Aging is a major contributor to the decline in egg quality, with uterine inflammaging playing a key role in this process. Implementing anti-aging strategies to prevent uterine inflammaging and sustain optimal eggshell quality is imperative. This study aimed to characterize age-related changes in the eggshells and uteri of hens at different laying stages and the regulatory effect of baicalin (BAI). Uterine inflammaging became progressively more evident with advancing hen age, as indicated by fibrosis of the lamina propria connective tissue, decreased height and width of primary uterine folds (P < 0.05), an increased immunohistochemically positive area for the age-related protein p53, a component of the p53/p21 pathway involved in cellular senescence, elevated expression levels of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), and decreased messenger RNA (mRNA) expression of the longevity gene sirtuin 1 (SIRT1) (P < 0.05). Additionally, uterine inflammaging was associated with decreased eggshell thickness and breaking strength and with ultrastructural deterioration (P < 0.05). Conversely, in vivo, BAI treatment alleviated uterine inflammaging, mainly reflected in reduced secretion of the proinflammatory cytokines interleukin-1 beta (IL-1β), IL-6, and interleukin-8 (IL-8) and reduced expression of TNF-α, IL-1β, p53, and p21 (P < 0.05). SIRT1 mRNA expression was significantly increased after BAI treatment (P < 0.05). Furthermore, BAI ameliorated eggshell ultrastructure, with fewer type B mammillary knobs and increased effective-layer thickness; it also increased eggshell thickness and breaking strength (P < 0.05). In vitro, compared to uterine epithelial cells cultured with β-galactosidase, BAI pretreatment increased cell viability, decreased the positive staining rate of senescent cells, downregulated the relative expression of IL-6, IL-1β, TNF-α, p53, and p21, and increased SIRT1 mRNA levels (P < 0.05). Overall, uterine inflammaging was closely associated with age-related deterioration in eggshell quality, and BAI administration was associated with improved eggshell quality and reduced uterine inflammaging.

Alleviating hepatic lipid deposition in aging laying hens is critical for maintaining liver health and extending their productive lifespan. This study aimed to identify potential indicators and elucidate the underlying mechanisms associated with liver fat accumulation. Hepatic lipid ratio is a key indicator of the lipid deposition in the liver. A total of 509 healthy G1 line hens at 66 weeks of age were assessed for hepatic lipid ratio and stratified into three groups: low (L, <5%), medium (M, 5-10%), and high (H, >10%). The results revealed that the correlation coefficients of liver triglyceride (TG) and total cholesterol (TC) with the hepatic lipid ratio were 0.907 and 0.870, respectively, indicating a strong and highly significant association. All three metrics differed significantly among the three groups (P < 0.01), validating the grouping approach. Compared with the L group, the M and H groups showed significantly higher body weight, abdominal fat weight, abdominal fat index, plasma TG, TC, and LDL-c (P < 0.05), while plasma HDL-C was significantly lower in group H compared with groups L and M (P < 0.05). Abdominal skinfold thickness differed significantly across all groups (P < 0.05). Transcriptomic analysis revealed 115 up-regulated and 50 down-regulated genes in the H group compared with the L group. We identified: four genes (PCSK9, ABCG8, G6PC2, FOLH1) were associated with lipid metabolism; three (IL1RAPL1, TNIP2, HPSE2) with inflammatory response; five (CCL3, CCL17, CCL20, SAMSN1, ICOS) with immune response; and six (HBA1, HBAD, HBBA, CHAC1, CREG1, DDIT4) with antioxidant function. KEGG pathway analysis highlighted enrichments in lipid metabolism-related pathways such as "ABC transporters" and "Insulin secretion," as well as in the inflammatory response-related pathway "Cytokine-cytokine receptor interaction." In conclusion, body weight, abdominal skinfold thickness, plasma TG, TC, LDL-c, and HDL-c may serve as practical indicators for evaluating hepatic lipid deposition in laying hens. Excessive lipid accumulation perturbs hepatic metabolic homeostasis, triggering transcriptional reprogramming associated with both inflammatory and oxidative stress responses, alongside adaptive antioxidant defense and anti-inflammatory responses. However, further studies are required to determine whether these changes reflect a bona fide compensatory protective mechanism in the liver.

This study aimed to determine the effects of feeding patterns and dietary available phosphorus levels on laying performance, eggshell quality, calcium, and phosphorus metabolism in aged laying hens. The experiment followed a 3 × 2 factorial arrangement of three feeding patterns (feeding twice a day, 1/2 daily feeding at 8:00, and 1/2 daily feeding at 14:00; disequilibrium feeding twice a day, 1/3 daily feeding at 8:00, and 2/3 daily feeding at 14:00; feeding thrice a day, 1/3 daily feeding at 8:00, 1/3 daily feeding at 14:00, and 1/3 daily feeding at 18:00) and two available phosphorus levels (0.32 %, 0.27 %) was carried out with a total of 528 Hy-Line Brown laying hens aged 62–74 weeks. Each group had 8 replicates of 11 hens. The results revealed that feeding patterns and phosphorus levels significantly interacted with egg production ratios, soft shell and broken egg ratios in weeks 9–12 (P < 0.05). Feeding thrice a day and disequilibrium feeding twice a day significantly improved the equatorial and average eggshell thickness (P < 0.05), and had a trend of increasing eggshell strength at week 12 (P = 0.068). They also significantly increased the effective layer thickness and the calcified layer thickness of the eggshell (P < 0.05). Additionally, feeding thrice a day significantly increased serum calcium content compared with feeding twice a day (P < 0.05), and feeding thrice a day significantly increased the calcium content of the eggshell, mRNA expression level of CaBP-D28k in the uterine compared with the other two feeding patterns (P < 0.05). While disequilibrium feeding twice a day resulted in higher phosphorus content in the excreta compared with the other two feeding patterns (P < 0.05). These results indicated that feeding hens thrice a day with 0.27 % dietary available phosphorus level might improve in laying performance and eggshell quality of aged laying hens.

This study investigated the effects of astaxanthin (AST) supplementation in drinking water on the growth performance, intestinal barrier function, and cecal microbiota of broilers challenged with Salmonella Enteritidis. During the 20-day experiment, two hundred and forty 1-day-old male Arbor Acres birds were randomly assigned into a 2 × 2 factorial design with four groups: a non-challenged control (CON), an S. Enteritidis-challenged group (SA), a group receiving AST treatment (AST), and an S. Enteritidis-challenged group receiving AST treatment (SA+AST). Each treatment comprised six replicate groups, and challenged groups were inoculated with S. Enteritidis from day 2 to day 4. The results indicated that S. Enteritidis infection significantly reduced the average daily feed intake (ADFI) in broilers and adversely affected average daily gain (ADG) and feed conversion ratio (FCR) by day 20. AST supplementation significantly improved FCR. While S. Enteritidis infection did not significantly affect ileal mucosa antioxidation, it significantly decreased villus height and the villus height-to-crypt depth ratio (VCR), and significantly downregulated mRNA expression of ZO-1 and Occludin. However, AST supplementation significantly enhanced antioxidant capacity (T-AOC), increased villus height and VCR in the ileum, and notably upregulated ZO-1 and MUC2 expression levels, particularly mitigating the adverse effects of S. Enteritidis infection on ileal crypt depth. Furthermore, S. Enteritidis infection significantly affected both the α- and β-diversity of cecal microbiota. Infection with S. Enteritidis was associated with changes at the phylum level, including significant increases in Alistipes, unclassified_f__Lachnospiraceae, and bacteria of the Clostridia UCG-014 grouping, alongside notable decreases in Bacteroides, Akkermansia, Blautia, and Butyricicoccus. AST supplementation significantly decreased the abundance of norank_f__Ruminococcaceae and increased the abundance of Lachnoclostridium and unclassified_f__Lachnospiraceae in the challenged group. In conclusion, AST supplementation in drinking water could improve growth performance and intestinal health in broilers challenged with S. Enteritidis.

Disequilibrium feeding pattern, as a new feeding technique, more suitable for egg-laying physiology, was feeding two-thirds diet to hens after 14:00 every day without modifying diet nutrient levels and changing daily feed rationing, to better meet calcium requirement of hens during eggshell formation. To verifying its application on eggshell quality of aged laying hens, 288 Hy-line laying hens (average body weight 2.03 ± 0.09 kg) at the age of 70 wk, as experimental birds, were randomly allocated into four groups (6 replicates/group, 12 hens/replicate); the experiment for eight weeks used a 2 × 2 arrangement with the factors- dietary calcium level (3.5% and 3.0%) and feeding pattern (equilibrium and disequilibrium), and univariate general linear model to analyze the main effects. The disequilibrium feeding decreased average daily feed intake (ADFI) (P < 0.001) and feed conversion ratio (FCR) (P < 0.001) of hens from the age of 71 to 74 wk. Low dietary calcium level decreased eggshell proportion (P = 0.007), eggshell strength (P = 0.046), and average eggshell thickness (P = 0.025) of hens at the age of 74 wk. Noticeably, the ultrastructure measurement of equatorial section confirmed that disequilibrium feeding increased eggshell thickness of hens at the age of 78 wk by increasing palisade layer thickness (P = 0.013) and mammillae layer thickness (P = 0.018). Disequilibrium feeding improved eggshell ultrastructure, possibly by increasing dietary calcium utilization. Decreased calcium excretion in feces during the daytime and increased calcium deposition in bones at night showed a positive correlation with increased bone mineral density at night by disequilibrium feeding (P < 0.05). These results were attributed to modified intestinal integrity, improved intestinal permeability and calcium absorption, which occurred through the increased thickness of duodenal mucus layer (P = 0.006), up-regulated mRNA expression of intestinal permeability–related genes occludin (P = 0.031) and MUC-2 (P = 0.002), and some involved intestinal bacteria such as decreased Parabacteroides (P = 0.007) and increased Lachnoclostridium (P = 0.017) being beneficial to calcium absorption strength and mucosal inflammation. Disequilibrium feeding pattern could improve eggshell quality, which may provide a protection for suitable reduction in dietary calcium level in aged laying hens, not affecting eggshell quality, but reducing intestinal burden and improving welfare.

Fat has a high energy density, and excessive fatness has been recognized as a problem for egg production and the welfare of chickens. The identification of a genetic polymorphism controlling fat deposition would be helpful to select against excessive fatness in the laying hen. This study aimed to estimate genomic heritability and identify the genetic architecture of abdominal fat deposition in a population of chickens from a Dongxiang blue-shelled local breed crossbred with the White Leghorn. A genome-wide association study was conducted on abdominal fat percentage, egg production and body weights using a sample of 1534 hens genotyped with a 600 K Chicken Genotyping Array. The analysis yielded a heritability estimate of 0.19 ± 0.04 for abdominal fat percentage; 0.56 ± 0.04 for body weight at 72 weeks; 0.11 ± 0.03 for egg production; and 0.24 ± 0.04 for body weight gain. The genetic correlation of abdominal fat percentage with egg production between 60 and 72 weeks of age was −0.35 ± 0.18. This implies a potential trade-off between these two traits related to the allocation of resources. Strong positive genetic correlations were found between fat deposition and weight traits. A promising locus close to COL12A1 on chromosome 3, associated with abdominal fat percent, was found in the present study. Another region located around HTR2A on chromosome 1, where allele substitution was predicted to be associated with body weight gain, accounted for 2.9% of phenotypic variance. Another region located on chromosome 1, but close to SOX5, was associated with egg production. These results may be used to influence the balanced genetic selection for laying hens.

Pyrroloquinoline quinone disodium (PQQ·Na2) has been considered a human food supplement for human health promotion with its antioxidant properties. To determine whether PQQ·Na2 had similar functions to improve the antioxidant ability of layers and eggs, 180 laying hens were fed with 0 or 0.4 mg/kg PQQ·Na2 diets. Supplementation with PQQ·Na2 increased the albumen height, Haugh unit of the eggs. PQQ·Na2 also led to a higher glutathione peroxidase (GSH-Px) concentration in plasma and a lower malondialdehyde (MDA) content in the liver and egg yolk. Similarly, liver gene and protein expression of nuclear factor erythroid 2-related 2 (Nrf2) and heme oxygenase 1 (HO-1) were up-regulated by PQQ·Na2. Moreover, PQQ·Na2 increased the abundance of Firmicutes, Microbacterium, Erysipelatoclostridium, Mailhella, Lachnospiraceae_UCG-010, and Herbaspirillum in gut. Overall, these results suggested PQQ·Na2 increased the antioxidant ability of layers and eggs which might be in connection with the activation of the Nrf2/HO-1 pathway and optimized gut microflora.

试验旨在探讨密闭式鸭舍通风小窗的合理设置方案,通过对一种密闭式立体笼养肉鸭舍的通风小窗间距(d=1.00、2.00和3.00 m)、离地高度(h=3.00、3.45和3.90 m)及开合角度(α=50°、65°和80°)为研究参数进行CFD模拟分析.结果显示:密闭式立体笼养肉鸭舍通风小窗不同参数组合下其鸭舍内温度值分布均匀性变异系数在0.54%～1.42%,整体分布均匀性较好;温度分布特点表现为通风小窗下存在局部温度高于其他区域的温度区域,鸭舍内整体温度的渐变趋势表现为由鸭舍前端到后端舍内温度逐渐上升或先升后降.气流速度分布表现为不同水平高低截面,低截面到高截面的气流速度逐渐增大;纵向水平上,不同距离截面上气流受通风小窗开合角度的影响,气流集中于鸭舍上部,且因鸭舍上部建筑结构的阻碍,更多的气流流向远离进风一侧的鸭笼.密闭式立体笼养肉鸭舍通风小窗的最佳组合参数是间隔距离为3.00 m,安装高度为3.45 m,开合角为50°;对鸭舍内温度均匀性影响最大的是通风小窗间隔距离,其次是通风小窗开合角度,最后是通风小窗离地高度.综上,立体笼养肉鸭舍(99.0 m×16.5 m×4.50 m)通风小窗安装参数以间距为3.00 m、离地高度为3.45 m、开合角度为50°时能够获得较好的舍内温度均匀性.

Investigating the genetic footprints of historical temperature selection can get insights to local adaptation and potential influences of climate change on long-term population dynamics. Chicken is a significative species to study genetic adaptation on account of its similar domestication track related to human activity with the most diversified varieties. Yet, few studies have demonstrated the genetic signatures of its adaptation to naturally tropical and frigid environments. Here, we generated whole genome resequencing of 119 domesticated chickens in China including the following breeds which are in order of breeding environmental temperature from more tropical to more frigid: Wenchang chicken (WCC), green-shell chicken (GSC), Tibetan chicken (TBC), and Lindian chicken (LDC). Our results showed WCC branched off earlier than LDC with an evident genetic admixture between WCC and LDC, suggesting their closer genetic relationship. Further comparative genomic analyses SLC33A1 and TSHR genes exhibited stronger signatures for positive selection in the genome of the more tropical WCC. Furthermore, genotype data from about 3,000 African local ecotypes confirmed that allele frequencies of SNPs in these two genes appeared strongly associated with tropical environment adaptation. In addition, the NDUFS4 gene exhibited a strong signature for positive selection in the LDC genome, and SNPs with marked allele frequency differences indicated a significant relationship with frigid environment adaptation. Our findings partially unravel how selection footprints from environmental temperature stress can lead to advantageous genomic adaptions to tropical and frigid environments in poultry and provides a valuable resource for selective breeding of chickens and other domestic animals.

Our previous study screened out dietary 0.1% dimethylglycine (DMG), which had beneficial effects on egg production and fat deposition in laying hens during the late laying period. In this paper, it was further found that dietary DMG alleviated fatty liver disease and enhanced lipid deposited into the yolk while promoting hepatic lipid transport. There are intestinal estrogen-metabolizing bacteria (EBM) having β-glucuronase (GUS) activity that regulates the content of circulating estrogen (E2) in mammals. There were 39 related bacteria found in laying hens, and DMG increased E2 in blood, Staphylococcus abundance among EBM and GUS activity in cecum chyme. Interfered in situ, Staphylococcus with GUS activity was proved the target bacteria for DMG. Furthermore, E2 could modify hepatic lipid deposition through promoting lipid transport by the steatosis LMH model. These perspectives confirm that DMG, mediated by Staphylococcus, alleviates the restriction of hepatic lipid transport due to reduced levels of E2 in laying hens.

霉菌毒素(mycotoxins)是霉菌滋生产生的代谢产物,已了解的霉菌毒素多达300种以上.畜禽生产中常见的霉菌毒素主要有黄曲霉毒素(AFB1)、玉米赤霉烯酮(ZEA)、呕吐毒素(DON)、赭曲霉毒素A(OTA)、伏马毒素(FB)、T-2毒素.

Pyrroloquinoline quinone disodium (PQQ·Na2) has been considered a human food supplement for human health promotion with its antioxidant properties. To determine whether PQQ·Na2 had similar functions to improve the antioxidant ability of layers and eggs, 180 laying hens were fed with 0 or 0.4 mg/kg PQQ·Na2 diets. Supplementation with PQQ·Na2 increased the albumen height, Haugh unit of the eggs. PQQ·Na2 also led to a higher glutathione peroxidase (GSH-Px) concentration in plasma and a lower malondialdehyde (MDA) content in the liver and egg yolk. Similarly, liver gene and protein expression of nuclear factor erythroid 2-related 2 (Nrf2) and heme oxygenase 1 (HO-1) were up-regulated by PQQ·Na2. Moreover, PQQ·Na2 increased the abundance of Firmicutes, Microbacterium, Erysipelatoclostridium, Mailhella, Lachnospiraceae_UCG-010, and Herbaspirillum in gut. Overall, these results suggested PQQ·Na2 increased the antioxidant ability of layers and eggs which might be in connection with the activation of the Nrf2/HO-1 pathway and optimized gut microflora.

脂肪肝是动物常见的脂类代谢性疾病,它的发生与动物肝脏脂肪代谢紊乱有着密不可分的关系,可导致蛋鸡产蛋率严重下降、奶牛酮病和母猪胎衣不下等,给养殖业造成巨大的经济损失.褪黑素可参与脂肪代谢调节,缓解脂肪代谢紊乱,其在生产实践中的应用前景越来越广阔.本文介绍了脂肪肝产生的原因及机制,综述了褪黑素参与脂类代谢的机理以及外源褪黑素改善动物脂肪肝的研究进展,为褪黑素在畜牧业中的应用提供参考.

High-through chromosome conformation capture (Hi-C) technique is widely used to study the functional roles of the three-dimensional (3D) genome architecture of genomes. However, knowledge of 3D genome structure and its dynamic during extreme environments adaption remain poor. Here we characterized 3D genome architectures with Hi-C technique for chicken liver cells. By comparing Lindian chicken (LDC) liver cells with Wenchang chicken (WCC) liver cells, we discovered that environmental adaption contributed to the switching of A/B compartments, the reorganization of topologically associated domains (TADs) and TAD boundaries in both liver cells. Besides, analysis of the switching of A/B compartments combined with liver transcriptome revealed the corresponding changes of gene expression were strongly associated with extreme environment adaption-related pathways, including Tight junction, Notch signaling pathway, Vascular smooth muscle contraction, RIG-I-like receptor signaling pathway and Glycosphingolipid biosynthesis pathways. This study advanced our understanding of evolutionary role of chicken 3D genome architecture and their significance in genome activity and transcriptional regulation.

基于当前饲料"禁抗"、养殖"限抗、减抗"的畜禽生产环境,为了进一步了解在"限抗、减抗"环境下蛋鸡养殖企业的养殖现状和存在的问题,对江苏省9个地级市的63个蛋鸡养殖企业开展了本次调研,调研结果表明,在"限抗、减抗"环境下,蛋鸡健康问题仍旧普遍,调研中蛋鸡健康问题有9种,其中发生率较高的四种蛋鸡健康问题分别为应激,呼吸道疾病,消瘦、瘫痪及体重不达标和免疫力差,其占比分别为 24.60％,21.43％, 13.49％和11.90％.不同市区蛋鸡健康问题发生率差异结果表明,蛋鸡的健康需要良好的养殖环境与更精细的饲养管理技术.对蛋鸡养殖企业的替抗产品应用选择分析发现,增强免疫力和提升抗病力的替抗产品应用占比最高,分别为80.95％和71.43％;其次,提高消化率的替抗产品应用占69.84％;增强抗菌力的替抗产品应用占61.90％;调研发现,益生菌替抗产品成为当前蛋鸡养殖者最认可的替抗产品,其应用率达80.95％,高于中草药(77.78％),远高于酸化剂及其它替抗产品.

The high-throughput chromosome conformation capture (Hi-C) technique is widely used to study the functional roles of the three-dimensional (3D) architecture of genomes. However, the knowledge of the 3D genome structure and its dynamics during extreme environmental adaptations remains poor. Here, we characterized 3D genome architectures using the Hi-C technique for chicken liver cells. Upon comparing Lindian chicken (LDC) liver cells with Wenchang chicken (WCC) liver cells, we discovered that environmental adaptation contributed to the switching of A/B compartments, the reorganization of topologically associated domains (TADs), and TAD boundaries in both liver cells. In addition, the analysis of the switching of A/B compartments revealed that the switched compartmental genes (SCGs) were strongly associated with extreme environment adaption-related pathways, including tight junction, notch signaling pathway, vascular smooth muscle contraction, and the RIG-I-like receptor signaling pathway. The findings of this study advanced our understanding of the evolutionary role of chicken 3D genome architecture and its significance in genome activity and transcriptional regulation.

脂肪肝综合征是蛋鸡生产中一种常见的营养代谢性疾病,由长期的脂肪代谢障碍引起.主要由遗传、营养、管理、应激等诸多因素共同作用所致,发病原因较多,形成机制较为复杂,给其病因的研究及防治工作带来很大的困难.文章对蛋鸡脂肪肝综合征表现特征、发病原因、影响因素和防治措施进行了阐述,为蛋鸡脂肪肝的预防和治疗提供参考.

龙骨损伤是福利和健康受损的主要表现之一.文章从蛋鸡生产的角度出发,阐述了蛋鸡龙骨损伤的概况、蛋鸡龙骨损伤的研究现状及其对蛋鸡福利状况的影响,旨在呼吁重视蛋鸡龙骨损伤现象,促进蛋鸡产业的健康可持续发展.

本试验旨在研究一种不均衡饲喂方式对产蛋后期蛋鸡生产性能和蛋壳质量的影响,并通过检测血浆、粪便和胫骨钙含量的变化来解释该方式对蛋壳质量产生影响的原因.试验选取288只70周龄、体况健康的海兰褐蛋鸡,随机分为4个组,每组6个重复,每个重复12只鸡.正常钙水平常规饲喂方式组(NCA组)和正常钙水平不均衡饲喂方式组(NCD组)饲喂钙含量为3.5％的正常钙水平饲粮,低钙水平常规饲喂方式组(LCA组)和低钙水平不均衡饲喂方式组(LCD组)饲喂钙含量为3.0％的低钙水平饲粮;其中,NCA组和LCA组每天08:00和14:00平均投喂全天耗料量的饲粮,NCD组和LCD组每天08:00和14:00分别投喂全天耗料总量1/3和2/3的饲粮.试验预试期1周,正试期8周.结果表明,与常规饲喂方式相比:1)不均衡饲喂方式显著降低产蛋后期蛋鸡平均日采食量和料蛋比(P<0.05),而对产蛋率和平均蛋重无显著影响(P>0.05).2)不均衡饲喂方式显著提高蛋壳厚度、蛋壳重量和壳重比(P<0.05).3)不均衡饲喂方式能够显著提高蛋鸡夜间胫骨钙含量(P<0.05),并且有提高胫骨骨密度的趋势(P=0.060).4)不均衡饲喂有降低蛋鸡粪便中钙含量的趋势(P=0.075),在蛋壳钙沉积上与饲粮钙水平存在显著交互作用(P<0.05).由此可见,采用不均衡饲喂方式能够提高产蛋后期蛋鸡产蛋性能,降低骨钙动员,并且通过提高蛋鸡夜间对饲粮中钙的利用来促进蛋壳钙沉积,改善蛋壳质量.

蛋壳质量是评价蛋品质的重要指标,和鸡蛋的运输和保存过程中的破损率相关,且直接与种蛋的合格率、孵化率和鸡苗的健康密切相关,是影响蛋鸡生产效益的要素之一.蛋鸡老龄化是导致产蛋后期蛋壳质量下降的主要因素.特别是近年来,商品蛋鸡的产蛋周期大大延长,蛋鸡老龄化程度更高,这导致产蛋后期面临的蛋壳质量下降的问题更为严峻.本文对蛋壳的形成过程和钙代谢过程引起产蛋后期蛋鸡蛋壳质量下降的原因进行了概述,并对提高产蛋后期蛋壳质量的调控措施进行了总结和展望.