硫酸铜对西门塔尔牛发情周期生殖激素分泌的影响

选用16头18月龄、体况良好、体重380±14kg的西门塔尔牛育成母牛,采用完全随机区组设计分为4组,研究日粮添加硫酸铜(0、8、16和24mg铜/kg)对母牛发情周期生殖激素分泌规律的影响。结果表明:与对照组比较,8mg/kg组发情周期促黄体素(LH)、促卵泡素(FSH)、孕酮(P4)、雌二醇(E2)水平显著提高(P<0.05);16mg/kg组有提高趋势,但差异不显著(P>0.05)。添加8mg铜/kg的硫酸铜对母牛发情周期生殖激素分泌有促进作用,加上基础日粮的含铜量,建议日粮以硫酸铜为铜源时铜水平为13.87mg/kg。     

三元杂交肉鸽与其亲本生产性能的比较

选取成年EK×W系与其亲本E、K和W系成年鸽各150对统计繁殖性能,并对28日龄乳鸽各30只进行体尺、屠宰性能测定,对生产性能进行对比研究。结果显示:EK×W系繁殖性能优良,产蛋窝数、产蛋数和出栏数极显著高于E系(P<0.01);EK×W系体型较大,体斜长比W系约提高2.61%,胸宽和胸深分别比W系约提高3.11%和0.92%,胫围极显著低于E系(P<0.01);EK×W系活重极显著高于W系(P<0.01),屠宰体重、半净膛重和全净膛重分别比W系约提高了5.83%、5.40%和5.14%(P>0.05);EK×W系胸肌重显著高于K和W系(P<0.05),胸肌率比W系约提高1.94个百分点(P>0.05),腹脂率比E系约降低0.49个百分点(P<0.01)。研究表明:EK×W系三元杂交效果良好,繁殖性能优良,乳鸽体重大、胸肌发达。     

Low Incident Light Combined with Partial Waterlogging Impairs Photosynthesis and Imposes a Yield Penalty in Cotton

Through field studies, cotton responses to dual stresses – waterlogging and low light (shade) were investigated. The hypothesis was that shade would amplify yield losses in waterlogged (WL) cotton. Either early or late in the reproductive phase, the crop was WL (96 h and 120 h, in 2012–2013 and 2013–2014, respectively) and/or shaded (6 days or 9 days in 2012–2013 and 2013–2014, respectively). Waterlogging at early reproductive phase significantly reduced lint yield (17 % averaged across both years) of cotton, although shade‐induced yield losses (18 %) were only significant in 2013–2014. Shade significantly exacerbated yield losses only when the impact of waterlogging damage was modest (2013–2014). More intense waterlogging impaired lint yield independently of the light levels. Yield reductions in these experiments were the consequence of both accelerated fruit abscission and fewer fruiting nodes produced. Plants had lower leaf nitrogen levels and photosynthetic rates after waterlogging and/or shade treatments and produced fewer fruiting nodes. Although long‐term shade increased specific leaf area (30 %) and leaf N (20 %) immediately following 5 days of waterlogging, it did not restore shoot growth, node formation or lint yield because of suppressed photosynthetic performance (area basis) and carbohydrate supply.     

饲粮中性洗涤纤维对泌乳母兔生产性能、血清生化和生殖激素指标的影响

本试验旨在研究饲粮中性洗涤纤维(NDF)对泌乳母兔生产性能、血清生化和生殖激素指标的影响。将100只预产伊拉肉兔随机分为4组,每组25个重复,每个重复1只。各组(A、B、C、D组)分别饲喂NDF水平为24%、27%、30%和33%的饲粮。试验期28 d。结果表明:1)C组母兔平均日增重显著低于其他3组(P0.05);D组母兔平均日采食量显著高于其他3组(P0.05),C组泌乳力显著低于其他3组(P0.05),C、D组仔兔断奶个体重显著高于A、B组(P0.05)。2)B组血清总蛋白、白蛋白、球蛋白含量显著高于D组(P0.05),C组血清胰岛素含量显著高于A组(P0.05),各组血清甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇和极低密度脂蛋白胆固醇含量差异不显著(P0.05)。3)B、C组血清促黄体生成激素、孕酮、雌二醇、泌乳素、促卵泡生成激素含量均显著高于A、D组(P0.05)。综合分析认为,在本试验条件下,饲粮NDF水平能够影响泌乳母兔的生产性能和血清生殖激素含量,并对血清生化指标产生一定的影响,泌乳期肉兔适宜的饲粮NDF水平为24%~27%。     

Can female preference drive intraspecific diversity dynamics in brown trout (Salmo trutta,L.)?

Intraspecific diversity can be strongly impacted by the dynamics of reproductive isolation during secondary contacts. The high levels of hybridisation and introgression between Atlantic and Mediterranean lineages in contemporary populations of brown trout in the Northern part of the French Alps are a good case in point. After a long period of allopatry, which one assumes has facilitated their divergent phenotypic and genetic evolution, man has removed a geographical reproductive barrier via stocking the Atlantic lineage in the Mediterranean area, thereby potentially enabling gene flow between native and non native populations. We investigate how much a prezygotic reproductive behaviour, that is female preference for male phenotype, can influence hybridisation in natural environments, using subaquatic video recording of reproduction. Our statistical model indicates that female preference appears to be largely heterogamous: females tend to select dissimilar males with respect to their own phenotype; thus, rather than acting as a barrier to gene flow, female preference is favouring gene flow between lineages that have been artificially placed in sympatry. This finding based on observational data is in agreement with previously reported genetic data, high levels of hybridisation between the lineages. We suggest that a knowledge of reproductive behaviour in natural environments is an essential tool for biodiversity managers to assess the potential risks associated with the introduction into recipient populations of non‐native lineage fish at the intraspecific level.     

Review for Porcine Reproductive and Respiratory Syndrome Virus

Abstract Porcine reproductive and respiratory syndrome(PRRS)is the severest disease of pigs worldwide,caused by a highly genetically diverse RNA virus,called Porcine reproductive and respiratory syndrome virus(PRRSV).The research summarized the genome characteristics of PRRSV particles and the most updated knowledge of structure protein function,and introduced the intellectual of PRRSV transmission and host immune response,which is very important for prevention and control for PRRS.A report showed that mass vaccination can stabilize the immunity of the entire herd,and this is the first required step for a PRRS eradication plan.However,the attenuated live vaccines may not achieve a valid prevention.The final goal of the EU project is to develop new generation,efficacious and safe maker vaccines that can be adapted to temporary changes and geographical differences.Robinson reported that broadly antibodies could neutralize all rapidly evolving typeⅠand typeⅡviruses,while further studies are expected to elucidate mechanisms of neutralizing antibody production and maturation and to investigate conserved epitope targets of cross-neutralization in this rapidly evolving virus.     

四季鹅母鹅生殖内分泌的研究

本实验用放射免疫法测定了四季鹅母鹅在生长发育、产蛋和抱窝期生殖激素分泌变化的规律。结果发现，在生长发育期血浆促黄体素（ＬＨ）和１７β—雌二醇（１７β—Ｅ２）水平随日龄增长而呈上升趋势，至１８０日龄ＬＨ和１７５—Ｅ２均达到最高值，分别为１．１５６±０．１４７ｎｇ／ｍｌ和２３６．５６±３４．２９Ｐｇ／ｍｌ，开产后二者均有所下降。孕酮（Ｐ）在初生时较高达１．８６±０．４８ｎｇ／ｍｌ，之后逐步下降，至开产后Ｐ含量大幅度增加，提示：ＬＨ和１７β—Ｅ２能促进生殖器官的发育。母鹅卵巢小卵泡的Ｐ转变为１７β—Ｅ２的能力较强。在产蛋期，产蛋前ＬＨ在１３小时内，Ｐ在１２小时内（个别为２０小时）出现２次高峰。产蛋前Ｐ高峰为４—５小时，而ＬＨ峰则于产蛋前１—３小时出现。ＬＨ的峰可诱导成熟卵泡排卵，Ｐ则引起ＬＨ峰的出现。在抱窝期，促卵泡素（ＦＳＨ）、Ｐ、１７β—Ｅ２有相似的变化模式。初期较高，中期最低，至雏鹅出壳则三者水平有所回升。但促乳素（ＰＲＬ）则相反，初期急剧上升，至中期最高，接近雏鹅出壳时下降，出壳后仍维持一定水平，至休产期才降至低水平。ＰＲＬ对抱窝和母性行为上具有重要作用。