首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 531 毫秒
1.
对广东郁南7个代表性沙糖桔果园土壤和结果树植株叶片营养状况进行了分析。结果显示,坡地果园的酸度比水田果园的大。土壤质地以粘土和粘壤土为主,其中砂页岩坡地果园土壤质均为粘土,而花岗岩坡地为粉砂质粘土,水田改种的多为壤土。土壤有机质含量总体处于中等偏低水平。全氮主要在中等至偏低水平之间;坡地果园的有效磷偏低,水田果园有效磷处于低量至适量水平;缺磷和缺钾的主要是坡地果园,而高磷和高钾的主要是水田果园。土壤交换性钙、镁和有效硼普遍缺乏;铜、锌个别缺乏;铁、锰、硫含量均较高。沙糖桔结果树周年营养状况随着生育期的不同而发生动态变化,土壤磷钾高的果园其叶片磷钾水平并不是全都相应提高。叶片N、P、K、Cu平均含量在开花期最高,N、K、Cu均处于柑桔类的适量范围,而P则高于适量范围;叶片N、P平均含量在幼果期最低。叶片Ca平均含量在果实成熟期最高,郁南沙糖桔叶片Mg低于柑桔类适量水平的较多,说明缺镁的情况较多;叶片Fe、Mn含量从开花期最低至成熟期达到最高,地下水位较高的果园叶片锰含量全年每个生育期均较高,在后期甚至超过适宜水平的1倍多。  相似文献   

2.
研究不同周龄SPF级SD大鼠胰腺自发性病变的种类及其病变发生率,为药物安全性评价提供背景资料。收集3年安评试验中11、19、31周龄试验对照组大鼠胰腺制作病理切片,光学显微镜下观察SD大鼠胰腺病变的种类及组织形态学特点,并统计其病变发生率。结果显示,大鼠胰腺主要出现了以下病变:①单核细胞浸润:11周龄大鼠该病变的总体发生率为0.6%,其中雌性为0,雄性为1.25%;19周龄大鼠该病变的总体发生率为1.0%,其中雌性为1.0%,雄性为1.0%;31周龄大鼠该病变的总体发生率为1.0%,其中雌性为0,雄性为1.96%。②腺泡细胞空泡变性:11周龄大鼠未观察到该病变的发生;19周龄大鼠该病变的总体发生率为1.0%,其中雌性为0,雄性为2.0%;31周龄大鼠该病变的总体发生率为3%,其中雌性为2.1%,雄性为3.9%。③腺泡细胞萎缩、腺管增生:11周龄大鼠未观察到该病变的发生;19周龄大鼠该病变的总体发生率为0.5%,其中雌性为0,雄性为1.0%;31周龄大鼠该病变的总体发生率为3.0%,其中雌性为1.0%,雄性为4.9%。结果表明,SPF级大鼠胰腺可发生单核细胞浸润、腺泡细胞空泡变性、腺泡细胞萎缩及腺管增生等自发性病变,且病变发生率可随着年龄的增加而增加。  相似文献   

3.
鲤鱼急性喹乙醇中毒的病理学研究   总被引:15,自引:0,他引:15  
试验对鲤鱼进行了喹乙醇急性中毒的病理学研究。喹乙醇对鲤鱼 (60± 5g)口服给药的LD50 为 :32 4 9 4mg/kg体重。中毒鱼表现出特征性的“应激性出血症” ,鳍条基部、嘴部和腹部充血、出血发红 ,肠道排出白色半透明粘液便 ,临死前出现明显的神经症状。病理组织学上 ,肝脂肪变性或水泡变性及凝固性坏死 ,肾上腺空泡变性 ,肠呈卡他性肠炎 ,肾小管上皮细胞、心肌纤维空泡变性 ;鳃小片水肿 ,上皮增生、变性、坏死和脱落。超微结构上 ,心肌、肝和肾小管上皮细胞的线粒体肿胀 ,嵴断裂、溶解 ,肝细胞内糖原颗粒减少。中毒早期肠上皮微绒毛断裂 ,脱落 ,随着病程的发展肠上皮细胞变性、坏死、脱落。  相似文献   

4.
为了解新疆伊犁某肉牛场潜在的致病性大肠埃希菌,对新疆伊犁地区某养殖场2013年秋季和2014年夏冬两季的饲草料和粪样及定点屠宰场2013年和2014年秋季屠宰加工环节的样品进行大肠埃希菌的分离鉴定,采用PCR方法检测大肠埃希菌毒力基因(stx1和stx2、eae)存在的数量。结果表明,该养殖场饲草料样品在夏季、秋季、冬季的大肠埃希菌分离率分别为44.8%、31.4%和6.0%,其毒力基因的检出率为3.6%;该养殖场粪样样品在夏季、秋季、冬季的大肠埃希菌分离率分别为70.7%、75.0%和74.4%,其毒力基因的检出率为23.5%;定点屠宰场在加工环节样品中2013年和2014年秋季的大肠埃希菌分离率为32.4%和32.5%,只有1株菌株携带有毒力基因stx1和stx2,检出率为4.2%。新疆伊犁地区不同季节对饲草料中大肠埃希菌的污染分布具有影响,粪样中具有比较稳定的大肠埃希菌数量,其毒力基因的检出率最高。  相似文献   

5.
对高寒草甸不同放牧强度下矮蒿草无性系分株内各构件的年度动态进行了研究。结果表明,矮蒿草分株面积呈现V字型的变化规律,复合分蘖6月最低,增长到9月达到高峰,芽分蘖6月、7月开始增加到10月份达到高峰,复合分蘖和芽分蘖活叶数从6月开始增加到9月达到高峰。单分蘖和生殖秆分蘖活叶数6月份最高,以后逐渐降低。轻度放牧有利于复合分蘖数和单分蘖数的增加;中度放牧有利于芽分蘖的增加。  相似文献   

6.
试验旨在对商品肉鸡层叠式立体养殖模式的环境参数进行监控,分析不同季节笼养肉鸡环境参数的差异,为科学养殖提供数据支撑。选择规模化肉鸡养殖场的同一栋鸡舍,在秋季和冬季饲养周期中,采用分次多点测量法,连续监测3~6周龄肉鸡舍内温度、湿度和空气质量,测定点均匀分布在舍内4个位置,比较秋季和冬季舍内环境参数的变化。结果显示,在肉鸡生长后期,冬季舍内环境温度略高于秋季,差异不显著(P>0.05);秋季舍内湿度显著高于冬季(P<0.05),两个季节的温湿度均可满足不同日龄肉鸡生长需求。有害气体和微生物检测结果显示,冬季舍内氨气浓度略高于秋季,差异不显著(P>0.05);冬季舍内二氧化碳浓度显著高于秋季(P<0.05);同时冬季舍内空气微生物总菌数显著高于秋季(P<0.05)。层叠式立体笼养肉鸡舍内温度在不同季节可保持恒定;在冬季饲养期,舍内湿度降低,二氧化碳浓度升高,空气微生物总菌数升高。因此,冬季饲养肉鸡在做好保温的同时应适当增加通风换气。  相似文献   

7.
The study was conducted to detect the indoor environmental quality parameters of broiler house with three-overlap cages and analyze the differences in winter and autumn. In the process of feeding, the same farming house in the same farm was chosen to carry out the test. The indoor ambient temperature, humidity and the air quality were determined in chicken house in different seasons. The measure points were distributed in 4 different positions in the house. The experiment period was from 3 to 6 weeks of broilers.The results showed that there was no significant difference in the ambient temperature between autumn and winter during experimental period (P >0.05). The ambient temperature in the house in winter was slightly higher than in autumn. The humidity in autumn was significantly higher than that in winter (P <0.05).The temperature and humidity in two seasons could meet the requirements of broiler growth. There was no significant difference in ammonia concentration between autumn and winter, while ammonia level in winter was slightly higher than that in autumn. The carbon dioxide in the house was significantly higher in winter than that in autumn (P <0.05). The total number of airborne bacteria in winter was significantly higher than that in autumn (P <0.05). The indoor temperature kept constant in autumn and winter seasons in closed poultry house. In winter, the humidity was reduced, the carbon dioxide concentration was increased, and the total number of bacteria in the air was increased.So, the ventilation should increase at the same time of heating in winter.  相似文献   

8.
通过调查民勤白土井的芦苇群落,对盐沼、盐碱地、覆沙地的芦苇群落、土壤机械组成、土壤水分等的空间分布进行分析,结果表明:随着生境不同,芦苇群落的伴生种数量和种类均表现出差异,盐沼地土壤含水率和植被覆盖度最大,物种丰富度最小。3种生境土壤含水率是盐沼盐碱地覆沙地。土壤水分决定芦苇生态型,盐沼地分布3种芦苇生态型。3种生境土壤颗粒组成主要以粉粒与沙粒为主,土壤质地以粉沙质壤土与沙质壤土为主,不同生境各层次间土壤机械组成存在差异。  相似文献   

9.
水牛乳是中国南方地区重要奶源,为了解中国广西地区水牛乳中微量元素含量及不同因素如地域、品种和泌乳期对水牛乳中微量元素含量的影响,于广西南宁市兴宁区、邕宁区和钦州市灵山县共3个水牛场采集了摩拉、尼里2个品种,3个泌乳时期的水牛乳样品共60份,通过微波消解,利用电感耦合等离子体质谱检测了铬(Cr)、锰(Mn)、钴(Co)、铜(Cu)、砷(As)、硒(Se)、铯(Cs)、钡(Ba)、钼(Mo)、铅(Pb)、镉(Cd)、镍(Ni)共12种微量元素的含量,采用皮尔逊相关分析解析了12种元素含量之间的相关性,采用单因素方差分析比较了不同地域、品种和泌乳期水牛乳之间微量元素含量差异,采用多因素方差分析解析交互作用对元素含量的影响。结果表明,该法测定水牛乳12种微量元素含量的加标回收率在84.94%~120.91%之间。不同地域间水牛乳中Mn、Se、Cs、Ni含量差异显著(P<0.05),钦州市灵山县水牛乳中Mn、Cs含量较高,南宁市兴宁区水牛乳中Se、Ni含量较高;不同品种间水牛乳中Se、Ni含量差异显著(P<0.05),尼里水牛乳中Se、Ni含量高于摩拉水牛;不同泌乳期水牛乳中Mn、Co、Cu、Se、Mo含量差异显著(P<0.05),初乳中Co、Cu、Se含量较高,常乳中Mn含量较高,晚乳中Mo含量较高;地域与品种的交互作用对水牛乳中微量元素含量无显著影响。  相似文献   

10.
东北农牧交错带玉米适宜收获方式的研究(Ⅱ)   总被引:1,自引:1,他引:1  
从增加农牧交错地区饲料来源的角度出发,尝试改变当地玉米Zea mays常规的收获方式,采用提前收获果穗、植株继续生长5 d后收回的方式.试验结果表明,该收获方式使籽粒产量下降,秸秆产量提高.籽粒的总淀粉及粗蛋白含量下降;茎、叶粗蛋白含量增加;NDF,ADF和ADL含量下降,秸秆的饲用价值提高.通过能量折合计算,籽粒产量损失可由秸秆产量的增加弥补,该收获方式在农牧交错地区具有一定的可行性.  相似文献   

11.
本文首次深入研究了中国柴胡属29种,5变种及2变形果实的三维结构。结构显示果实结构变化较大,分果表面平滑,横切面近圆形,脊略微突出。中果皮有两种分泌结构,伴生油管及非伴生油管(油管)。前者仅存在于少数物种,且直径小,后者包括不分支及分支油管。不分支油管存在于多数物种的沟(1~5)和结合面(2~7),油管通常与分果近等长,但亦存在短油管。少数物种的油管呈分支状,在中果皮不规则分布。种皮由1或2层薄壁细胞构成。胚乳在结合面平直或微凹。中果皮无结晶。心皮柄多为2个,在结合面彼此相对。柴胡属果实的多数特征存在于芹亚科其他类群,但分支状油管及2层细胞的种皮仅见于牵环花亚科,变豆菜亚科及芹亚科的基础类群。柴胡属果实的解剖结构支持分子系统学将柴胡属位于芹亚科其他类群的基础位置。  相似文献   

12.
The topography of the thoraco-abdominal viscera in the ostrich was studied in 20 birds varying in age from 2 weeks to 12 months. The lungs occupied the dorsal third of the thorax, and the heart lay in the cranioventral thorax perpendicular to the long axis of the body. There was no pleural cavity. The liver was situated in the caudoventral part of the thorax, and the proventriculus occupied the left cranial part of the abdomen between the 7th vertebral rib and the acetabulum. The gizzard lay in the cranioventral part of the abdomen, resting on the sternum and abdominal floor. The duodenum formed a loop from right to left, with the pancreas lying between the 2 limbs of the loop. The coiled jejunum and ileum occupied the ventral part of the abdomen between the gizzard and pelvis. The two caeca lay on either side of the terminal ileum with their apices in the pelvis. The rectum was the longest part of the intestine and could be divided into a thick proximal segment situated in the right dorsal part of the abdomen, and a thin distal part that occupied the left caudodorsal part of the abdomen. The trilobed kidneys lay along the ventral surface of the synsacrum, with the adrenal glands at their cranioventral poles. The testes lay ventrally to the cranial divisions of the kidneys, whereas the left ovary was situated ventrally to the cranial division of the left kidney. The spleen lay wedged in between the right kidney, caudal vena cava and proventriculus. The thyroid glands were situated at the cranial borders of the subclavian arteries, and the thymus lay at the base of the neck.  相似文献   

13.
The small and large intestine of 30 healthy Saanen goats were examined ultrasonographically using a 5.0 MHz-linear transducer. The goats were examined on the right side, from the eighth rib to the caudal aspect of the flank. The small and large intestine could be easily differentiated. The descending duodenum could be imaged in 19 goats, and the jejunum and ileum seen in all goats. The jejunum and ileum were most often seen in cross-section and rarely in longitudinal section in the ventral region of the right flank. The intestinal contents were usually homogenously echoic, and active motility was observed in all the goats. The diameter of the small intestine was 0.8–2.7 cm (1.6 [0.33] cm). The spiral ansa of the colon was imaged in all the goats, and in 21 the caecum was also seen. Both these sections of large intestine were most commonly seen in the dorsal region of the right flank. The spiral ansa of the colon was easily identified by its spiral arrangement of centripetal and centrifugal gyri, which had a garland-like appearance. Because of intraluminal gas, only the wall of the colon closest to the transducer could be imaged. The diameter of the spiral colon ranged from 0.8 to 2.0 cm (1.1 [0.24] cm). Usually only the wall of the caecum closest to the transducer could be imaged and it appeared as a thick, echoic, slightly undulating line. The greater omentum could be seen in all the goats.  相似文献   

14.
大样地循环采样的草地生物量空间异质性及误差分析   总被引:2,自引:0,他引:2  
利用2008年和2010年青海省草地生物量野外采样结果,用变差函数探讨地下和地上生物量的空间变异情况,二者存在空间相关性的阈值分别为3720.52和2258.7 5 m。结果表明:玛多采样点前后2年地上生物量的变异程度都高于海北;2010年各样地地上生物量变化相对较小。珍秦/巴塘平均地下生物量高于海北地下生物量,玛多平均地下生物量最小;海北和玛多前后2年平均地下生物量年际间变异程度低于珍秦/巴塘样地。对海北、玛多、巴塘和珍秦的地下、地上生物量的误差进行分析,地下生物量和地上生物量误差变异不同。研究不同采样距离对误差的影响发现,随着采样距离的加大,不论地上还是地下生物量,其误差总体呈增加的趋势,但在2500 m采样间距下,地下生物量、地上生物量以及二者的比值都出现较为明显的低值。  相似文献   

15.
马杜霉素对柔嫩艾美耳球虫(Eimeria tenella)超微结构的影响   总被引:1,自引:0,他引:1  
将马杜霉素按 0 .0 0 0 5 %的比例混入饲料 ,作用于鸡体内柔嫩艾美耳球虫 (Eimeria tenella) ,透射电镜观察 ,发现裂殖体变小 ,内含裂殖子的数目减少 ,裂殖子膨胀变为椭圆 ,裂殖子间 (带虫空泡内 )微管结构模糊、膨胀 ,裂殖体中有髓鞘样结构出现 ;细胞膜外突和细胞质分离形成空隙 ,细胞膜有破损、结构模糊 ;细胞质出现空泡化 ,内部出现附加体和髓鞘样结构 ;少数细胞核的外膜外突和内膜分离 ,有的部位的核膜模糊、破损。裂殖子顶体结构发生异常变化 ,棒状体消失 ,微线数目减少或者消失。线粒体表现为形态改变 ,肿大变圆 ,或者变为马蹄形 ,内膜和嵴脱落 ,内部形成空泡、膜状结构、螺旋状或者髓样结构 ,线粒体的嵴与长轴平行排列 ,且贯穿线粒体。作者推测 ,抗生素类抗球虫药的作用机理可能是 ,通过使虫体结构的完整性受损 ,抑制虫体的物质代谢及能量代谢等生理机能 ,达到杀死虫体或者抑制虫体生长、发育和繁殖的目的。  相似文献   

16.
The objective of the study has been to verify the hypothesis that the coat colour is regarded in the selection of Polish Thoroughbred horse population. Formally, the colour is not a selection criterion in this breed selected mainly for speed. The material consisted of twelve groups of foals registered in successive volumes of the Stud Book (11,688 foals, in total) and their parents selected to the breeding stud. The frequency of alleles in ASIP, MC1R and GREY loci controlling the coat colours was estimated from the recessive phenotype frequency square in the groups of foals. The inflow of foreign genes was limited and the population great, hence the migration effect was very low. The drift and Wahlund effect hardly influenced the genetic structure in the groups which enabled to analyze the population not divided. The total offspring frequency of recessive a, e and g alleles amounted to 0.1552, 0.4877 and 0.9773, respectively. Accuracy of the assessment of the a and e frequency was confirmed on the basis of test matings. The a, e and g alleles were more frequent in dams than in sires and the a alleles occurred more often in fillies than in colts. The frequency of a and e alleles was higher in the offspring than in the parents. The genotype distribution in the offspring differed from the expected one, assessed from the gamete frequency in sires and in dams. Fewer bay foals were born than anticipated. All the results show that the coat colour is not entirely disregarded in the breeding of Thoroughbred horses. The dominant A and E alleles producing the colour are preferred in the selection, particularly in the sires. This leads to some alterations in the phenotypic structure of the population. On the other hand, the horses are mated randomly, irrespective of the coat colour.  相似文献   

17.
为了解亚热带无隔热层钟楼式单层彩钢瓦屋面棚舍栓系饲养模式下的环境特征,在凤阳测定了肉牛舍的温度、湿度、气流、PM10、NH3等指标。结果:夏季,棚舍内外温湿度几乎相同,换气量超过了最大换气量,PM10优于卫生标准,温湿指数范围为78~87,肉牛处于热应激状态。考虑了气流影响的体感温度范围为25.1~32.2℃,气流显著地减少了高温的影响。晴天棚顶内外表面温度最大相差1.2℃,棚顶隔热能力差,棚顶内表面最高可达48.3℃,此时的舍内气温仅为33.1℃,棚舍自然换气调节是环境控制的主体,适当架高棚顶,开设钟楼换气口有利于畜舍通风换气。冬季,舍内温度范围为-1~7.5℃,舍外温度范围-3.3~5.5℃,温差仅2℃,舍内风速为0.2~0.4 m/s,舍外风速为1.01~2.53 m/s。舍内湿度高于舍外,超过了肉牛生长的适宜湿度范围,NH3浓度优于卫生标准,冬季棚舍四周围挡塑料薄膜,减少了换气量,保温作用弱,空气质量下降。  相似文献   

18.
The renal structure of a female Asian elephant (Elephas maximus) was observed in both macroscopic and light microscopic levels. The left kidney was elongated-ellipse in shape, whereas the right appeared round. The left kidney was 31 cm in cranio-caudal length, 21 cm in medio-lateral length, and 2950 g in weight. The right kidney was 34 cm in cranio-caudal length, 22 cm in medio-lateral length, and 3250 g in weight. The external appearance showed the six separated renal lobes in both sides of the kidney. The four pairs of the lobes were fused in the deepest region in both sides of kidney, so we considered it as an incompletely lobated kidney in this species. We observed the proximal and distal urinary tubules in histological sections. Many renal corpuscles consisted of the glomerulus and Bowman's capsule. Many mesangial cells and some podocytes were confirmed in each glomerulus; however, Bowman's capsules were larger than those in other mammalian species.  相似文献   

19.
The levels of total calcium, inorganic phosphorus, magnesium, sodium, potassium, and chlorides in the blood plasma, and the osmolality of the plasma, were determined in bovine foetuses (n = 20) and the dams (n = 20) in the third trimester of gravidity. The cows of the Bohemian Spotted breed were 2.5 to 7 years old. The foetuses were taken from the uterus by the Caesarean section with local anaesthesia. The foetuses were of both sexes (nfemale = 12, n male = 8). Only the level of total calcium and inorganic phosphorus in the blood plasma was much higher in the foetuses than in the dams and this difference was highly significant. The levels of other minerals showed no statistically significant differences in the two categories of animals tested. The osmolality of the blood plasma of the foetuses was almost the same as in the cows. The higher calcaemia and phosphoraemia of the foetuses ensues from the function of osteotrophic minerals in the process of quick growth and ossification in the third trimester of intrauterine life. The closeness of the levels of sodium, potassium and chlorides as well as the very similar osmolality of the blood plasma in the foetuses and the dams prove the "stability" of the dynamic balance of these parameters between the foetus and the dam in the internal environment of the womb.  相似文献   

20.
利用透射电镜对柔嫩艾美耳球虫大配子发育和卵囊的超微结构进行了观察。结果表明,大配子体和小配子体寄生于相邻的宿主细胞内,相伴产生。大配子体的发育、大配子的形成、受精及卵囊形成均于带虫空泡内完成。大配子体系由末代裂殖子侵入肠上皮细胞后,缩短、长大、变圆而形成,大配子体和大配子外被单位膜,细胞核位于大配子体中央,早期大配子体的细胞核有1个明显的核仁,细胞质内逐渐形成大量成囊体1、成囊体2、大量支链淀粉和脂肪体,成囊体1比成囊体2形成的早。卵囊壁有5'层,内有大量支链淀粉和指肪体。含有大配子体、大配子和合子的带虫空泡内有丰富的泡内小管,它们是大配子体、大配子和合子获得营养物质和排出代谢废物的途径。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号