行距和播量对沙芦草种子产量及其构成因子的影响

为探究干旱半干旱区沙芦草(Agropyron mongolicum)种子生产适宜的行距和播量配比，本试验采用双因素裂区试验设计，分别设4个行距水平(20,30,40,50 cm)和4个播量水平(10,15,20,25 kg·hm^-2),研究了不同行距和播量配比对沙芦草种子产量及产量构成因子的影响。结果表明，行距对沙芦草实际种子产量和理论种子产量有极显著影响(P<0.01),播量对沙芦草实际种子产量有显著影响(P<0.05),行距和播量对沙芦草实际种子产量有极显著的正交互作用(P<0.01)。通径分析表明，小穗数、小花数、种子数、穗长和生殖枝数对种子产量的影响具有直接作用，对种子产量贡献最大的是生殖枝数；回归寻优模型分析得出，当行距为20 cm,播量为15 kg·hm^-2时实际种子产量最高。因此，在宁夏中部干旱区沙芦草种子生产中建议种植密度应为行距为20 cm,播量为15 kg·hm^-2最佳。     

播量对黄花苜蓿草产量与种子生产的影响

试验以黄花苜蓿为研究对象,在呼伦贝尔草甸草原进行固定行距为30cm的播量试验,探讨了播量对黄花苜蓿草产量及种子产量的影响规律。结果表明:随着播量的增大,黄花苜蓿的草产量、分枝数、每枝小花数、结荚数和种子粒数均呈先增加后减少的趋势。当播量为10.5kg/hm2时,分枝数与草产量显著(P0.05)高于其他处理,且二者之间呈显著正相关(P0.05),回归方程Y=34.06X+2064;播量为14kg/hm2时,每枝小花数、结荚数和种子数最多(P0.05),而且结荚数与种子数呈显著正相关(P0.05),回归方程为Y=2.626X-0.241。若在生产过程中同时兼顾草产量与种子产量,最适的播量范围是10.5~14kg/hm2。     

宁夏干旱区行距与播量对无芒雀麦种子产量和质量的影响

为研究宁夏干旱区行距与播量对无芒雀麦种子产量和质量的影响，采用双因素裂区试验设计，主区行距为20，30，40和50 cm，副区播量为10，15，20和25 kg·hm^-2，利用灰色关联度以及回归模型进行了分析。结果表明，行距对潜在种子产量和发芽势有极显著影响（P<0.01），对发芽率有显著影响（P<0.05）；播量对实际种子产量、潜在种子产量和发芽势有极显著影响，对发芽率影响不显著；行距和播量对实际种子产量、潜在种子产量和发芽势有极显著交互作用，对发芽率、发芽指数和活力指数影响不显著。行距30 cm和播量15 kg·hm^-2处理的种子产量最高；行距30 cm和播量20 kg·hm^-2处理的种子发芽率、发芽势及发芽指数均最高；通过建立多元回归及通径分析可得，无芒雀麦种子产量的提高主要由生殖枝数实现。综上所述，为求得宁夏干旱区无芒雀麦最高种子产量和最优种子质量应将行距设为30 cm，播量设为15～20 kg·hm^-2为宜。     

黑龙江省西部苜蓿优化栽培技术研究

在黑龙江省齐齐哈尔市,应用正交试验设计对苜蓿进行行距、灌水、施肥种类及施氮肥试验。试验结果表明,行距以30 cm处理产草量最高,每公顷产干草11 049 kg,比45 cm处理增产干草9.9%,差异显著(P<0.05);以灌水1次为好;施农家肥22 500 kg/hm2产干草11 403 kg/hm2,增产效果最佳,比施复合肥150 kg/hm2增产干草17.1%(P<0.05)和施磷酸二铵150 kg/hm2增产干草6.6%(P<0.05),施磷酸二铵比施复合肥增产9.8%(P<0.05);施尿素112.5 kg/hm2增产效果好于施尿素75 kg/hm2和150 kg/hm2处理;处理6(行距30 cm,灌水3次,施磷酸二铵150 kg/hm2,施氮肥112.5 kg/hm)2和处理2(行距15 cm,灌水2次,施农家肥22 500 kg/hm2,施氮肥112.5 kg/hm)2分别产干草11 818 kg/hm2和11 730 kg/hm2,显著高于其他处理。     

高寒地区不同行距、播种量及施肥量对青稞种子产量的影响

为了研究在高寒地区不同行距、播种量及施肥量对青稞种子产量的影响,试验测定了巴青1号青稞的生育期、株高、考种、种子产量等。结果表明:行距和播种量对青稞生育期影响不大;株高随播种量的增加而减少,随行距的增加而增加;种子产量在行距为15 cm、播种量为220 kg/hm2时达到最大值(242.5 kg/667 m2),故在生产上推荐采用中等播量、中等行距的栽培方式;当施肥量为60 kg/hm2时种子产量最高,达到3 856.5 kg/hm2。     

‘和燕1号’农艺性状和产量对不同播量和行距的响应

为研究‘和燕1号’燕麦(Avena sativa)的栽培措施,挖掘其高产潜力,本研究在甘肃省和政县进行了不同播量和不同行距的试验,探讨了播量和行距对‘和燕1号’农艺性状、干草产量和种子产量的影响。结果表明,播量和行距对‘和燕1号’的农艺性状、干草产量及种子产量均有显著影响;干草产量在行距30 cm+播量300 kg·hm~(–2)时最高,达9 059.73 kg·hm~(–2);种子产量则在行距20 cm+播量300 kg·hm~(–2)时最高,达2 728.40 kg·hm~(–2)。通过相关分析和通径分析,株高、分蘖数、干草产量、种子产量与行距极显著正相关(P 0.01),茎粗、叶长、有效分蘖数与行距显著正相关(P 0.05);种子产量与播量显著正相关(P 0.05),分蘖数、茎粗、叶宽与播量显著负相关(P 0.05),其中穗长与播量极显著负相关(P 0.01);种子产量与株高、干草产量极显著正相关(P 0.01);株高对干草产量的直接作用最大。实际生产中可以通过影响‘和燕1号’株高、有效分蘖数、叶长、茎粗等指标来挖掘该品种产量潜力,做到经济效益的最大化。     

不同播种因素对扁穗冰草生产性能的影响

在青海省铁卜加高寒地区,在不施肥、不灌溉和人工清除杂草的条件下,通过田间试验研究不同行距(20,30,40cm)和播种量(67.5,101.1和135kg/hm2)对野生扁穗冰草生长、种子产量和干草产量的影响,以确定最佳的扁穗冰草田建植条件。结果表明:不同播种因素处理对鲜重、株高、茎叶比及生长速度的影响不明显。但对草产量和种子产量的影响较大。其中,行距20cm,播种量67.5kg/hm2处理下的干草产量和种子产量均最大,分别为6 065.35和1 610.33kg/hm2。     

松嫩平原苜蓿高产栽培技术研究

在松嫩平原,应用正交试验对苜蓿产量进行行距、灌水、施肥影响研究.结果表明,以30cm行距处理产草量最高,干草产量15389.66kg/hm2;灌水以3次和1次为好;施农家肥22500kg/hm2增产效果好于施磷酸二铵150kg/hm2和施复合肥150kg/hm2处理;施尿素112.5kg/hm2增产效果最佳,平均产干草14673.61kg/hm2;行距30cm、灌水3次、施磷酸二铵150kg/hm2、施氮肥112.5kg/hm2处理产干草19395.83kg/hm2,极显著高于其它处理.     

刈割对白三叶种子及草产量的影响

刈割期是影响白三叶种子产量和草产量的主效因子;间隔期越短,白三叶在总产草量中所占比例越高;留茬过高(10 cm)或过低(5 cm)、间隔期过长(45 d)或过短(15 d)均对种子生产不利;其中以30 d-8 cm种子产量最高(412.9kg/hm²),极显著高于其余处理(P<0.01),且杂草量少、干草产量4505.3 kg/hm²,品质高,其中白三叶所占比例为46.97%;15 d-10 cm干草产量最高(11011.4 kg/hm²);15 d-5 cm白三叶干草产量最高(4422.1 kg/hm²)。     

行距与播种量对无芒雀麦种子产量及产量组分的影响

在酒泉、通辽、绥化3地同时进行了行距与播种量对无芒雀麦种子产量及产量组分影响的试验研究,结果表明:同一地区行距是影响无芒雀麦种子产量的主要因素,播种第2年30 cm行距的种子产量显著高于50 cm,70 cm和90 cm行距处理;播种量对种子产量没有显著影响;3地间种子产量具有显著差异(P<0.05),通辽地区产量最高为1368.4 kg.hm^-2,酒泉次之是1005.2 kg·hm^-2,绥化最低为284.8 kg·hm^-2。行距对无芒雀麦生殖枝数/m2和千粒重影响显著(P<0.05),播种量对无芒雀麦产量组分影响不显著。     

H9N2亚型禽流感病毒传播途径特性的比较及其表面基因序列分析

选择中国大陆最早分离的H9N2亚型禽流感病毒(avian influenza virus,AIV)A/Chicken/Guangdong/SS/94(H9N2)(缩写为SS株)和1998年大流行时期分离的H9N2亚型AIVA/Chicken/Shanghai/F/98(H9N2)(缩写为F株)为研究对象,对其在SPF鸡体内的复制能力和传播途径特性比较后发现,F株在4周龄SPF鸡气管中的复制能力高于SS株,F株可以经气溶胶传播途径传播,SS株不能经气溶胶传播途径传播;利用反转录-聚合酶链反应(RT-PCR)方法获取F株和SS株的HA和NA基因的cDNA,序列分析得知,F株和SS株的HA和NA基因的同源性分别是96.6%和98.1%;HA基因的裂解位点氨基酸序列都是PARSSR↓GL,但有5个氨基酸的差异,即166位N(F)→D(SS)、198位A(F)→V(SS)、217位V(F)→I(SS)、335位G(F)→R(SS)、504位L(F)→S(SS);2株病毒的NA基因在63~65位都存在氨基酸缺失,但在NA基因红细胞吸附位点的氨基酸序列不同,分别是IKKDSRSG(F)和IKEDLRSG(SS)。F株和SS株的传播特性差异是否与其表面基因序列有关,有待进一步研究。     

禽类的起源、演化及我国主要家禽品种类型与分布

家禽是重要经济价值动物.本文从禽类种群进化学说出发,简介了禽类的起源、演化、动物学分类和家禽的驯化(养)与品种的形成,并对我国主要家禽(鸡、鸭、鹅)地方品种和培育品种(配套系)的分布与类型作了描述,以期为研究我国家禽起源系统,保护与利用我国家禽品种,促进家禽生产可持续发展提供参考.     

一起猪链球菌病和伪狂犬病的混合感染的诊治

近年以来,由于市场因素的刺激,生猪的存养量大幅上升,再加上由于流通环节较多,流通非常频繁,流通距离越来越远。这对繁荣经济,增加养殖效益起了重要的推动作用,但也同时给疾病的感染和传播创造了有利条件,给猪病的防治带来了困难。有的猪场感染了传染病后,由于治疗不及时不得法,而造成了惨重的经济损失。2008年7月中旬,我街道一养猪户因盲目从外地购进中猪,发生猪病疫情,引起猪只连续死亡,造成一定的经济损失。根据流行病学、临床症状、剖检变化和实验室诊断,诊断该病为猪链球菌病和猪伪狂犬病混合感染,现报告如下。     

种鹅矛形剑带绦虫与背孔吸虫混合感染的诊治

2005年9月份,大庆市红岗区个体养鹅专业户送检6只病死的5月龄左右隆昌鹅和长白鹅,经过实验室诊断确诊为矛形剑带绦虫与背孔吸虫混合感染。矛形剑带绦虫属膜壳科     

秋冬季预防和治疗虫媒性传染病鸡白冠病和鸡痘

１前言１．１鸡白冠病鸡白冠病是由卡氏住白细胞原虫寄生于鸡的红细胞和单核细胞而引起的鸡的贫血性疾病。吸血昆虫蚋和库蠓叮咬鸡引起传播，是主要的传播媒介，一般在夏末和秋季多发，由于夏季降雨量较大，部分沟渠积水，库蠓和蚋多孳生，因此在多雨水涝的年份发病率明显增高。１９９８年中国从南到北发生洪涝灾害，吸血昆虫的孳生格外严重，出现了一个白冠病多发年，而后两年发病稍轻，并有地区性，今年８月中旬以来白冠病的发病呈抬头趋势，有一定的死亡率，对蛋鸡产蛋率也会引起一定程度的降低，应引起养鸡户的重视。１．２鸡痘鸡痘也是…     

Shape and size of teeth of dogs and cats-relevance to studies of plaque and calculus accumulation

Crown width, height and buccal surface areas were measured on heads or skulls of four dogs and four cats, and were compared with similar measurements on models of human dentition. Buccal surface area variability was greater in dogs and cats than in humans, and teeth of cats were smaller. Horizontal (gingival and occlusal halves) and vertical (mesial, middle, and distal thirds) buccal surface area variability was also greater in canine and feline teeth compared with human teeth. This increased variability suggests the need for testing of reliability and repeatability of scoring when using plaque and calculus indices based on horizontal or vertical segmentation. Buccal surface area variability between teeth also prompts questioning the validity of equal weighting of smaller, irregularly-shaped teeth when calculating a mean mouth score. Whether equal or more reliable results would be obtained from scores of whole teeth in comparison with segmentation indices used currently has yet to be determined.     

Estimations of repeatability and heritability of egg albumen antimicrobial activity and of lysozyme and ovotransferrin concentrations

1. The repeatability and heritability of growth inhibition by egg albumen of two major pathogenic bacteria, a Gram-negative (Salmonella Enteritidis) and a Gram-positive (Staphyloccocus aureus) and of two antimicrobial albumen proteins, lysozyme and ovotransferrin, were estimated in commercial pedigree hens. 2. Repeatability was evaluated in 100 egg-type hens at the beginning, middle and end of the laying cycle on eggs collected for 3 weeks. Heritabilities were estimated at 36 to 40 weeks of age on 400 pedigree hens (2 eggs/hen), which were the offspring of 25 sires each mated with 4 dams. Ovotransferrin and lysozyme were quantified by ELISA. Salmonella Enteritidis (S.E.) and Staphyloccocus aureus (S.A.) were inoculated into a sample of sterilised albumen and enumerated after incubation. 3. Total protein content in albumen decreased with age of laying hens, whereas there were increases in lysozyme or ovotransferrin concentrations and in the bacteriostatic effect of albumen. 4. Repeatability for bacterial growth in albumen ranged from 0.29 to 0.39 for the number of S.E. (log cfu/ml) one day post inoculation (p.i.) but was lower and more variable at 5 d p.i. or for S.A. number. It ranged from 0.27 to 0.38 for S.E. and S.A. number at the mid period of the laying cycle. Repeatabilities were low and variable for total egg albumen protein or lysozyme and ovotranferrin concentrations (0 to 0.22). 5. Negative phenotypic correlations were observed between lysozyme concentrations and S.E. number but that between lysozyme and S.A. number was not significant. 6. Heritabilities were low (0.01 to 0.09) for protein traits. They were 0.11 for S.A. number and 0.16 for S.E. number one day p.i. 7. It appears to be more efficient to select on global bacterial growth than on specific antimicrobial proteins. The most promising trait is the number of S.E. one day p.i.     

Evaluation of lysozyme and lactoferrin in lacrimal and other ocular glands of bison and cattle and in tears of bison

OBJECTIVE: To evaluate lactoferrin and lysozyme content in various ocular glands of bison and cattle and in tears of bison. SAMPLE POPULATION: Tissues of ocular glands obtained from 15 bison and 15 cattle and tears collected from 38 bison. PROCEDURE: Immunohistochemical analysis was used to detect lysozyme and lactoferrin in formalin-fixed, paraffin-embedded sections of the ocular glands. Protein gel electrophoresis was used to analyze ocular glands and pooled bison tears by use of a tris-glycine gel and SDS-PAGE. Western blotting was used to detect lactoferrin and lysozyme. RESULTS: Immunohistochemical staining for lactoferrin was evident in the lacrimal gland and gland of the third eyelid in cattle and bison and the deep gland of the third eyelid (Harder's gland) in cattle. Equivocal staining for lactoferrin was seen for the Harder's gland in bison. An 80-kd band (lactoferrin) was detected via electrophoresis and western blots in the lacrimal gland and gland of the third eyelid in cattle and bison, Harder's glands of cattle, and bison tears. An inconsistent band was seen in Harder's glands of bison. Lysozyme was not detected in the lacrimal gland of cattle or bison with the use of immunohistochemical analysis or western blots. Western blots of bison tears did not reveal lysozyme. CONCLUSIONS AND CLINICAL RELEVANCE: Distribution of lactoferrin and a lack of lysozyme are similar in the lacrimal gland of cattle and bison. Differences in other tear components may be responsible for variability in the susceptibility to infectious corneal diseases that exists between bison and cattle.