Blood-testis barrier (BTB) made of concomitant junction apparatus between Sertoli cells (SCs) is crucial for spermatogenesis. The tight junction (TJ) function is impaired in SCs with age, exhibiting an intimate relationship to testicular dysfunction induced by age. In this study, compared with those in young boars, TJ proteins (i.e., Occludin, ZO-1, and plus Claudin-11) were discovered to have reduced expressions in testes, and spermatogenesis ability declined in old boars. An in vitro age model for D-gal-treated porcine SCs was established, the performance of Curcumin as a natural antioxidant and anti-inflammatory compound in affecting the TJ function of SCs was appraised, and related molecular mechanisms were exploited. The results manifested that 40 g/L D-gal downregulated ZO-1, Claudin-11, and Occludin in terms of the expression in SCs, whereas Curcumin restored such expressions in D-gal-treated SCs. Using the AMPK and SIRT3 inhibiters demonstrated that activation of the AMPK/SIRT3 pathway was associated with Curcumin, which not only rescued the expression of ZO-1, Occludin, Claudin-11, and SOD2 but also inhibited the production of mtROS and ROS and the activation of NLRP3 inflammasome and release of IL-1β in D-gal-treated SCs. Furthermore, with mtROS scavenger (mito-TEMPO), NLRP3 inhibitor (MCC950) plus IL-1Ra treatment ameliorated D-gal-caused TJ protein decline in SCs. In vivo data also showed that Curcumin alleviated TJ impairment in murine testes, improved D-gal-triggered spermatogenesis ability, and inactivated the NLRP3 inflammasome by virtue of the AMPK/SIRT3/mtROS/SOD2 signal transduction pathway. Given the above findings, a novel mechanism where Curcumin modulates BTB function to improve spermatogenesis ability in age-related male reproductive disorder is characterized.

犬尿石症是一种十分常见的宠物营养代谢类疾病.文章通过收集北京农学院动物医院犬尿石症临床病例4例,跟进诊断与治疗过程,探讨最佳临床处理方法,旨在为临床医生和宠主提供明确的诊疗方向.通过查阅资料,进一步讨论分析了尿石症诊疗过程中的注意事项和预防措施.4例病例中1例手术治疗,3例保守治疗,目前均恢复良好.

Chicken meat quality and flavor are determined by abundant metabolites. In this study, HPLC-QTRAP-MS-based metabolomic analysis was used to evaluate the characteristic metabolites in the breast muscle of Beijing You chickens aged 56, 98, and 120 days. A total of 544 metabolites in 32 categories were identified, among which amino acids and organic acids were the most abundant. 60 and 55 differential metabolites were identified between 56 and 98 days of age, 98 and 120 days of age, respectively. The content of l-carnitine, l-methionine and 3-hydroxybutyrate increased significantly at 98 or 120 days of age. Arginine biosynthesis, purine metabolism, alanine, aspartic acid, and glutamic acid metabolism were important metabolic pathways that affect chicken meat flavor. This study can help to elucidate the metabolic mechanism of breast muscle during Beijing You chicken development and provide a theoretical reference for the improvement of chicken meat quality and flavor.

种公鸡的精子活力对养禽业的可持续发展至关重要,通过加权基因共表达网络(WGCNA)分析法挖掘种公鸡睾丸、附睾中调控精子活力的基因共表达模块和核心基因,并构建与种公鸡精子活力相关的调控网络.基于团队前期对不同精子活力种公鸡睾丸、附睾组织转录组测序数据的分析,用WGCNA方法构建基因共表达网络,识别与表型性状显著相关的基因模块,并对关键模块基因进行GO功能注释、KEGG通路富集分析.用Cytoscape软件筛选每个关键模块的核心基因并构建可视化共表达网络.结果表明,14 227个基因聚类到 11 个模块,以决定系数(R2)≥0.6、P<0.05 为标准挖掘出青绿色(Turquoise)模块、黄色(Yellow)模块、红色(Red)模块与表型显著相关.对 3 个关键模块的基因进行功能分析,发现这些基因显著富集在核苷酸切除修复、同源重组、细胞色素P450对异类物质代谢、MAPK信号通路和细胞凋亡等通路上.选出的IFT家族基因与HMOX2、CYP4B1、ANG、ITGB2 基因是与种公鸡精子活力相关的核心基因,可作为提高精子活力的潜在基因.

Aims: The study aimed to evaluate the effects of pretreated Chinese herbal medicine (PCHM) on egg quality, production performance, histopathological changes in the uterus, antiox idant capacity, and antioxidant gene expression in late-phase layers. Methods: Jinghong No.1 layers (n = 360, 68 weeks old) were assigned randomly to one of f our dietary interventions. Each treatment was replicated six times. Repeat 15 chickens per g roup. All birds were fed a diet composed of a corn-soybean meal-based diet supplemented with 0, 0.2, 0.4, or 0.8% PCHM for 6 weeks. Results: Dietary PCHM supplementation had no significant effects on laying rate, feed con sumption, yolk color, and shape index. With increasing PCHM level the Haugh unit linearly increased (P < 0.05). Supplementation of 0.8% PCHM increased egg weight, compared with the control (P < 0.05). PCHM can effectively alleviated the pathological changes caused by aging in the uterus including hemorrhage, and many inflammatory cell infiltrations. Supplementation of 0.4% PCHM increased glutathione peroxidase (GSHPx) in liver, magnum, and plasm considerably, compared with the control (P < 0.05). Supplementation of PCHM decr ease in the liver, magnum, and uterus on malondialdehyde (MDA) content, compared with the control (P < 0.05). Compared with the control group, mRNA expressions of glutathione peroxidase 1 (GPX1), peroxidase 4 (GPX4), catalase (CAT), and nuclear factor E2-related factor 2 (Nrf2) in the magnum, liver, and uterus were dramatically rose in the 0.4% PCHM supplementation group (P < 0.05). In summary, dietary supplementation after PCHM increased egg weight and quality in late-phase laying hens. Conclusion: Dietary PCHM increased the antioxidative capacity of late-phase laying hens, which could be associated with increased mRNA expression of antioxidant enzymes and Nrf2. These findings provide potential for using PCHM to increase the production performance in late-phase laying hens.

To investigate the effect of HIF-1α on the migration and invasion of trophoblast cells in placenta of dairy cows affected by cobalt dichloride（CoCl 2 ）,and reveal the formation mechanism of placenta of dairy cows under hypoxia conditions, bovine placental trophoblast cells（BTCs）were isolated and purified from the placenta of early pregnancy cows.The cell morphology was observed by giemsa staining method, and the expression of cell markers cytokeratin 7（CK7）and Thy/CD90 were detected by immunofluorescence method.pCI-neo-hTERT plasmid was then transfected into BTCs, qPCR and Western Blot methods were used to detect the TERT mRNA and protein expression in BTCs.Proliferation rate and placental lactogen（PL）secretory ability were analyzed with CCK8 method and ELISA,respectively.siRNA was further used to silence the expression of Hypoxia inducible factor-1α（HIF-1α）,vascular endothelial growth factor A（VEGFA）secretion ability in BTCs was detected by ELISA and the ability of migration and invasion of BTCs was detected by scratch test and transwell.According to the above all results, the isolated and purified BTCs were typical epithelioid cells with a certain number of binucleated cells and expressed epithelial marker protein CK7,but Thy/CD90 expression was not observed.The transfected cells could stably express telomerase reverse transcriptase（TERT）mRNA and protein.No cell aging was observed after 50 generations of continuous passage, and the proliferation rate was significantly higher than these primary BTCs（P＜0.05）,and the PL secretion ability showed no significantly different from that of primary BTCs（P＞0.05）.The cell viability of BTCs treated with CoCl 2 decreased with the increase of CoCl 2 concentration and time（P＜0.05）,and HIF-1α mRNA and protein expression decreased with the increase of CoCl 2 concentration（P＜0.05）.BTCs was treated with 400 μmol/L CoCl 2 for 24 h to establish a hypoxia model, and VEGFA secretion and invasion ability were significantly increased under BTCs hypoxia（P＜0.05）,while HIF-1α silencing decreased VEGFA secretion and invasion ability of BTCs（P＜0.05）.In conclusion, immortalized BTCs was established through exogenous TERT gene transduction.The immortalized BTCs had similar biological characteristics to the primary cells, and have stronger VEGFA secretion and invasion ability under hypoxia condition, and were associated with HIF-1α up-regulation.

基于抗原抗体反应检测奶牛(Bos taurus)血液中妊娠相关糖蛋白(pregnancy-associated glycoproteins,PAGs)是目前世界上应用最普遍的牛早孕检测技术,以boPAG6作为标志物应用于母牛早期妊娠诊断的准确性更高,因此制备高敏感性的boPAG6多克隆抗体,能为奶牛早期妊娠诊断试剂盒的研发提供支持.本研究利用PCR技术扩增荷斯坦奶牛boPAG6(GenBank No.NM_176617.2)基因,构建重组质粒pET30a-boPAG6;在大肠杆菌(Escherichia coli)BL21(DE3)中表达His-boPAG6蛋白并优化,以重组蛋白His-boPAG6作为免疫原免疫BALB/c小鼠(Mus musculus)制备多克隆抗体,用ELISA方法检测血清效价,Western blot方法检测纯化后的抗体分别与重组蛋白His-boPAG6和奶牛血清的特异性反应,利用免疫荧光技术定位boPAG6在原代滋养层细胞中的表达.结果显示,本研究成功构建出大小为6534 bp的重组质粒pET30a-boPAG6,并在异丙基-β-D-硫代半乳糖苷(isopropyl-beta-D-thiogalactopyranoside,IPTG)终浓度为0.5 mmol/L、诱导时间为8 h的条件下表达的His-boPAG6量最高,其蛋白分子质量为50 kD.以纯化后浓度为0.412 mg/mL的His-boPAG6蛋白免疫,ELISA中抗血清的效价为1:102400,多克隆抗体能特异性识别His-boPAG6抗原并有效区分妊娠和未妊娠奶牛血清,还可检测到原代滋养层细胞中存在boPAG6蛋白.本研究成功制备了boPAG6多克隆抗体,为奶牛早期妊娠ELISA检测系统的开发提供了理论支持.

[目的]探明单侧犬隐睾症中阴囊睾丸与腹腔睾丸组织内5α-还原酶1型(5α-reductase 1,5α-red1)、5α-还原酶2型(5α-reductase 2,5α-red2)与雄激素受体(Androgen receptor,AR)的表达模式.[方法]应用HE染色观察阴囊睾丸和腹腔睾丸的组织形态变化,利用免疫组织化学技术分析5α-red1、5α-red2和AR在阴囊睾丸和腹腔睾丸中的表达定位.利用酶联免疫吸附试验(ELISA)测定双氢睾酮(Dihydrotestosterone,DHT)浓度在单侧犬隐睾症中阴囊睾丸与腹腔睾丸中的水平变化.同时,实时荧光定量PCR(qPCR)和蛋白质免疫印迹(Western blot)分析5α-red1、5α-red2和AR的转录和翻译水平.[结果]结果显示腹腔睾丸组织中胶原纤维增多,曲精小管内精原细胞和成熟精子消失,同时5α-red1、5α-red2和AR在腹腔睾丸和阴囊睾丸中的间质细胞、支持细胞中均有表达.腹腔睾丸中DHT水平显著降低,5α-red1、5α-red2及AR转录水平和翻译水平在阴囊睾丸中的表达均显著高于腹腔睾丸.[结论]单侧犬隐睾症中腹腔睾丸中DHT水平不足,提示其可能与隐睾的发生发展密切相关,此结果为今后研究犬隐睾疾病提供新的研究思路和试验数据.

精子凋亡广泛存在于精液冻融过程,冷应激或氧化应激刺激及获能样变化均可引起精子凋亡.产生凋亡样变化的精子其结构、线粒体功能、膜电位、DNA完整性和参与凋亡反应的蛋白均发生变化,导致精子死亡率升高,活率下降.简述了冻融过程中精子凋亡的成因及抗冻保护剂的研究进展,以期为进一步提高冻融后的精子质量提供理论参考.

The cryopreservation of mammalian embryos is an important technology in embryo engineering. The discovery and application of the embryo's own high freezing resistance factors are the main methods to improve the utilization of mammalian embryos in cryopreservation. Cathepsin L gene expression in the frozen and thawed dormant embryos displayed a significant difference from those normal hatched ones. The aim of the present study was to dig out the potential role of Cathepsin L in anti-freezing capacity of murine blastocysts by investigating the location and expression of Cathepsin L in frozen and thawed both activated and dormant hatching blastocysts. Different concentrations of Cathepsin L recombinant protein and E-64d were then respectively added into the embryo cryoprotectant and pre-cryo culture medium. Our results found that down-regulation of Cathepsin L improves the freezing resistance of murine normal hatching embryos by reducing apoptosis. Cathepsin L inhibitors can be used to improve the efficiency of cryopreservation and recovery of blastocysts in vitro. Our study provides a theoretical basis for the further development and application of Cathepsin L.

Cryptorchidism, as a common congenital disease of canine testes, is mainly caused by factors leading to endocrine abnormalities in testes and infertility in a heat stress and hypoxia microenvironment. Moreover, heat stress and hypoxia, as critical microenvironmental factors, promote epithelial-mesenchymal transition (EMT), which occurs during adult tissue remodelling responses including carcinogenesis and fibrosis and is the main cause of testicular tumours. In this study, we found by haematoxylin-eosin staining that the canine cryptorchid tissue produced a lot of collagen fibres. Also, the quantitative PCR and Western blot results showed that the mRNA and protein levels of the heat stress makers HSP70 and HO-1 and the hypoxia maker HIF-1α are significant higher compared with normal testes. Moreover, we found the expression levels of TGF-βs and its two receptors TGF-βRI and TGF-βRII increased in case of cryptorchidism. From the study in vitro, we found both heat stress and COCl2 mimic hypoxia inhibited the secretion of testosterone (T) and androstenedione (A4) and promoted the expression of the EMT maker α-SMA and vimentin in Leydig cells, and also that heat stress and COCl2 stimulated with the TGF-β signalling promoted the expression of TGF-βs and its two type receptors and also the active phosphorylation of Smad2 and Smad3. The use of LY2109761, a receptor inhibitor of TGF-βs/Smad signalling pathway, was associated with heat stress and COCl2 suppression of androgens' secretion and stimulated EMT in Leydig cells. These findings characterized a novel pathogenesis of cryptorchidism and provided a new idea for therapeutics.

睾丸间质细胞(Leydig cells,LCs)的主要功能是合成和分泌睾酮.在睾丸间质细胞内,以胆固醇为原料,位于线粒体外膜上的类固醇合成急性调节蛋白(steroidogenic acute regulatory protein,StAR)促进胆固醇向线粒体内膜转运,在线粒体内膜胆固醇侧链裂解酶(cholesterol side-chain cleavage cytochrome,P450scc)的催化下生成孕烯醇酮,而后通过光面内质网的羟基类固醇脱氢酶(3β-hydroxysteroid dehydrogenase,3β-HSD)和转运蛋白(translocator protein,TSPO)的共同作用合成睾酮.因此,睾丸间质细胞合成和分泌睾酮与线粒体密切相关,线粒体结构和功能的完整性直接影响睾酮的生物合成,而位于线粒体上的StAR和P450scc是睾酮合成的关键调控因子.睾酮能够促进雄性生殖器官发育成熟并维持其功能,对促进蛋白质合成(如肌肉、骨骼及生殖器官的蛋白质合成)具有重要意义.近年来,通过维持线粒体结构完整性和改善线粒体氧化损伤、线粒体生物发生等功能进而促进睾酮的合成已成为睾酮合成机制的研究热点,受到国内外学者的广泛关注.作者介绍了睾丸间质细胞内睾酮合成的分子机制及影响睾酮合成的重要因子,综述了睾丸间质细胞线粒体结构、线粒体氧化损伤、线粒体调控的细胞凋亡和线粒体的生物发生等对睾酮合成的影响,阐述了线粒体与睾酮合成之间的关系,为改善睾丸间质细胞线粒体结构和功能从而促进睾酮合成提供依据,对于深入了解雄性动物的睾酮合成调节和提高雄性动物的繁殖性能具有重要的意义.

[目的]为研究奶牛胎盘发育提供基础依据.[方法]使用CoCl2构建奶牛胎盘滋养层细胞低氧模型,并筛选出试验所需最适CoCl2浓度;实时荧光定量PCR方法检测低氧对胎盘滋养层细胞胎盘生长因子(Placental growth factor,PLGF)mRNA表达的影响;显微镜观察低氧对Transwell小室中细胞迁移和浸润能力的影响;采用蛋白质印迹法(Western Blot)检测细胞中E-钙黏蛋白(E-Cadherin)的表达.[结果]通过检测细胞中低氧诱导因子-1a表达量确定试验所需的最适CoCl2浓度为200 μg/mL;Trans well小室法检测发现,低氧环境下细胞增殖缓慢,伪足数量和合胞体数量减少,迁移减缓,迁移率下降;实时荧光定量PCR结果显示,PLGF mRNA的表达并不受氧分压变化的影响;Western Blot结果显示E-Cadherin的表达量在低氧环境下表现出显著下降趋势.[结论]低氧能够抑制奶牛胎盘滋养层细胞的增殖、迁移与E-Cadherin的表达,但对PLGF mRNA的表达无显著作用.

Interferon-tau (IFNτ), as an antiluteolytic factor secreted by trophoderm during the pregnancy of ruminants, actually functions by activating the IFNτ receptor 1 (IFNAR1) and IFNτ receptor 2 (IFNAR2). However, it has not been clearly understood how IFNτ-IFNAR cascade regulation processes between the embryo and uterine epithelial cells in ruminants. In this study, we found the expression and location of IFNτ in the bovine blastocysts from different production sources. IFNτ, IFNAR1 and IFNAR2 were all located in the trophoblast cells of the blastocyst. However, the fluorescence intensity of IFNAR1 was consistent with that of IFNτ. Antagonizing the expressions of IFNAR1 and IFNAR2 in embryos and co-culture with endometrial epithelium cells (EECs) reduced the expressions of Integrin αv β3, WNT7A, and ISG15 in EECs. Knocking out IFNAR1 and IFNAR2 reduce the expressions of Integrin αv β3 and WNT7A in EECs, the deletion of IFNAR2 gene has a greater impact than that of IFNAR1 gene. IFNAR1-/IFNAR2+ and IFNAR1+/IFNAR2- EECs were co-cultured with IVF embryos, the expression of Integrin αv β3 was inhibited, and the inhibition of IFNAR1+/IFNAR2- was much stronger, and the expression of WNT7A was not inhibited. The expressions of Integrin αv β3 and WNT7A did not change significantly after IFNAR1-/IFNAR2+ and IFNAR1+/IFNAR2- co-culture with PA embryos. All of these results strongly suggest that specific activation of embryonic IFNAR1 and endometrial IFNAR2 induced by embryonic IFNτ directs normal uterine preparation for bovine early implantation.

Inadequate fetomaternal interactions could directly lead to pregnancy failure in dairy cows. Exosomes are widely involved in endometrial matrix remodeling, immune function changes, placental development, and other processes of embryo implantation and pregnancy in dairy cows. However, the role of exosomes derived from placental trophoblast cells in regulating the receptivity of endometrial cells and facilitating fetomaternal interaction remains unclear. In this study, bovine trophoblast cells (BTCs) were obtained from bovine placenta and immortalized by transfection with telomerase reverse transcriptase (TERT). Immortalized BTCs still possess the basic and key properties of primary BTCs without exhibiting any neoplastic transformation signs. Subsequently, the effect of trophoblast-derived exosomes (TDEs) on endometrial receptivity in endometrial epithelial cells (EECs) was determined, and the mechanism whereby TDEs and their proteins participate in the fetomaternal interaction during bovine pregnancy were explored. EECs were co-cultured with the exosomes derived from BTCs treated with progesterone (P4). Such treatment enhanced the expression of the endometrial receptivity factors, integrin αv, β3, Wnt7a, and MUC1 by changing the extracellular environment, metabolism, and redox balance in EECs via proteome alignment, compared with no treatment according to the DIA quantitation analysis. Our study demonstrated that trophoblast-derived exosome proteins are one of the most critical elements in fetomaternal interaction, and their changes may act as a key signal in altering endometrial receptivity and provide a potential target for improving fertility.

Cryopreservation of rooster sperm leads to relatively low semen quality due to cytoskeletal damage during the freeze-thawing process. This study aimed to explore how the addition of RhoA recombinant protein affected the viability and subcellular structure of rooster sperm after freeze-thawing and elucidated the molecular mechanisms of sperm cryopreservation. Semen quality and acrosome integrity testing revealed that the addition of 0.5 μg/mL RhoA recombinant protein to the cryoprotectant fluid significantly increased sperm motility, survival rate, linearity, straight-line velocity, and acrosome integrity after freeze-thawing (P < 0.05). Ultrastructure analysis of cryopreserved sperm showed structural damage to the sperm plasma membrane, nuclear membrane, and tail. However, compared to the control, these structural changes were reduced upon the addition of RhoA recombinant protein to the cryoprotective fluid (P < 0.05). Western blotting revealed that the expression of Rho/RhoA-associated kinase and p-cofilin was increased, and cofilin expression was decreased after sperm cryopreservation with recombinant RhoA protein. Treatment with Y-27632, a ROCK antagonist, suppressed ROCK and p-cofilin expression and decreased semen quality, acrosome integrity, and ultrastructure integrity. In summary, we have demonstrated a cryoprotective effect in spermatozoa involving the Rho/ROCK pathway during freeze-thawing. Furthermore, the addition of 0.5 μg/mL RhoA recombinant protein to the cryoprotective fluid improved rooster semen quality and subcellular structural homeostasis after freeze-thawing via the Rho/ROCK pathway. This pathway may regulate the dynamic reorganization of the actin cytoskeleton by regulating the cofilin phosphorylation.

Endometritis affects the reproductive capacity of dairy cows and leads to serious economic losses in dairy farming. Clarification of the pathogenesis of endometritis is necessary to improve the reproductive efficiency of dairy cows. Exosomes and their miRNAs have been proven to play an important role in inflammatory regulation. Exosomal miR-218 is a differentially expressed miRNA found in endometrial epithelial cells (EECs) under endometrial inflammation. Therefore, we investigated the expression of miR-218 in the uterine tissue of dairy cows, lipopolysaccharide (LPS) treated EECs, exosomal vesicles, and regulation of exosomal miR-218 by targeting TGIF-2 inducible factor homology frame 2 (TGIF2)/transforming growth factor-beta (TGF-I3). The expression of miR-218 was suppressed in inflammatory uterine tissues and LPS treated EECs. The expression of TGIF2 and TGF-I3 in inflammatory uterine tissues and LPS treated EECs was significantly higher than those in healthy uterine tissues and EECs (p < 0.01). Interestingly, miR-218 derived from donor cells was found to regulate the expression of the target gene TGIF2 in recipient cells through the fusion of exosomes. Concurrently, the expression of its target gene TGIF2 was also suppressed by miR-218 in donor cells resulting in fewer TGIF2 being transported into recipient cells with exosomal fusion. This may be a novel mechanism of miRNAs-mediated regulation and provides a new reference for analyzing the pathogenesis of endometritis in dairy cows.

旨在利用高通量测序技术对松辽黑猪和长白猪背最长肌组织样本进行mRNA测序和差异分析,筛选影响猪肌肉生长、肉质和脂肪沉积的关键基因,从而为猪肉品质研究提供新的参考信息.采集6头松辽黑猪和6头长白猪的背最长肌组织样本,提取其RNA,采用Illumina HiSeq 2500高通量测序技术对mRNA进行测序,并对获得的reads进行比对、注释和差异表达分析,用NOISeq筛选出差异表达基因并进行相关生物学功能富集分析.结果表明,从2个猪种间共筛选出了664个差异表达基因,其中,364个基因在松辽黑猪中高表达,300个基因在长白猪中高表达.通过对差异表达基因进行生物学功能分析,筛选出LPIN1、FADS1、FADS2、PLIN2、PPARGC1A、PRKAG2和ACSL1等基因参与脂类代谢和肌肉发育相关的调控,相关通路为脂肪酸代谢、PPAR信号通路、AMPK信号通路、胰岛素信号通路和脂肪细胞因子信号通路等.

This study's objective was to investigate the effects of dietary Se (in the form of selenomethionine) on the antioxidant activity and selenoprotein gene expressions in layer breeder roosters. One hundred and eighty, 36-wk-old Jingfen layer breeder roosters were randomly allocated to one of 5 dietary treatments (0, 0.25, 0.5, 1, or 2 mg/kg Se) for 6 wk on a corn-soybean meal-based diet. Antioxidant parameters and selenoprotein gene expressions were assessed at the end of the experiment. The results showed that Se supplementation significantly increased the activity of T-SOD, CAT, GSH-Px, and superoxide anion scavenging ability in plasma (P ≤ 0.05), and activities of T-SOD, CAT, GSH-Px, superoxide anion scavenging ability, and hydroxyl radical scavenging ability in the liver, kidney, and testis (P < 0.05). Moreover, MDA levels were significantly reduced in plasma, liver, kidney, and testis (P < 0.01), compared to the control group. Furthermore, the dietary administration of Se significantly increased TrxR2 and GPx4 mRNA levels in kidney and testis, and ID1 mRNA levels in liver and kidney. Most of the antioxidant parameters and selenoprotein-related gene expressions significantly increased, and MDA significantly decreased at dietary supplementation with 0.5 mg/kg Se. Whereas a higher dose of Se level (1 or 2 mg/kg) inhibited the activities of some of the antioxidant enzymes and selenoprotein-related gene expressions in selected tissues. In conclusion, dietary Se supplementation with 0.5 mg/kg significantly improved roosters’ antioxidant status and selenoprotein-related gene expression in liver, kidney, and testis, while higher doses led to inhibit these; dietary Se might increase reproductive performance by enhancing their antioxidant status in roosters.

Spermatogenesis, sperm motility, and apoptosis are dependent on the regulation of glandular hormones and mitochondria. Natural astaxanthin (ASTA) has antioxidant, anti-inflammatory, and anti-apoptotic properties. The present study evaluates the effects of ASTA on testosterone synthesis and mitochondrial function in aging roosters. Jinghong No. 1 layer breeder roosters (n = 96, 53-week old) were fed a corn–soybean meal basal diet containing 0, 25, 50, or 100 mg/kg ASTA for 6 weeks. The levels of plasma reproductive hormones and the mRNA and protein levels of molecules related to testosterone synthesis were significantly improved (p < 0.05) in the testes of the ASTA group roosters. In addition, antioxidant activities and free radical scavenging abilities in roosters of the ASTA groups were higher than those of the control group (p < 0.05). Mitochondrial electron transport chain complexes activities and mitochondrial membrane potential in sperm increased linearly with dietary ASTA supplementation (p < 0.05). The levels of reactive oxygen species and apoptosis factors decreased in roosters of the ASTA groups (p < 0.05). Collectively, these results suggest that dietary ASTA may improve testosterone levels and reduce sperm apoptosis, which may be related to the upregulation of the testosterone synthesis pathway and the enhancement of mitochondrial function in aging roosters.