Gonadotropin‐induced Puberty Does Not Impair Reproductive Performance of Gilts over Three Parities     

OHO Eckhardt  SMMK Martins  ME Pinese  FC Horta  AC Rosseto  MA Torres  AFC De Andrade  BBD Muro  CT Marino  PHM Rodrigues  AS Moretti 《Reproduction in domestic animals》2014,49(6):964-969

The aim of this study was to evaluate the reproductive performance of three parities of gilts treated or not treated with gonadotropin to induce puberty. Sixty gilts received 600 IU of equine chorionic gonadotropin (eCG) followed by 2.5 mg of porcine luteinizing hormone (LH) 72 h later. Fifty‐nine other gilts were exposed only to a mature boar for 15 min twice daily. Artificial insemination (AI) was performed at 0, 12 and 24 h after the detection of oestrus, and gestation was confirmed by ultrasound after 35 days. Sows were inseminated at the first post‐weaning oestrus. The total numbers of piglets born, piglets born alive, stillborn, mummified foetuses, as well as pregnancy and farrowing rates were evaluated for each of the three parities. Culling rates, farrowing intervals and weaning‐to‐oestrous intervals (WEI) were also analysed. Mean age at puberty and oestrous manifestation were not significantly different between treatments (p = 0.0639; 179.20 ± 17.52 compared with 173.96 ± 16.94, 91.66% compared with 94.92%) across the experimental period. However, females that underwent puberty induction showed modest increases both in the number of total pigs born and in the number of piglets born alive. In conclusion, puberty induction through exogenous gonadotropin administration in field conditions did not induce a more concentrated first oestrous manifestation, but trended to a modest increase in the number of pigs born alive in the first parity and a reduced culling rate during the first gestation.  相似文献   

Perkinsus sp. infestation in carpet-shell clams, Ruditapes decussatus (L), along the Portuguese coast. Results from a 2-year survey     

Ricardo B. Leite  Ricardo Afonso  M. Leonor Cancela   《Aquaculture (Amsterdam, Netherlands)》2004,240(1-4):39-53

This study characterises Perkinsus atlanticus disease prevalence and intensity within the economically important beds of the clam Ruditapes decussatus along the Iberian Atlantic coast. Samples were collected from five different sites along the Portuguese coast (Ria Formosa, Ria do Alvor, V.N. Milfontes, Aveiro, Lagoa de Obidos) and in Galicia (Ria de Arosa) between winter 2000/2001 and 2002/2003. The infection level was evaluated by the Ray Fluid Thioglycollate medium (RFTM) method using the body burden assay. In addition, the measure of the condition index (CI) (percentage between the edible part and the total weight of the clams) was conducted to investigate a possible correlation between this parameter and the intensity of the infection. However, no clear relationship between infection intensity and condition index (CI) could be determined although a significant decline in CI was found for heavily infected clams. Results of a 2-year survey demonstrate the presence of Perkinsus sp. in all sampling sites albeit with different intensities. Sites where human interference was minimal showed the lowest levels of infection. There were no significant differences in Perkinsus sp. infection intensity between samples collected in winter and summer, in contrast with several studies describing higher intensities at the end of the summer. Nevertheless, major differences were observed from year to year and site to site, indicating that factors other than those responsible for seasonal climatic variations might affect the prevalence and the intensity of Perkinsus sp. infection.  相似文献   

Dissolution Factors of Ta, Th, and U Oxides Present in Pyrochlore     

K. Dias da Cunha  M. Santos  F. Zouain  L. Carneiro  G. Pitassi  C. Lima  C. V. Barros Leite  K. C. P. Dália 《Water, air, and soil pollution》2010,205(1-4):251-257

Air pollution can be a problem in industrial processes, but monitoring and controling the aerosols in the work place is not enough to estimate the occupational risk due to dust particle inhalation. The solubility in lung fluid is considered to estimate this risk. The aim of this study is to determine in vitro specific dissolution parameters for thorium (Th), uranium (U), and tantalum (Ta) associated to crystal lattice of a niobium mineral (pyrochlore). Th, U, and Ta dissolution factors in vitro were obtained using the Gamble solution (simulant lung fluid, SLF), particle induced X-ray emission, and alpha spectrometry as analytical techniques. Ta, Th, and U are present in the pyrochlore crystal lattice as oxide; however, they have shown different dissolution parameters. The rapid dissolution fraction (f _r), rapid dissolution rate (λ _r), slow dissolution rate (f _s), and slow dissolution fraction (λ _s) measured for tantalum oxide were equal to 0.1 and 0.45 and 0.00007 day^?1, respectively. For uranium oxide, f _r was equal to 0.05, λ _r was equal to 1.1 day^?1, and λ _s was equal to 0.000068 day^?1. For thorium oxide, f _r was 0.025, λ _r was 1.5 day^?1, and λ _s was 0.000065 day^?1. These results show that chemical behavior of these three compounds in the SLF could not be represented by the same parameter. The ratio of uranium concentration in urine and feces samples from workers exposed to pyrochlore dust particle was determined. These values agree with the theoretical values of estimated uranium concentration using specific parameters for uranium oxide present in pyrochlore.  相似文献   

Fimbria-like adhesive factor (EAF 44) from verocytotoxigenic Escherichia coli of bovine origin   总被引：1，自引：0，他引：1  

T Yano  M Garcia  D S Leite  I J de Camargo  A F de Castro 《Research in veterinary science》1988,45(3):418-419

An adhesin with fimbria-like properties was present in four strains of verocytotoxigenic Escherichia coli isolated from diarrhoeic calves in Brazil.  相似文献   

Chronic renal failure and urolithiasis in a 2-years-old colt     

JA LAING  AL RAISIS  RJ RAWLINSON  AC SMALL 《Australian veterinary journal》1992,69(8):199-200

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Prickly paddy melon (Cucumis myriocarpus) poisoning of cattle     

RA McKENZIE  RD NEWMAN †  AC RAYNER †  PJ DUNSTER 《Australian veterinary journal》1988,65(6):167-170

Twenty-six Hereford heifers died after eating mostly ripe fruit of Cucumis myriocarpus growing in a fallowed cultivation paddock. Four affected cattle were dehydrated and apparently had abdominal pain. Necropsy of three revealed intense congestion with haemorrhage of the alimentary tract, numerous C. myriocarpus seeds in ruminal contents, pulmonary congestion and oedema and, in two, swollen livers. Midzonal swelling and vacuolation of hepatocytes occurred in these two. C. myriocarpus fruit (83% by weight ripe) were dosed to two calves at 60 g wet weight/kg live weight. Both collapsed with tachycardia and dyspnoea and died within 6 h. Their packed cell volumes just before death had increased to 0.7. They had hydropic degeneration and necrosis of the ruminal mucosa, intense congestion and oedema of the rumen, abomasum and intestines, swollen and vacuolated hepatocytes and foci of myocardial degeneration and necrosis. Two other calves were dosed daily with 20 g fruit/kg for three days, then 40 g/kg for three days. One calf received a further 40 g/kg next day. Both calves developed persistent diarrhoea and neutrophilia, and their plasma gamma glutamyltransferase and bilirubin concentrations increased. Necropsy revealed necrosis and oedema of the rumen and swollen degenerate hepatocytes.  相似文献   

Populational dynamics of Stomoxys calcitrans (Linneaus) (Diptera: Muscidae) in three biocenosis, Minas Gerais, Brazil     

Rodríguez-Batista Z  Leite RC  Oliveira PR  Lopes CM  Borges LM 《Veterinary parasitology》2005,130(3-4):343-346

Populational flux of the adult phase of Stomoxys calcitrans was observed in the municipal district of Pedro Leopoldo, Minas Gerais, Brazil. Three biocenoses were selected for the study: stable agrobiocenosis, pastural agrobiocenosis and eubiocenosis. The occurrence and the populational flux of the insects, using the Magoon trap for their capture, were established. For each trap located in different biocenoses, a crossbred calf (Bos taurus × Bos indicus) approximately 6-month-old was used as “live bait,” exposed weekly for 48 h in the traps. Of the three agrobiocenoses studied, the stable agrobiocenosis contributed the greatest number of specimens of. S. calcitrans captured, corresponding to 96.9% of the total flies of this species collected. S. calcitrans shows seasonal behavior for approximately 6 months (spring and summer being the rainiest months of the year). The population peaked during the months of November and December. During the months of July and August, there was no capture of flies.  相似文献   

G and P genotypes of group A rotavirus from diarrhoeic calves born to cows vaccinated against the NCDV (P[1],G6) rotavirus strain     

Barreiros MA  Alfieri AF  Médici KC  Leite JP  Alfieri AA 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2004,51(3):104-109

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Complexities of the pathogenesis of Mannheimia haemolytica and Haemophilus somnus infections: challenges and potential opportunities for prevention?     

Czuprynski CJ  Leite F  Sylte M  Kuckleburg C  Schultz R  Inzana T  Behling-Kelly E  Corbeil L 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2004,5(2):277-282

Progress in producing improved vaccines against bacterial diseases of cattle is limited by an incomplete understanding of the pathogenesis of these agents. Our group has been involved in investigations of two members of the family Pasteurellaceae, Mannheimia haemolytica and Haemophilus somnus, which illustrate some of the complexities that must be confronted. Susceptibility to M. haemolytica is greatly increased during active viral respiratory infection, resulting in rapid onset of a severe and even lethal pleuropneumonia. Despite years of investigation, understanding of the mechanisms underlying this viral-bacterial synergism is incomplete. We have investigated the hypothesis that active viral infection increases the susceptibility of bovine leukocytes to the M. haemolytica leukotoxin by increasing the expression of or activating the beta2 integrin CD11a/CD18 (LFA-1) on the leukocyte surface. In vitro exposure to proinflammatory cytokines (i.e. interleukin-1beta, tumor necrosis factor-alpha and interferon-gamma) increases LFA-1 expression on bovine leukocytes, which in turn correlates with increased binding and responsiveness to the leukotoxin. Alveolar macrophages and peripheral blood leukocytes from cattle with active bovine herpesvirus-1 (BVH-1) infection are more susceptible to the lethal effects of the leukotoxin ex vivo than leukocytes from uninfected cattle. Likewise, in vitro incubation of bovine leukocytes with bovine herpesvirus 1 (BHV-1) potentiates LFA-1 expression and makes the cells more responsive to leukotoxin. A striking characteristic of H. somnus infection is its propensity to cause vasculitis. We have shown that H. somnus and its lipo-oligosaccharide (LOS) trigger caspase activation and apoptosis in bovine endothelial cells in vitro. This effect is associated with the production of reactive oxygen and nitrogen intermediates, and is amplified in the presence of platelets. The adverse effects of H. somnus LOS are mediated in part by activation of endothelial cell purinergic receptors such as P2X7. Further dissection of the pathways that lead to endothelial cell damage in response to H. somnus might help in the development of new preventive or therapeutic regimens. A more thorough understanding of M. haemolytica and H. somnus virulence factors and their interactions with the host might identify new targets for prevention of bovine respiratory disease.  相似文献   

Tumor necrosis factor-alpha enhances Haemophilus somnus lipooligosaccharide-induced apoptosis of bovine endothelial cells     

Sylte MJ  Kuckleburg CJ  Leite FP  Inzana TJ  Czuprynski CJ 《Veterinary immunology and immunopathology》2006,110(3-4):303-309

Haemophilus somnus lipooligosaccharide (LOS)-induced apoptosis of bovine pulmonary artery endothelial cells has been shown previously to be dependent on capsase-8 activation. Activation of caspase-8 can occur via a death receptor-dependent mechanism (e.g., TNF- binding to TNF- receptor 1 (TNF-R1)). In this study, we tested the hypothesis that TNF- can enhance LOS-induced apoptosis of bovine endothelial cells. Addition of exogenous recombinant human TNF- alone failed to cause apoptosis, or enhance LOS-induced apoptosis, of bovine endothelial cells. However, blocking de novo protein synthesis by addition of cycloheximide significantly enhanced apoptosis of bovine endothelial cells by TNF-, LOS or TNF- and LOS in combination. Conversely, addition of soluble recombinant human (sTNF-R1) diminished LOS-induced apoptosis. Overall, these data suggest that LOS-mediated apoptosis may be due, in part, to activation of a TNR-R1-dependent death pathway.  相似文献