黄土丘陵区植被演替中不同草本植物间的化感效应

为了解植被演替过程中不同植物间的化感作用,选取黄土丘陵区退耕地撂荒演替中不同阶段的优势物种茵陈蒿(Artemisia capillaries)和铁杆蒿(Artemisia sacrorum),分析它们对其他植物种子萌发及幼苗生长的影响。结果表明:不同部位水浸提液由于其化感物质及其释放方式的不同,化感作用存在明显差异。演替前期物种茵陈蒿水浸提液对铁杆蒿和白羊草(Bothriochloa ischaemum)种子萌发有明显抑制作用,而对达乌里胡枝子(Lespedeza davurica)和白羊草幼苗的生长总体表现为促进作用;茵陈蒿根际土和根系水浸提液促进铁杆蒿、白羊草和达乌里胡枝子根的生长,而地上部水浸提液可促进白羊草和胡枝子根的生长。演替后期物种铁杆蒿对茵陈蒿和白羊草种子萌发有较强的抑制作用;其根际土和根系水浸提液可促进茵陈蒿、白羊草和达乌里胡枝子幼苗的生长;地上部水浸提液抑制白羊草和达乌里胡枝子幼苗的生长。茵陈蒿和铁杆蒿对于自身种子萌发以及幼苗的生长具有一定的自毒作用,表现为茵陈蒿根系和地上部水浸提液强烈抑制自身种子萌发;高浓度的铁杆蒿根系和地上部水浸提液对自身的种子萌发以及根、芽的生长具有明显抑制作用。综上所述,茵陈蒿和铁杆蒿不同部位水浸提液对4种受体植物种子萌发表现出不同程度的抑制作用,对根和芽的生长呈现出由"高抑低促"的作用。     

松嫩平原两个生态型羊草叶构件异速生长规律

对在不同生境的2个生态型羊草叶片、分蘖株的生长指标进行测定,为提高牧草生产产量和质量提供理论依据。在沙土和盐碱土生境下,灰绿生态型和黄绿生态型羊草不同龄级分蘖株叶生物量均随分蘖株生物量、高度的增加而增加,不同叶位的叶宽也随叶长的增加而增加。经回归分析,叶生物量与分蘖株生物量、高度之间,叶宽与叶长之间关系符合y=axb幂函数的生长关系,达到显著或极显著相关。方程中的b值表示叶生物量或叶宽的增加速率。在所用函数中,幂函数变化规律更具有生物学和生态学意义。在松嫩平原的繁殖期,灰绿型和黄绿型羊草不同龄级分蘖株叶构件具有相同的异速生长和生物量积累规律。2个生态型羊草叶构件的生物量、叶长、叶宽、生长和生物量积累规律等在相同生态型不同生境之间,相同生境不同生态型之间,以及不同龄级分蘖株之间的各个数量指标均有一些差异,但变化幅度不大,是2个生态型对其所在生境产生的相应适应性反应,具有明显的生态可塑性。     

柴达木盆地6种灌木主要渗透调节物质分布特征和抗旱性研究

对青海省柴达木盆地温性荒漠区主要野生灌木驼绒藜、唐古特白刺、柽柳、盐爪爪、梭梭、木本猪毛菜不同器官(根、枝、叶)的脯氨酸和可溶性糖含量,以及叶片和嫩枝叶绿素a和叶绿素b含量进行测定。结果表明,唐古特白刺和柽柳各器官的脯氨酸和叶绿素含量显著高于其他4种灌木,木本猪毛菜根系具较高脯氨酸含量;植物可溶性糖含量不同器官存在差异,木本猪毛菜各器官、唐古特白刺和柽柳叶片的根系可溶性糖含量较高;所有植物叶绿素a>叶绿素b,嫩枝叶绿素含量比叶片少。由模糊数学隶属函数得出,唐古特白刺抗旱性最强,柽柳和木本猪毛菜次之,梭梭,盐爪爪和驼绒藜的抗旱性较弱。     

大狼毒对紫花苜蓿种子萌发及幼苗生长的化感效应研究

为探究大狼毒(Euphorbia jolkinii)是否会对其它物种产生化感作用,促进大狼毒蔓延区退化草地的恢复治理,本研究以紫花苜蓿(Medicago sativa)为受体材料,采用培养皿滤纸法和穴盘培养法,开展大狼毒对紫花苜蓿种子萌发及幼苗生长的化感效应研究,结果表明:大狼毒对紫花苜蓿种子萌发率和萌发进程体现为"化...     

雷州山羊部分脏器的组织形态观察

对15只雷州山羊肺、肾、卵巢、肝、脾、胰进行了组织学观察,结果如下：①肺的实质由导气部和呼吸部组成,导气部中主要见到的是细支气管和终末细支气管,偶见小支气管,细支气管黏膜上皮形成许多明显的皱襞,固有膜下有完整的平滑肌。肺泡呈多面形囊泡,壁极薄,由肺泡上皮围成;②肾内皮质肾单位和髓旁肾单位在数量上无明显差别,髓放线发达,有一些髓放线深入皮质浅层,在延伸中逐渐变细;③卵巢被膜下有许多原始卵泡,皮质中生长卵泡也很多,偶见成熟卵泡;④肝间质组织少,肝小叶分界不清,切面呈不规则的多边形,肝细胞以中央静脉为中心呈放射状排列;⑤脾脏表面覆有一层较厚的由平滑肌组成的被膜,染成红色,被膜结缔组织伸入脾内形成许多分支的小梁。白髓中脾小结呈圆形或卵圆形,淋巴细胞密集。脾索含有较多的血细胞而红染,相互连接成网;⑥胰的表面由少量结缔组织组成的被膜,胰岛大小不等,胰岛细胞呈梭形或圆形,核染色较淡。     

Effect of xylanase and beta-glucanase supplementation of wheat- or wheat- and barley-based diets on the performance of male turkeys

The efficiency of a mixture of xylanase and beta-glucanase enzymes was evaluated in two separate experiments on growing turkeys offered diets based on wheat or wheat and barley. 2. In the first experiment, the addition of 560 and 2800 IU of xylanase and beta-glucanase, respectively, per kg of diet significantly improved feed efficiency in turkeys fed on wheat- and barley-based diet throughout the entire experiment (42 d). 3. In the second experiment, the enzyme mixture significantly increased N-corrected apparent metabolisable energy (AMEN) by approximately 5%. 4. Furthermore, the combination of xylanase and beta-glucanase significantly improved body weight gain and feed efficiency. Feed efficiency was increased by 2.94, 2.47 and 5.91% in diets based on 500 then 540 g of wheat/kg of diet, 394 then 384 g of wheat and 100 then 150 g of barley/kg of diet and 180 g of wheat and 300 then 350 g of barley/kg of diet, respectively. 5. This enzyme mixture decreased in vitro viscosity of wheat, barley and soybean meal, the effect being larger for wheat and barley than for soybean meal. 6. In conclusion, the supplementation of diets based on wheat and barley with xylanase and beta-glucanase significantly improved body weight gain and feed efficiency. Therefore, wheat and barley could be used more efficiently by turkeys in the presence of an appropriate enzyme preparation.     

水貂多态蛋白位点与经济性状相关的研究

通过建立一般线性模型对美国短毛黑、大连金州黑和左家型水貂遗传标记的筛选,方差分析表明,Pi-3对左家型水貂皮张长度有显著影响,Pi-3位点与美国短毛黑针绒毛长度比之间存在显著相关,Est是对金州黑水貂体重影响较大的位点,Po是对金州黑水貂针绒毛长度比影响较大的位点,Po和Est对金州黑水貂绒毛长度有显著影响。最小二乘均数结果表明,左家型水貂Pi-3的AA型与AB型间皮长差异显著,美国短毛黑中Pi-3的AA型与AB型间针绒毛长度比差异显著,金州黑水貂Est的AB和BB型体重之间也有显著差异,金州黑水貂Po的AA型与AB型的针绒毛长度比有显著差异,金州黑水貂Po的AA型与BB型和Est的AB和BC基因型之间的绒毛长度也有显著差异。     

Histomorphological findings and expression of matrix metalloproteinases and their tissue specific inhibitors (TIMPs) in normal tricuspid valves and in chronic tricuspid valvular disease in dogs

The histomorphological findings and immunohistochemical expression of matrix metalloproteinases (MMPs-1, 2, 9 and 14) and their tissue inhibitors (TIMPs-2, 3 and 4) are reported in the parietal (pTV) and septal leaflets (sTV) of the tricuspid valves in normal dogs and dogs with chronic valvular disease (CVD). The layers of the normal sTV were not as well defined as in the pTV and the spongiosa of the sTV contained abundant mucopolysaccharides (MPS) and adipocytes. In CVD, there was expansion of the spongiosa of the pTV due to deposition of MPS, leading to formation of nodules along the free edge. In CVD, there was fibrosis of the atrialis of the sTV and formation of nodular deposits of MPS in the spongiosa and ventricularis, mainly affecting the proximal and middle parts of the leaflet. In dogs with normal pTV and sTV, MMPs-1 and 14 and TIMPs-2, 3 and 4 were expressed, while MMPs-2 and 9 were absent. In mild CVD, expression of MMPs-2, 9 and 14 were increased in the pTV, whereas small foci within the spongiosa contained MMP-9 and TIMP-3 positive cells. In advanced CVD, MMP-14 also was increased in the pTV. In mild CVD, there was increased expression of MMPs-1 and 2 and TIMP-2, but decreased expression of TIMP-4, in the sTV. Small foci with expression of MMP-14 and TIMPs-2, 3 and 4 were also present in the sTV in mild CVD. In advanced CVD, there was increased expression of MMPs-2 and 9 and TIMP-2 in the sTV. In CVD there is upregulation of various MMPs in the pTV, whereas there is a complex alteration in expression of MMPs and TIMPs in the sTV.     

白三叶和高羊茅对青菜幼苗生长的化感抑制效应

用白三叶和高羊茅茎叶的水浸提溶液处理,初步探讨了白三叶和高羊茅对青菜种子发芽和幼苗生长的化感抑制效应及机理.结果表明,白三叶和高羊茅茎叶浸提液对青菜种子的发芽率和幼苗生长均有不同程度的抑制作用;抑制作用具有明显的供体种和品种间差异,白三叶的抑制作用显著大于高羊茅.化感物质定性鉴定表明,白三叶和高羊茅浸提液中含邻位和间位羟基的酚类化感物质.这些化感物质通过抑制细胞生长和影响细胞膜的功能而抑制青菜幼苗的生长.     

Evaluation of modified Wright-staining of dried urinary sediment as a method for accurate detection of bacteriuria in cats

Background: Urinary sediment examination and quantitative urinary culture results are frequently discordant. Objectives: The aims of this study were to compare accuracy of light microscopic examination of wet‐mounted unstained (wet‐unstained) and air‐dried modified Wright‐stained (dry‐stained) sedimented preparations of urine with results of quantitative aerobic bacterial culture for detection and characterization of bacteriuria in cats. In addition, the presence of pyuria detected by urinalysis and potential risk factors were assessed. Methods: A blinded prospective study was conducted on 472 urinary samples collected from 410 cats by cystocentesis. The age and sex of each cat were recorded. Complete urinalyses were performed and included quantification of WBCs. Quantity and morphology of bacteria in each specimen were determined by light microscopic examination of wet‐unstained (performed by certified medical technologists) and dry‐stained (performed by a veterinary clinical pathologist) sedimented preparations of urine and compared with results of quantitative bacterial cultures. Results: Of 472 urinary specimens, 29 were positive for bacteriuria by culture and considered true positives and 443 were considered true negatives. Compared with these results, examination of wet‐unstained and dry‐stained urines had sensitivities of 75.9% and 82.8%, specificities of 56.7% and 98.7%, and test efficiencies of 57.8% and 97.7%, respectively. Positive likelihood ratios were 1.8 and 63.7 and negative likelihood ratios were 0.42 and 0.17 for wet‐unstained and dry‐stained examinations, respectively. Compared with 29 culture‐positive samples, the wet‐unstained method had morphologic concordance and misclassification rates of 37.9% and 62.1%, respectively, whereas the dry‐stained method had morphologic concordance and misclassification rates of 65.5% and 34.5%, respectively. Only 34% of samples with bacteriuria had pyuria. Frequency of bacteriuria was not significantly different based on age and sex of the cats, but there was a tendency for increased frequency in female cats and in cats >10 years old. Conclusions: Staining dried urinary sediment with a modified Wright‐stain significantly improved sensitivity, specificity, and test efficiency of microscopic detection and classification of bacteriuria compared with the wet‐unstained method. Pyuria should not be a criterion for determining the presence or absence of bacteriuria.     

Perception and Management of Spatio-Temporal Pasture Heterogeneity by Hungarian Herders

The goal of our study was to document traditional steppe herders' perception and management of spatial and temporal heterogeneity of forage availability of their seminatural pastures. Ninety-two herders living in the Hortobágy saline steppe, Hungary, Central Europe were interviewed, and participatory observation was used to understand herding and habitat improvement techniques. The herders recognized 47–66 habitat types (mostly grassland types), and listed at least 90 plant species important for grazing. They have a nuanced knowledge of the intra- and interannual variations of forage quality and quantity. They perform very strong and well-planned herding practices. Daily spatial pattern of grazing is, however, often opportunistic and flexible, but has a more-or-less regular year-round cycle, in which marshes and stubbles provide forage in drought periods. Reciprocal learning and continuous communication between the herder and his driving dogs and livestock strongly influence grazing pattern. Herders manage and improve different habitats of their pastures differently by traditional and, less frequently, modern methods. The main method is grazing supplemented by manuring, burning, and removal of spiny weeds. Traditional knowledge of herders could be effectively used in evidence-based conservation and pasture management of European saline steppes; e.g., the reintroduction of some old herding techniques (opportunistic pasture use, grazing of marshes, and burning). Herders' knowledge could also help the fine-tuning and local adaptation of European agri-environmental regulations (e.g., how to balance subsidies for hay-making and grazing in saline steppes). More research is needed, however, on the ecological effects of different traditional grazing techniques, e.g., rotation, manuring, and burning. In general a more complex socio-ecological understanding of the internal and external factors affecting adaptation of the Hortobágy herders to changing environment, society, and European Union policies is needed.     

几种豆禾牧草混播初期生长互作效应的研究

选用豆科与禾本科牧草各两种互为混播组合，研究其混播状态下种子萌发及幼苗生长的互作效应，结果表明：当以白三叶、紫花苜蓿为作用牧草，并随期播量增加时，受体牧草高羊茅与紫羊茅种子萌发及幼轩生长受到显著影响，受体牧草紫花苜蓿种子萌发及幼苗生长则对幼苗生长有促进作用。互作效应强度的进一步分析表明，豆科牧草对禾本科牧草的作用一般较强，并在初期生长阶段有较好的表现。这一结果与混播草地豆科牧草所表现的特征相符。因此本研究可从一个侧面为混播草地豆禾组合相容性提供可资借鉴的高效简捷的判定方法。     

不同玉米品种（系）的全株、果穗与秸秆青贮特性比较

为比较不同玉米品系的全株、果穗及秸秆青贮效能和利用特性,以3个粮饲通用玉米新品系和1个专用青贮玉米为材料,于3/4乳线期测定生物产量及相关农艺性状,制作全株、果穗及秸秆青贮,发酵60 d后测定营养成分和发酵品质。结果表明：4个品种（系）生育期变幅为120~123 d,MTP-080生育期最长且绿叶数及绿叶比最高,MTP-082生育期居中但全株和果穗鲜干产量均最高。全株青贮中雅玉青贮8号的中性洗涤纤维和酸性洗涤纤维含量最高,MTP-082粗蛋白、淀粉和可溶性碳水化合物含量均最高,MTP-082泌乳净能显著高于雅玉青贮8号和MTP-080。各品种（系）全株及果穗青贮pH为3.53~4.07,氨态氮/总氮小于10%,费氏评分均在110分以上,青贮发酵品质总体评价均为优级。果穗青贮总能、总可消化养分、消化能、代谢能、维持净能、增重净能及泌乳净能显著高于全株青贮和秸秆青贮。果穗青贮相对饲用价值为全株青贮的2.05倍、秸秆青贮的3.37倍。综上,粮饲通用型青贮玉米如MTP-082全株青贮产量高,持绿性适中,营养价值和发酵品质优,而且是制作果穗青贮的优质原料,因地制宜选择粮饲通用玉米发展果穗青贮将有利于种养殖业节本增效。     

Potential Bacillus probiotics enhance bacterial numbers, water quality and growth during early development of white shrimp (Litopenaeus vannamei)

Epidemics of epizootics and occurrence of multiresistant antibiotics of pathogenic bacteria in aquaculture have put forward a development of effective probiotics for the sustainable culture. This study examined the effectiveness of forms of mixed Bacillus probiotics (probiotic A and probiotic B) and mode of probiotic administration on growth, bacterial numbers and water quality during rearing of white shrimp (Litopenaeus vannamei) in two separated experiments: (1) larval stages and (2) postlarval (PL) stages. Forms of Bacillus probiotics and modes of probiotic administration did not affect growth and survival of larval to PL shrimp. The compositions of Bacillus species in probiotic A and probiotic B did not affect growth and survival of larvae. However, postlarvae treated with probiotic B exhibited higher (P<0.05) growth than probiotic A and controls, indicating Bacillus probiotic composition affects the growth of PL shrimp. Total heterotrophic bacteria and Bacillus numbers in larval and PL shrimp or culture water of the treated groups were higher (P<0.05) than in controls. Levels of pH, ammonia and nitrite of the treated shrimp were significantly decreased, compared to the controls. Microencapsulated Bacillus probiotic was effective for rearing of PL L. vannamei. This investigation showed that administration of mixed Bacillus probiotics significantly improved growth and survival of PL shrimp, increased beneficial bacteria in shrimp and culture water and enhanced water quality for the levels of pH, ammonia and nitrite of culture water.     

Relationships among growth hormone and prolactin secretory parameter estimates in Holstein bulls and their predicted differences for lactational traits

Selection of dairy sires is based on the production records of their female ancestors, half-sibs and daughters. No trait expressed by the sire is used. Concentrations of growth hormone (GH) and prolactin (PRL), hormones produced in both males and females that are fundamental in lactation, may be correlated with production. A study was conducted to determine whether measures of these hormones in the sire would be useful predictors of lactational ability of daughters. Blood samples were collected at 15-min intervals for 8 h from 26 Holstein bulls (5.5 yr of age) that had one progeny summary available. Plasma concentrations of GH and PRL were quantified and the mean and baseline concentrations and the frequency and mean amplitude of the secretory peaks were determined for each bull. Concentrations among these values and bulls' predicted differences (PD) were determined. Significant negative correlations were detected for frequency of GH peaks and PD for yield of milk, fat and protein; correlations were positive for PRL baseline concentrations and PD for fat and protein (P less than .10), and correlations were negative for frequency of PRL peaks and PD for milk, fat and protein (P less than .10). Addition of estimates of bull hormone secretory parameters to breeding values based on performance of relatives considerably improved the accuracy (R2) for predicting progeny performance from sire information. Certain characteristics of the patterns of GH and PRL secretion may be heritable and aid in identification of superior dairy animals.     

空心莲子草水浸液对黑麦草和高羊茅种子发芽和幼苗生长的影响

用浓度为0,0.05,0.10,0.20,0.40 g/mL的空心莲子草肉质根和根状茎的浸提液及浓度为0,0.01,0.05,0.10,0.20 g/mL肉质根和根状茎的粉碎液分别处理黑麦草和高羊茅种子。结果显示,随着浸提液和粉碎液浓度增加,它们的发芽势、苗长和根长均小于对照;与对照相比,发芽率和鲜重发生明显变化;叶绿素含量和根系脱氢酶活性均低于对照;随着浸提液处理浓度增加,丙二醛含量先升高后下降,而粉碎液处理其含量均高于对照。表明空心莲子草地下部浸提液和粉碎液对黑麦草和高羊茅种子萌发和幼苗生长均有抑制作用,且浓度越高抑制作用越强;就同一浓度而言,粉碎液处理对它们的抑制作用大于浸提液处理。     

Cartilage canals and lesions typical of osteochondrosis in growth cartilages from the distal part of the humerus of newborn pigs

Vessels in cartilage canals supplying the articular-epiphyseal cartilage complex and growth plate of the distal part of the humerus of pigs between on day and 15 weeks old were examined in perfused and cleared specimens, and histochemical preparations. An extensive capillary network surrounded the arterioles and venules and probably maintained the circulation of blood as the ends of the cartilage canals underwent involution. Pits and grooves were in predilection sites for osteochondrosis and osteoarthrosis and were typical of early lesions of these conditions. Some ghosts that were observed mesoscopically were chondrified cartilage canals or remnants of cartilage canals in histological sections, and were considered to be the result of a normal process. However, abnormal involution may predispose to chrondrolysis, and the presence of involuting transverse cartilage canals at predilection sites implicated damaged canals in the aetiopathogenesis of osteochondrosis and osteroarthrosis in some pigs. Cleared specimens provided the most useful demonstration of the form and distribution of cartilage canals, ghosts, and pits or grooves. The association of cartilage canals with areas of chondrolysis, and the distribution of ghosts in the predilection sites for lesions, warrant further investigation of blood vessels within cartilage canals.     

中草药饲料添加剂对奶牛乳房炎的影响研究进展

奶牛乳房炎制约了奶牛养殖业的快速发展,目前奶牛乳房炎的预防与治疗主要依靠抗生素,抗生素的滥用和乱用对人、动物、生态环境的危害越发严峻,寻找安全有效的防治措施尤为重要。中草药及其提取物具有良好的抗菌、消炎等功效,且安全、绿色、无残留,能有效抑制病原菌,缓解炎症反应,改善泌乳功能,成为防治奶牛乳房炎的热点课题。因此,本文对中草药饲料添加剂对奶牛乳房炎的影响研究进展进行综述,为中草药及其提取物的开发利用、奶牛乳房炎防治提供可行的参考依据。 [关键词] 中草药|提取物|奶牛乳房炎|抗生素|饲料添加剂     

Diagnosis and surgical management of vascular ectasia in a dog

CASE DESCRIPTION: An 8-year-old male Golden Retriever was evaluated because of an 8-week history of intermittent diarrhea with melena and hematochezia that were not responsive to medical treatment and resulted in severe anemia. CLINICAL FINDINGS: Exploratory celiotomy with intestinal and colonic biopsy revealed mild enterocolitis but did not result in diagnosis of the cause of melena and hematochezia. Endoscopy of the upper portion of the gastrointestinal tract and colonoscopy were performed. Multifocal areas of coalescing, tortuous mucosal blood vessels were observed in the cecum and all regions of the colon. A diagnosis of vascular ectasia (VE) was made on the basis of the endoscopic and histologic appearance of the lesions. TREATMENT AND OUTCOME: An ileorectal anastamosis was performed. Melena and hematochezia resolved within 3 days after surgery, and the anemia resolved within 6 weeks after surgery. Surgical resection of the cecum and colon and feeding of a highly digestible diet resulted in long-term (22 months) resolution of clinical signs. CLINICAL RELEVANCE: Initial exploratory celiotomy with intestinal and colonic biopsy failed to reveal the VE lesions responsible for the melena, hematochezia, and anemia. Endoscopic evaluation was necessary for detection of the colonic VE lesions. Surgical resection of the cecum and colon and feeding of a highly digestible diet may result in a favorable outcome in affected dogs.     

青藏高原高寒草原放牧方式对植被、土壤及微生物群落的影响

为探究牦牛、藏羊六种不同组合放牧对土壤微生物群落结构的影响，本试验选择青藏高原高寒草原为研究对象，基于基因组扩增子技术，分析相同放牧强度不同放牧方式下植被、土壤以及土壤微生物的差异。研究结果显示，放牧显著降低植被地上生物量，其中豆科生物量降幅达到90.9%，放牧对植被地下生物量以及盖度影响较小。土壤有机质、全氮、全磷含量在牛、羊混合放牧下增加，在牛、羊单牧下降低；各放牧方式对土壤真菌Shannon指数、Simpson指数和pielou指数均没有显著影响，单牛放牧增加真菌Chao1指数和细菌的Shannon指数，而单羊放牧和混合放牧均降低细菌多样性指数；放牧显著降低了真菌担子菌门比例，不同放牧方式对细菌门水平丰度影响不大。本研究结果表明相同放牧强度下，不同牛、羊放牧组合对草地植被指标的影响差异不大，但显著改变了土壤养分含量、土壤细菌和真菌的群落组成，相比牛、羊单牧，牛羊混合放牧有助于提高土壤碳氮磷含量。