Effects of Straw Volume and Equex-STM® on Boar Sperm Quality after Cryopreservation

The present experiments were designed to study the effect of adding the detergent Equex-STM^® to freezing extender, and of straw volume (0.25 ml vs 0.5 ml), on boar sperm quality after cryopreservation. Three ejaculates from each of four purebred boars (three Landrace and one Yorkshire) were collected and frozen with a lactose-egg yolk extender containing glycerol with or without 1.5% Equex-STM^®. The extended semen was loaded into either 0.25- or 0.5-ml straws. The straws were placed in liquid nitrogen (LN₂) vapour approximately 3 cm above the level of LN₂ for 20 min and then were plunged into LN₂. Thawing was achieved in warm water at 50°C for 12 s and then was incubated in a 38°C water-bath for 30 min before evaluating sperm quality. Results showed that the individual motility, viability and acrosomal normal apical ridge (NAR) were improved (p < 0.001) when Equex-STM^® was added to the freezing extender. There was no difference (p   =   0.48) in sperm motility between 0.25- and 0.5-ml straws when Equex-STM^® was added. The percentages of viable and of NAR sperm in 0.5-ml straws were higher than those in 0.25-ml straws (p   =   0.02, p   =   0.0003 respectively). The percentages of membrane intact sperm evaluated using the short hypo-osmotic swelling test were not affected by straw volume or the adding of Equex-STM^® (p   >   0.05). The results of these investigations suggested that Equex-STM^® exerts a beneficial effect on the quality of cryopreserved boar semen and this cryopreservation protocol was favourable for a 0.5-ml straw.     

Response of Boar Sperm to the Treatment with Cholesterol‐Loaded Cyclodextrins Added Prior to Cryopreservation

Cryopreserved boar sperm is not used extensively for artificial insemination, owing to the poor fertility rates of the sperm after freezing and thawing. The sperm membrane is damaged as the cells are cooled from body temperature to 5°C (cold shock), as well as during the freeze–thaw process. Increasing the cholesterol content of boar sperm membranes could help them survive cryopreservation, similar to sperm from other species that are cold shock sensitive. The aim of this study was to determine the optimal cholesterol‐loaded cyclodextrin (CLC) concentration to use for boar sperm cryopreservation, and the influence of CLCs on the cryosurvival of sperm from boars classified as good or poor freezers. Treating boar sperm with 1 mg of CLC/120 × 10⁶ sperm slightly improved (p < 0.05) the percentage of viable sperm after freezing–thawing. On the other hand, sperm, from both good and poor freezers, responded similarly to CLC treatment. Nevertheless, additional studies will be needed to study the effect of this treatment on other parameters of sperm quality.     

Cryopreservation of Piau‐Breed Wild Boar Sperm: Assessment of Cooling Curves and Centrifugation Regimes

This study aimed to assess the effects of different cooling curves and centrifugation regimes used in cryopreservation protocols on the post‐thaw viability of Piau‐breed wild boar (Sus scrofa) sperm using in vitro assessment tests. Two centrifugations (800  g for 10 min and 2400  g for 3 min) and two cooling curves (conventional cooling using nitrogen vapour – freezing 1 and automated cooling using a programmed freezing machine – freezing 2) were tested. Therefore, the treatments were divided into M3 – centrifugation at 2400  g for 3 min and freezing 2; M10 – centrifugation at 800  g for 10 min and freezing 2; R3 – centrifugation at 2400  g for 3 min and freezing 1; and R10 – centrifugation at 800  g for 10 min and freezing 1. No significant differences (p > 0.05) between treatments occurred post‐thawing regarding the total sperm motility means recorded. The mean values of the different treatments were not different from each other regarding the supravital staining (SV), hypo‐osmotic test (HO), sperm–egg binding assay or sperm morphology. This study showed that both the cooling curve and the centrifugation regime affected the quality of post‐thaw sperm, and centrifugation for shorter times and cooling curves using automated cooling are the most suitable for minimizing sperm injury.     

OC5Filtration Thought Sephadex Columns Does not Alter the Subpopulation Characteristics in Fresh Boar Semen

The aim of this study was to analyse the effect of filtration through Sephadex on the subpopulation characteristics of the boar semen. For this purpose 3 ml of 16 commercial doses of fresh diluted boar semen were filtered through a Sephadex G‐15/Polypropylene column. Motility parameters were analysed by a CASA system and statistical study was performed by SAS package using the VARCLUS and the FASTLUST procedures. Statistical study revealed four subpopulations in fresh boar semen, as previously had described (Theriogenology 61: 673–690).Total motility was higher in control than in filtered semen, but there were not statistical differences (65.63 ± 9.65 vs 41.40 ± 9.02). Moreover, the analysis did not show many changes neither in the characteristics nor in the distribution of the four subpopulations. As example although ALHmed of filtered samples were slightly higher, there were only significant differences (p < 0.001) in two subpopulations (subpopulation 2 : 2.2 ± 0.05 in control vs 2.7 ± 0.08 in filtered. Subpopulation 3 : 4.5 ± 0.11 in control vs 5.8 ± 0.23 in filtered semen). HME was also statistically different (p < 0.005) in one subpopulation, showing great values in filtered semen (1.7 ± 0.15 vs 3.0 ± 0.30). In conclusion, the filtration by Sephadex/Polypropylene column does not cause strong changes in subpopulation sperm distribution.     

猪精子获能前后细胞亚组分蛋白分离及酪氨酸磷酸化蛋白的鉴定

本研究对猪精子获能前后细胞亚组分蛋白进行分离以及对酪氨酸磷酸化蛋白进行鉴定,旨在为哺乳动物精子受精生物学研究奠定理论基础。利用动物精子体外获能培养、细胞亚组分分离技术及蛋白免疫印迹的方法,分离猪精子细胞亚组分蛋白及酪氨酸磷酸化蛋白鉴定。结果表明,猪精子经过获能培养后各项活力指标均得到显著提高,且与精子蛋白发生酪氨酸磷酸化修饰密切相关;获能精子中126、108、79ku的高分子量蛋白磷酸化程度明显高于未获能精子;分子质量约为25、47、50ku的膜蛋白及47ku胞浆蛋白发生酪氨酸磷酸化,其中25、47ku的膜蛋白酪氨酸磷酸化程度显著高于未获能精子(P<0.05);分子量约为23、37、42～50ku的核蛋白发生酪氨酸磷酸化,获能精子中23ku的核蛋白酪氨酸磷酸化程度显著高于未获能精子(P<0.05)。结果提示,猪精子细胞不同亚组分中,发生酪氨酸磷酸化修饰的蛋白以膜蛋白及核蛋白为主,同时有少量的胞浆蛋白。     

Addition of Cholesterol‐Loaded Cyclodextrins to the Thawing Extender: Effects on Boar Sperm Quality

The aim of the present study was to evaluate the effect that the addition of cholesterol‐loaded cyclodextrins (CLC) to the thawing extender has on the quality of frozen‐thawed boar sperm. Pooled semen (n = 5) from three boars was used for the experiments. The semen was cryopreserved with an egg‐yolk‐based extender, it was diluted after thawing in Beltsville thawing solution (BTS) supplemented with different concentrations of CLC (0, 12.5, 25, 50 or 100 mg/500 × 10⁶ sperm), and these samples were incubated at 37°C for 150 min. The following parameters of sperm quality were evaluated 30 and 150 min after incubation: sperm with intact plasma membrane (SIPM; %), sperm with normal acrosomal ridge (NAR; %), total motile sperm (TMS; %), progressively motile sperm (PMS; %) and kinetic parameters. Both SIPM and NAR increased (p < 0.05) when the thawing extender was supplemented with 12.5, 25 and 50 mg CLC/500 × 10⁶ sperm. Nevertheless, motility decreased (p < 0.05) when the concentration of CLC exceeded 12.5 mg CLC/500 × 10⁶ sperm. In conclusion, our results suggest that the supplementation of thawing extenders with CLC improves sperm viability and reduces acrosome damage after freezing/thawing.     

Studies on the Effect of Supplementing Boar Semen Cryopreservation Media with Different Avian Egg Yolk Types on in Vitro Post-thaw Sperm Quality

Fertility after insemination of cryopreserved boar semen is currently below that of fresh semen. In an attempt to improve the post-thaw motility and acrosome integrity of boar sperm, semen was frozen using an adapted Westendorf method in which the chicken egg yolk was replaced by either duck or quail egg yolk. The different composition of the yolk types, particularly the amount of cholesterol, fatty acids and phospholipids, were thought to potentially afford a greater level of protection to sperm against damage during freezing and thawing. Sperm frozen in medium containing chicken egg yolk displayed higher motility immediately after thawing, but there was no difference in the motility of sperm frozen with different types of egg yolk 3 or 6 h after thawing and maintenance at 37 degrees C. Sperm frozen in media containing chicken or duck egg yolk had a higher proportion of intact acrosomes immediately after thawing than sperm frozen in medium containing quail egg yolk, but 6 h after thawing and maintenance at 37 degrees C the sperm that had been frozen in medium containing chicken egg yolk had a higher proportion of intact acrosomes than the sperm frozen in media containing duck or quail egg yolk. Analysis of the composition of the different yolk types showed that the basic components of the yolks were similar, but the ratios of fatty acids and phospholipid classes differed. Duck egg yolk had more monounsaturated fatty acids (MUFA) than chicken egg yolk, which had more MUFA than quail egg yolk. Duck egg yolk contained more phosphotidylinositol (PI) than chicken or quail egg yolks and quail egg yolk contained more phosphotidylserine than either chicken or duck egg yolks. The differences in post-thaw motility and acrosome integrity of boar sperm when frozen in media containing the different types of egg yolk may be due to the variation in composition.     

Fluorescent Stain Method for the Simultaneous Determination of Mitochondrial Potential and Integrity of Plasma and Acrosomal Membranes in Boar Sperm

The purpose of this study was to validate a technique for simultaneous evaluation of the plasma, acrosomal and mitochondrial membranes in boar spermatozoa, using an association of fluorescent probes: Propidium iodide (PI), fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and JC-1. Three ejaculates from each of four different boars, all showing motility >or=80% and abnormal morphology 相似文献   

Comparative Immunolocalization of GLUTs 1, 2, 3 and 5 in Boar,Stallion and Dog Spermatozoa

Spermatozoa, as other eukaryotic cells, need hexoses to produce energy to maintain membrane homeostasis, to move along the female genital tract and to carry the male genome to the female gamete. GLUTs are a family of proteins that permit and improve the passive transport of hexoses inside cells. This study was aimed at investigating the presence and localization of GLUTs 1, 2, 3 and 5 in boar, stallion and dog spermatozoa by both immunofluorescence and western blotting. GLUTs exhibited a peculiar distribution along the sperm cell depending on the isoforms considered, the hexose they transport and the different species. The localization of GLUTs after capacitation and acrosome reaction highlighted the possible changes in their distribution because of the different functional moment. Only in dog spermatozoa changes in GLUTs distribution were demonstrated; these changes could be related to the different metabolic needs and modifications occurring in the sperm cell.     

OC4Influence of Seminal Plasma Added to Highly Diluted Semen on Sperm Motility of Young Boar Feed with Selenium and Vitamin E

High dilution rates have been documented as detrimental for boar spermatozoa, shortening their lifespan (Centurion et al. 2003, Biol Reprod 69: 640–646). Addition of seminal plasma (SP) to semen extenders, or selenium (Se) and vitamin E (VE) in diet of boars could increase motility of highly diluted spermatozoa (HDS). The aim of this work was to evaluate the effect of seminal plasma on sperm motility of HDS from boars feed with Se and VE. Sixteen 12 month-old boars were designed to one of four dietary treatments: (i) control, Se 0 ppm–VE 0 IU/kg; (ii) Se 0–VE 250; (iii) Se 0.5–VE 250 and (iv) Se 0.5–VE 0. Boars were treated for 8 weeks before semen collection. Sperm rich fractions from each boar were diluted to 5 × 10⁶ sperm/ml in PBS medium and incubated at 37°C with or without 10% SP. The measurements were done at 0, 2 or 5 h. Data were analyzed as a mixed model for a factorial design [2 (Se) × 2 (VE) × 2 (SP) × 3 (h)]. Percentage of sperm motility (PSM) increases significantly (p < 0.001) with addition of Se (81.3 ± 1.52), VE (81.0 ± 1.62) and SP (81.5 ± 1.57) vs control (73.4 ± 1.61). There was significant interaction Se × VE (p < 0.001) and Se × VE × SP (p < 0.05) in PSM. However, PSM was affected significantly by time (0 h 83.4 ± 1.92; 2 h 80.7 ± 1.92 and 5 h 67.9 ± 1.92; p < 0.001). There was significant interaction SP × Time (p < 0.05) in PSM. These results indicate that Se, VE and SP improve seminal viability. Addition of 10% of SP maintains PSM at least during 5 hours.     

肉碱对冻融猪精子总抗氧化能力、抗氧化酶基因及凋亡相关基因表达的影响

试验旨在探究肉碱对冻融猪精子质量、抗氧化、抗凋亡及精卵结合能力的影响。试验分鲜精组和冻融组,冻融组的肉碱浓度分别为0、0.025、0.05、0.075 mg/mL,对冻融后的精子质量、总抗氧化能力、抗氧化酶相关基因及凋亡相关基因mRNA表达、精卵结合能力进行检测。结果显示,在冻融组中,经过肉碱处理的精子存活率、质膜完整率和顶体膜完整率均显著高于0 mg/mL处理组（P < 0.05）,其中肉碱浓度为0.05 mg/mL时改善效果最好;经过冻融处理的精子中丙二醛（MDA）浓度与鲜精组相比显著升高（P < 0.05）,其中肉碱浓度为0.05 mg/mL时显著低于其他肉碱处理组（P < 0.05）;与鲜精组相比,各冻融组精子总抗氧化能力均显著降低（P < 0.05）,肉碱浓度为0.05 mg/mL时总抗氧化能力最高。此外,与鲜精组相比,0 mg/mL肉碱处理组中凋亡相关基因Caspase-3与Bax的相对表达量显著升高（P < 0.05）,抗凋亡基因Bcl-2的相对表达量显著降低（P < 0.05）,抗氧化酶相关基因SOD2、CAT与GPx的相对表达量显著降低（P < 0.05）;冻融组精卵结合能力均下降,但肉碱浓度为0.05 mg/mL时可得到显著改善（P < 0.05）。结果表明,添加肉碱可以改善冻融猪精子的质量、抗氧化能力、抗凋亡能力及精卵结合能力。     

Ameliorative Effects of Melatonin against Hydrogen Peroxide‐Induced Oxidative Stress on Boar Sperm Characteristics and Subsequent In Vitro Embryo Development

Melatonin, the major secretory product of the pineal gland, scavenges a variety of reactive oxygen and nitrogen species in vivo and in vitro, indicating that melatonin is a potent function as an antioxidant. The objective of this study was to investigate the effect of melatonin in the presence or absence of hydrogen peroxide (H₂O₂) on sperm characteristics (motility, viability, survival rate, membrane integrity, lipid peroxidation (LPO) and mitochondria activity) and also to examine the developmental rates to the blastocysts stage of porcine oocytes fertilized in vitro with semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ). The sperm were treated with melatonin in the presence or absence of H₂O₂ for 3, 6, 9 and 12 h at 37°C and then analysed for the sperm characteristics. The porcine embryos were produced by in vitro maturation and in vitro fertilization (IVM/IVF) using semen treated with or without melatonin (100 nm ) in the presence or absence of H₂O₂ (250 μm ) for 6 h. The semen characteristics, including motility, viability, survival rate, membrane integrity and mitochondria activity, were higher in the groups that were treated with melatonin in comparison to other groups, irrespective of incubation periods. Malondialdehyde levels in control, melatonin and melatonin + H₂O₂ groups were lower than H₂O₂ only group. A positive correlation was shown among motility, viability, survival rate and membrane integrity, but a negative correlation was observed between LPO and the other evaluation methods. The developmental rates to blastocysts of IVM/IVF porcine oocytes fertilized by semen treated with melatonin were significantly increased compared with any other groups, with the cell number of blastocysts shown to have a similar trend to the developmental rates. These results demonstrate that melatonin can improve the semen characteristics during in vitro storage and support the developmental ability of IVM/IVF embryos in pigs.     

"雅士勇"口服液对猪的射精量和精子畸形率的影响

以大白猪和长白猪为研究材料,对照组不饲喂"雅士勇"口服液,两试验组分别饲喂25 mL和30 mL"雅士勇"口服液,研究"雅士勇"口服液对猪的射精量和精子畸形率的影响。结果表明,"雅士勇"口服液对射精量无明显影响(P>0.05),但对种公猪的精子畸形率有显著影响,对照组的精子畸形率均极显著地高于两个试验组(P<0.01),而两试验组之间精子畸形率差异不显著(P>0.05)。     

Expression of retinoic acid‐metabolizing enzymes,ALDH1A1, ALDH1A2, ALDH1A3, CYP26A1, CYP26B1 and CYP26C1 in canine testis during post‐natal development

Mammalian spermatogenesis involves highly regulated temporal and spatial dynamics, carefully controlled by several signalling processes. Retinoic acid (RA) signalling could have a critical role in spermatogenesis by promoting spermatogonia differentiation, adhesion of germ cells to Sertoli cells, and release of mature spermatids. An optimal testicular RA concentration is maintained by retinaldehyde dehydrogenases (ALDHs), which oxidize RA precursors to produce RA, whereas the CYP26 class of enzymes catabolizes (oxidize) RA into inactive metabolites. The objective was to elucidate gene expression of these RA‐metabolizing enzymes (ALDH1A1, ALDH1A2, ALDH1A3, CYP26A1, CYP26B1 and CYP26C1) and their protein presence in testes of young, peripubertal and adult dogs. Genes encoding RA‐synthesizing isozymes ALDH1A1, ALDH1A2 and ALDH1A3 and RA‐catabolizing isomers CYP26A1, CYP26B1 and CYP26C1 were expressed in testis at varying levels during testicular development from birth to adulthood in dogs. Based on detailed analyses of mRNA expression patterns, ALDH1A2 was regarded as a primary RA‐synthesizing enzyme and CYP26B1 as a critical RA‐hydrolysing enzyme; presumably, these genes have vital roles in maintaining RA homeostasis, which is imperative to spermatogenesis and other testicular functions in post‐natal canine testis.     

Effect of the Interaction Between Cryoprotectant Concentration and Cryopreservation Method on Frozen/Thawed Chicken Sperm Variables

This work examines the effect of the interaction between different concentrations of two cryoprotectants – glycerol (GLY) and dimethylacetamide (DMA) – and two methods of cryopreservation – pellets produced by plunging into liquid nitrogen and gradual in‐straw freezing – on frozen/thawed chicken sperm variables. Sperm was cryopreserved using: (i) 6% DMA, following the in‐straw and the pellet methods (ii) 11% GLY, following the in‐straw and the pellet methods; and (iii) 8% GLY in the in‐straw method and 3% DMA in the pellet method (i.e. reduced cryoprotectant concentrations). When 6% DMA was used as the cryoprotectant, no differences were seen between the in‐straw and pellet methods in terms of frozen/thawed sperm variables or fertility (10.8% and 12.8%, respectively). The viability and motility variables of the frozen/thawed sperm produced using the in‐straw method with 11% GLY were higher (p < 0.05) than those recorded for the sperm preserved using the same cryoprotectant and concentration in the pellet method. However, fertility was extremely low in both groups (2.1% and 4.2% for the in‐straw and pellet methods, respectively). Finally, the use of 8% GLY in the in‐straw method returned higher sperm viability, intact acrosome and motility values than the use of 3% DMA in the pellet method (p < 0.01). No differences were seen, however, in the fertility results obtained (28.8% and 25.0%, respectively). These results suggest that cryoprotectant concentrations can be reduced and still provide acceptable fertility rates.     

Expression analysis of an α‐1, 3‐galactosyltransferase,an enzyme that creates xenotransplantation‐related α–Gal epitope,in pig preimplantation embryos

α‐1,3‐Galactosyltransferase (α‐GalT), an enzyme creating Galα1‐3Gal (α‐Gal) epitope on the cell surface in some mammalian species such as pigs, is known to be a key factor that causes hyperacute rejection upon transplantation from pigs to humans. To establish the RNA interference‐based suppression of endogenous α‐GalT messenger RNA (mRNA) synthesis in porcine preimplantation embryos, we determined the suitable embryonic stage at which stage such approach is possible by using the semi‐quantitative RT‐PCR (qRT‐PCR) and the cytochemical method using a fluorescence‐labeled Bandeiraea simplicifolia Isolectin B₄ (BS‐I‐B₄). Staining with BS‐I‐B₄ demonstrated that α‐Gal epitope expression was first recognized at the 8‐cell stage, and increased up to the hatched blastocyst stage. Single embryo‐based qRT‐PCR also confirmed this pattern. These results indicate that creation of α‐Gal epitope is proceeded by de novo synthesis of α‐GalT mRNA in porcine preimplantation embryos with peaking at the blastocyst stage.     

蓝舌病病毒血清Ⅰ型VP2与VP5、VP3与VP7两组蛋白在杆状病毒系统中的表达与鉴定

为表达具有天然构象的蓝舌病病毒血清1型(BTV1)主要结构蛋白VP2、VP3、VP5和VP7,研制针对流行于我国的BTV1型毒株的病毒样颗粒(virus-like particles,VLP)疫苗提供基础,将编码BTV1 VP2和VP5蛋白的基因分别克隆到双表达载体pFastBacDual的启动子pPH和pP10下游,构建重组质粒pFastBacDualBTV1-VP2-VP5,将重组质粒转化DH10Bac感受态细胞,获得重组穿梭质粒rBacmidBTV1-VP2-VP5,转染Sf9昆虫细胞,获得重组杆状病毒rBacBTV1-VP2-VP5;按照同样策略,制备重组杆状病毒rBacBTV1-VP3-VP7。使用兔抗BTV1-VP5蛋白多克隆抗体和鼠抗BTV-VP7蛋白单克隆抗体,分别对rBacBTV1-VP2-VP5和rBacBTV1-VP3-VP7感染的Sf9细胞进行间接免疫荧光试验(IFA)检测,结果病毒感染细胞可见特异性荧光出现;使用兔抗BTV1-VP2蛋白多克隆抗体和兔抗BTV1-VP3蛋白多克隆抗体,分别对rBacBTV1-VP2-VP5和r BacBTV1-VP3-VP7感染的Sf9细胞进行Western-blot检测,可见相对分子质量约100 kDa左右的条带,大小与预期相符。IFA检测和Western Blot检测结果显示,BTV1 VP2、VP3、VP5和VP7蛋白均得以表达,且具有良好的反应原性。     

Effect of Sperm Cryopreservation and Supplementing Semen Doses with Seminal Plasma on the Establishment of a Sperm Reservoir in Gilts

Frozen-thawed (FT) boar sperm have a reduced fertile life, due in part to a capacitation-like status induced by cooling. Reversal of this cryocapacitation in vitro by exposure to boar seminal plasma (SP) has been demonstrated. The objective of these studies was to determine the effect of SP on the ability of FT sperm to create an oviductal sperm reservoir following artificial insemination (AI). In Experiment one, 35 pre-pubertal gilts were injected (IM) with 400 IU eCG plus 200 IU hCG to induce oestrus. At detection of oestrus, gilts were inseminated with 3 x 10(9) live sperm, either fresh (FS; n = 13), FT (n = 10), or FT supplemented with 10% v/v SP (n = 12). Gilts were killed 8 h later, their reproductive tracts recovered and the uterotubal junctions (UTJs) flushed to recover sperm. Fewer (p < 0.01) sperm were recovered following FT, compared to FS, inseminations, and there was no evident effect of SP. In Experiment two, 30 pre-pubertal gilts received IM injections of 1000 IU eCG followed by 5 mg pLH 80 h later to control time of ovulation. Gilts were inseminated with 3 x 10(9) live FS sperm (n = 6), FT sperm (n = 15) or FT sperm plus 10% SP (n = 9) at 12 h before ovulation and then sacrificed 8 h later. The UTJs were dissected and flushed for sperm recovery. Fewest (p < 0.001) sperm were recovered following FT insemination and there was no evident effect of SP. These data demonstrate that the size of the sperm reservoir is markedly reduced in gilts inseminated with FT sperm. However, the lack of effect of SP suggested that either it did not reverse cryocapacitation or that such a reversal does not impact the in vivo ability to create a sperm reservoir.     

5α-Androstenone and Testosterone in Peripheral Plasma of the Boar During and Following Copulation

Copulation was generally followed by increases in peripheral plasma 5α-androstenone and testosterone levels lasting for periods of about 60 to 100 min. The effect of copulation on the plasma levels of these steroids did, however, vary between boars. In seven out of eight boars the maximum levels of 5α-andro-stenone in the period 60 to 100 min. after copulation were from 114 to 218 % (mean 150 %) of the levels in samples collected before copulation. The corresponding figures for testosterone were from 104 to 283 % (mean 190 %). One boar showed decreasing plasma steroid levels after copulation.The coefficient of correlation between the peripheral plasma levels of 5α-androstenone and testosterone was found to be + 0.61 (n = 2.03).     

日粮精氨酸水平对蛋鸭卵泡膜血管形成相关基因及蛋白表达的影响

本试验旨在研究日粮精氨酸（Arg）水平对蛋鸭卵泡膜血管形成相关基因及蛋白表达的影响。试验选用健康、体重相近的15周龄龙岩山麻鸭396只,随机分为3组,每个组6个重复,每个重复22只,地面平养。试验蛋鸭饲喂不添加Arg的基础日粮（含0.66%精氨酸）2周后,分别饲喂在基础日粮中添加0、0.4%、0.8% L-精氨酸盐酸盐（L-Arg·HCl）的试验日粮,其Arg水平分别为0.66%、1.06%和1.46%,试验期17周。结果显示：①1.06%和1.46% Arg组试验蛋鸭血浆低密度脂蛋白-胆固醇（LDL-C）、卵巢一氧化氮（NO）浓度均显著高于0.66% Arg组（P < 0.05）。②与0.66% Arg相比,1.06%、1.46% Arg组显著上调了试验蛋鸭F2优势卵泡膜同源结构域相互作用蛋白激酶2（HIPK2）mRNA表达水平。而1.46% Arg试验蛋鸭F2优势卵泡膜血管生成素1（Ang1）mRNA表达水平显著高于0.66%、1.06% Arg组（P < 0.05）。③与0.66% Arg相比,1.06%、1.46% Arg组著上调了试验蛋鸭F2优势卵泡膜HIPK2及转化生长因子β1（TGFβ1）蛋白表达水平（P < 0.05）。综上所述,日粮1.46% Arg（在基础日粮中添加0.8% L-Arg·HCl）可通过激活TGFβ信号通路关键因子TGFβ1和HIPK2促进龙岩山麻鸭F2优势卵泡膜血管的形成,增加血流量,促进其优势卵泡的卵黄沉积。