An investigation of Leishmania spp. in Didelphis spp. from urban and peri-urban areas in Bauru (São Paulo, Brazil)

Blood and bone marrow samples were taken from 112 Didelphis spp., collected between March 2005 and February 2006, from urban and peri-urban areas of Bauru, São Paulo State, Brazil, to evaluate the hypothesis that these animals might constitute a reservoir of Leishmania spp. Anti-Leishmania ssp. antibodies were screened in the serum samples using an enzyme-linked immuno-sorbent assay (ELISA) and the polymerase chain reaction (PCR). PCR was performed on fragments of DNA samples from Leishmania spp. using primers 13A and 13B, and showed a positive outcome in 91.6% of the 112 samples tested. Of the 107 samples analyzed by ELISA, 71% were positive. Evidence of epidemiological risk factors such as a circulating parasite and freely moving vectors suggests that Didelphis spp. may participate in the transmission cycle of Leishmania spp. in Bauru.     

Effects of different types of dietary non-digestible carbohydrates on the physico-chemical properties and microbiota of proximal colon digesta of growing pigs

The effect of different types of fibre on the intestinal digesta and microbial diversity was evaluated in growing pigs. The animals were fed during forty-two days with one of four experimental diets including a control group, a diet enriched with resistant starch type I, by coarse ground corn, and other two diets containing sugar beet pulp (8%) and wheat bran (10%) (as sources of soluble and insoluble non-starch polysaccharides respectively). Body weight (BW) and average daily feed intake (ADFI) were assessed at day 7, 21 and 42. Luminal samples of digesta from proximal colon were collected to analyse water retention capacity (WRC), concentration of short-chain fatty acids (SCFA) and the microbial diversity. Overall, animals fed with higher amounts of non-digestible carbohydrates had lower ADFI and BW. Sugar beet pulp provoked an increase of WRC, a higher concentration of SCFA, and a more stable microbial diversity throughout the experimental period. On the other hand, animals fed with wheat bran presented a lower bacterial diversity.     

Intermittent suckling improves post-weaning feed uptake but does not change functional gut characteristics of piglets

Suckling pigs were separated from their dam for 24 h on day 21 (1 × 24 h fasting, n = 10) or day 21 and 24 (2 × 24 h fasting, n = 10). Pigs in the control group (n = 10) were not fasted before weaning. All pigs were weaned on day 28 postpartum. Feed intake during the first 4 days post-weaning was higher (P < 0.05) for pigs exposed to 1 × 24 h fasting compared with controls. Water consumption was not affected by fasting prior to weaning. The difference in post-weaning feed uptake was not reflected in any clinical traits, intestinal morphology, or activity of digestive enzymes (maltase, dipeptidylpeptidase IV, aminopeptidases A and N; P > 0.15). In conclusion, a short period of fasting prior to weaning can increase post-weaning feed uptake, although this had no clinical impact under the present experimental conditions.     

野兔圈养管理技术

野兔肉质细嫩、香醇、味美,并含有丰富的人体所需的营养物质,特别是胆固醇含量很低(仅为0.4%),是消费者特别是心血管患者及肥胖者理想的动物蛋白食品。野兔家养成为近几年来发展起来的新兴产业,由于需要较高的管理技术,在很多地方还处于试养阶段,还没有形成规模,野兔的供应还远远不能满足市场的需要,发展前景看好。我所于2006年引进种兔5组,采取圈养的方式进行饲养并获得成功。为了使这一产业在我州得以推广,现将野兔家养的关键技术总结如下。1圈舍的准备根据不同的条件,可修建砖混结构的圈舍,也可利用废弃的猪圈、牛圈、羊圈和鸡鸭舍稍加改…     

Immunopathology of <Emphasis Type="Italic">Dirofilaria immitis</Emphasis> Infection

Heartworm disease caused by Dirofilaria immitis affects canine and feline hosts, with infections occasionally being reported in humans. Studies have shown that both dirofilarial antigens and those derived from its bacterial endosymbiont Wolbachia, interact with the host organism during canine, feline and human infections and participate in the development of the pathology and in the regulation of the host’s immune response. Both innate and acquired immune responses are observed and the development of the acquired response may depend on the host and, or on its parasitological status. This review aims at illustrating current research on the role of both D. immitis and Wolbachia, in the immunology and immunopathology of dirofilariosis.     

Mutation and virulence assessment of chromosomal genes of Rhodococcus equi 103

Rhodococcus equi can cause severe or fatal pneumonia in foals as well as in immunocompromised animals and humans. Its ability to persist in macrophages is fundamental to how it causes disease, but the basis of this is poorly understood. To examine further the general application of a recently developed system of targeted gene mutation and to assess the importance of different genes in resistance to innate immune defenses, we disrupted the genes encoding high-temperature requirement A (htrA), nitrate reductase (narG), peptidase D (pepD), phosphoribosylaminoimidazole-succinocarboxamide synthase (purC), and superoxide dismutase (sodC) in strain 103 of R. equi using a double-crossover homologous recombination approach. Virulence testing by clearance after intravenous injection in mice showed that the htrA and narG mutants were fully attenuated, the purC and sodC mutants were unchanged, and the pepD mutant was slightly attenuated. Complementation with the pREM shuttle plasmid restored the virulence of the htrA and pepD mutants but not that of the narG mutant. A single-crossover mutation approach was simpler and faster than the double-crossover homologous recombination technique and was used to obtain mutations in 6 other genes potentially involved in virulence (clpB, fadD8, fbpB, glnA1, regX3, and sigF). These mutants were not attenuated in the mouse clearance assay. We were not able to obtain mutants for genesfurA, galE, and sigE using the single-crossover mutation approach. In summary, the targeted-mutation system had general applicability but was not always completely successful, perhaps because some genes are essential under the growth conditions used or because the success of mutation depends on the target genes.     

Resorcylic acid lactone as an anabolic agent in cattle

This paper discusses the use of resorcylic acid lactone as an anabolic agent in cattle. When given to finishing steers it increases daily gain by 10–18% and final carcass weight by 6–10 kg. When given to finishing steers in conjunction with trenbolone acetate, there is an additive response in terms of growth rate and carcass weight. The final carcass weights were 310±2.1, 319±2.0, 316±2.0 and 328±2.0 for unimplanted steers, or steers implanted with resorcylic acid lactone or trenbolone acetate or a combination of both compounds respectively. Responses in finishing steers in spring at pasture were similar to responses obtained in winter. In male calves, average liveweights at the end of a 134-day experimental period were 123, 142 and 140 kg (SE ± 5.4 kg) respectively for control calves or calves given resorcylic acid lactone or a combination of resorcylic acid lactone and trenbolone acetate. After a further 134 days grazing together these calves weighed 271, 294 and 297 kg (SE ± 7.9 kg) respectively, indicating that the extra gain was retained once the implants ceased to be effective. No significant effect on daily gain or carcass weight of heifers was obtained in our trials with resorcylic acid lactone. Results from feed efficiency trial indicated resorcylic acid lactone significantly increased feed efficiency. Therefore, resorcylic acid is an effective growth promoter in male castrate cattle.     

Esophagotomy in the pony: comparison of surgical techniques and form of feed

Esophageal healing was studied in 12 ponies after cervical esophagotomy. The esophagus was sutured, feed and water were withheld for 48 hours, and then all ponies were permitted to eat. In group I (n = 6), a longitudinal esophagotomy was made. In group II (n = 6), a rotational esophagotomy was made with the mucosal incision 180 degrees away from the incision in the esophageal muscle. Three ponies in each group were fed a soft diet ad libitum for 9 days, and then were allowed access to hay and grain. The remaining ponies were fed hay and grain. The esophagotomies of all hay-fed ponies dehisced and healed by second intention, whereas esophagotomies healed by first intention in the ponies given a soft diet. Endoscopic and radiographic examinations indicated that the progression of healing in the present study was a function of diet (form of food), rather than surgical technique. The cross-sectional width of the muscularis externa at the incision site was 39.6% greater in mash-fed ponies than in hay-fed ponies. Based on density-dependent image analysis, average elastin content and reticulin fiber of the submucosa and muscularis externa at the incision were not influenced by the form of feed or surgical technique, although elastin fiber regeneration did not occur at the site of the incision.     

Acute experimentally induced aflatoxicosis in the weanling pony

Nineteen weanling ponies and 1 adult pony were given a single oral dose of aflatoxin B1 (AFB1). Dosages were: 0, 0.5, 1, 2, 4, 5, 6, and 7.4 mg of AFB1/kg of body weight. Vital signs were monitored, and whole blood and serum collected for analysis of serum enzymes, prothrombin time, blood cell counts, and serum urea nitrogen. Ponies that died were examined for gross lesions, and tissues were collected for histopathologic examination and analysis of AFB1 and AFM1 residues. Two of the 4 ponies given the 2 mg/kg dose and all ponies given the larger dosages died within 76 hours. Clinical signs included increased rectal temperature, faster heart and respiratory rates, abdominal straining, bloody feces, and tetanic convulsions. At necropsy, ponies that died of acute aflatoxicosis showed visceral petechiae and hepatic focal lesions. Histopathologic changes included severe hepatic necrosis, vacuolation, and bile duct hyperplasia. Aflatoxins B1 and M1 were recovered from liver, kidney, skeletal muscle, and gastrointestinal contents. One other pony given the 2 mg/kg dose died 32 days after dosing, and 1 control pony died after 70 days. Continuous elevations in prothrombin time and serum aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transpeptidase levels were observed in ponies dosed at 4 mg/kg or more. Significant (P less than 0.05) elevations in these values, which peaked 2 to 3 days after dosing, were seen in ponies given the 2 mg/kg dose. This group also had significant increases over controls in PCV and hemoglobin concentration 5 days after dosing.