浙江省中华蜜蜂形态特征研究

选择浙江省12个样点36群中华蜜蜂样本,每群随机抽取15只工蜂,每只工蜂测定27项形态特征指标。利用SPSS16.0对形态特征数据进行因素分析、聚类分析和变异分析。结果表明:浙江省境内的中华蜜蜂存在较大的形态差异及种群分化。因素分析结果提取3个特征值高(>3)的因素,包括了63.798%的变异。利用提取的主因子进行聚类分析,分为4个类群:永康、义乌、金华、杭州和丽水的样本为第1类;长兴、黄岩、慈溪的样本为第2类;江山、嵊州和舟山的样本为第3类;苍南的样本与其他地区样本的遗传距离最远,单独为一类。变异分析结果显示:浙江省12个样点中华蜜蜂除后翅钩数样点间差异不显著(P>0.05)外,其余26项形态指标样点间差异较大。其中,舟山中华蜜蜂的翅长、翅宽、第3、4背板总长、第4、7腹板总长及腿相关4项指标平均值最大,与其余地区中华蜜蜂形态差异性较大;苍南中华蜜蜂的蜡镜长、蜡镜间距离和蜡镜斜长指标均值最大,与其它地区中华蜜蜂形态差异显著(P<0.05)。     

高铁高硒日粮对鸡蛋品质的影响

用高铁高硒日粮饲喂产蛋母鸡,观察蛋品质的变化,结果表明,蛋黄重、蛋黄重／蛋重比略有下降,蛋白质／蛋重比、哈夫单位有所提高,蛋壳／蛋重比,蛋壳厚度及蛋壳密度无明显变化,提示：高铁高硒日粮不会引起蛋品质的明显下降。     

饲料中不同脂肪酸对草鱼组织脂质含量和脂肪酸构成的影响

实验选用初始作重约1．4g的草鱼，在60天的饲养期中分别投喂1种不含脂肪的饲料和8种含3％不同脂质的饲料，观察了饲料中添加油酸（18：1n-9）、亚油酸（18：2n－6）、亚麻酸（18：3n－3）和n－3系列高度不饱和脂肪酸（n－3HUFA；20：5n－3＋22：6n－3）对草鱼肝胰脏、肌肉、头部和去肝胰脏内脏脂质含量和脂肪酸构成的影响。实验结果表明，与摄食单纯含油酸饲料的草鱼相比，含1％18：2n－6和1％18：3n－3或1％18：2n－6和0．5％n－3HUFA饲料组草鱼的肝胰脏脂质含量显著降低，但内脏脂质含量升高。向饲料中添加18：2n－6、18：3n－3和n－3HUFA能明显影响草鱼肝胰脏、肌肉和头部脂质多不饱和脂肪酸的相对含量；组织中n－6系列和n－3系列高度不饱和脂肪酸含量分别与饲料中添加18：2n－6和18：3n－3有相关关系，表明草鱼具有生物转化18：2n－6和18：3n－3为高度不饱和脂肪酸的能力。     

犬春季饲养管理要点

俗话说,一年之计在于春。原意是强调春天对农业生产的重要性。实际上也适用于犬的饲养管理,搞好犬的春季饲养管理,如同程序的启动阶段,启动顺利,程序才能正常运行,这对于全年工作是十分重要的开端。     

基于MODIS数据的伊犁河谷植被指数变化及其对气候的响应

利用2006-2014年主要生长季(5-9月)的MODIS遥感数据,分析了2006-2014年的年平均NDVI和生长季月NDVI变化规律。同时,收集整理同期伊犁河谷地区的气温与降水资料,并对NDVI与当月、2个月滑动、3个月滑动和5个月滑动的平均气温、降水值进行了相关性分析。结果表明,NDVI与气温、降水都存在一定的相关性,NDVI受当月平均气温的影响最大;NDVI与当月降水和滑动平均降水的相关性都很好,但3个月滑动平均降水对NDVI的影响最大,并且通过了0.01的极显著性检验。     

酸与胆汁耐性芽孢益生菌的筛选

试验选用允许直接饲喂的安全微生物中的芽孢杆菌,按照益生菌的特定要求,考察各菌株对低pH和高胆盐的耐受性及产酶特性。筛选获得的凝结芽孢杆菌AHU1366,耐受性优良,并能产生淀粉酶和蛋白酶,是一株比较理想的饲用益生菌。     

绵羊多胎性状基因调控研究进展

绵羊的繁殖性状受多基因控制，本文综述了现已发现并证明的主基因和QTL住点，如FecB基因、FecX基因、FecX2基因、BMP15(形态发生蛋白15)突变、Q249R突变及Thoka基因等。通过分析这些基因或QTL位点的作用、遗传方式、遗传效应及基因定位，旨在为探讨绵羊多胎性状的基因调控规律提供理论依据。     

Tilmicosin enteric granules and premix to pigs: Antimicrobial susceptibility testing and comparative pharmacokinetics

The purpose of this study was to compare the pharmacokinetics and relative bioavailability of tilmicosin enteric granules and premix after oral administration at a dose of 40 mg/kg in pigs. Three kinds of different respiratory pathogens were selected for determination of minimal inhibitory concentration (MIC) to tilmicosin. Eight healthy pigs were assigned to a two‐period, randomized crossover design. A modified rapid, sensitive HPLC method was used for determining the concentrations of tilmicosin in plasma. Pharmacokinetic parameters were calculated by using WinNonlin 5.2 software. The MIC₉₀ of tilmicosin against Haemophilus parasuis, Actinbacillus pleuropneumoniae, and Pasteurella multocida were all 8 μg/ml. These results indicated that these common pig respiratory bacteria are sensitive to tilmicosin. The main parameters of time to reach maximum plasma concentration (T_max), elimination half‐life (t_1/2β), mean residence time (MRT), and apparent volume of distribution (V_F) were 2.03 ± 0.37 hr, 29.31 ± 5.56 hr, 25.22 ± 2.57 hr, 4.06 ± 1.04 L/kg, and 3.05 ± 0.08 hr, 17.06 ± 1.77 hr, 15.55 ± 1.37 hr, 2.95 ± 0.62 L/kg after the orally administrated tilmicosin enteric granules and premix. The relative bioavailability of tilmicosin enteric granules to premix was 114.97 ± 7.19%, according to the AUC_0‐t values. These results demonstrated that tilmicosin enteric granules produced faster tilmicosin absorption, slower elimination, larger tissue distribution, and higher bioavailability compared to the tilmicosin premix. The present study results manifest that tilmicosin enteric granules can be used as a therapeutic alternative to premix in clinical treatment.     

6个种源地不同桑树品种叶柄解剖结构与水分运输能力初探

叶柄是水分和营养物质在茎和叶间运输的重要组织。采用石蜡切片技术和木材离析技术,分析6个种源地不同的桑树品种一年生扦插苗叶柄的显微结构特征,对叶柄的水分运输能力和抗蒸腾能力进行评价,并对桑树的抗旱性进行探讨。结果显示在6个桑品种中,吴堡桑的叶柄角质层和厚角组织厚度较小,但维管束最为发达,具有较高的维管束面积占比、中等水平的导管直径和最大的导管长度,水分运输能力最强,同时还能保持对栓塞较强的抵抗性,推测其抗旱能力可能较强,适宜种植在较为干旱的地区;育711号的叶柄角质层较薄,云果桑1号叶柄的厚角组织最薄,这2个品种的叶柄具有较多的维管束,但其维管束面积占比、导管孔腔面积以及导管直径在6个品种中较小,故抗蒸腾能力与水分运输能力均较低,其抗旱能力可能相对较弱,更加适合在水分充足的环境中生长。研究结果为阐释桑树叶柄结构、水分运输能力与桑树抗旱能力之间的关系提供了一定的实验依据。     

Dynamics of methanogenesis,ruminal fermentation and fiber digestibility in ruminants following elimination of protozoa: a meta-analysis

Background: Ruminal microbes are vital to the conversion of lignocellulose-rich plant materials into nutrients for ruminants.Although protozoa play a key role in linking ruminal microbial networks,the contribution of protozoa to rumen fermentation remains controversial; therefore,this meta-analysis was conducted to quantitatively summarize the temporal dynamics of methanogenesis,ruminal volatile fatty acid(VFA) profiles and dietary fiber digestibility in ruminants following the elimination of protozoa(also termed defaunation).A total of 49 studies from 22 publications were evaluated.Results: The results revealed that defaunation reduced methane production and shifted ruminal VFA profiles to consist of more propionate and less acetate and butyrate,but with a reduced total VFA concentration and decreased dietary fiber digestibility.However,these effects were diminished linearly,at different rates,with time during the first few weeks after defaunation,and eventually reached relative stability.The acetate to propionate ratio and methane production were increased at 7 and 11 wk after defaunation,respectively.Conclusions: Elimination of protozoa initially shifted the rumen fermentation toward the production of more propionate and less methane,but eventually toward the production of less propionate and more methane over time.