Search Results (49)

The deterioration of uterine calcium transport capacity induced by aging is a common problem for late-laying period hens, causing decline in eggshell quality. This study aimed to investigate the effects and possible regulatory mechanisms of dietary puerarin (PU) on calcium transport and eggshell quality in aged hens. Two hundred eighty-eight Hubbard Efficiency Plus broiler breeder hens (50-week-old) were randomly allocated to three dietary treatments containing 0, 40, or 200 mg/kg puerarin (PU), with 8 replicates of 12 birds each, for an 8-week trial. The results demonstrated that dietary PU ameliorated the eggshell thickness and strength, which in turn reduced the broken egg rate (p < 0.05). Histological analysis showed that PU improved uterus morphology and increased epithelium height in the uterus (p < 0.05). Antioxidative capacity was significantly improved via upregulation of Nrf2, HO-1, and GPX1 mRNA expression in the uterus (p < 0.05), along with enhanced total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-PX) activity, and decreased levels of the oxidative stress marker malondialdehyde (MDA) (p < 0.05). Meanwhile, PU treatment reduced the apoptotic index of the uterus, followed by a significant decrease in expression of pro-apoptotic genes Caspase3 and BAX and the rate of BAX/BCL-2. Additionally, calcium content in serum and uterus, as well as the activity of Ca²⁺-ATPase in the duodenum and uterus, were increased by dietary PU (p < 0.05). The genes involved in calcium transport including ERα, KCNA1, CABP-28K, and OPN in the uterus were upregulated by PU supplementation (p < 0.05). The 16S rRNA gene sequencing revealed that dietary PU supplementation could reverse the age-related decline in the relative abundance of Bacteroidota within the uterus (p < 0.05). Overall, dietary PU can improve eggshell quality and calcium transport through enhanced antioxidative defenses and mitigation of age-related uterine degeneration. Full article

The improvement in poultry production performance varies with different microbial strains used in fermented feed. This study investigates the efficacy of Lactiplantibacillus-plantarum-ZG7-fermented feed (ZG7-FF) on the productivity of laying hens. Results indicated that ZG7-FF significantly reduced the daily feed intake while increasing egg weight and decreasing the feed-to-egg ratio during peak production (p < 0.05), in addition to enhancing the late-phase laying rate (p < 0.05). Further intestinal morphological results showed that ZG7-FF significantly increased the length of villi in each intestinal segment, most significantly in the duodenum and jejunum (p < 0.01). ZG7-FF also significantly increased the abundance of the phylum Desulfobacterota, while showing a notable increase in the abundance of Cyanobacteria. Conversely, there was a significant reduction in the abundance of intestinal Firmicutes (p < 0.05), specifically Limosilactobacillus and Ligilactobacillus. The LEfSe (LDA Effect Size) analysis indicated that the differential species in the duodenum associated with ZG7-FF are primarily Bifidobacteriales and Aeriscardovia. In contrast, the jejunum is predominantly composed of Cyanobacteria, while the colon is mainly characterized by Enterococcus. Non-targeted metabolomics revealed that ZG7-FF drives the suppression of key metabolites, including 3-hydroxybutyric acid, ethylnitronate, 6-chlorocoumarin-3-carboxylic acid, lotaustralin, and oleoylcarnitine, while enriching pathways related to amino acid metabolism. The downregulated metabolites were functionally linked to ABC transporters and neuroactive ligand–receptor interactions. Correlation analyses demonstrated positive associations between Limosilactobacillus/Ligilactobacillus and suppressed metabolites, whereas Enterococcus and chloroplast-related taxa exhibited negative correlations. In summary, the administration of ZG7-FF significantly enhances intestinal morphology, reduces feed intake, increases egg weight, decreases ingredient usage, elevates the abundance of intestinal Enterococcus, and diminishes the overall microbial load. Full article

The modern livestock industry faces significant challenges due to the extension of production cycles and a growing shortage of feed resources. Low-protein (LP) diets offer potential environmental advantages whereas damage intestinal integrity and increase pro-inflammatory cytokines. Bile acids (BAs), metabolic products of cholesterol in the liver, possess strong antioxidative and immune properties. This study evaluated the effects of dietary porcine BA supplementation at different protein levels on the antioxidant status, immune function, and gut microbiota of late-laying hens. A 2 × 2 factorial design was employed with 198 Hy-Line Brown laying hens (62 weeks old), randomly divided into one of four treatment groups with 8 replicates for each treatment. Diets included normal (16.42%) or low-protein (15.35%) levels, with porcine BAs supplemented at 0 or 120 mg/kg (62–69 weeks) and 0 or 200 mg/kg (70–75 weeks) over 14 weeks. Dietary protein levels and bile acids had no effect on organ development in laying hens. Low-protein diets increased serum anti-inflammatory cytokines IL-4 and IL-10 but elevated pro-inflammatory cytokines IL-1β (p < 0.05), corroborated by higher IL-10 gene expression in the ileum mucosa (p < 0.05). The supplementation of bile acids improved immune function by increasing serum IL-4 and TGF-β while decreasing IL-6 levels (p < 0.05). Moreover, bile acids treatments upregulated IL-10, TGF-β and ZO-1 gene expression in the ileum mucosa (p < 0.05) and alleviated oxidative stress by enhancing serum GSH-Px activity (p < 0.05). Additionally, both low-protein diets and bile acids enriched beneficial cecal bacteria, including Hungatella and Blautia, primarily linked to immune function. These findings demonstrate that porcine bile acids administration improve antioxidant capacity, immune function and gut microbiota dysbiosis. These beneficial effects were associated with Hungatella and Blautia levels, which may be responsible for the porcine bile acids efficacy in poultry nutrition. Full article

This study evaluated the effects of kaempferol (KAE), and vitamin E (VE) on the performance, reproductive hormones, and the composition of the cecum and uterus microbiota in late-laying hens. A total of 192 49-week-old Jinghong No. 1 laying hens were randomly divided into four groups, with six replicates in each group and eight laying hens in each replicate, pre-reared for one week and formally tested for ten weeks. The CON group was fed basal diets, the VE group, the KAE group, and the KAE + VE group were fed a basal diet to which was added 0.2 g/kg VE, 0.4 g/kg KAE, and 0.2 g/kg VE + 0.4 g/kg KAE, respectively. The results are as follows. Compared to the CON group, the VE group, the KAE group, and the KAE + VE group significantly increased the egg production rate, average daily egg weight and significantly decreased the feed-to-egg ratio. The VE + KAE group significantly improved the Haugh unit. The VE group, the KAE group, and the KAE + VE group considerably enhanced the eggshell strength, eggshell relative weight, eggshell thickness, yolk color, and relative yolk weight. The serum E₂ and LH levels of the KAE group and the KAE + VE group and the serum FSH levels of the KAE + VE group were significantly higher. In the ovary, the KAE group and the KAE + VE group’s ESR1 gene expression levels were significantly higher, and the KAE + VE group’s FSHR gene expression levels were markedly higher. In the uterus, the KAE group and the KAE + VE group’s ESR1 gene expression levels were dramatically higher, and the KAE + VE group’s ESR2 and FSHR gene expression levels were significantly higher. 16S rRNA gene sequencing revealed a significant aggregation of cecum and uterus colonies in the Beta diversity PCoA. In the cecum, Firmicutes, Bacteroidetes, and WPS-2 were the dominant phylums. In the uterus, the Firmicutes, Proteobacteria, and Bacteroidetes were the dominant phylums. The KAE + VE group’s F/B was significantly higher at the phylum level than in the CON group and the VE group. In summary, the addition of VE and KAE to the diet can improve the production performance of late-laying hens, increase the content of reproductive hormones, and stabilize the cecal and uterus microbiota, which may be related to the hormone and microbiota linkage of the gut–uterus axis. Full article

This research evaluated the impact of incorporating dried olive pulp (OP) into the feed of laying hens on the fatty acid profile, cholesterol, triglyceride, total phenolic, oleuropein and hydroxytyrosol content, and health lipid indices of eggs produced by mid- (39 weeks) and late-laying (59 weeks) birds. Over a 36-week trial, 300 eggs from 180 Isa-Brown hens, assigned to three dietary groups with different OP levels (CON, OP4 and OP6), were analyzed. OP reduced egg cholesterol, with significant effects in late-age eggs (p < 0.05). In mid-age hens, the OP6 eggs had higher total phenolics than the controls (p < 0.05) and more PUFAs than the other groups (p < 0.05). The concentration of total phenolics, cholesterol, n3 PUFAs and % fat increased with hen age (p < 0.05), while triglycerides and oleuropein decreased (p < 0.05). With increasing hen age, the SFAs in the OP eggs decreased (p < 0.05) and the MUFAs increased (p < 0.05). Eggs from older hens had higher nutritional value, as indicated by the lower n6/n3 PUFA ratio, lower AI and TI indices, and higher h/H ratio (p < 0.05). Overall, dietary OP supplementation improved the nutritional quality of eggs, suggesting potential health benefits. Our results also highlighted eggs from older hens as a valuable source of high-quality fats. Full article

Multiply adverse effects including declines in production performance and excessive fat deposition were noticed with the extension of the laying cycle in hens, which are pertinent to animal welfare and human food safety. This study aimed to investigate the effect of dietary supplementation of bile acids (BAs) on production performance and lipid metabolism in late-phase laying hens. A total of 144 70-week-old hens were distributed into three treatments with eight replicates per treatment, including the basal diet with 0 (Ctrl), 95.01 (Low-BA), and 189.99 mg/kg (High-BA) of porcine BAs, respectively. The test period was from 70 to 75 weeks. The supplementation of BAs did not significantly alter laying performance during the trial, whereas it increased (p < 0.05) the total follicles compared to the Ctrl diet. The eggs from the hens fed the BA diet exhibited increased (p > 0.05) relative weight of eggshell and yolk color than those that consumed the Ctrl diet. There were no significant changes following BA treatment regarding the serum lipid profile. Dietary BA treatment reduced the total triglyceride in livers to different extents, resulting in the decreased diameter and area of vacuoles in liver tissues. The low-dose BA treatment decreased the mRNA levels of fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD), while promoting the expression of lipoprotein lipase (LPL) compared to the Ctrl group (both p < 0.05). Of note, the expressions of farnesoid X receptor (FXR), apical sodium-dependent bile acid transporter (ASBT), and ileum bile acid-binding protein (IBABP) were notably downregulated (p < 0.05) by the low-dose BA treatment. Dietary BA treatment had no apparent effects on laying performance, whereas it increased the follicle frequency, eggshell weight, and yolk color. Moreover, a diet containing 95.01 mg/kg of BAs depressed ileal BA resorption and hepatic fatty deposition by reducing lipogenesis and promoting lipolysis, which may have a beneficial effect on the liver in late-phase layers. Full article

Improving egg quality is one of the main objectives of the poultry industry. The objective of this study was to investigate the effects of dietary oregano oil supplementation with different concentrations on the egg quality, intestinal morphology and cecal microbiome of late-phase laying hens. A total of 300 55-week-old Snowy white laying hens were randomly divided into five groups and fed a basal diet (control) or basal diets supplemented with oregano oil at 25, 50, 75 and 100 mg/kg (O25, O50, O75 and O100) over a 100-day period. Compared with the control group, eggshell thickness and eggshell weight were increased significantly in eggs when oregano oil was added (p < 0.05). The highest content of polyunsaturated fatty acids (PUFAs) and C18:2n6c was observed in yolks with 25 mg/kg supplement among 5 groups (p < 0.05). The highest average content of riboflavin in egg yolk and thiamine in egg white was observed in the O25 group (p < 0.05). When the supplemental levels of oregano oil were 25 mg/kg and 50 mg/kg, the selenium and phosphorus content in the egg was significantly increased (p < 0.05). The ratio of villus height to crypt depth (V/C) and villus height of the small intestine was significantly increased compared with the chickens fed the basal diet (p < 0.05). Compared with the control group, the abundance of Megamonas was increased in the O50 group (p < 0.05). The unclassified_o__Bacteroidales in the O25 group were significantly higher than those in the other four groups (p < 0.05). These differential microorganisms were significantly correlated with egg quality characteristics. Dietary supplementation of oregano oil can significantly improve egg quality via gut microbiota alteration in laying hens. Full article

This study examined the influence of chlorogenic acid (CGA) on gut antioxidant status, morphology, barrier function, immunity, and cecal microbiota in late-peak laying hens. A total of 240 Hy-Line Brown hens, aged 43 weeks, were randomly assigned to four groups, the basal diet +0, 400, 600, and 800 mg/kg CGA, for 12 weeks. The results revealed that CGA significantly reduced ileal H₂O₂ and malondialdehyde levels; increased duodenal height, ileal villus height, and villus height-to-crypt depth ratio; while decreasing jejunal crypt depth. The 600 and 800 mg/kg CGA significantly upregulated the duodenal, jejunal, and ileal ZO-1 and occludin gene expression; increased IgG levels in serum and ileum; and upregulated ileal IgA gene expression. The 600 mg/kg CGA significantly upregulated CD3D and CD4 gene expression, while downregulating IL-1β gene expression in duodenum, jejunum, and ileum. Moreover, CGA changed the gut microbiota structure. The SCFA-producing bacteria unclassified_f__Peptostreptococcaceae, unclassified_f_Oscillospiraceae, Pseudoflavonifractor, Lachnospiraceae_FCS020_group, Oscillospira, Elusimicrobium, Eubacterium_ventriosum_group, Intestinimonas, and norank_f_Coriobacteriales_Incertae_Sedis were significantly enriched in the 400, 600, and/or 800 mg/kg CGA groups. The bacteria Lactobacillus, Bacillus, and Akkermansia were significantly enriched in the 600 mg/kg CGA group. Conclusively, dietary CGA (600–800 mg/kg) improved intestinal antioxidant status, morphology, barrier and immune function, and beneficial microbiota growth in late-peak laying hens. Full article

The cuticle covering the outer surface of an eggshell functions as both a physical and chemical barrier against invading microorganisms. Contamination of eggs by microbial pathogens progresses in four stages: bacterial attachment to the egg surface, penetration through the cuticle and eggshell, multiplication within the underlying membranes, and the final stage of contaminating the egg contents. Therefore, it is important to study bacterial count at the first point of contact, i.e., on the surface of the eggs. In this study, we have evaluated the impact of differences in cuticle quality (due to egg washing and hen age) on bacterial load. We compared bacterial adherence on the eggshell surface of white eggs which were either washed (graded) or unwashed (ungraded), collected from Lohmann laying hens of different ages: early (24–28 weeks), mid-lay (44–48 weeks), and late (66–70 weeks). We aimed to determine the impact of hen age and egg washing on differences in cuticle quality and bacterial adherence. Our results indicate that hen age (up to 70 weeks) and commercial egg washing do not significantly impact bacterial adherence on eggshell surfaces. We have developed a novel method using green fluorescent protein (GFP)-expressing Salmonella typhimurium to estimate adherence of bacteria to the eggshell surface, with independent measurement of autofluorescence to quantitate cuticle deposition. S. typhimurium were localized, adhering to cracks visible on the outer cuticle in ungraded eggs, indicating that egg-associated pathogens usually enter the egg interior either through respiratory pores in eggshells or through shell micro-cracks. The results of this study can be utilized to optimize innovative methods for predictive microbiology in order to achieve egg safety. Full article

This study aimed to investigate the effects of fermented blueberry pomace (FBP) on the intestinal barrier function and cecal microbiome of aged laying hens. A total of 320 Yukou Jingfen No. 8 laying hens (345-day-old) were randomly divided into a control group, 0.25% FBP group, 0.5% FBP group, or 1.0% FBP group. The results showed that the villus height (VH) in the jejunum of the 0.25–0.5% FBP groups and villus surface area in the jejunum of the 0.25% FBP group were higher (p < 0.05), while 0.25% FBP supplementation displayed a higher (p = 0.070) VH in the ileum compared to the control group. Mucin-2 expression was upregulated (p < 0.05) in the jejunum of the 0.5% FBP group and the ileum of the 0.25–0.5% FBP groups. Compared to the control group, interleukin (IL)-4 and IL-13 expressions were upregulated (p < 0.05) in the 1.0% FBP group. Microbiota analysis revealed that Prevotella abundance in the cecum of the 0.5–1.0% FBP groups was higher (p < 0.05) than in the 0.25% FBP group. In addition, microbial function prediction analysis showed that cecal microbiota in the 0.25% FBP group were mainly enriched by alanine/aspartate/glutamate metabolism and methane metabolism. Moreover, Spearman’s correlation analysis revealed the potential correlations between the abundance of the cecal microbiota and intestinal-barrier-function-related gene expressions, as well as the short-chain fatty acid content, of laying hens. In summary, dietary FBP supplementation enhanced intestinal barrier function by improving intestinal morphology, upregulating gene expressions related to barrier function, and altering the cecal microbiota of aged laying hens. Full article

(1) Background: Improving feed efficiency and the vitality of the reproductive system in the late stage of the egg-laying period is of great significance for prolonging the egg-laying cycle and improving egg quality. In the present study, a new flavonoid, which was extracted from kudzu leaf, was chosen to investigate its effects on the productive performance and egg quality of late-laying hens. (2) Methods: A total of 360 500-day-old Hy-Line Brown layer hens were randomly divided into a control treatment group (no KLF supplementation), and groups that received 0.2%, 0.4%, 0.6%, 0.8%, and 1.0% KLF supplement treatments. Each treatment contained 6 replicates, with 10 hens in each replicate. Productive performance metrics, including the daily egg production, egg weight, the number of deformed eggs, egg quality, egg density, egg shape index, eggshell strength, yolk color, and the Haugh unit, were meticulously recorded for each replicate. Furthermore, microbial communities and hypothalamus gene expressions were investigated based on the results of the productive performance and egg quality. (3) Results: KLF supplementation significantly decreased the deformity rate while significantly increasing the eggshell strength in the finishing phase afterward (p < 0.05). Specifically, hens supplemented with 0.6% KLF possessed the lowest deformed egg rate. KLF supplementation significantly increased the relative abundances of Bifidobacterium sp., Blautia sp., Lactococcus sp., and Lactobacillus sp., while significantly decreasing Parasutterella sp. and Escherichia-Shigella sp. (p < 0.05). Furthermore, the interactive analysis showed the hypothalamus gene expression mainly interacted with probiotics, such as Bifidobacterium sp. and Lactobacillus sp., through ribosome biogenesis, nucleocytoplasmic transport, and cAMP signaling pathways. (4) Conclusions: The findings of the present study indicate that KLF supplementation significantly proliferated probiotics, such as Bifidobacterium and Lactobacillus, which may have further interacted with hypothalamus genes, thus decreasing the deformity rate while increasing eggshell strength in the finishing phase. Full article

To tease apart differences between conventional cage (CC) and cage-free (CF) housing systems, this study focuses on the effects of excreta exposure and age by comparing microbial communities, intestinal permeability, and corticosterone in hens in enriched colonies (EC) and CF housing systems during early- and late-lay. Hens were randomly selected from two rooms of CF (n = 20) and EC (n = 20) at 35 and 76 weeks of age. One hour following an oral gavage of fluorescein isothiocyanate dextran (FITC-D), hens were euthanized, and ileal contents and blood were collected. Serum FITC-D using a fluorescent spectrophotometer and corticosterone using a commercial competitive ELISA kit were analyzed. Following DNA isolation from the ileum contents, the V4 region of the 16S rRNA gene was sequenced. Sequence data were filtered in Mothur v1.43.0, followed by de novo operational taxonomic unit (OTU) clustering and classifying with the SILVA SSU v138 reference database. Serum FITC-D was altered by housing type, age of hens, and the interaction between housing type and age of hens (p < 0.001), with 76-week-old hens housed in EC having the highest FITC-D. Corticosterone increased with age (p = 0.023). Microbial community diversity measurements favored hens housed in the CF housing system as ileal contents tended to have increased species evenness (p = 0.008) and greater alpha diversity (p = 0.006). The majority of the over-representation of OTUs were associated with peak lay. Full article

This study investigated the effects of the β-mannanase enzyme and soyhulls on production performance, economics, egg quality, hematology and serum biochemistry, nutrient digestibility, gut morphology, digesta viscosity, and excreta consistency in laying hens during the late peak production phase (37 to 40 weeks of age). Golden brown hens (RIR × Fayoumi; n = 200) were fed a control diet (no soyhulls or enzymes) and diets containing four combinations, i.e., 3% soyhulls with 20 mg/kg β-mannanase (D1), 3% soyhulls with 30 mg/kg β-mannanase (D2), 9% soyhulls with 20 mg/kg β-mannanase (D3), and 9% soyhulls with 30 mg/kg β-mannanase (D4), for four weeks in four replicates of 10 birds each. Overall, a significantly higher (p < 0.05) feed intake, weight gain, feed conversion ratio, and water intake were calculated in the D2 group as compared to the control and remaining combinations of soyhulls and β-mannanase. No mortality was recorded during the entire experiment. Economically, the D1 and D2 groups showed the best results as compared to the D3 and D4 groups. Egg quality parameters like egg weight, shell weight and shell thickness, yolk weight, albumen weight and height, and the Haugh unit remained unchanged (p > 0.05). Similarly, the D2 group showed significantly lower total cholesterol, LDL, and VLDL levels and enhanced gut morphology with greater villus width, height, crypt depth, and surface area across intestinal segments. Crude protein (CP), crude fiber (CF), crude fat, and ash digestibility were higher (p < 0.05) in the D1 and D2 groups compared to the control. Digesta viscosity, excreta consistency, and other egg quality parameters remained unaffected. In conclusion, the dietary inclusion of a combination of 3% soyhulls and 30 mg/kg β-mannanase may have potential benefits for laying hens by improving some production performance and egg quality indicators and economics, lowering blood cholesterol, LDL, and VLDL levels, enhancing nutrient digestibility, and improving gut morphology without affecting egg quality. Full article

Eggs are a vital dietary component for humans, and it is beneficial to increase egg production to support poultry farming. Initially, the egg production rate rises rapidly with young hens until it reaches its peak, and then it declines gradually. By extending the duration of peak egg production, the hens’ performance can be enhanced significantly. Previous studies found dynamic changes in gut microbiota during egg-laying, and several species of microbiota isolated from the chicken gut improved egg-laying performance. However, the interaction between microbes and host gene expression is still unclear. This study provides a more comprehensive understanding of chicken egg-laying by examining dynamic alterations in the microbiota of the entire intestinal tract (i.e., duodenum, jejunum, and ileum) and gene expression. The microbial community in the intestine underwent significant changes during different egg-laying periods (i.e., pre-, peak-, and late-laying periods). Metagenomic functional analysis showed that the relative abundance of biosynthesis of amino acids, secondary metabolites, and cofactors decreased significantly in the duodenum, jejunum, and ileum of aging hens. The relative levels of aldosterone, GnRH, insulin, growth hormone, and other hormone-related pathways increased dramatically in the intestinal microbiota during egg-laying, but only in the microbiota located in the duodenum and ileum. Transcriptome analysis suggested that genes associated with various transport processes were upregulated consistently in the small intestine during egg-laying; genes involved in the development of intestinal structure were down-regulated; and genes involved in response to DNA damage and stress were consistent with changes in laying rate. The abundance of Lactobacillus was related to the expression of ANGPTRL1, ANGPTRL2, ANGPT1L, and NOXO1 in the duodenum; Muricomes was correlated significantly with NFKBIZ, LYG2, and IRG1L expression in the jejunum; and Campylobacter was correlated positively with the expression of KMT2A and USF3 in the ileum. These results indicated that the intestinal microbiota and host gene expression may influence egg production jointly. Full article

Ca and P homeostasis across the egg-laying cycle is a complex process involving absorption in the small intestine, reabsorption/excretion in the kidneys, and eggshell gland secretion. Diets with inadequate calcium and phosphorus can interfere with their absorption and digestibility, resulting in eggshell quality losses and reduced productive life, affecting egg production and welfare. A better understanding of gene expression profiles in the kidneys of laying hens during the late egg-laying period could clarify the renal role in mineral metabolism at this late stage. Therefore, the performance, egg quality and bone integrity-related traits, and expression profiles of kidney candidate genes were evaluated in 73-week-old laying hens receiving different Ca and P ratios in their diet: a high Ca/P ratio (HR, 22.43), a low ratio (LR, 6.71), and a medium ratio (MR, 11.43). The laying hens receiving the HR diet had improved egg production and eggshell quality traits compared to the other two groups. Humerus length was shorter in the HR than in the other groups. The CYP24A1 and TRPC3 genes were differentially expressed (p.adj ≤ 0.05) among the groups. Therefore, their expression profiles could be involved in calcium and phosphate transcellular transport in 73-week-old laying hens as a way to keep mineral absorption at adequate levels. Full article