities in the CS-CC- (HELP) group proved that FLHS was successfully induced. Dietary supplementation of CS, CC, or both (CS+CC+) in HELP diets relieved the pathological changes, significantly (P < 0.05) reduced the AST and ALT levels, and strengthened the antioxidant potential in laying hens under FLHS. The highest (P < 0.001) plasma adiponectin concentration was observed in the CS+CC- and lowest in the CS-CC- (HELP) group. In addition, CS and CC supplementation lowers the elevated levels of hepatic T-CHO and TG by increasing the HDL-C and reducing LDL-C levels (P < 0.05) than CS-CC- (HELP) group. CS supplementation, either alone or with CC, helps laying hens restore their egg production. It could be stated that CS and CC supplements could ameliorate the adverse effects of FLHS by regulating antioxidant enzymes activities, modulating the hepatic lipid metabolism, and restoring the production performance in laying hens. Hence, adding CS and CC could be an effective way to reduce FLHS in laying hens.

Dietary betaine supplementation improved egg quality and gut microbes of laying hens under dexamethasone-induced oxidative stress

Oxidative stress is a frequent concern in the breeding of laying hens, and limit the healthy development of poultry. Dexamethasone (DXM) has been demonstrated to induce oxidative stress. Conversely, betaine is an alkaloid with a potent antioxidant activity. The study was designed to investigate the ameliorative effect of betaine on DXM-induced oxidative stress in laying hens. The results revealed that DXM treatment significantly decreased laying rate, shell strength, albumen height, Haugh unit, egg weight, folk weight and albumen weight, alongside increased malondialdehyde (MDA) and decreased total antioxidant capacity (T-AOC) in serum and liver (P < 0.05). In contrast, dietary betaine addition reversed those parameters mentioned above (P < 0.05). Hepatic RNA-seq analysis showed that there existed 110 up- and 88 down-regulated genes in DXM group when compared with the control. Meanwhile there were 117 upregulation and 169 downregulation genes in BT group when compared with DXM group. Besides, we found that dietary betaine addition significantly down-regulated cell adhesion molecules, glycerolipid metabolism and glycolysis gluconeogenesis pathways. In addition, a total of 44 and 94 differential metabolites were identified respectively from Con vs. DXM and DXM vs BT. More importantly, dietary betaine addition significantly increased the levels of pantothenic acid, gamma-Aminobutyric acid, equol and choline, all of which were related to antioxidant and anti-inflammatory properties. Furthermore, gut microbiota analysis indicated that the Chao and Observed_species indexes were remarkably higher in BT group (P<0.05). Heatmap analysis revealed that Subdoligranulum, Prevotella, Blautia, YRC22, Bacteroides, Ruminococcus and Coprococcus were notably restored in BT group (P<0.05). Taken together, our findings collectively illustrate that dietary betaine addition could attenuate DXM-induced oxidative stress, improve egg quality and gut microbes of laying hens.

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.

Dietary vasodilator and vitamin C/L-arginine/choline blend improve broiler feed efficiency during finishing and reduce woody breast severity at 6 and 7 wks

Woody breast has become a considerable economic concern to the poultry industry. This myopathy presents rigid, pale breasts characterized by replacement of lean muscle protein with connective tissue, a result of hypoxia and oxidative stress in a metabolically starved muscle with inadequate circulation. Hence, the objectives were to supplement broiler diets with ingredients specifically aimed to improve circulation and oxidative status. About 1,344 male Ross 708 broilers were assigned to 1 of 4 diets: 1) a basal diet (control), 2) basal diet plus a blend of 0.2% supplemental L-arginine, 0.17% choline bitartrate, and 0.03% vitamin C (blend), 3) 0.1% vasodilator ingredient (vasodilator), or 4) 0.02% Astaxanthin ingredient (AsX). At d 14, 28, 42, and 49, performance outcomes were collected on all birds and serum from 16 broilers/diet (n = 64) was analyzed for creatine kinase and myoglobin. Once weekly beginning on d 28, a subset of 192 broilers were measured for breast width. On d 42 and 49, breast fillets from 16 broilers/diet (n = 64) were palpated for woody breast severity, weighed, and analyzed for compression force at 1-day postmortem and water-holding capacity at 2-day postmortem. mRNA was isolated from 15 breast fillets/timepoint for qPCR quantification of myogenic gene expression. Data were analyzed using Proc Mixed (SAS Version 9.4) with the fixed effect of diet. Feed conversion ratio was improved in the blend and vasodilator-fed birds d 42 to 49, each by over 2 points (P < 0.05). Breast width was increased in the control on d 42 compared to the vasodilator and AsX-fed broilers (P < 0.05). At d 42, there were 12% greater normal fillets in blend diet-fed birds and 13% more normal scores in vasodilator-fed birds at d 49 compared to the control. At d 49, myogenin expression was upregulated in the AsX diet compared to blend and control diets (P < 0.05), and muscle regulatory factor-4 expression was increased by 6.5% in the vasodilator diet compared to the blend and AsX diets (P < 0.05). Blend and vasodilator diets simultaneously improved feed efficiency in birds approaching market weight while reducing woody breast severity.

Performance, Egg Quality, and Yolk Antioxidant Capacity of the Laying Quail in Response to Dietary Choline Levels

The current study determined the ideal dose of choline in the diet of laying quails based on egg development, egg quality, and antioxidant capacity. A total of 120 female quails (244.7 ± 10.38 g) were randomly assigned to 6 experimental groups with 5 replicates of 4 quails each. In the 10-week trial, treatment diets were formed by adding 6 choline chloride−60% concentrations providing 1500 (control), 2000, 2500, 3000, 3500, and 4000 mg/kg of choline. The feed intake of quails was quadratically affected (p < 0.05) by the choline level of the diet, in other developmental parameters, and by egg quality among these treatments. The feed intake was reduced to 2500 and 3000 mg/kg levels of choline in the diet compared to the control group. Free radical scavenging capacity (DPPH) of the yolk increased linearly (p < 0.001) with dietary choline levels. In contrast, the thiobarbituric acid reactive substances (TBARS) value decreased as dietary choline levels increased, except for 4000 mg/kg levels. Based on the findings of the current study, 1500 mg/kg of dietary choline is adequate to maintain performance parameters and egg quality in laying quails. However, to increase egg antioxidant capacity, in terms of the DPPH value, the dietary choline dose needs to be increased to 3500 mg/kg.

Efficacy of hepatoprotectors in prophylaxis of hepatosis of laying hens

Hepatoses of laying hens are quite common in poultry farms as a result of improper practices of poultry maintenance consisting in excessive number of protein feeds for provision of high productivity. The objective of the study was preventive efficacy of Gep-A-Stress hepatoprotectors (carnitine hydrochloride, D L methionine, sorbitol, choline chloride, magnesium sulfate heptahydrate) and Hepasan VS (L-carnitine hydrochloride, sorbitol, choline chloride, magnesium sulfate hepahydrate, betaine hydrochloride, L-arginin) against hepatosis of laying hens. To determine the efficacy of Hep-A-Stres and Hepasan-VS hepatoprotectors during production tests (n = 4,500), we monitored the parameters of survival rate (the final number of individuals as percentage of the initial number) and egg productivity of laying hens. We determined that after 30 days of using the hepatoprotectors, the content of overall protein in blood serum of laying hens of the first and the second experimental groups decreased by 21.4% and 18.9% compared with the parameters prior to providing the hepatoprotectors and by 26.3% and 23.3% compared with the control group after receiving the drug. The urea contents in blood serum increased by 19.0% and 10.5%. Compared with the control, the activity of alanine aminotransferase decreased by 43.7% and 24.1% in the first experimental group and by 23.4% and 14.9% in the second. The activity of aspartate aminotransferase in blood serum of the experimental groups decreased by 10.7%. The cholesterol concentration decreased by 50% and 58.3%. The content of triaglycerols decreased by 24.1% and 8.9% respectively. The concentrations of high-density lipoproteins after 30 days of the experiment decreased by 33.3% and 77.8% respectively, the content of low-density lipoproteins decreased by 61.3% and 40.4% and 42.3%. Population maintenance equaled respectively 97.1%, 98.3% and 98.1%. At the end of the experiment, the egg productivity of laying hens of the first and second groups increased by 4% and 3.6% compared with the control. Therefore, intake of the hepaprotectors by laying hens stimulated their metabolism, positively influenced the blood parameters, survival and egg productivity. The conducted studies confirm the benefits of using hepatoprotectors for the prohylaxis of hepatosis of hens.

MCFA alleviate H2 O2 -induced oxidative stress in AML12 cells via the ERK1/2/Nrf2 pathway

Oxidative stress is an important factor in the occurrence and development of liver disease. Medium-chain fatty acids (MCFAs) have potential antioxidant function, whereas the exact underlying mechanism of MCFA in oxidative injury of hepatocytes remains unclear. In our present study, three different MCFAs, 8-carbon octanoic acid (OA), 10-carbon capric acid (CA), and 12-carbon lauric acid (LA), have been performed to observe their protective action for hepatocyte under the H₂ O₂ challenge. The result showed that MCFA treatment significantly increased the cell viability, T-AOC, and expression of antioxidant-related genes in AML12 cells under oxidative stress condition, and reduced reactive oxygen species (ROS) production. Moreover, MCFA treatment significantly increased the protein expression of Nrf2 and the phosphorylation level of ERK1/2; LA treatment significantly promoted the Nrf2 nuclear translocation. With a further test, the rescue ability of MCFA was blocked by treating with the ERK inhibitor U0126. Overall, our data suggested that MCFA treatment has positive impact on protecting AML12 cells against oxidative stress through ERK1/2/Nrf2 pathway.

Dietary herbaceous mixture supplementation reduced hepatic lipid deposition and improved hepatic health status in post-peak laying hens

Fatty liver hemorrhagic syndrome is characterized by hepatic damage and hemorrhage impairing animal welfare in birds, which was well-known to be moderately relieved through dietary choline chloride supplementation in laying hens. Chinese herb has been proven to exert a positive role on hepatic health in human and rodents. Here, we investigated the effect of herbaceous mixture (HM), which consists of Andrographis paniculate, Silybum marianum, Azadirachta Indica, and Ocimum basilicum (2:3.5:1:2), on the hepatic lipid metabolism and health status in laying hens. A total of 240 Hy-line Brown hens (389-day-old) were randomly fed the basal diet with 0 mg/kg choline chloride (negative control, NC), 1,000 mg/kg choline chloride (control, Ctrl), or 300 mg/kg HM for 28 d. Birds fed HM diet exhibited lower serum triglyceride (TG) and low-density lipoprotein cholesterol concentration, and higher high-density lipoprotein cholesterol level than those received NC and Ctrl diets (P < 0.05). When compared to control and NC group, the diets with HM decreased the contents of total cholesterol and TG in liver, as well as upregulated the mRNA abundance of hepatic hormone-sensitive lipase and lipoprotein lipase. Meanwhile, the hepatic area and diameter of steatosis vacuoles were also decreased by dietary HM administration (P < 0.05), which accompanied by decreased serum alanine aminotransferase activity (P < 0.05). Birds fed HM diets enhanced the hepatic antioxidative capacity than those received NC and Ctrl diet. Dietary HM depressed the mRNA level of inflammatory cytokine as compared to NC but not Ctrl group. Collectively, the diet with 300 mg/kg HM has a favorable effect in decreasing the lipid deposition and protecting liver injury by alleviating hepatic oxidant stress and inflammation in post-peak laying hens.

Effect of Antarctic krill phospholipid (KOPL) on high fat diet-induced obesity in mice

Phospholipids are the main lipid components in Antarctic krill oil, and the combination of n-3 polyunsaturated fatty acids (n-3 PUFAs) shows multiple nutritional advantages. At present, the research about Antarctic krill phospholipid (KOPL) mainly focuses on the purification, and there are few reports on the anti-obesity effect. Thus, this study aimed at evaluating the effect of KOPL on the high-fat diet (HFD)-induced obesity mice. All the mice were divided into five groups, which were fed chow diet, HFD, and different doses of KOPL + HFD, respectively. The results showed that KOPL treatment could reduce the weight gain, fat accumulation, and liver tissue damage in HFD-induced mice. KOPL treatment could reduce the levels of serum lipid (TC, TG, L-LDL) and fasting blood glucose in HFD-induced mice, and the inflammatory cytokines (IL-1β and TNF-α) in serum. Further analysis showed that KOPL could promote the normal expression of lipid-synthesis-related genes and proteins, including sterol regulatory element-binding protein-1c (SREBP-1c), fatty acid synthetase (FAS), and peroxisome proliferator-activated receptor alpha (PPAR-α) in liver tissue. Besides, it inhibited the overexpression of inflammatory cytokine genes (IL-1β and TNF-α), but increased the expression of tight junction genes (ZO-1 and Occludin) in the colon tissue. Additionally, KOPL improved the decrease of diversity and imbalance of intestinal microbiota, which could contribute to its beneficial effects. In summary, the KOPL treatment improves the effects of HFD-induced obese mice by maintaining normal lipid levels, protecting the liver tissue, reducing inflammation response and intestinal damage, and regulating intestinal microbiota abnormalities. It refer to KOPL could be a promising dietary strategy for treating obesity and improving its related metabolic diseases.

Choline and methionine supplementation in layer hens fed flaxseed: effects on hen production performance, egg fatty acid composition, tocopherol content, and oxidative stability

Choline is an essential nutrient in laying hen diets and is needed for the formation of phosphatidylcholine (PC), that serves as a rich source of long chain (≥20 C) n-3 fatty acids (FA) in eggs. Methionine (Met) is the first limiting amino acid in layer hen diets and serves as a lipotropic agent with antioxidant properties. The objectives of the current study is based on the hypothesis that choline and Met supplementation will enhance egg PC and n-3 FA status, lipid stability, and production indices in layer hens fed flaxseed. Ninety-six, 40-wk-old laying hens (W-36 White Leghorns) were randomly allocated to 4 treatment groups, with 6 replicates containing four hens per cage. Hens were fed corn-soybean meal-based diet containing 0% flaxseed (Control), 15/100 g flaxseed (Flax), Flax+50% more methionine requirement for W-36 White Leghorns (Flax+Met), or Flax+0.15g/100g choline chloride (Cho) (Flax+Cho). All experimental diets were isocaloric and isonitrogenous and fed for a period of 120 d. Egg production and egg mass (g/hen/d) was higher for Flax+Met and Flax+Cho when compared to Flax and Control (P < 0.05). Egg weight was greater (P < 0.05) among hens fed the Control and Flax+Cho diets compared to Flax diet. Feeding flaxseed to hens led to over 6-fold increase in total n-3 FA. Choline supplementation increased egg α-tocopherol content (P < 0.05) while reducing lipid oxidation products measured as thiobarituric acid reactive substances in egg yolk (P < 0.05). Neither Met nor Cho had any impact on docosahexaenoic (22:6 n-3) acid concentration in eggs from hens fed flaxseed. However, addition of Met and Cho to layer diets increased docosapentaenoic acid (22:5 n-3) levels in eggs from hens fed flaxseed (P < 0.05). The PC content was lower in Control and Flax+Met (P < 0.05) when compared to Flax+Cho group. No difference was found in total lipid or phosphatidylethanolamine content of eggs (P > 0.05). The results from the current study suggest that n-3 FA content of egg yolk can be greatly increased by feeding flaxseed but reduced egg production. However, dietary Met and Cho can improve production performance in hens fed flaxseed-containing diets. Addition of Cho to flaxseed increased in egg weight, yolk α-tocopherol levels, PC content and oxidative stability of eggs when compared to hens fed flaxseed. Met and choline could be used in flaxseed (>15%) to increase egg production and egg mas.

Serum metabolomics in chickens infected with Cryptosporidium baileyi

Background

Cryptosporidium baileyi is an economically important zoonotic pathogen that causes serious respiratory symptoms in chickens for which no effective control measures are currently available. An accumulating body of evidence indicates the potential and usefulness of metabolomics to further our understanding of the interaction between pathogens and hosts, and to search for new diagnostic or pharmacological biomarkers of complex microorganisms. The aim of this study was to identify the impact of C. baileyi infection on the serum metabolism of chickens and to assess several metabolites as potential diagnostic biomarkers for C. baileyi infection.

Methods

Ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) and subsequent multivariate statistical analysis were applied to investigate metabolomics profiles in the serum samples of chickens infected with C. baileyi, and to identify potential metabolites that can be used to distinguish chickens infected with C. baileyi from non-infected birds.

Results

Multivariate statistical analysis identified 138 differential serum metabolites between mock- and C. baileyi-infected chickens at 5 days post-infection (dpi), including 115 upregulated and 23 downregulated compounds. These metabolites were significantly enriched into six pathways, of which two pathways associated with energy and lipid metabolism, namely glycerophospholipid metabolism and sphingolipid metabolism, respectively, were the most enriched. Interestingly, some important immune-related pathways were also significantly enriched, including the intestinal immune network for IgA production, autophagy and cellular senescence. Nine potential C. baileyi-responsive metabolites were identified, including choline, sirolimus, all-trans retinoic acid, PC(14:0/22:1(13Z)), PC(15:0/22:6(4Z,7Z,10Z,13Z,16Z,19Z)), PE(16:1(9Z)/24:1(15Z)), phosphocholine, SM(d18:0/16:1(9Z)(OH)) and sphinganine.

Conclusions

This is the first report on serum metabolic profiling of chickens with early-stage C. baileyi infection. The results provide novel insights into the pathophysiological mechanisms of C. baileyi in chickens.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04834-y.

Comparative Analysis of Metabolites in the Liver of Muscovy Ducks at Different Egg-Laying Stages Using Nontargeted Ultra-High-Performance Liquid Chromatography-Electrospray Mass Spectrometry-Based Metabolomics

Liver plays an important physiological function in the synthesis of yolk materials during egg laying in birds. Liver metabolite profiles of Muscovy ducks at different egg-laying stages from the perspective of nontargeted metabolomics were analyzed in this study. Twelve Muscovy ducks were selected at pre-laying (22 weeks, TT group), laying (40 weeks, FT group), and post-laying (60 weeks, ST group) stages, resulting in 36 hepatic metabolite profiles by using ultra-high-performance liquid chromatography-electrospray mass spectrometry. A total of 324 differential metabolites (156 increased and 168 decreased) in FT as compared to the TT (FT/TT) group and 332 differential metabolites (120 increased and 212 decreased) in ST as compared to the FT (ST/FT) group were screened out. Metabolic pathways enriched in FT/TT and ST/FT groups were mainly amino acid metabolism, glycerophospholipid metabolism, nucleotide metabolism, and vitamin metabolism. The amino acid metabolism pathways were upregulated in the FT/TT group and downregulated in the ST/FT group (P < 0.05). The glutathione and ascorbic acid abundances were downregulated, and the choline abundance was upregulated during egg laying (P < 0.05). The liver provides amino acids, lipids, nucleotides, vitamins, and choline, and so on, which are essential materials for yolk precursor synthesis. The decrease in the abundance of glutathione and ascorbic acid indicates that Muscovy ducks might be in a relatively stable physiological state during egg laying.