饲养条件对黄粉虫幼虫生长及存活的影响

采用5因素2次正交旋转组合设计,以黄粉虫幼虫饲养过程中饲养温度(X1)、相对湿度(X2)、虫粪筛除频率(X3)、饲养密度(X4)以及饲料含水量(X5)5因素为参试因素,考查它们对黄粉虫高龄幼虫的生长及存活的影响,建立并进行了简化得到了以黄粉虫幼虫增重率及死亡率为目标函数的回归模型：Y增＝127．5079 18．6559x5 2．7894x3x4-2．3854x3x5-3．0594x1^2 1．824lx3^2-3．8559x5^2;y死＝1．7459 0．4l08x1 0．0975x2 0．9025x4 0．3442x5 0．0834x1^2 0．3060x4^2-0．2623x5^2。分析结果表明：影响黄粉虫幼虫生长后期增重及死亡的主要因素分别为饲料含水量和饲养密度;饲料含水量和温度对黄粉虫增重有着重要的影响,饲养密度、温度、饲料含水量对黄粉虫的死亡有着重要的影响,其影响均达1％或5％显著水平;推荐的饲养条件为：温度24—27℃、相对湿度64％一70％、筛粪频率2—4d／次、饲养密度0．42-0．49g／cm^2、饲料含水量l3．48％-l7．48％。     

窝雏数处理对两种雀形目幼鸟生长的影响

基于 1 997～ 1 999年野外实验 ,对高寒草甸小云雀和黄嘴朱顶雀两种雀形目鸟的窝雏数进行增减处理。结果表明 ,对照组的幼鸟生长率和离巢体重都大于增加组 ,说明窝雏数增加后 ,幼鸟质量下降。随着窝雏数增加 ,这两种幼鸟生长率显著下降 (小云雀 :r =-0 965 ,P =0 0 3 5 <0 0 5 ;朱顶雀 :r =-0 82 8,P =0 0 2 2 <0 0 5 )。窝雏数改变对小云雀幼鸟出飞重影响不显著 (r =-0 41 8,P =0 5 2 8>0 0 5 ) ,而对黄嘴朱顶雀有显著的影响 (r=-0 90 1 ,P =0 0 1 4<0 0 5 )。     

滑鼠蛇的繁殖输出及孵化热环境对孵出幼体表型特征的影响

用15条2002年6月中旬捕自浙江丽水的怀卵滑鼠蛇研究繁殖输出及孵化热环境对孵出幼体表型特征的影响。母体在捕后3周内各产一窝柔性卵。窝卵数、窝卵重和卵大小均随母体体长增加而增大,平均值分别为13．3(枚卵)、332．4g和24．8g。窝卵数和卵大小的变异系数分别为0．18和0．13。窝卵数与产后母体状态呈正相关,卵数量和大小无关。每窝部分可孵卵分别用恒温(24、27、30、33℃)和21．0-39．0℃(平均28．3℃)范围内的波动温度孵化,每隔5d记录恒温孵化卵的重量。孵化热环境对卵与环境之间的水分交换有显著影响,并影响孵化卵重量的时间变化。24、27、30、33℃和波动温度的平均孵化期分别为105．4、78．0、57．8、51．3和58．6d。不同热环境下的孵化成功率和幼体畸形率有一定差别,但统计上不显著。24℃和30℃孵出幼体雄性比例较高,27℃、33℃和波动温度孵出幼体雌性比例较高,但没有证据表明孵化温度能决定滑鼠蛇性别。除孵出幼体灰分含量外,孵化温度对其它幼体特征均有显著影响。33℃孵出幼体SVL较小,但剩余卵黄和其中的灰分含量大于其它温度孵出的幼体。24℃和30℃孵出幼体的总干重、总能量、躯干干重、脂肪体干重总体上小于27℃和波动温度孵出幼体。24℃孵出幼体特征性具有最小的剩余卵黄,33℃孵出幼体则特征性地具有最大的剩余卵黄。24℃和30℃孵出幼体特征较为接近,27℃和波动温度孵出幼体较为接近。对9个幼体特征变量做主成分分析发现,第一和第二主成分共解释81．2％的变异。幼体SVL、湿重、干重、脂肪含量、能量、躯干干重和脂肪体干重在第一主成分有较高的正负载系数(解释56．9％变异),剩余卵黄干重在第二主成分有较高的正负载系数(解释24．3％变异),第一和第二主成分的分值均差异显著。主成分分析进一步显示,24、30和33℃孵出幼体总体上小于27℃和波动温度孵出幼体[动物学报50(4)：541-550,2004]。     

灰仓鼠的室内繁殖研究

根据实验室饲养的灰仓鼠资料和观察对该鼠的繁殖进行了研究。结果显示：该鼠的好斗习性经过5年驯养已较温顺。性成熟为50d,动情周期4～4．5d,交配高峰在晚上23．00点至次日1．00点,妊娠周期19d（16～21）,平均产仔间隔39．25d.窝仔数4．59只／窝（1～10）,离乳成活率64．5％,雌雄性比0．883（242／274）,并就以上三个指标在不同季节、不同胎次和不同繁殖代数进行了比较。雌体繁殖高峰3～12月,雌、雄体最长繁殖年限分别1．5和2．0年,寿命2．5年以上。     

海枣曲霉木聚糖酶的提纯和性质

通过硫酸铵分段、异丙醇分段、Sephadex G一100凝胶过滤、及DEAE-Sephadex A-50离子交换柱层析等提纯步骤,从海枣曲霉(Aspetgillu,phornicis)的麦麸培养物抽提液中分离到4个成份的木聚糖酶,分别称之为X一1、X—II、x—III和X—IV。 经7％凝胶浓度的圆盘电泳及薄层等电聚焦分析,x一1、X．IJ和x—Ill皆为均一成分,x—Iv中则仍杂有少量X~llIo X-I的最适pH为4．0,最适温度45℃,在pH 5．0--9．0之间稳定,保温30分钟时的半失话温度t为90℃。X一和x一 的最适 分别为{．及5．,最适温度均为,稳定pH范I 11 IlI pH 50 50~(3画分别为6．0—10．0及7．0--10．0,t1分别为60及55"C。SDS一凝肢电泳法测得x一’、x-r／和x—111的分子量分别为26,500、35。,500及22,000。薄层凝胶等电聚焦法测得三者的等电点分别为{．7、{．4和4．0。在所测定的化学试剂中,Ag’、Hg’’和Mn冲对这三个酶均有较强烈的抑制作用。sDS对x—I活力影响较小,对x_I】和x—Ill则有强烈的抑制作用。脲对X-1的抑制作用大,对X-II和X—Ill的抑制作用小。     

台湾中部暗绿绣眼鸟的繁殖生物学

本研究将暗绿绣眼鸟 (Zosteropsjaponicasimplex)捕捉、套彩色环后释放 ,分别于 1999年和 2 0 0 1年 3～ 8月追踪监测 7对和 13对暗绿绣眼鸟的繁殖行为。总结此二年对 2 0对暗绿绣眼鸟的监测 ,其繁殖期始于 3月中旬 ,终止于 8月下旬。 1对最多可年产 5窝 ,但以 3～ 4窝为常见。初次筑巢所需时间平均为 10 4d ,筑第 2、3巢的时间依次减少 ;窝与窝之间的繁殖间隔视情况而定 ,如孵化或喂养失败 ,通常都在 1～ 2d内再筑巢 ,如繁殖育雏成功 ,平均相隔 7d再筑巢。 2年 6 3窝的窝卵数平均为 2 6 8± 0 71(n =6 3)枚 ;孵化期平均为 11±0 6 4 (n =4 7)d ;6 3窝孵化成功 4 7窝 ,孵化成功率为 74 6 % ;雏鸟离巢日龄平均为 10 5± 0 88(n =35 )d ;4 7窝雏鸟喂养成功 35窝 ,育雏成功率为 74 5 % ;6 3窝繁殖成功 35窝 ,繁殖成功率为 5 5 5 %。失败因素包括气候、动物掠食、人为破坏和其它不明原因     

中年男性红细胞压积正常参考值与地理因素的因子分析

目的:为制定中国中年男性红细胞压积正常参考值的统一标准提供科学依据．方法:收集了中国380个地区用温氏法(Wintrobe)测定的32475例健康中年男性红细胞压积正常参考值,运用偏相关分析和因子分析对其与海拔高度(x1),年日照时数(x2),年平均相对湿度(x3),年平均气温(x4),年降水量(x5)的关系进行了研究．结果: 5个地理影响因素值与中年男性红细胞压积正常参考值的偏相关系数分别为: r1,2345=0.651,r2,1345= -0．039,r3,1245=-0．040,r4,1235=-0．281,r5,1234=0．125．运用因子分析将5个地理影响因素综合成两个公共因子F1,F2,并用其得分值代替原始数据推导出一个回归方程: y=48 464 0．1738F1-0.4125F2±4 5％结论:海拔高度是影响中年男性红细胞压积正常参考值的最主要因素．随着海拔高度逐渐增大,中年男性红细胞压积正常参考值也逐渐增大,相关性很显著．如果知道中国某地的地理因素值,可以用公因子的回归方程来估算中国某地的中年男性红细胞压积正常参考值．依据中年男性红细胞压积正常参考值与地理因素的依赖关系把中国分为青藏区,西南区,西北区,东南区,华北区,东北区六个区．     

子宫内膜癌组织中survivin蛋白和VEGF表达的意义及相关性分析

目的：探讨子宫内膜癌组织中survivin（存活素）蛋白和VEGF（血管内皮生长因子）表达及其意义。方法：运用免疫组织化学S-P法,检测20例正常子宫内膜组织、20例不典型增生子宫内膜和63例子宫内膜癌组织中survivin蛋白和VEGF的表达,并结合临床病理特点进行分析。结果：survivin蛋白、VEGF的阳性表达率在正常子宫内膜组织、不典型增生子宫内膜、子宫内膜癌中逐渐升高,三者之间有显著性差异（x2=-24．97,P〈0．01;x2=18．65,P〈0．01）。在子宫内膜癌中,survivin蛋白的表达与组织学分级和手术-病理分期密切相关（X2=9．20,P〈0．05;X2=20．60,P〈0．01）;VEGF的表达与组织学分级无关（X2=4．93,P〉0．05）,而与手术-病理分期分期密切相关（x2=-38．10,P〈0．01）。survivin表达与VEGF表达呈显著正相关（r=0．257;p〈0．05）。结论：survivin、VEGF分别通过抑制细胞凋亡、诱导新生血管的形成而影响子宫内膜癌的发生和发展,其在子宫内膜癌的发生中可能存在协同作用。     

母猪生产力性状的遗传分析

对二花脸猪、大白猪及其杂交一代３个群体共１６８６窝的生产力性状资料进行了遗传分析。用公畜模型估计了初生窝重、初生仔猪平均重、２０日龄窝重、２０日龄仔猪平均重、４５日龄窝重、４５日龄仔猪平均重的表型参数和遗传参数。与大白猪相比,二花脸猪抚育能力较强,生长速度较慢。前４个性状受母体影响较大,后２个性状受母体影响较小。６个性状的遗传力分别为０．２５１、０．２７７、０．３４１、０．３３０、０．２３５、０．     

桓仁滑蜥生殖行为及生殖策略的研究

桓仁滑蜥（Scincella huanrensis）系卵胎生,1年生殖1次,生殖季节为7月下旬到8月上旬。平均每只雌蜥产仔4．556（2～6）只。雌蜥的分娩在洞穴中进行,分娩时间可持续60-90min,仔蜥在产出时卵膜已破裂。雌性采取的是高投入的生殖策略,平均生殖投入率0．436（0．212～0．526）。相关性回归分析表明：窝仔数与雌蜥体重、体长和生殖投入呈正相关关系;生殖投入与雌蜥的体重和体长不相关;幼蜥的体长、体重与窝仔数呈负相关关系。     

Breeding replacement gilts for organic pig herds

In this study, breeding structures and commercial sow lines were evaluated by economic and genetic simulation studies for their suitability to provide the Dutch organic pig sector with replacement gilts. Sow and litter performance from over 2000 crossbred sows from 2006 to 2007 were collected on 11 to 14 Dutch organic pig herds, respectively, and compared with conventional herds. Results showed that organic herds had lower farrowing rates (3.6% to 7.5%), more live born piglets per litter (0.4% to 1.2%) and higher preweaning mortality rates (7% to 13%) compared to conventional herds. These results were used to simulate economic performance of various combinations of breeding structures and sow lines under organic conditions, under the assumption of absence of genotype-environment interactions. Sow and litter performance data under organic conditions (total piglets born/litter, stillborn piglets/litter, mortality until weaning, lactation length, interval weaning-oestrus and sow culling rate) and the costprice calculation for the Dutch organic pig sector were used as input for the economic simulation studies. The expected genetic progress was simulated for three potential breeding structures of the organic sector: organic breeding herds producing F1 gilts (OrgBS), a flower breeding system (FlowerBS) and a two-line rotation breeding system (RotBS). In FlowerBS, an organic purebred sow line is bred, using on-farm gilt replacement. The OrgBS with a Yorkshire × Landrace cross had the highest margin per sow place (€779), followed by RotBS with Yorkshire × Landrace cross (€706) and FlowerBS with Yorkshire sow line (€677). In case that an organic purebred sow population of 5000 sows would be available, FlowerBS gave the highest genetic progress in terms of cost price reduction (€3.72/slaughter pig per generation), followed by RotBS and OrgBS (€3.60/slaughter pig per generation). For FlowerBS, additional costs will be involved for maintaining a dedicated breeding programme. In conclusion, OrgBS using conventional genetics is economically the most viable option for the organic pig sector. However, this structure has clear disadvantages in terms of risks with regard to disease transmission and market demand. FlowerBS using a dedicated purebred organic line will only be cost-effective if sow population size is sufficiently large. RotBS might be a viable alternative, especially in combination with artificial insemination (AI) boars that are ranked according to an organic selection index. Regardless of breeding structure, the Yorkshire sow line gave the highest prolificacy and the highest economic returns on organic herds.     

母猪繁殖力性状影响因素分析及遗传参数估计

母猪繁殖力是影响种猪场经济效益的重要因素。文章对纯种大白猪、长白猪、杜洛克猪的8491窝产仔记录进行统计分析,建立固定效应模型对总产仔数、健仔数、初生窝重、弱仔数、死胎数、木乃伊胎数和畸形胎数共7个繁殖性状进行最小二乘分析,分析胎次、配种季节、品种对母猪繁殖性能的影响,同时比较了纯繁和杂交的效果。利用动物模型REML(约束最大似然)方法估计繁殖性状的遗传力和遗传相关。结果表明,胎次、配种季节和品种对总产仔数、健仔数、初生窝重影响极显著(P<0.001),胎次和品种对弱仔数影响极显著(P<0.001),但配种季节对弱仔数影响不显著。胎次对死胎数影响显著(P<0.05),而配种季节和品种对死胎数影响不显著,胎次、配种季节和品种对木乃伊胎、畸形胎数影响不显著。长白♂×大白♀交配组合具有最高的总产仔数、健仔数和初生窝重。繁殖性状遗传力估计结果显示,长白猪初生窝重的遗传力最高,为0.227。其余性状遗传力均在0.2以下,为低遗传力性状。3个品种母猪的健仔数与初生窝重、总产仔数与健仔数之间的遗传相关达0.96以上。研究结果为降低非传染性因素造成的种母猪产仔数低的问题以及种猪场对母猪繁殖力的选育提高提供了参考数据和理论依据。     

A Genome-Wide Association Study in Large White and Landrace Pig Populations for Number Piglets Born Alive

The number of piglets born alive (NBA) per litter is one of the most important traits in pig breeding due to its influence on production efficiency. It is difficult to improve NBA because the heritability of the trait is low and it is governed by a high number of loci with low to moderate effects. To clarify the biological and genetic background of NBA, genome-wide association studies (GWAS) were performed using 4,012 Large White and Landrace pigs from herdbook and commercial breeding companies in Germany (3), Austria (1) and Switzerland (1). The animals were genotyped with the Illumina PorcineSNP60 BeadChip. Because of population stratifications within and between breeds, clusters were formed using the genetic distances between the populations. Five clusters for each breed were formed and analysed by GWAS approaches. In total, 17 different significant markers affecting NBA were found in regions with known effects on female reproduction. No overlapping significant chromosome areas or QTL between Large White and Landrace breed were detected.     

猪产仔数性状基因效应与有效基因数的研究

利用太湖猪（Ｐ１）、长白猪（Ｐ２）、杂交一代（Ｆ１）、杂交二代（Ｆ２）、杂交三代（Ｆ３）;和回交一代（Ｂ２）等６个世代产仔数的材料,分析了猪产仔性状的基因效应和基因数。结果表明上位效应不显著,猪产仔数性状符合加性－显性遗传模式,受一个有效基因控制。太湖猪产仔数性状基因加性值比长白猪高１．３９头,太湖猪高产仔数基因对长白猪等位基因呈显性,显性度为０．８１。     

Body weight loss during lactation and its influence on weaning-to-service interval and ovulation rate in Landrace and Yorkshire sows in the tropical environment of Thailand

The aim of this study was to investigate the ovulation rate and the weaning-to-service interval (WSI) of sows in relation to their body weight loss during lactation in tropical climatic conditions. Effect of lactation length (LL), number of total born piglets, number of live born piglets, litter birth weight, average piglet birth weight, number of pigs weaned, litter weaning weight and average pig weaned weight on sow weight loss during lactation were also studied. This study was conducted in two commercial purebred sow herds (A, B) in the central part of Thailand from August to December 1997. The herds had both Landrace (L) and Yorkshire (Y) sows. The 123 sows (55 L and 68 Y) in herd A and 153 sows (95 L and 58 Y) in herd B, parity 1-4, were weighed within 4 days after farrowing and at weaning. Lactation length, litter size at birth and at weaning, litter weight at birth and at weaning, and WSI were recorded for each of these sows. In herd A, 52 sows (20 L and 32 Y) were examined once by laparoscopy between days 8 and 14 after AI-service. These sows had farrowed at least seven piglets in the previous parturition. The numbers of corpora lutea (CL) in both ovaries were counted, and were assumed to equal the ovulation rate. L-sows had significantly (P < 0.05) higher relative weight loss during lactation (RWL) than Y-sows. The RWL increased by 0.7% for each extra pig weaned. When LL increased by 1 day, within the interval of 17-34 days, RWL decreased by 0.6%. Sows with a high weight loss had significantly (P < 0.05) longer WSI than sows with medium or low weight loss. Weight loss had a significant (P < 0.05) effect on WSI in parity 1 and 2 sows. Y-sows had more CL than L-sows (15.7 versus 14.0) (P < 0.05). RWL, parity and regression on lactation length had no significant effect on number of CL. In conclusion, sows with higher number of pigs weaned lose more weight. Under the restricted feeding regime applied, high weight loss during lactation prolongs WSI in parity 1 and 2 sows, but has no influence on the ovulation rate at first oestrus after weaning. The ovulation rate is higher in Yorkshire than in Landrace sows. The ovulation rate is independent of parity.     

母猪繁殖力性状影响因素分析及遗传参数估计

母猪繁殖力是影响种猪场经济效益的重要因素。文章对纯种大白猪、长白猪、杜洛克猪的8491窝产仔记录进行统计分析, 建立固定效应模型对总产仔数、健仔数、初生窝重、弱仔数、死胎数、木乃伊胎数和畸形胎数共7个繁殖性状进行最小二乘分析, 分析胎次、配种季节、品种对母猪繁殖性能的影响, 同时比较了纯繁和杂交的效果。利用动物模型REML(约束最大似然)方法估计繁殖性状的遗传力和遗传相关。结果表明, 胎次、配种季节和品种对总产仔数、健仔数、初生窝重影响极显著(P<0.001), 胎次和品种对弱仔数影响极显著(P<0.001), 但配种季节对弱仔数影响不显著。胎次对死胎数影响显著(P<0.05), 而配种季节和品种对死胎数影响不显著, 胎次、配种季节和品种对木乃伊胎、畸形胎数影响不显著。长白♂×大白♀交配组合具有最高的总产仔数、健仔数和初生窝重。繁殖性状遗传力估计结果显示, 长白猪初生窝重的遗传力最高, 为0.227。其余性状遗传力均在0.2以下, 为低遗传力性状。3个品种母猪的健仔数与初生窝重、总产仔数与健仔数之间的遗传相关达0.96以上。研究结果为降低非传染性因素造成的种母猪产仔数低的问题以及种猪场对母猪繁殖力的选育提高提供了参考数据和理论依据。     

Molecular Cloning of Porcine SUN5 Gene and Association between a SNP with Litter Size Trait

SUN domain-containing protein 5 (SUN5) is an important reproduction related gene. In this study, we cloned the full-length coding sequence of porcine SUN5 gene through RT-PCR. Sequence analysis of this gene revealed that the pig SUN5 gene encodes a protein of 383?amino acids that has high homology with the SUN5 protein of eight species: wild Bactrian camel (95%), alpaca (95%), Yangtze River dolphin (94%), sperm whale (94%), sheep (93%), black flying fox (93%), goat (92%), and horse (91%). This gene is structured into 13 exons and 12 introns as revealed by computer-assisted analysis. The prediction of transmembrane helices showed that pig SUN5 protein might be a transmembrane protein. PCR-Taq I-RFLP was established to detect the GU475008:c.138 G>A substitution of porcine SUN5 gene coding sequence and eight pig breeds displayed obvious genotype and allele frequency differences at this mutation locus. Association of this SNP with litter size traits was assessed in Large White (n?=?200) and Landrace (n?=?200) pig populations, and the results demonstrated that this polymorphic locus was significantly associated with the litter size of all parities in Large White and Landrace sows (P?相似文献   

Effects of teat number on litter size in gilts

This study was carried out to investigate the effects of teat number and interval at first estrus and mating on litter size in Duroc, Landrace and Yorkshire gilts. Gilt body weight at first estrus was from 101.5 kg to 115.3 kg and gilts normally attained puberty at 170.5-181.5 days of age. Breed differences among Duroc, Landrace and Yorkshire in body weight and age at first estrus and mating were found. Total teat number of Duroc, Landrace and Yorkshire were 12.5, 14.9 and 13.7, respectively. Teat interval from pectoral to inguinal region and from left to right at first estrus and mating did not show any differences among the breeds. In conclusion, 14 or more teat number compared to 11-13 teat number in gilts increased litter size at birth and at 21 day weaning.     

Evaluation of the porcine melanocortin 4 receptor (MC4R) gene as a positional candidate for a fatness QTL in a cross between Landrace and Hampshire

Melanocortin 4 receptor (MC4R) is expressed in the appetite-regulating areas of the brain where it is central in the regulation of feed intake and energy balance. A mutation in MC4R causing an Asp298Asn substitution has been associated with fatness, high daily gain and feed intake in the pig. In a previously performed genome scan based on a Hampshire x Landrace cross, we detected one quantitative trait loci (QTL) affecting carcass fat/meat ratio and one QTL affecting the biceps femoris muscle, both close to the position of MC4R on porcine chromosome 1. In this study, the two lines were found to be close to fixation for alternative alleles of the Asp298Asn polymorphism. Additional QTL analyses supported our hypothesis of MC4R as a positional candidate gene but only for the fat/meat QTL. The Asp298Asn polymorphism was also evaluated as a selection target for daily gain in a Danish pig breeding population that included four breeds (Hampshire, Duroc, Landrace and Yorkshire). Over a 12-year period (1990-2002), a significant increase in the allele frequency of 298Asn was found in Landrace and Duroc, whereas a non-significant decrease in the 298Asn allele frequency was observed in Yorkshire. The Hampshire breed was fixed for the 298Asn allele in 1990. The high 298Asn allele frequencies in Hampshire, Landrace and Duroc are most likely due to selection for daily gain, whereas selection for daily gain in the Yorkshire breed apparently focuses on other loci.     

Influence of major histocompatibility complex on reproduction and production traits in swine

The effects of the swine lymphocyte antigen (SLA) system on different performance traits were investigated in Swiss pig breeds. Litter size and piglet weight at birth and at weaning were considered and in gilts the average daily weight gain, backfat and muscle thickness as well as percentage valuable cuts were measured. These data were analysed with least squares procedures. Although the effect of SLA on these traits was very small, a few haplotypes seemed to have some influence. Sows of the Large White breed carrying H12 had a significant smaller and those with H24 had a bigger litter size at weaning. Some mating studies were performed to investigate the effects of SLA homozygosity. The obtained results suggest that this has a negative effect on the litter size, especially when H19 in the Large White breed and H7 in Landrace are involved.