Development of maternal antibodies after oral vaccination of young female wild boar against classical swine fever

An experimental study was performed to investigate the development of maternal antibodies after oral immunisation of young female wild boar against classical swine fever (CSF) using C-strain vaccine. Our results demonstrated that maternal antibodies do not persist in the offspring for more than 3 months. Based on the neutralising serum antibody titres, we assume that piglets of wild sows vaccinated orally twice or immunised once a long time before conception have protective antibodies for approximately 2 months. Furthermore, it seems that the level and the duration of maternal antibodies in the offspring are depend on the age of the female animals at the moment of vaccination as demonstrated in our experiment. The recent vaccination procedure consists of three double vaccinations in spring, summer and autumn. Especially vaccinations in summer and autumn could be crucial for transfer of high maternal antibody titres to the offspring.     

The effect of testosterone on gastrocnemius muscle fibres in growing and adult male and female rats: a histochemical,morphometric and ultrastructural study

In this study, the effect of testosterone on gastrocnemius muscle fibres in growing and adult rats (male and female) was examined using histochemical, morphometric and ultrastructural techniques. After physiological saline (PS), olive oil (OvO) or olive oil + testosterone (OvOT) injections on 72 rats (growing and mature, 36 male and 36 female), the sample tissues of fibre types of the gastrocnemius muscle taken were examined by histochemical [alkaline adenosine triphosphatase (alk-ATPase), acid ATPase (ac-ATPase)], morphometric and ultrastructural techniques. In PS-injected control groups, the gastrocnemius muscle of both sexes contained all the fibre types studied [slow-oxidative muscle fibres (type I), fast-oxidative glycolytic muscle fibres (type IIA) and fast-glycolytic muscle fibres (type IIB)]. The type I fibres had the smallest diameter, type IIA had a medium diameter and type IIB fibres had the largest diameter. In OvO-injected groups, it was observed that the OvO had little effect on the gastrocnemius muscles of either sex, although there was significant enlargement of type IIB fibres. After the injection of OvOT, hypertrophy of muscle fibres was determined by morphometric study. The biggest increase in diameter was on type I fibres. In addition, degenerations on some mitochondria, accumulation of lipid droplets on type I and type II fibres, an increase in glycogen particles, bifurcation of myofibrils, an increase in the number and diameter of units resembling T tubules and an increase in ribosomal content were also observed in the same group by transmission electron microscope. Consequently, it was determined that testosterone can induce protein synthesis in gastrocnemius muscle fibres, and induces changes in shape and size, and also can change the appearance and the number of fibres.     

Cutaneous lesions in experimental acute and subacute African swine fever: an immunohistopathological and ultrastructural study

Histopathological, immunohistochemical and ultrastructural cutaneous changes are described in acute and subacute forms of experimental African Swine Fever (ASF). Fourteen 3-month-old Large White cross pigs were infected intramuscularly with the Dominican Republic 78 (DR78) ASF virus isolate and euthanized in pairs on alternatives days (3 to 17) post-inoculation (dpi). Three pigs were found dead at 8, 10 and 13 dpi, respectively. Antibodies against viral antigen Vp73, human fibrinogen, glycoprotein IIIa and Factor VIII-ra were used to evaluate viral antigen distribution, fibrin microthrombi and platelets in dermal vessels, respectively. Cutaneous lesions were characterised by vascular changes ranging from hyperaemia, mild oedema, scarce fibrin microthrombi and microhaemorrhages in euthanized animals, to generalized fibrin microthrombosis and microhaemorrhages in dead pigs. Secondary pustules and superficial folliculitis were observed in two animals dead at 10 and 13 dpi. Diffuse cytoplasmic Vp73 labelling was found in numerous intravascular monocytes and dermal macrophages. Ultrastructural studies showed mature viral particles in the lumen of dermal vessels but viral replication was not observed; nonetheless, microtubuloreticular structures were observed in the cytoplasm of some endothelial cells and macrophages which showed cytopathic effects, signs of cell activation or degeneration. Morphological and immunohistochemical evidences of platelet activation, degranulation and consumption were observed from 5 dpi onward.     

Classical swine fever in wild boars in Switzerland

In May 1998, wild boars with classical swine fever (CSF) symptoms were detected in the southern part (Canton Ticino) of Switzerland. CSF virus was isolated from the submitted samples and RT-PCR followed by direct nucleotide sequencing of the 5' non-translated region showed that this virus was identical to the isolate previously recognized in wild boars from the area of Varese (Italy). In most animals, antibodies to CSF virus were detected as well. An immediate measurement was taken by limiting the movement of pigs and identifying both risk and surveillance zones. In order not to disturb potentially infected wild boars within their habitat a complete hunting prohibition for 2 months was enforced. The different possibilities of the control of CSF outbreaks in wild boars are discussed.     

野猪、家猪及野家杂种猪calpain3基因的多态性分析

Calpain3(CAPN3)在肌肉组织中特异表达,其活性显著影响宰后肉的嫩化,研究以野猪、家猪及野家杂种猪为研究对象,对其上的一个点突变进行了基于限制性内切酶HincⅡ的PCR-RFLP分析.结果表明:2个等位基因在野猪、家猪中的分布存在着极显著的差异,在长白、大白、杜洛克这3个欧洲引进猪种中没有检测到B等位基因;民猪共检测了35头,只发现了3个AB杂合体,其余都是AA型;而野猪却以B为优势基因,B等位基因频率明显高于A等位基因,结合品种(品系)特性说明该突变可能与瘦肉率和嫩度有关.     

母猪玉米赤霉烯酮中毒的诊断

玉米赤霉烯酮是由禾谷镰刀菌产生的代谢物质，它是一种生长在玉米、高梁和小麦上的具有雌激素样作用的霉菌毒素。玉米赤霉烯酮是一种取代的2，4-二羟基苯甲酸内酯，其结构与牛用合成代谢剂玉米霉醇相似。饲喂这种发霉变质的谷物饲料，可引起母猪的繁殖障碍，怀孕母猪流产，后备母猪屡配不孕，生长期小母猪阴道炎等。     

Survey of selected diseases in wild swine in Texas

Tissue, fecal, and serum specimens and swabs of nasal turbinates and tracheas were collected from 100 wild swine (Sus scrofa) from 10 populations in Texas and, along with 24 additional serum specimens, were evaluated for selected swine diseases. Swine positive for pseudorabies were detected in 7 populations. Brucella suis biovar 1 was isolated from 4 swine from 2 populations, but positive serologic results may indicate a more widespread distribution of the organism. All populations contained swine that were positive for leptospirosis. Trichinella spiralis was not found in the swine evaluated.     

Variation of Aujeszky's disease viruses in wild swine in USA

In the United States of America, Aujeszky's disease (pseudorabies) has been eradicated from all domestic swine. Some re-emergence of infection occurred as vaccine use diminished. Sporadic outbreaks have also occurred because of the reservoir of infection in feral swine that have spread across the southern two-thirds of the country and Hawaii. In order to be able to understand the origins of re-emerging virus, sequence analysis of variable genes in pseudorabies virus (PRV) has been used to differentiate strains. Most PRV from feral swine can be distinguished from virus circulating in domestic pigs during the national epizootic. However, several feral swine isolates of PRV from south central states are closely related or identical in sequence to strains from domestic pigs. Extensive study by PCR for the presence of virus in the oral cavity of feral pigs disclosed that the viral DNA is distributed widely in tonsils salivary glands, taste buds and even mucosa in the vicinity of tusks. Clearly the virus in feral swine has multiple mechanisms of transmission to insure persistent infection and the threat of re-emergence in domestic swine continues.     

Lifetime reproductive and financial performance of female swine

OBJECTIVE: To evaluate reproductive and financial performance for commercial swine herds grouped on the basis of pattern of removal of female swine. DESIGN: Cohort study. SAMPLE POPULATION: 25 swine herds. PROCEDURES: Lifetime reproductive productivity was summarized as number of pigs weaned per herd day per mated female and as number of herd days per pig weaned per mated female. Factors associated with these 2 measures were determined by use of linear regression. Financial data from a commercial database were used to estimate maximum number of parities at removal associated with profitability. Sensitivity analysis was used to simulate how variations in daily maintenance cost and value per weaned pig would influence profitability. RESULTS: Mean number of pigs weaned per herd day per mated female was 0.054; mean number of herd days per pig weaned per mated female was 20.2. Both these measures were associated with proportion of nonproductive days during herd life, preweaning mortality rate per litter weaned, mean lifetime number of pigs born alive per litter weaned, and mean lifetime lactation duration. Maximum parity at time of removal associated with profitability ranged from 5 to 8. Daily maintenance costs per female had a greater impact on lifetime profitability than did value per weaned pig. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that lifetime reproductive and financial performance is optimized among swine herds that have higher proportions of high-parity females.     

An ultrastructural analysis of osteochondritic growth plate cartilage in growing swine

In growing swine, ossification failure due to osteochondrosis has an incidence of nearly 100% in the distal ulna of animals at six months of age, yet the etiology of the disease is understood poorly. In this study, the ultrastructure of the chondrocyte and its pericellular matrix is analyzed in normal growth plates and in growth plates with lesions characteristic of osteochondrosis using aldehyde primary fixatives and osmium-ferrocyanide as the secondary fixative. Chondrocytes in lesion areas fail to undergo normal hypertrophic cell maturation, and they have an accumulation of rough endoplasmic reticulum, lipid droplets and mitochondria. These morphological changes are interpreted to be both variable and nonspecific for osteochondrosis. Within the pericellular matrix of chondrocytes from lesion areas, the most striking abnormality is the presence of a highly condensed matrix with an accumulation of large, irregularly shaped deposits of electron dense material. These morphological alterations are characteristic of a matrix which either is not secreted normally, or in which the highly ordered interactions of diverse macromolecules has been lost. These pericellular matrix changes have not been described in other diseases of growing cartilage. They may be significant in the failure of metaphyseal vascular penetration of the pericellular matrix which is characteristic of osteochondrosis.     

Estimation of lifetime productivity of female swine

OBJECTIVE: To develop estimates of lifetime productivity for breeding female swine calculated longitudinally during time in the breeding herd, and to compare estimates of lifetime productivity for female swine removed from the herd at different parities. DESIGN: Retrospective cohort study. ANIMALS: 9,416 breeding female swine from 29 herds. PROCEDURE: A frequency distribution for parity at the time of removal was generated. Estimates of lifetime productivity (lifetime nonproductive days [NPD], lifetime NPD as a proportion of herd life, total number of pigs born per litter weaned, number of pigs born alive per litter weaned, number of pigs weaned per litter weaned, number of NPD per year in the herd, number of litters weaned per year in the herd, and number of pigs weaned per year in the herd) were calculated for females with parity > or = 1 at the time of removal. RESULTS: For 58% of all females, parity at the time of removal was < or = 3. On average, 20.7% of herd life was spent in nonproductive activities, but the proportion of herd life that was nonproductive decreased significantly as parity at the time of removal increased. Number of NPD per year in the herd decreased and number of litters weaned per year in the herd and number of pigs weaned per year in the herd increased significantly as parity at the time of removal increased. CLINICAL IMPLICATIONS: Higher parity at the time of removal from the herd is associated with improved lifetime productivity for female swine. Parity at time of removal is commonly used as an approximation for lifetime productivity, but it does not take into account the impact of NPD, especially NPD during early reproductive cycles.     

豫医卷毛大鼠皮肤毛囊形态学及超微结构观察

为比较卷毛大鼠与SD大鼠皮肤毛囊形态学区别,探讨卷发机理,采用病理组织学和电镜技术观察突变大鼠皮肤毛囊结构。组织学结果显示卷毛大鼠皮肤毛囊弯曲,毛囊皮质内根鞘鞘小皮层排列不规则。扫描电镜下卷毛大鼠毛干弯曲,毛干横断面为扁平形,根鞘厚薄不均。透射电镜观察发现突变大鼠毛囊内根鞘细胞内见多量透明蛋白颗粒与角蛋白丝形成的均质状复合物,排列不规则。研究结果表明,突变基因可能引起毛囊内根鞘细胞角化过程不一致和中间丝的不规则排列而导致卷发。     

A histopathologic,immunohistochemical, and ultrastructural study of the intestine in pigs inoculated with classical swine fever virus

The aim of this study was to report on the lesions occurring in the intestine during experimental classical swine fever (CSF) and to clarify the nature of infected cells and the distribution of viral antigen. Thirty-two pigs were inoculated with the virulent CSF virus (CSFV) isolate Alfort 187 and slaughtered from 2 to 15 postinoculation days; four animals of similar background served as a control group. Immunohistochemistry, electron microscopy, and the transferase-mediated deoxyuridine triphosphate nick-end labeling method were used to detect viral antigens and apoptosis. The results showed progressive lymphoid depletion and mucosal necrosis. The lymphoid depletion could have been caused by apoptosis of lymphocytes but could not be directly attributed to the effect of CSFV on these cells. Vascular changes, pathogenic bacteria, and viral infection of epithelial cells were ruled out as causes of necrotic lesions. However, large virally infected monocytes-macrophages with ultrastructural changes indicative of activation were observed in the intestine. This suggests that monocytes-macrophages play an important role in the pathogenesis of intestinal lesions. An understanding of the function of these cells will require additional study.     

Two outbreaks of classical swine fever in wild boar in France

In 2002 and 2003, two successive outbreaks of classical swine fever were declared in wild boar in northern France. The first was in Moselle, near the town of Thionville and the border with Luxembourg, and the second was in the northern Vosges area, near the German border. The outbreaks were investigated by serological and virological diagnosis of dead or shot animals. Hunting restrictions were applied to limit the spread of the outbreaks. The virus was detected eight times between April and July 2002 in the Thionville area, an area well delimited by natural or artificial barriers such as rivers or highways. Cooperation between the authorities concerned was good, and hunting restrictions were applied for one year. No virus was detected after July 2002 and the Thionville outbreak was officially considered over in March 2005. In the northern Vosges the situation was different, with no barriers to animal movements, continuous forest, difficulties in establishing hunting restrictions in this huge area, and the circulation of the virus in Germany close to the frontier. Virus of a different strain from that isolated in the Thionville outbreak was still being isolated in the northern Vosges in 2004, and owing to the failure of the hunting restrictions, the French health authorities decided to vaccinate wild boar.