Evaluation of hepatitis E virus infection between different production systems of pigs in Brazil     

Marconni Victor da Costa Lana  Noemi Rovaris Gardinali  Raquel Aparecida Sales da Cruz  Letícya Lerner Lopes  Gustavo Sousa Silva  João Garcia Caramori Júnior  Anderson Castro Soares de Oliveira  Marcos de Almeida Souza  Edson Moleta Colodel  Amauri Alcindo Alfieri  Caroline Argenta Pescador 《Tropical animal health and production》2014,46(2):399-404

The objectives of this study were to (1) investigate the occurrence of hepatitis E virus (HEV) in pigs from large-scale and family-scale farms, (2) genetically characterize the strains isolated, and (3) study the pathogenesis of swine HEV infection via immunohistochemistry. A total of 50 pigs from 10 farms in Mato Grosso State, Brazil were divided according to type of production system into either large-scale farms (n?=?5) or family-scale farms (n?=?5). Samples of liver, gallbladder, small and large intestines, bile, and feces from the pigs were analyzed by nested PCR with primers targeting the ORF2 region of HEV and by immunohistochemistry. Of the eight HEV-positive samples from pigs of family-scale farms, phylogenetic analysis revealed that seven of the swine HEV isolates clustered with subtype 3b of genotype 3 and one isolate was categorized with subtype 3 f. The HEV antigen was detected mainly in the small intestine samples from family-scale farms, suggesting an early stage HEV infection. HEV was not detected in the samples of pigs from large-scale farms, reinforcing the need for additional studies to evaluate the risk of transmission of HEV to humans from pigs from family-scale farms in Mato Grosso State.  相似文献   

Evaluation of the effectiveness of Duddingtonia flagrans and Monacrosporium thaumasium in the biological control of gastrointestinal nematodes in female bovines bred in the semiarid region     

Manoel Eduardo da Silva  Fabio Ribeiro Braga  Luana Alcântara Borges  Jair Mendes de Oliveira  Walter dos Santos Lima  Marcos Pezzi Guimarães  Jackson Victor de Araújo 《Veterinary research communications》2014,38(2):101-106

Brazil has a herd of 212 million cattle and 171 million hectares of pastures that produce approximately 96 % of Brazilian beef. The Brazilian production system enables animal infection by endoparasites, which are considered one of the main obstacles for the development of this industry and are responsible for considerable economic losses. The control of parasitic diseases is performed via the administration of antiparasitic drugs, but they leave residues of the products in the treated animal, affect non-target organisms and select resistant strains of the parasites. The species D. flagrans and M. thaumasium are promising and sustainable alternatives for controlling gastrointestinal helminths of ruminants and other herbivores. In this study, we evaluated the efficacy of isolates of these species, formulated in a sodium alginate matrix and administered twice a week, to reduce the number of environmental infective larvae of gastrointestinal nematodes that affect prepubescent zebu females. The treated animals presented fewer eggs and a lower number of infective larvae per gram of faeces (p?<?0.05). The pastures occupied by treated animals showed a statistically significant reduction (p?<?0.05) of the number of L₃ and, furthermore, the genera Cooperia sp., Haemonchus sp., and Oesophagostomum sp. were the most prevalent. The average weight of the animals did not differ statistically (p?>?0.05) among the treated and control groups. The use of sodium alginate pellets as vehicle for delivery of the fungus mycelia D. flagrans (isolate AC001) and M. thaumasium (isolate NF34A) proved effective in controlling trichostrongylids in prepubescent cows bred in the semi-arid region, with an effective reduction in the number of infective larvae in the pastures.  相似文献   

Higher feeding diets effects on age and liveweight gain at puberty in crossbred Nelore × Hereford heifers   总被引：1，自引：1，他引：0  

Júlio Otávio Jardim Barcellos  Gabriel Ribas Pereira  Eduardo Antunes Dias  Concepta McManus  Leonardo Canellas  Mari Lourdes Bernardi  Adriana Tarouco  Ênio Rosa Prates 《Tropical animal health and production》2014,46(6):953-960

This study was conducted to determine the age and liveweight at puberty of 120 crossbred beef heifers submitted to four diets to achieve predetermined weight gains (kg/day): 0.5 (G500; n?=?32), 0.75 (G750; n?=?32), 1.0 (G1000; n?=?29), and 1.25 (G1250; n?=?27). Animals were classified depending on their level of crossing between Nelore (N) and Hereford (H): 25%N-75%H, 37.5%N-63.5%H, 43.7%N-56.7%H, 50%N-50%H, and 75%N-25%H. Reproductive evaluation was performed at the beginning and at the end of the experimental period by ultrasonography and hormone analysis. The average age and liveweight at puberty were 388.0?±?1.9 days and 331.4?±?1.3 kg, respectively. Animals from the 25%N-75%H group reached puberty earlier than heifers from other genetic groups supplemented with G1250 diet (P?<?0.05). Heifers with higher degree of Nelore (75%N-25%H) fed with G1000 diet showed estrus 42 days prior to mating, but only 57 % reached puberty at mating (P?<?0.05). Heifers with follicles of higher diameter reached puberty (P?<?0.05) earlier. Higher average daily weight gain showed a positive effect on follicular diameter and IGF-I level at puberty (P?<?0.01). Concentrations of GH were lower in heifers fed G1250 compared to G1000 diet (P?<?0.05). There was a significant interaction between nutritional level and insulin levels at puberty (P?<?0.01). We demonstrated the relationship between IGF-I and average daily gain on the onset of puberty in heifers. In conclusion, heifers submitted to the higher feeding level showed a higher follicular diameter and were younger at puberty.  相似文献   

Genomic analysis of influenza A virus from captive wild boars in Brazil reveals a human-like H1N2 influenza virus     

Natalha Biondo  Rejane Schaefer  Danielle Gava  Mauricio E. Cantão  Simone Silveira  Marcos A.Z. Mores  Janice R. Ciacci-Zanella  David E.S.N. Barcellos 《Veterinary microbiology》2014

Influenza is a viral disease that affects human and several animal species. In Brazil, H1N1, H3N2 and 2009 pandemic H1N1 A(H1N1)pdm09 influenza A viruses (IAV) circulate in domestic swine herds. Wild boars are also susceptible to IAV infection but in Brazil until this moment there are no reports of IAV infection in wild boars or in captive wild boars populations. Herein the occurrence of IAV in captive wild boars with the presence of lung consolidation lesions during slaughter was investigated. Lung samples were screened by RT-PCR for IAV detection. IAV positive samples were further analyzed by quantitative real-time PCR (qRRT-PCR), virus isolation, genomic sequencing, histopathology and immunohistochemistry (IHC). Eleven out of 60 lungs (18.3%) were positive for IAV by RT-PCR and seven out of the eleven were also positive for A(H1N1)pdm09 by qRRT-PCR. Chronic diffuse bronchopneumonia was observed in all samples and IHC analysis was negative for influenza A antigen. Full genes segments of H1N2 IAV were sequenced using Illumina's genome analyzer platform (MiSeq). The genomic analysis revealed that the HA and NA genes clustered with IAVs of the human lineage and the six internal genes were derived from the H1N1pdm09 IAV. This is the first report of a reassortant human-like H1N2 influenza virus infection in captive wild boars in Brazil and indicates the need to monitor IAV evolution in Suidae populations.  相似文献   

Comparative digestibility of low‐quality grass hay by two breeds of cattle differing in mature live weight     

A. L. Lourenço  A. Dias‐da‐Silva  A. S. Santos  M. A. M. Rodrigues  J. W. Cone  L. M. M. Ferreira 《Journal of animal physiology and animal nutrition》2014,98(3):453-457

The digestive capacity of the Portuguese native breed of Barrosão cattle and the Holstein–Friesian breed was measured when fed meadow hay (72–74 g CP and 641–671 g NDF/kg dry matter), offered either alone or supplemented with soya bean meal (150 g/kg dry matter), at maintenance level. Four mature cows of each breed were used. Average initial live weight (LW) was 457 and 635 kg for the Barrosão and the Holstein–Friesian cows respectively. The organic matter digestibility (OMD) of the meadow hay was higher in Holstein–Friesian than in Barrosão cows (p < 0.08) whether supplemented or not. The neutral detergent fibre digestibility of the hay was also higher in Holstein–Frisian when the hay was fed alone (p < 0.08). The soya bean meal supplementation increased the OMD and the NDFD digestibility of the total diet (p < 0.05), but not the OMD digestibility of the hay (p > 0.05). The results obtained in this study suggest a higher ability to digest fibre in the large dairy breed than in the small native breed. This suggestion is also supported by previous findings with sheep breeds largely differing in mature live weight.  相似文献   

Growth, digestibility and nutrient utilization of rainbow trout (Oncorhynchus mykiss) and European sea bass (Dicentrarchus labrax) juveniles fed different dietary soybean oil levels     

D. Alves Martins  E. Gomes  P. Rema  J. Dias  R.O.A. Ozório  L.M.P. Valente 《Aquaculture International》2006,14(3):285-295

A shortage of marine raw ingredients, such as fish oil, is predicted in the near future. The use of suitable alternative lipid sources, such as vegetable oils, is crucial for sustainable growth of the aquaculture sector. Three isonitrogenous (50% Crude Protein) and isoenergetic (19 kJ g⁻¹) diets, in which fish oil was gradually replaced by soybean oil (0, 25 and 50% of the oil fraction) were tested for 12 weeks, using European sea bass (Dicentrarchus labrax) and rainbow trout (Oncorhynchus mykiss) juveniles. No dietary effects (p>0.05) on growth performance, feed conversion, digestibility or body composition were observed with either species. The results obtained suggest the inclusion of soybean oil up to 50% of the dietary lipid is possible, in diets for sea bass and/or rainbow trout juveniles.  相似文献   

The relative influence of catchment and site variables on fish and macroinvertebrate richness in cerrado biome streams     

Diego R. Macedo  Robert M. Hughes  Raphael Ligeiro  Wander R. Ferreira  Miriam A. Castro  Nara T. Junqueira  Deborah R. Oliveira  Kele R. Firmiano  Philip R. Kaufmann  Paulo S. Pompeu  Marcos Callisto 《Landscape Ecology》2014,29(6):1001-1016

Landscape and site-scale data analyses aid the interpretation of biological data and thereby help us develop more cost-effective natural resource management strategies. Our study focused on environmental influences on stream assemblages and we evaluated how three classes of environmental variables (geophysical landscape, land use and cover, and site habitat), influence fish and macroinvertebrate assemblage richness in the Brazilian Cerrado biome. We analyzed our data through use of multiple linear regression (MLR) models using the three classes of predictor variables alone and in combination. The four MLR models explained dissimilar amounts of benthic macroinvertebrate taxa richness (geophysical landscape R ² ≈ 35 %, land use and cover R ² ≈ 28 %, site habitat R ² ≈ 36 %, and combined R ² ≈ 51 %). For fish assemblages, geophysical landscape, land use and cover, site habitat, and combined models explained R ² ≈ 28 %, R ² ≈ 10 %, R ² ≈ 31 %, and R ² ≈ 47 % of the variability in fish species richness, respectively. We conclude that (1) environmental variables differed in the degree to which they explain assemblage richness, (2) the amounts of variance in assemblage richness explained by geophysical landscape and site habitat were similar, (3) the variables explained more variability in macroinvertebrate taxa richness than in fish species richness, and (4) all three classes of environmental variables studied were useful for explaining assemblage richness in Cerrado headwater streams. These results help us to understand the drivers of assemblage patterns at regional scales in tropical areas.  相似文献   

Effects of dietary l-carnitine supplementation on growth and lipid metabolism in European seabass (Dicentrarchus labrax)   总被引：1，自引：0，他引：1  

J Dias  J Arzel  G Corraze  & J Kaushik 《Aquaculture Research》2001,32(S1):206-215

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Tolerance of Juvenile Flatfish Paralichthys orbignyanus to Acid Stress   总被引：1，自引：0，他引：1  

Wilson  Wasielesky  Jr. Adalto  Bianchini  Marcos H. S.  Santos Luis H.  Poersch 《Journal of the World Aquaculture Society》1997,28(2):202-204

Abstract.— The tolerance of juvenile flatfish Paralichthys orbignyanus to acid stress, was studied in 30-L plastic tanks using ten flatfishes (95 ± 13 g) per treatment. Water pH was monitored every 3 h and re-adjusted to the test pH using either HCl or NaOH. The photoperiod was fixed at 12L:12D, water temperature at 23 ± 0.8 C, and salinity at 30 ppt. Fish survival and ventilatory rate were monitored daily. At pH 4.0, we observed 100% mortality and ventilation rates different from controls. At pH 5.2, there was 100% survival even after 96 h. However, ventilation rate was higher than in controls. At pH equal or higher than 6.0, we observed 100% survival and normal ventilation rates. The estimated pH which would kill 50% of test organisms were: 4.51, 4.50 and 4.40 after 48, 72, and 96 h of experiment, respectively. These results show that juvenile flatfish are relatively tolerant to acid stress.  相似文献   

Tenerife's freshwater macroinvertebrates: Status and threats (Canary Islands,Spain)     

Bjrn Malmqvist  Anders N. Nilsson  Marcos Baez 《水产资源保护:海洋与淡水生态系统》1995,5(1):1-24

• 1 This paper lists 171 freshwater macroinvertebrate taxa from Tenerife (excluding chironomids) based on this study and other published information. Canarian endemism and a Mediterranean origin are dominant features in the data set. At least 14 species are Tenerife endemics. Endemism is especially high in the Diptera, Trichoptera and Coleoptera.
• 2 Extensive investigations were carried out at 57 sites in six different habitat categories and from at least two seasons. The most species-rich habitats were those with permanently running water, a biotope that is rare and diminishing in Tenerife.
• 3 The principal threat to freshwater environments is an increase in human exploitation of the water resources, which, if it is not moderated, will cause extinctions in the near future. Taxa that do not favour man-made canals are especially at risk—a risk that is increased by the small number of populations. These include the Canarian endemics Wormaldia tagananana, Tinodes canariensis (Trichoptera), Dixa tetrica (Diptera) and Baetis pseudorhodani (Ephemeroptera). Thirty-nine species were found at five or fewer sites.
• 4 Some species can survive in intermittent streams, although we found less than half of the taxa present in this habitat, indicating the extent of the diversity reductions that might be expected to follow the drying up of permanent streams.
• 5 Species living in the thin film of water in the madicolous habitats are similarly at risk. Three Canarian endemics were found exclusively in this habitat: Hydrotarsus pilosus, Limnebius punctatus (Coleoptera) and Satchelliella binunciolata (Diptera).
• 6 As a first step, protective measures are proposed for five of the most species-rich streams. If these were to be implemented, they would make a significant contribution towards maintaining biodiversity in the fresh waters of Tenerife.

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