药物脱绒对辽宁绒山羊血清激素及酶水平的影响

将12只4岁雌性健康辽宁绒山羊,随机分为4组,分别为对照组、埋植褪黑素（每只60 mg）组、埋植褪黑素（每只60 mg）+注射环磷酰胺（26 mg·kg-1）组及注射环磷酰胺（26 mg·kg-1）组,分别于试验开始后0、30和50 d采样,检测血清激素及酶水平,以分析药物脱绒对辽宁绒山羊血清激素及酶水平的影响。结果表明,褪黑素可提升辽宁绒山羊血清α 淀粉酶（A AMY）、碱性磷酸酶（ALP）的水平,降低肾上腺皮质激素（ACTH）、皮质醇（Cor）、表皮生长因子（EGF）、血清肌酸磷酸激酶(CPK)的含量;环磷酰胺可提升CPK、A AMY、Cor的水平,降低碱性磷酸酶（ALP）、褪黑素（MT）的含量。说明,埋植褪黑素可以在一定程度上降低环磷酰胺脱毛引起的应激反应。     

褪黑素对核苷酸结合寡聚域样受体蛋白3炎性小体的影响及其机制

随着畜牧业集约化生产水平的不断提高,动物炎症带来的经济损失逐渐受到重视。细胞表面Toll样受体(TLRs)可以通过活化胞浆内核转录因子-κB(NF-κB),诱导核苷酸结合寡聚域样受体蛋白3(NLRP3)炎性小体表达,加剧炎症反应。本文就NLRP3炎性小体与炎症疾病,褪黑素对TLRs、NF-κB和NLRP3炎性小体的作用以及炎症对动物生产的影响作一综述。     

褪黑激素对长毛兔产毛性能及兔毛品质的影响

试验旨在研究褪黑激素(Melatonin,MT)对长毛兔夏季产毛的影响。选择1.5岁左右的皖系长毛兔60只,其中公兔40只,母兔20只,随机分为4组,分别皮下埋植0、25、40、55 mg的褪黑激素,经过70 d的养毛期后测定各组产毛量及粗毛和细毛的长度变化差异,分析褪黑激素对长毛兔产毛性能的影响。结果显示:公兔40 mg埋植组产毛量显著高于埋植前产毛量(P<0.05),55 mg埋植组产毛量显著高于对照组产毛量(P<0.05);母兔对照组试验后剪毛量显著低于试验前剪毛量(331.0 g vs 284.8 g,P<0.05),而3个褪黑激素埋植组试验后产毛量下降幅度并不显著(P>0.05)。皮下埋植40 mg或55 mg褪黑激素能够增加皖系长毛兔公兔或母兔的粗毛长度,但对细毛长度和兔毛细度均无显著影响(P>0.05)。说明长毛兔皮下埋植40 mg和55 mg褪黑激素能够提高公兔夏季产毛量且抑制母兔夏季产毛量的降低,同时增加公、母兔粗毛长度。研究结果可为褪黑激素的合理利用提供参考,并为揭示其对促进长毛兔夏季兔毛生长的作用机制奠定基础。     

外源褪黑激素对昆明白鼠生长和繁殖性能的影响

研究外源褪黑激素(MT)对昆明白小鼠生长和繁殖性能的影响,为外源MT在畜牧生产上的应用提供依据。将40只昆明白小鼠(公、母各半)随机分成4组,用皮下埋植的方法埋植不同剂量(0、1、4、8mg)的外源MT,每3d称量1次小鼠的体重并记录;MT处理11周后,试验公鼠与正常母鼠交配,记录受精卵的数量;试验母鼠与正常公鼠交配,记录冲出卵的数量,14周后HE染色,制作睾丸和卵巢切片。在体重增长方面,外源MT对昆明白公鼠体重增长有促进作用,皮下埋植8mg组的促进作用显著(P<0.05);对昆明白母鼠体重增长有抑制作用,皮下埋植8mg组的抑制作用显著(P<0.05)。在繁殖性能方面,外源MT对昆明白鼠公鼠繁殖性能抑制作用显著,皮下埋植1mg和4mg组抑制作用显著(P<0.05),但皮下埋植外源MT8mg组和对照组间无统计学差异(P>0.05)。外源MT对昆明白鼠生长和繁殖性能有影响,并存在性别和剂量的依赖性。     

光照和褪黑激素对非生绒期绒山羊激素分泌和绒毛生长的影响

为了研究光照和褪黑激素对绒山羊激素分泌和绒毛生长的影响。作者采用随机试验区组的方法,把36只绒山羊平均分成3组,分别进行长光照、短光照和自然光照处理,每组当中一半埋植褪黑素,分别检测血液激素水平和绒毛生长状况。结果表明,光照时间和埋植褪黑素显著影响绒山羊体内的激素分泌,长光照抑制褪黑素的分泌,短光照促进褪黑素的分泌,埋植褪黑素组的血浆褪黑素水平显著高于不埋植组。光照和褪黑素显著影响PRL、IGFI的分泌类型,并与绒山羊的绒毛生长有关,短光照或褪黑激素处理各组绒毛平均增加338.83 g;新生羊绒的长度、细度、强度等品质指标均符合纺织工业标准的要求。     

Effect of Acute Sleep Deprivation on Melatonin Level of Plasma and Clock Gene Expression of Hypothalamus in Mice

This study was conducted to investigate the changes in plasma Melatonin (MT) level and hypothalamic clock gene expression in mice after sleep deprivation (SD). Seventy-two mice were randomly divided into SD group and non-sleep-deprived control group (n=36). The SD mice were subjected to a modified multiple platform water path for 72 h sleep deprivation. After that, blood samples were taken every four hours (CT4,8,12,16,20 and 24) for the detection of plasma MT content, and hypothalamus samples were collected for the detection of the expressions of clock genes including mClock, mBmal1, mCry1/2, mPer1-3, mRorβ and mReverbα. The results showed that compared with control group, circadian rhythm of plasma MT was disordered in SD group. The median values of mClock, mRorβ and mReverbα in the hypothalamus decreased significantly (P<0.05), but mPer1 and mPer2 increased significantly (P<0.01); the circadian rhythms of mCry1 and mCry2 disappeared; the expression rhythms of mBmal1, and mClock were advanced in phase, while mRorβ and mPer1-3’s were delayed. These results suggested that acute sleep deprivation of 3 d could cause disorders of MT secretion and hypothalamic clock gene expression in mice.     

Effects of tryptophan supplementation on plasma tryptophan and related hormone levels in heifers and dairy cows

This study was conducted to investigate the effects of rumen-protected tryptophan (125 g tryptophan per day) in heifers and dairy cows. Blood samples from dairy cows and heifers were collected for 24h in 3-h intervals on the day before tryptophan supplementation, on day 2, 5 and 7 of tryptophan supplementation, and in heifers additionally on d 14 after tryptophan supplementation was ceased. Plasma tryptophan, melatonin, serotonin, and prolactin concentrations were determined. Tryptophan plasma concentrations on d 5 were augmented at day (11:00 h) and nighttime (02:00 h), (P<0.05) in response to tryptophan supplementation in heifers by 119% and in dairy cows by 47%, respectively, as compared with d 0. Melatonin increased (P<0.05) in response to tryptophan supplementation in heifers, but not in cows. The effect of tryptophan supplementation on plasma tryptophan and melatonin was reversible as demonstrated in heifers on d 14 after cessation of tryptophan supplementation. Serotonin and prolactin in plasma did not respond to tryptophan supplementation. However, milk yield during morning milking increased significantly in tryptophan supplemented cows on d 1, 3 and 4 as compared to the day before tryptophan supplementation. Additional blood samples were taken during afternoon milking in cows at 1-min intervals for the analyses of oxytocin and prolactin on the day before the start and on d 7 of tryptophan supplementation. Milk flow curves were recorded during milking. No effect of tryptophan supplementation on the milking related release of oxytocin and prolactin and on any characteristic of milk flow was observed. In conclusion, tryptophan supplementation caused increased plasma tryptophan in cows and heifers and plasma melatonin in heifers. However, plasma serotonin, prolactin and oxytocin release in cows remained unchanged by tryptophan supplementation. Milk yield at morning milking increased slightly and transiently in response to tryptophan supplementation.     

不同稀释液对猪精液常温保存效果的研究

主要从稀释液的组分，抗生素的种类以及抗氧化剂的添加来研究猪精液常温保存的稀释液配方，结果表明，含有一定量的牛血清白蛋白有利于猪精液的保存，通过恩诺沙星，氧氟沙星，庆大霉素，菌特灵与青，链霉素对精液保存效果的比较，表明添加50μg/mL的恩诺沙星的保存效果优于其它抗生素，不同浓度的褪黑激素对精液保存有一定的影响，10^-5mol/L的褪黑激素可延长精子的存活时间。     

褪黑激素ELISA方法的建立

将褪黑激素（MLT）与牛血清白蛋白（BSA）连结的复合物（MLT：BSA＝12：1）免疫5只雄性新西兰大耳兔，收集高效价血清，并提纯抗体。在96孔微量反应板上，以1：10000的抗体包被，将MLT与酶标MLT先后加入到板中竞争结合抗体，制定标准曲线，建立了MLT酶联免疫测定法（MLT－ELISA）。此方法灵敏度为17．31pg,板内变异系数8．1％，板间变异系数15．4％，用建立的此法测定夏至时考力代羊昼夜血样，测定结果跟国外报道的基本一致；用放射免疫法检测同一批血样，也获得类似结果，从而表明此方法可信。     

光照和埋植褪黑激素对非生绒期内蒙古白绒山羊体成分的影响及应用

本文从体成分的角度研究了褪黑激素对内蒙古白绒山羊营养分配的影响,研究结果显示光照时间和埋植褪黑激素显著影响绒山羊的有关激素水平,进而影响体成分组成。随着光照时间的缩短,绒山羊的体脂肪含量增加,体蛋白含量减少;光照相同条件下,埋植褪黑激素组的体脂肪含量高于不埋植组,体蛋白含量低于不埋植组,短光照和埋植褪黑激素之间有显著(P<0.01)的互作效应。证明了光照和褪黑激素在动物营养分配中的作用,为褪黑激素在生产实践中的合理应用提供理论依据。