不同饲用燕麦品种生产性能的综合评价

基于熵权赋权法,运用灰色系统理论中的灰色关联度法对26个燕麦品种的生产性能进行综合评价,结果表明,生产性能综合表现较好的是初岛燕麦、青永久409、青永久709及青永久316;青永久18综合评价值最低,生产性能最差,其余品种生产性能表现一般。经逐步回归分析,发现其中的绿叶数、叶长、茎叶比、鲜干比、生长速度、叶面积指数、相对生长速率及生长天数8个指标对饲用燕麦生产性能贡献显著。     

Successful drug development despite adverse preclinical findings part 1: processes to address issues and most important findings

Unexpected adverse preclinical findings (APFs) are not infrequently encountered during drug development. Such APFs can be functional disturbances such as QT prolongation, morphological toxicity or carcinogenicity. The latter is of particular concern in conjunction with equivocal genotoxicity results. The toxicologic pathologist plays an important role in recognizing these effects, in helping to characterize them, to evaluate their risk for man, and in proposing measures to mitigate the risk particularly in early clinical trials. A careful scientific evaluation is crucial while termination of the development of a potentially useful drug must be avoided. This first part of the review discusses processes to address unexpected APFs and provides an overview over typical APFs in particular classes of drugs. If the mode of action (MoA) by which a drug candidate produces an APF is known, this supports evaluation of its relevance for humans. Tailor-made mechanistic studies, when needed, must be planned carefully to test one or several hypotheses regarding the potential MoA and to provide further data for risk evaluation. Safety considerations are based on exposure at no-observed-adverse-effect levels (NOAEL) of the most sensitive and relevant animal species and guide dose escalation in clinical trials. The availability of early markers of toxicity for monitoring of humans adds further safety to clinical studies. Risk evaluation is concluded by a weight of evidence analysis (WoE) with an array of parameters including drug use, medical need and alternatives on the market. In the second part of this review relevant examples of APFs will be discussed in more detail.     

星星草对碱化土壤物理性质的影响

研究不同生长年限的星星草对碱化土壤及对应碱斑土壤的机械组成、土壤孔隙度、容重和含水量的影响。结果表明,星星草生长1、2和3年后,粘粒和细砂所占比例减小,而粗粉和细粉所占比例增大。土壤总孔隙度、毛管孔隙度和非毛管孔隙度随着生长年数的增加呈不同程度的增加,而土壤容重则越来越小,>0.25mm的水稳定性团聚体随之增加。星星草地土壤含水量和田间持水量均高于碱斑土壤。星星草改善了碱化土壤结构、通透性、保水性和土壤物理环境。     

朝鲜鹌鹑屠宰性能及其与体重的相关性分析

选择7日龄的朝鲜鹌鹑300只(公、母各半),在相同管理条件下饲养至38日龄,每周定期称重,并在38日龄时随机抽取150只(公、母各半)进行屠宰,系统分析公、母鹑的体重及主要屠宰性能指标。结果表明,除10日龄体重外,朝鲜母鹌鹑的体重均极显著地高于公鹌鹑(P<0.01);母鹑的宰前重、放血重、屠体重、半净膛重、全净膛重、半净膛率、胸肌率、腿肌重和胸肌重显著高于公鹑(P<0.05或P<0.01);相关分析显示,公、母鹑不同日龄体重间均呈极显著的正相关(P<0.01);除母鹑的半净膛率、全净膛率、胸肌重、腿肌重及公鹑的屠宰率、半净膛率、胸肌重、腿肌重外,不同日龄体重与其他屠宰性状间多呈显著的正相关(P<0.05或P<0.01)。     

Interaction of GH polymorphism with body weight and endocrine functions in Japanese black calves

We assessed the interaction of GH gene polymorphisms (AA, AB and BB genotypes) with body weight and measures of endocrine function in Japanese black calves at 10 months of age. The average body weight for the BB genotype (281+/-5 kg) was significantly lower (P=0.0017, ANOVA) than those for the AA (324+/-9 kg) and AB (317+/-7 kg) genotypes. Plasma concentrations of insulin and IGF-I were greater for the AA genotype than for the AB genotype, and AB and BB genotypes, respectively. There were significant differences in the triglyceride and cholesterol concentrations among the GH genotypes. The area under the basal GH concentration was significantly greater (P=0.0314) for the AA genotype than for the two other genotypes. The incremental area over the basal GH concentrations in response to intravenous GHRH injection (0.4 microg/kg BW) was significantly smaller (P=0.0005) for the BB genotype than for the two other genotypes. In addition, linear regression analysis between GH incremental area induced by GHRH and body weight demonstrated that there was a positive linear correlation (r=0.6496, P<0.002) for incremental areas less than 600 ng min/ml, but a negative correlation (r=0.6473, P<0.05) for incremental areas over 600 ng min/ml. These findings indicate that the GH genotypes of the animals could be associated with difference in the GH response in Japanese black cattle at 10 months of age. We also observed a relationship between genotype and animal performances, but other studies on more animals in different conditions must be realized to make a definite conclusion.     

猪粪干、湿法厌氧发酵过程中碳、氮的流失

试验以新鲜猪粪为发酵原料,研究湿法和干法两种不同厌氧发酵过程的碳、氮排放量。湿发酵和干发酵组发酵料液的总固体(TS)含量分别为8%和20%,发酵液pH为6.8~7.4,发酵温度为35℃,体积为1.2 L,周期为21 d。试验期间每天测产气量,每4天取发酵样,测其全氮含量和TS降解率。结果表明,湿法和干法发酵组的CH4总产气量分别为9114 mL和12537 mL;CO2的总产气量分别为251.90 mmol和343.67 mmol;TS降解率分别为52.5%和29%。湿发酵的碳流失率和全氮流失率极显著高于干发酵(P<0.05)。     

梅花鹿成纤维细胞因子受体2基因多态性及其与茸重性状的关联分析

【目的】探索梅花鹿成纤维细胞因子受体2(fibroblast growth factor receptor 2,FGFR2)基因多态性及其对茸重性状的影响。【方法】应用直接测序法对梅花鹿FGFR2基因的全部外显子进行测序分析,通过MassARRAY^® SNP分型技术对314头24月龄梅花鹿进行基因分型和单倍型分析,分析FGFR2基因不同基因型和单倍型与茸重的关联性。【结果】在梅花鹿FGFR2基因中共发现12个多态性位点,其中5个位于外显子区域,且突变均未引起氨基酸改变,属于同义突变,其余7个位点均存在于内含子区域。分型结果显示,g.80975864 T>G位点未分型成功,后续对其余11个位点进行了分析,g.80943673 T>C、g.80943683 C>A及g.80938352 C>T 3个位点属于中度多态位点(0.25＜P＜0.5),其余位点均属于低度多态位点(P＜0.25)。χ²检验结果表明,g.80998742 G>A和g.80987708 G>A 2个位点偏离Hardy-Weinberg平衡(P＜0.05),其他9个位点均处于Hardy-Weinberg平衡(P＞0.05)。关联分析结果表明,11个多态性位点各基因型之间的茸重差异均不显著(P＞0.05)。单倍型结果显示,FGFR2基因存在5种单倍型,不同单倍型间梅花鹿茸重差异均不显著(P＞0.05)。【结论】FGFR2基因的11个突变位点可能不是影响梅花鹿茸重性状的关键位点。     

短穗兔耳草的克隆生长特征

以调查统计的方法研究了高寒草甸匍匐茎植物短穗兔耳草Lagotis brachystachya无性系的生长特征、形态特征以及能量分配规律,研究结果表明:匍匐茎只有1条的短穗兔耳草最多,占60．47％,匍匐茎有4条的短穗兔耳草只占6．98％。在牧草生长盛期,短穗兔耳草无性系的基株高度4．03 cm,根长为9．11 cm,叶数为7．98;分株高度0．85 cm,根长2．73 cm,叶数为3．08;匍匐茎的茎生叶数为12．54,长度为15.14 cm,匍匐茎比节间重为2．18 mg／cm,粗度为0．97 mm,不同构件的干质量呈现出基株>匍匐茎>分株>茎生叶的规律。随着匍匐茎数目的增多,短穗兔耳萆无性系的基株根长逐渐增加,用于克隆繁殖的能量投资也有增加的趋势,其他参数都没有明显的变化规律。     

不同机械干清粪频次对生长猪舍内环境和粪污排放的影响

本试验以刮板式机械干清粪系统为对象,研究不同清粪频次对生长猪舍内环境和粪污排放的影响。选取216头90日龄、体重39 kg左右的三元杂交生长猪,随机分配在12个猪栏中,根据猪的排泄特征设置2种清粪频次作为试验处理(2次/d、3次/d),试验期间每个处理重复7次。结果表明:与日清粪3次相比,日清粪2次猪呼吸高度处与人呼吸高度处的舍内氨气(NH_3)浓度都有所降低(P>0.05),猪呼吸高度处的舍内CO_2浓度降低8.78%(P<0.01),均能满足猪舍空气质量要求;单位体重粪便收集量提高32.3%(P<0.05),单位体重污水收集量降低3.39%(P>0.05);与日清粪3次相比,日清粪2次污水中各污染物浓度除TN外均有所降低(P>0.05)。结果表明生长猪舍运用机械干清粪系统清粪时采用2次/d的清粪频次可以满足猪舍空气质量要求和污水处理难度。     

鸸鹋卵人工孵化初探

对1998～2002年哈尔滨北方森林动物园鸸鹋卵人工孵化条件进行综合分析,以初步确定鸸鹋人工孵化的适宜条件,结果表明,卵型指数为1.52～1.56的鸸鹋卵,孵化温度控制在36.5～37.4℃,孵化湿度为50%～61%,孵化期失重在10%～15%之间能获得最佳孵化率和健雏率。Hoty方程计算出鸸鹋卵特异系数CSS为0.000565(n=60)。鸸鹋卵平放180°,每2h翻1次卵,晾1次卵,翻卵角度为90°能明显提高鸸鹋出雏率和健雏率,及时熟练的人工助产是避免鸸鹋后期死亡的重要手段。