单色光对肉鸡肌肉生长、肌纤维发育及血清睾酮水平的影响

为探索单色光影响肉鸡肌肉生长发育的机理,研究单色光对肉鸡肌肉生长、肌纤维发育和血清睾酮水平的影响。将260只0日龄AA肉鸡随机分为4组,分别在白（400-760nm）、红（660nm）、绿（560nm）、蓝光（480nm）下饲养49d,采用组织学技术和放射免疫法,检测肌纤维面积、密度和血清睾酮水平。结果如下：①质量：21日龄,绿光组胸肌、腿肌比其它组高6．46％～13．57％和6．37％～16．34％（P〈0．05）;49日龄,蓝光组胸肌和蓝、绿光组腿肌比其它组高21．42％和16．67％～25．44％（P〈0．05）。②肌纤维面积：21日龄,绿光组胸肌和绿、红光组腿肌比其他组高23．19％～54．01％和33．46％～56．67％（P〈0．05）;49日龄,蓝光组胸肌、腿肌比其他组高9．92％～21．69％和21．11％～57．44％（P〈0．05）。③肌纤维密度：21日龄,红光组胸肌和蓝光组腿肌比其他组高19．17％～42．94％和10．13％～49．33％（P〈0．05）;49日龄,红、白光组胸肌和红光组腿肌比其他组高27．36％（P〈0．05）和57．02％～112．03％（P〈0．05）。④21日龄,蓝、绿光组的睾酮水平比红、白光组高35．37％～37．13％（P〈0．05）;49日龄,蓝光组的睾酮水平比其他光组高14．36％～28．77％（P〈0．05）。研究表明单色光影响肉鸡生长,绿光和蓝光比红光和白光更能有效地促进肉鸡肌肉的生长、肌纤维的发育以及血清睾酮的分泌。     

单色光对肉鸡免疫功能的影响

选用260只刚出壳AA肉鸡公雏,随机分为红（660 nm）、绿（560 nm）、蓝（480 nm）和白（400-700 nm）4个光色处理组,分别用4种发光二级管作为光源进行处理。每个处理设5个重复,每个重复13只鸡,人工光照光强度均为15 lx,光照时间为23 h,试验期为7周。49日龄测定肉鸡脾脏的质量,21和49日龄测定外周血T淋巴细胞转化率和血清皮质醇水平,14、28、42和49日龄测定新城疫（NDV）抗体滴度。结果表明：与红光组比较,蓝光组49日龄肉鸡脾脏的质量提高42.2%（P〈0.05）,而白光、绿光和蓝光各组间差异不显著（P〉0.05）。与白光组相比,蓝光组21和49日龄皮质醇水平分别降低25.2%和26.2%（P〈0.05）。与红光组比较,28日龄时绿光组的新城疫抗体水平显著高32.9%（P〈0.05）,而白光、红光和蓝光各组间差异不显著（P〉0.05）;49日龄时蓝光组NDV的抗体水平显著高62.8%（P〈0.05）,但蓝光、绿光和白光组间差异不显著（P〉0.05）。与红光组比较,21日龄时白光和绿光组肉鸡外周血T淋巴细胞的转化率均显著提高（分别为107.1%和80.8%,P〈0.05）,49日龄时白光和蓝光组分别显著提高41.5%和26.9%（P〈0.05）。上述结果表明,在15 lx光强度下,肉鸡生长前期选用绿光照明,后期改为蓝光照明,可以提高肉鸡免疫功能,而且在一定程度上蓝光还有缓解免疫应激的作用。     

单色光对肉鸡SCN和视顶盖SGC层神经元c-Fos表达的影响

本研究比较了单色光对肉鸡SCN和视顶盖SGC层神经元c-Fos表达的影响。以LED灯为单色光源,选用刚出壳的雄性AA肉鸡40羽,分别饲养在白光(400～700nm)、红光(660nm)、绿光(540nm)和蓝光(480nm)下14d,光照度为15lx。光照制度20h∶4h(L∶D)。结果显示,在SCN中,蓝光组c-Fos表达分别显著低于白光、红光和绿光组29.76%、17.88%和22.23%(P0.05),白光组与红、绿光组差异不显著(P0.05)。同样,在视顶盖SGC层中,蓝光组c-Fos表达也显著低于白光、红光和绿光组17.78%、21.75%和23.63%(P0.05),白光组与红、绿光组差异也不显著(P0.05)。结果表明,与红光和绿光相比,蓝光抑制视顶盖SGC层和SCN神经元c-Fos的表达。     

单色光对肉鸡体质量和小肠免疫应激相关因子IL-6与TNF-α表达的影响

本试验旨在通过检测在单色光下饲养的肉鸡的体质量和空肠中细胞因子白细胞介素-6(IL-6)与肿瘤坏死因子(TNF-α)表达量的改变,探讨单色光对肉鸡生长发育和肠道免疫应激水平的影响。选用256只刚出壳的雄性AA肉鸡,随机分成4组,分别在蓝(480nm)、绿(560nm)、红(660nm)、白(400～700nm)4种光色下饲养。各组饲养管理制度相同,光照的强度为15lx,光照时间为23h。肉鸡42日龄时,称重后取空肠,用ELISA测定IL-6和TNF-α的表达量。试验结果显示与白光组肉鸡相比,蓝光组肉鸡的体质量高15.2%,而空肠IL-6和TNF-α的表达量分别降低了46.8%和33.4%(P<0.05),绿光组、红光组、白光组3组间差异均不显著(P>0.05)。结果表明蓝光能促进肉鸡生长和缓解光刺激诱发的小肠免疫应激。     

单色光对肉鸡视网膜和松果体视蛋白基因转录的影响

为了研究单色光对肉鸡视网膜和松果体黑素视蛋白基因(OPN4-1和OPN4-2)、视网膜绿敏感锥体视蛋白基因(CHK-1)和蓝敏感锥体视蛋白基因(CHK-2)mRNA转录的影响,笔者选用刚出壳的雄性AA肉鸡40羽,分别饲养在白光(400～700 nm)、红光(660 nm)、绿光(540 nm)和监光(480 nm)下2周,单色光源采用冷LED灯,光照度为15 lx.于第14天分别取视网膜和松果体,提取总RNA,RT-PCR反转录后用上述4种肉鸡相关视蛋白基因的引物进行PCR扩增.结果显示:(1)视网膜和松果体蓝光组OPN4-1 mRNA的表达均显著较白光组高13.44%和16.77%(P<0.05),但视网膜中红光组和绿光组均分别显著较白光组低16.62%和10.94%(P<0.05),而松果体中绿光组与白光组差异不显著(P>0.05);(2)视网膜和松果体OPN4-2 mRNA表达均是红光组最高,其次是蓝光组,而绿光组均最低(P<0.05);(3)视网膜中4个光组CHK-1 mRNA表达均大于CHK-2 mR-NA表达(P(0.05),其中绿光组CHK-1 mRNA表达分别显著较红光和蓝光组高24.37%和9.94%(P<0.05),但与白光组差异不显著;蓝光组CHK-2 mRNA表达分别显著较红光和绿光组高40.90%和8.94(P<0.05),但与白光组差异不显著(P>0.05).以上结果表明,不同视蛋白具有不同的光色敏感性.与红光和绿光相比,蓝光促进视网膜和松果体OPN4-1的转录.     

单色光对产蛋鸡蛋重和蛋形的影响

试验采用红(660nm)、绿(560nm)、蓝(480nm)三种发光二极管(处理组)和白炽灯(400～700nm)(对照组),对180只海兰褐蛋鸡进行人工光照,研究单色光对蛋重、蛋长径、短径和蛋形指数的影响。结果提示:蓝光使蛋长径变短而红光使蛋短径变短,蓝光和红光组蛋重随产蛋周龄而增长的趋势小于白光和绿光组。     

LED养殖灯对肉鸡、蛋鸡生理影响

正禽类具有优越的视觉机能,能辨别光线的明暗和颜色。选LED灯这种波长单一的光源照射肉鸡、蛋鸡,结果发现,在肉鸡生长前期,绿光组增重较快,料肉比较低;生长后期,蓝光组增重显著,料肉比最低,且胴体重、胸肌重、大腿重、小腿重和净膛重各项指标高于其它光组14.39%～19.86%。即与红、白光相比,绿光在生长早期促进肉鸡生长,蓝光在生长后期促进肉鸡生长。同时利用荧光灯照射肉鸡,发现蓝绿光下饲养的肉鸡增重效果显著高于红、白光下饲养的肉鸡。以上结果均提示单色光能显著影响鸡的生长发育。不同波长的光可影响肉鸡的行     

单色光对产蛋鸡蛋品质的影响

试验采用红(660nm)、绿(560nm)、蓝(480nm)3种发光二极管(处理组)和白炽灯(400～700nm)(对照组),对180羽海兰褐蛋鸡进行人工光照,研究了单色光对蛋重、蛋形指数、蛋长径、短径和蛋壳质量的影响。试验期为19～52周,光强度均为15lx,光照时间为16h。结果表明:在整个试验期,白光组蛋重最高(61.1g),红光组最低(59.2g),二者之间差异显著(P<0.05);38～52周龄,蓝光组蛋长径显著小于其他组,而其短径显著(P<0.05)小于白光组,另外,红光组蛋短径极显著(P<0.01)小于其他组;19～37周龄,绿光组蛋形指数(1.303)显著大于其他组,而38～52周龄,红光组蛋形指数(1.343)极显著(P<0.01)大于其他组;21～45周龄,绿光组蛋壳强度(3.54kg/cm2)极显著(P<0.01)高于白光和蓝光组而绿光组蛋壳厚度(0.368mm)显著(P<0.05)大于其他组;蓝光组蛋壳颜色值(31.6)显著(P<0.05)小于白光组(33.1)。结果提示:蓝光使蛋长、径变短而红光使蛋短径变短,从而使蓝光和红光组蛋重随产蛋周龄而增长的趋势小于白光和绿光组。单色光可影响蛋壳质量,其中绿光组的蛋壳质量最好。     

不同光色对黄羽肉鸡生产性能、胴体性能及性征发育的影响

试验采用LED(Light-emitting diodes)灯作为人工光源,研究4种光照颜色对黄羽肉鸡的生长性能、胴体性能及性征发育的影响,为科学合理的利用光色,提高肉鸡生产性能提供理论指导。试验选取720只1日龄北京油鸡,分为白光组、绿光组(λ=525nm)、蓝光组(λ=460nm)和红光组(λ=630nm)4个处理组,每个处理设6个重复,每个重复30只,自由采食、饮水。第1周光照强度为20lx,从第2周开始为5lx,采用16h夜间补光光照节律。详细记录加料重量,分别在第4周末、第8周末、第13周末结料并称重,称量各重复组重量前禁食12h。在第13周末抽样屠宰,获取胴体性能数据。结果显示,在育雏期和生长期红光组生长缓慢,在第8周末平均体重显著低于其他3组(P0.05),在育肥期红光组发生补偿性生长,在13周末各组体重无显著差异(P0.05);死亡统计分析显示,相对于白光,蓝光和红光能够提高肉鸡的成活率;红光组的胸肌重和胸肌率显著低于绿光组(P0.05),各组的腿肌重和腿肌率没有显著差异(P0.05);白光组脂肪沉积量低;红光能够提高公鸡睾丸重量和睾丸脏器指数。在黄羽肉鸡的生产中,育雏期使用蓝光,生长育肥期采用红光的光照制度,可提高肉鸡成活率,促进性腺发育。     

不同饲喂水平对绵羊睾丸发育、睾酮合成相关基因及雄激素受体(AR)表达的影响

旨在研究不同饲喂水平对绵羊睾丸发育、睾酮（T）合成相关基因与雄激素受体（androgen receptor, AR）表达的影响。本研究采用单因素完全随机试验设计,将18只健康、体重相近（（35±0.5） kg）的杜泊羊（♂）×晋中绵羊（♀）杂F1代4月龄公羔随机分为3组,每组6只,分别按照自由采食（AL组）、自由采食量的65%（AL65组）和自由采食量的40%（AL40组）3个水平进行饲喂。当AL组任意1只羔羊体重达到50 kg时全部屠宰,测定睾丸的周径与长度后采集睾丸组织,通过苏木精-伊红（hematoxylin-eosin,H-E）染色观察曲精细管生精上皮结构;酶联免疫（enzyme linked immunosorbent assay,ELISA）法测定睾酮（testosterone,T）的水平;用定量PCR（quantitative real-time PCR,qRT-PCR）检测T合成相关基因和AR mRNA的表达情况;通过免疫组化和Western blotting的方法对绵羊睾丸组织中的AR进行定位与定量分析。结果表明,AL40组羔羊睾丸周径和长度显著低于AL组（P<0.05）,但与AL65组差异不显著（P>0.05）;AL40组曲精细管生精上皮厚度与AL65组差异不显著（P>0.05）,但均显著低于AL组（P<0.05）。随着饲喂水平的提高,生精细胞和间质细胞密度显著增加（P<0.05）,T水平和STAR、3β-HSD基因以及AR mRNA和蛋白表达量均显著提高（P<0.05）;睾丸间质细胞、初级精母细胞、精子细胞、管壁肌样细胞层和间质血管平滑肌细胞中均观察到AR阳性产物。综上所述,绵羊的睾丸发育、T含量、T合成相关基因和AR的表达均受到日粮营养水平的调控。日粮营养水平可能通过改变T水平和生精细胞对T的敏感性来调控精子发生过程,从而影响其性成熟和繁殖性能。     

Changes in spermatogenesis and endocrine function in the ram testis due to irradiation and active immunization against luteinizing hormone-releasing hormone

Spermatogonial stem cell transplantation is a technique that has potential in livestock to enhance genetic gain and generate transgenic offspring through the male germ line. A means for depletion of endogenous germ cells in a recipient's seminiferous tubules is necessary for this technology to be applied. The objectives of this study were to evaluate several methods for depletion of endogenous germ cells in the testes of adult rams and to evaluate ultrasound-guided injections into the rete testes as a means for infusing a suspension into the seminiferous tubules. Sixteen adult rams were randomly divided into 4 treatment groups (n = 4 per group). Treatments consisted of active immunization against LHRH (IMM), localized testicular irradiation (IR), LHRH immunization + irradiation (IMM+IR), and untreated control. Serial bleedings were conducted pretreatment and monthly after treatment for 4 mo, at which time all rams were castrated. Both IMM and IMM+IR rams received exogenous gonadotropin in the form of Perganol weekly for 8 wk before castration to bypass the immunization. All rams also received an ultrasound-guided injection of PBS containing 0.4% trypan blue into the rete testis of one testicle before castration. Rams receiving IMM and IMM+IR treatments had higher (P < 0.05) average percentages of seminiferous tubule cross sections with depleted germ cells compared with controls. Serum testosterone was decreased (P < 0.05) in IMM and IMM+IR rams 1 mo after treatment and throughout the remainder of the study compared with controls and IR rams, which were not different from each other. Serum inhibin concentration was unchanged in all rams following treatment indicating that Sertoli cell function was unaltered. A greater (P < 0.05) average percentage of the total testicular area could be filled with the trypan blue solution by rete testis injection in IMM and IMM+IR rams. These data demonstrate the depletion of endogenous germ cells in adult ram testes without alteration of Sertoli cell viability and function that have potential as methods for preparing recipient animals for germ cell transplantation.     

单色光对肉鸡脑内促性腺激素释放激素分布和表达的影响

24只刚出壳的雄性AA肉鸡分别在白(400～760 nm)、红(660 nm)、绿(560 nm)和蓝色(480 nm) LED灯下饲养7周,光照强度15 lx,光照制度23h∶1 h(L:D).49日龄时取脑,利用免疫组化的方法显示GnRH神经元和神经纤维的分布及比较各光色下GnRH神经元的表达强度.结果显示,GnRH神经元和神经纤维在下丘脑、丘脑和中脑均有分布,且蓝光组下丘脑的视前室周核、视前内侧核、室周核、室旁大细胞核以及丘脑的圆核和卵圆核GnRH神经元表达强度显著高于红、绿光组.结果表明,光色可影响家禽下丘脑和丘脑GnRH的表达与分泌.     

Effects of Hemicastration on Testes and Testosterone Concentration in Stallions

The endocrine system is critical to the maintenance of testicular function. The homeostasis of sex hormone levels is orchestrated by positive and negative feedback systems controlled by the hypothalamic-pituitary-gonadal axis. This study investigated the long-term effects of hemicastration on testicular size and function in stallions. Four Thoroughbred stallions, 4–6 years of age, were included in this study. Several parameters, including testicular weight and volume, plasma testosterone concentrations, VASA-positive germ cell populations and cross-sectional areas of the seminiferous tubules were compared in stallions that underwent two hemicastrations, approximately 11 months apart. The weights and volumes of testes harvested at the second hemicastration were significantly higher than those of testes collected at the first hemicastration. However, VASA-positive germ cell populations and the cross-sectional areas of seminiferous tubules were not significantly different between testes harvested at the first and second hemicastrations. Similarly, plasma testosterone concentrations measured weekly for 3 weeks before the first hemicastration, 3 weeks after the first hemicastration, and 3 weeks before the second hemicastration were not significantly different. Our results suggest that hemicastration results in compensatory enlargement of the remaining testis and compensatory steroidogenesis to maintain normal reproductive function in stallions.     

Relationships among measures of testicular development and endocrine function in boars

Nine blood samples were taken at 30-min intervals from 36 Landrace X Large White boars at each of eight ages (42, 56, 70, 84, 98, 112, 126 and 140 d). Serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T) and estradiol-17 beta (E2) were quantified by radioimmunoassay procedures. The maximum concentration of LH and the age at maximum concentration were predicted for each boar. Variability of LH samples was described for each boar by the pooled within age variance among LH samples and by the number of LH peaks. Measurements of testicular development taken at 140 d of age included: in situ testis width and length, excised testis weights and histological traits of excised testes (seminiferous tubule diameter, percentage of tubules with a lumen and percentage of tubules with active spermatogenesis). Pooled within line correlations were calculated with data from boars selected for either high or low testis weight. Correlations among the testicular traits ranged from .45 to .88. Luteinizing hormone concentration (mean over all ages) was related to measures of testicular development (r = .24 to .49). Concentrations of LH from 42 to 84 d of age were more highly correlated with testicular traits than were the concentrations from 98 to 140 d.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of hyper‐ and hypothyroidism on the development and proliferation of testicular cells in prepubertal rats

Thyroid hormones are important in the development and regulation of testes. This study was conducted to determine the effects of hyper‐ and hypothyroidism on testicular development in prepubertal rats aged 20–70 days. Weaning male rats (20 days old) until day 70 age were randomly divided into four groups: control, hyperthyroid (hyper‐T), hypothyroid (hypo‐T) and hypothyroid treated with thyroxine (T4) (hypo‐T+T4). The results indicated that thyroid hormones caused a significant effect in body and testis weights, and food and water consumption. In addition there were changes in serum concentrations of tri‐iodothyronine, T4, thyroid stimulating hormone (TSH) and testosterone. Histomorphology showed a significant decrease in seminiferous tubule diameter in hyper‐T compared to the other groups. Leydig cell numbers showed a significant elevation in hyper‐T but not in hypo‐T groups. Immunostaining indicated that TSH receptor (TSHR), thyroid hormone receptors α/β (TRαβ) and proliferating cell nuclear antigen (PCNA) have the roles in testicular development. Our findings suggest that hyper‐ and hypo‐thyroidism regulate testicular cell proliferation and spermatogenesis in prepubertal rats, indicating that expression of TSHR, TRαβ and PCNA may be regulated by thyroid hormones that are involved in testicular development; and that the administration of T4 to the hypo‐T+T4 group leads to an improvement in the testicular condition.     

Leydig cell hyperplasia in an ENU-induced mutant mouse with germ cell depletion

Repro22 is an N-ethyl-N-nitrosourea (ENU)-induced mutation in mice showing depletion of both male and female germ cells. In the present study, we investigated the male phenotypes of the mutant mouse at the adult stage. The repro22/repro22 homozygous mice showed reduced body weights as well as markedly reduced testis weights. Histological examination of the testes at 4 and 10 months of age showed no germ cells in the seminiferous tubules of the affected testis while a number of Sertoli cells were observed in the tubules. In addition to the germ cell depletion, the testes of the affected mouse contained expanded intertubular spaces that were filled by Leydig cell-like interstitial cells. These interstitial cells were confirmed to be Leydig cells by immunohistochmical staining using anti-3beta-HSD antibody. The estimated number of Leydig cells in the affected testes at 10 months of age increased approximately 2 fold compared with those of normal testes. Furthermore, the plasma testosterone levels of the affected mice at 10 months of age were significantly higher than those of the normal mice. These findings indicated that the repro22/repro22 mouse developed hyperplasia of Leydig cells that was presumably caused by the absence of germ cells in the seminiferous tubules.     

促性腺激素释放激素类似肽主动免疫对公猪生殖机能的影响

10头公猪在3月龄时用促性腺激素并列体二聚体(GnRHTD)主动免疫,观测内源GnRH被免疫中和所产生的内分泌和生殖机能的变化。注射GnRHTD与卵清蛋白(OVA)的偶联物2次,结果发现GnRHTD主动免疫能降低外周血清睾酮浓度,睾丸重量也明显下降。组织切片显示,曲细精管有少数退化的精原细胞。这些变化表明:公猪接种GnRHTDOVA能诱发免疫反应,中和内源GnRH的生物活性,且抑制睾酮的合成,从而导致性器官发育受阻。     

不同光照周期对鸡睾酮合成的影响

为研究不同光照周期对公鸡睾酮合成的影响,试验选择120只20周龄体重相近的AA(爱拔益加)公鸡,随机分配到3个不同光照处理组,SD、CTR、LD组分别采用8L:16D、12.5L:11.5D、16L:8D光照周期,4周后采集血清和睾丸;用ELISA技术检测睾酮含量,用实时荧光定量PCR和Westernblot技术检测睾酮合成的3个关键酶(StAR、Cyp11a1、3β-HSD)表达量,HE染色观察睾丸中曲细精管横截面积。结果表明:睾酮含量随光照周期延长极显著增加(P<0.01),并伴随睾酮分泌关键酶StAR、Cyp11a1、和3β-HSD表达量极显著升高(P<0.01),曲细精管横截面积极显著增大(P<0.01)。综上,不同光照周期可通过影响睾酮合成3个关键酶表达而影响睾酮合成,随着光照时间延长,睾酮合成增加,睾丸生精功能增强。     

Green and Blue Monochromatic Lights Promote Growth and Development of Broilers Via Stimulating Testosterone Secretion and Myofiber Growth

Methods of light treatment such as light schedule, intensity or illuminance, and color are important factors that influence avian productivity. Therefore, artificial illumination has been widely used in modern poultry husbandry. Although progress had been made in understanding of the effects of light schedule and intensity on avian growth, effects of light color on avian growth are not clear. In this study, 276 male Arbor Acres broilers were reared under white, red, green, and blue lights from light-emitting diode lamps as light sources. Broilers’ growth and productive performance were increased under green light during the early period (0 to 26 d of age) or blue light during the later period (27 to 49 d of age). Furthermore, both blue and green lights were more effective to stimulate testosterone secretion and myofiber growth that led to increased body growth. These results indicate that light-emitting diode lamps have value in the modern broiler husbandry.