Experimental evidence of host specificity of Bartonella infection in rodents

A large number of Bartonella species and genetic variants were compared for their ability to cause bacteremia in different rodent species: the cotton rat (Sigmodon hispidus), white-footed mouse (Peromyscus leucopus), BALB/c mouse and Wistar rat. Experimental data supported field observations that host specificity can occur among certain Bartonella species and rodent species. Bacteremia could only be readily produced in cotton rats or white-footed mice if the strains used for inoculation were originally obtained from the same species or from a phylogenetically close species. A few Bartonella colonies could be observed in the blood of some BALB/c mice by 7 days after inoculation, but no evidence of the persistence of the infection was found. Host specificity suggests the possibility of a long co-speciation of Bartonella species with their rodent hosts. Host–parasite relationships measured by the duration and level of bacteremia and the minimal infectious dose may serve as additional criteria for classification of Bartonella isolates obtained from natural environments.     

Landscape connectivity and animal behavior: functional grain as a key determinant for dispersal

Landscape connectivity can be viewed from two perspectives that could be considered as extremes of a gradient: functional connectivity (refers to how the behavior of a dispersing organism is affected by landscape structure and elements) and structural connectivity (depends on the spatial configuration of habitat patches in the landscape like vicinity or presence of barriers). Here we argue that dispersal behavior changes with landscape configuration stressing the evolutionary dimension that has often been ignored in landscape ecology. Our working hypothesis is that the functional grain of resource patches in the landscape is a crucial factor shaping individual movements, and therefore influencing landscape connectivity. Such changes are likely to occur on the short-term (some generations). We review empirical studies comparing dispersal behavior in landscapes differing in their fragmentation level, i.e., with variable resource grain. We show that behavioral variation affecting each of the three stages of the dispersal process (emigration, displacement or transfer in the matrix, and immigration) is indeed likely to occur according to selective pressures resulting from changes in the grain of the landscape (mortality or deferred costs). Accordingly, landscape connectivity results from the interaction between the dispersal behavior of individuals and the grain of each particular landscape. The existence of this interaction requires that connectivity estimates (being based on individual-based models, least cost distance algorithms, and structural connectivity metrics or even Euclidian distance) should be carefully evaluated for their applicability with respect to the required level of precision in species-specific and landscape information.     

纳米技术在动物营养中的应用前景

纳米技术是20世纪90年代出现的一门新兴技术,由于纳米材料理化性质的奇特性,其将给动物营养带来巨大的革命。本文就纳米技术在动物营养的应用作一概述。     

双孢蘑菇常见病虫害及防治

了解和掌握双孢蘑菇常见病虫害发生的种类、危害特征，并采取相应的对策，是双孢蘑菇获得优质高产的保证。针对室内栽培中常见的病虫害，通过实践操作，总结出一些防治措施，供广大栽培者参考。     

意杨丰产林病虫害调查及其防治研究

意杨是睢宁县的重要用材树种.但目前病虫害日益增多.作者从1986年起,开展了主要病虫害的调查和防治试验.结果认为桑天牛、白杨透翅蛾、白杨舟蛾、杨树腐烂病是睢宁县意杨最重大的病虫害.文内还具体地论述了这些病虫害的危害症状、生物学特性、天敌及其防治方法.     

亚布力林业局适宜集材方式的探讨

本文根据几种集材方式的特点,结合亚布力林区的实际情况,对目前亚布力林业局适宜的集材方式进行了探讨。通过比较论证,认为畜力原木集材是目前亚布力林区适宜的集材方式。今后集材方式的改革应是机畜结合,以畜力原木集材为主,机械原条集材为辅。     

Evaluation of outcome associated with feline trauma: A Veterinary Committee on Trauma registry study

Objective

To evaluate outcome (survival to discharge) among trauma types (blunt, penetrating, both) in cats. Secondary objectives were to evaluate for associations between trauma type, injury severity, and the diagnostics and interventions selected by primary clinicians.

Design

Retrospective evaluation of veterinary trauma registry data.

Setting

Veterinary Committee on Trauma (VetCOT) veterinary trauma centers (VTCs).

Animals

A total of 3895 feline trauma patients entered in the VetCOT trauma registry from April 1, 2017 to December 31, 2019.

Interventions

Data collected included patient demographics, trauma type, Abdominal Fluid Score (AFS), Animal Trauma Triage (ATT) score, surgical intervention, glide sign on Thoracic Focused Assessment with Sonography for Trauma, Triage, and Tracking (TFAST), pleural effusion on TFAST, modified Glasgow Coma Scale (mGCS), and outcome (survival to discharge).

Measurements and Main Results

Data from 3895 cats were collected over a 30-month period. Incidence of trauma types was as follows: blunt, 58% (95% confidence interval [CI]: 56%–59%); penetrating, 35% (95% CI: 34%–37%); and combination, 7.4% (95% CI: 6.7%–8.3%). Differences in survival incidence among the trauma types were identified: blunt, 80% (95% CI: 78%–81%); penetrating, 90% (95% CI: 89%–92%); and combined, 68% (95% CI: 63%–74%) (P < 0.01). Cats in the penetrating trauma group had the lowest proportion of severe injuries (6%) and highest proportion of mGCS of 18 (89%); cats with combined trauma had the highest proportion of severe injuries (26%) and lowest proportion of mGCS of 18 (63%). Point-of-care ultrasound and surgery were not performed in the majority of cases. When surgery was performed, the majority of blunt cases’ procedures occurred in the operating room (79%), and the majority of penetrating cases’ procedures were performed in the emergency room (81%).

Conclusions

Cats suffering from penetrating trauma had the best outcome (survival), lower ATT scores, and higher mGCS overall. Cats that sustained a component of blunt trauma had a lower survival rate, higher ATT scores, and the highest proportion of mGCS <18.     

Status and prospects for livestock production in the Lao People’s Democratic Republic

Some 16 per cent of the Gross Domestic Product of the Lao PDR arises from the livestock sector. Almost all output - live animals and products - is from traditional small scale production and about 90 per cent of all households in the country keep one or more species of livestock. Industrial or large scale production is of very minor importance even for pigs and poultry. Considerable international assistance has been provided for livestock development, initially from the Socialist states that were of the same political persuasion as Lao PDR and more recently from multilateral and bilateral development assistance agencies. In general this assistance has not conferred lasting benefits on the sector in part due to the failure of the Lao Government to provide continuing support commensurate with the sector’s contribution to the national economy. Buffalo (1.1 million head in 2004) and cattle (1.3 million head) are the main ruminant species with goats and sheep (140 000 head) occupying a very minor position. Both pigs (1.7 million) and poultry (19.6 million) are major contributors to the household and national economies. Buffalo are now mainly meat producers, their former draught and transport roles having been taken over by mechanical equipment. Cattle, also once used for draught, are almost exclusively producers of beef. Pigs and poultry produce meat and poultry provide eggs. Lao indigenous livestock are mainly kept in low input systems, thus output is also low. Nothing is known of the genetic potential of the indigenous stock which are the victims of poor management, inadequate nutrition and minimal health care. There is strong and rising demand for products of animal origin within the country and in the greater Southeast Asia and East Asia regions. Given suitable and appropriate support the Lao livestock sector would be in a strong position to contribute to supplying this demand.     

Clays as dietary supplements for swine: A review

Clays are crystalline, hydrated aluminosilicate molecules composed of alkali and alkaline earth cations along with small amounts of various other elements. The best-known are montmorillonite, smectite, illite, kaolinite, biotite and clinoptilolite. The molecules in these clays are arranged in three-dimensional structures creating internal voids and channels capable of trapping a wide variety of molecules. As a result of this structure, clay minerals are regarded as a simple and effective tool for the prevention of the negative effects of many toxic compounds. Dietary supplementation with clays has been shown to improve weight gain and feed conversion in pigs. Where improvements in performance have been noted, one of the most likely explanations for the improvement is the fact clays increase nutrient digestibility. Clays reduce the speed of passage of feed along the digestive tract which allows more time for digestion. Feeding clays also causes morphological changes in the intestinal mucosa such as an increase in villus height and an increase in the villus height to crypt depth ratio. These changes increase the surface area of the gastrointestinal tract thus increasing nutrient digestibility. Several studies have indicated that feeding clay reduces the incidence, severity and duration of diarrhea in pigs. The mechanism for the reduction in diarrhea is likely due to increases in the numbers of Bifidobacteria and Lactobacillus and decreases in Clostridia and E. coli in the small intestine of pigs fed clays. In addition, the numbers of pigs born alive and weaned, birth weight and weaning weight have been shown to be higher for sows fed clays. Several studies have indicated that clays can help mitigate the effects of mycotoxins. The aim of the present review is to focus on the various clays which have been given attention in recent research and to discuss their potential to improve pig performance.     

硼肥不同施用方式对黄瓜生长的影响

以津早1号黄瓜为材料,研究硼砂不同施用方式对黄瓜生长的影响。试验结果表明,硼肥采用基肥条施和叶面喷施2种方式,均能有效地提高黄瓜体内叶绿素含量和净光合速率;使霜霉病和白粉病发病率显著降低,产量显著提高;使 VC 含量显著提高,可溶性固形物含量显著降低。生产中建议,硼砂采用叶面喷施（浓度为0.15%）,从定植后10 d 开始,每隔10 d 喷施1次,连续喷施2~3次;或者作基肥一次性施入,施用量0.5 kg/667 m2。