Virulent Serpulina hyodysenteriae from a pig in a herd free of clinical swine dysentery.     

D J Hampson  R Cutler  B J Lee 《The Veterinary record》1992,131(14):318-319

  相似文献   

Spawning time and place of the Japanese eel Anguilla japonica in the North Equatorial Current of the western North Pacific Ocean     

Satoshi Ishikawa  Kunihiro Suzuki  Tadashi Inagaki  Shun Watanabe  Yobuo Kimura  Akihiro Okamura  Tsuguo Otake  Noritaka Mochioka  Yuzuru Suzuki  Hiroshi Hasumoto  Machiko Oya  Michael J Miller  Tae Won Lee  Hans Fricke  Katsumi Tsukamoto 《Fisheries Science》2001,67(6):1097-1103

  相似文献   

Pathogenicity of porcine enterotoxigenic Escherichia coli that do not express K88, K99, F41, or 987P adhesins.     

T A Casey  B Nagy  H W Moon 《American journal of veterinary research》1992,53(9):1488-1492

Three-week-old weaned and colostrum-deprived neonatal (less than 1 day old) pigs were inoculated to determine the pathogenicity of 2 enterotoxigenic Escherichia coli isolates that do not express K88, K99, F41, or 987P adhesins (strains 2134 and 2171). Strains 2134 and 2171 were isolated from pigs that had diarrhea after weaning attributable to enterotoxigenic E coli infection. We found that both strains of E coli adhered in the ileum and caused diarrhea in pigs of both age groups. In control experiments, adherent bacteria were not seen in the ileum of pigs less than 1 day old or 3 weeks old that were noninoculated or inoculated with a nonpathogenic strain of E coli. These control pigs did not develop diarrhea. Antisera raised against strains 2134 and 2171 and absorbed with the autologous strain, grown at 18 C, were used for bacterial-agglutination and colony-immunoblot assays. Both absorbed antisera reacted with strains 2134 and 2171, but not with strains that express K99, F41, or 987P adhesins. A cross-reaction was observed with 2 wild-type K88 strains, but not with a K12 strain that expresses K88 pili. Indirect immunofluorescence with these absorbed antisera revealed adherent bacteria in frozen sections of ileum from pigs infected with either strain. We concluded that these strains are pathogenic and express a common surface antigen that may be a novel adhesin in E coli strains that cause diarrhea in weaned pigs.  相似文献   

Induced Maturation and Spawning of the Chinese Catfish Clarias fuscus     

Michael J. A.  Young Arlo W.  Fast Paul G.  Olin 《Journal of the World Aquaculture Society》1989,20(1):7-11

Chinese catfish ( Clarias fuscus ) were successfully spawned in Hawaii using human chorionic gonadotropin (HCG) at dosage rates of two and four international units (IU) per gram body weight. Fish not injected with HCG did not produce viable eggs. Successful spawns with HCG occurred between May and October. Hatch rates of up to 80% were obtained during June, July, and August for those fish given either a 2 or 4 IU per gram body weight injection of HCG. Fish spawned in either May or October yielded significantly higher hatch rates when injected with 4 rather than 2 IU per gram body weight. Fish held at elevated temperatures (28 to 30 C) prior to the normal spawning season developed significantly larger oocyte diameters, 60 days earlier than fish held under ambient temperature conditions (21.5 to 24 C). Photoperiod manipulation at ambient temperature conditions was associated with earlier oocyte maturation, but photoperiod effects were much less important than temperature.  相似文献   

Verification by polymerase chain reaction of vertical transmission of Theileria sergenti in cows   总被引：2，自引：0，他引：2       下载免费PDF全文

Byeong K. Baek  Kim B. Soo  Jin H. Kim  Jin Hur  Bou O. Lee  J. M. Jung  Misao Onuma  Anthony O. Oluoch  Chang-Hyun Kim    Ibulaimu Kakoma 《Canadian journal of veterinary research》2003,67(4):278-282

To evaluate the transplacental transfer of Theileria sergenti infection in cattle, we used DNA probes to detect T. sergenti in 6 pregnant cows and their calves. All the animals were monitored by parasitologic, serologic, and polymerase chain reaction (PCR) assays for a predicted 875-base-pair (bp) DNA product and a 684-bp amplicon detected by nested PCR in the blood and spleens of aborted fetuses. An open reading frame (ORF) starting at nucleotide 170 and terminating at position 1021 was shown to code for a polypeptide of 283 amino acid residues. All 6 dams and 5 calves were positive for T. sergenti in all tests. One calf was positive only with nested PCR. We conclude that transplacental transmission of T. sergenti is a significant problem. The relevance of the data in the programmed introduction of new (especially pregnant) animals into established clean herds needs serious consideration with regard to control of theileriosis and other tickborne diseases.  相似文献   

Reproductive efficiency and maternal-offspring transfer of gossypol in rainbow trout (Oncorhynchus mykiss) fed diets containing cottonseed meal.     

J H Blom  K J Lee  J Rinchard  K Dabrowski  J Ottobre 《Journal of animal science》2001,79(6):1533-1539

In a preceding study, complete substitution of fish meal protein with cottonseed meal (CM) protein did not affect the survival or growth rate of adult rainbow trout over a 6-mo period. Gossypol, a naturally occurring compound in cottonseeds, has an antifertility effect in terrestrial animals, but information regarding salmonid fish is lacking. Female rainbow trout in this experiment were fed diets with either 0, 25, 50, 75, or 100% (diets 1 to 5) of the fish meal protein replaced with CM protein until first maturation and spawning to study long-term effects on growth and reproduction. Feeding diets containing CM over a total period of 10 mo did not result in differences in growth and mortality compared to the control group (P > 0.05). Increased CM incorporation levels resulted in decreased (P < 0.05) blood hemoglobin (10.6 +/- 1.3, 8.4 +/- 1.8, 7.3 +/- 1.1, 6.9 +/- 0.8, and 5.6 +/- 1.4 g/dL) and hematocrit (49.6 +/- 3.9, 38.5 +/- 9.3, 34.4 +/- 3.7, 34.8 +/- 4.9 and 28.0 +/- 6.8%) levels in diets 1 to 5, respectively. The CM incorporation level had no effect (P > 0.05) on the number of eggs produced per female but led to a reduction (P < 0.05) in egg weight. Eyed stage survival of embryos was low in all dietary groups and did not show differences (P > 0.05). However, an increasing CM incorporation level led to a linear increase (P < 0.05) in the number of females that produced no viable embryos (23.1, 37.5, 42.9, 60.0, and 71.4%). Gossypol in the diet was absorbed by the female trout and transferred to the eggs (0, 2.2 +/- 0.5, 6.7 +/- 1.6, 10.6 +/- 4.2, and 20.0 +/- 2.6 micrograms/g in diets 1 to 5, respectively). A high concentration of gossypol remained in the juveniles at the swim-up stage (endogenous yolk-absorbed) (0.6 +/- 0.3, 2.4 +/- 0.3, 3.4 +/- 0.0, and 4.7 +/- 1.0 micrograms/g, diets 2 to 5, respectively). The findings suggest that replacement of the dietary fish meal protein with CM protein has no effect on fish growth and mortality but may lead to a reduction in reproductive performance in female rainbow trout.  相似文献   

Modeling multi-scale spatial ecological processes under the discrete event systems paradigm     

Maria J. Perestrello de Vasconcelos  Bernard P. Zeigler  Lee A. Graham 《Landscape Ecology》1993,8(4):273-286

A multi-scale spatial ecological model of a wet sclerophyllous forest subject to recurrent fires is presented. The model is specified in a Discrete Event Systems framework (DEVS) (Zeigler, 1990) interfaced with a Geographic Information System (GIS), and includes the ability to simulate landscape dynamics at several levels of resolution simultaneously. This is achieved by encoding a modular hierarchical representation of the forest landscape components into a set of nested, interconnected, and spatially referenced dynamic models. The results of the landscape dynamics simulations are displayed as sequences of maps through time, illustrating the potential of this modeling methodology for dealing with complex hierarchical structures that operate at several spatial and temporal resolutions.Research work supported by Junta Nacional de Investigaçäo Científica e Tecnológica, Portugal, and the Advanced Resource Technology Program, University of Arizona, USA.  相似文献   

Enzyme-linked immunosorbent assay for screening the plasma residues of tetracycline antibiotics in pigs.   总被引：6，自引：0，他引：6  

H J Lee  M H Lee  P D Ryu  H Lee  M H Cho 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(5):553-556

The recommended therapeutic doses of three kinds of tetracyclines, oxytetracycline (OTC, withdrawal period, 10 days), chlortetracycline (CTC, withdrawal period, 5 days) and tetracycline (TC, withdrawal period, 5 days), were each administered to a group of 15 pigs. Blood was sampled before drug administration and during the withdrawal period. The concentration of tetracyclines in plasma, determined by semi-quantitative ELISA, was compared with that of internal standard (10 ppb as oxytetracycline). The absorbance ratio of internal standard to sample (B/Bs) was employed as an index to determine the tissue residues in pigs. All 45 plasma samples from nontreated pigs showed negative in the residue of any of three tetracycline antibiotics. OTC was detected in plasma of pigs treated until the 8th day, CTC until the 4th day, and TC was detected until the 3rd day of its withdrawal period. The present study showed that the semi-quantitative ELISA easily be adopted in predicting tissue residues for tetracycline antibiotics in live pigs.  相似文献   

Hemagglutination and hemagglutination inhibition of turkey red blood cells with Mycoplasma hyopneumoniae   总被引：2，自引：0，他引：2  

T F Young  B Z Erickson  R F Ross  Y Wannemuehler 《American journal of veterinary research》1989,50(7):1052-1055

The ability of Mycoplasma hyopneumoniae to agglutinate RBC was evaluated to develop an in vitro cytadsorption assay. Using swine RBC in a microtitration hemagglutination test, no agglutination or partial agglutination was detected. Comparison of RBC from various other species indicated that improved hemagglutination was obtained with RBC from turkeys. This hemagglutination was detected only when mycoplasma cells used in the assay had been frozen and thawed, heated at 50 C for 30 minutes, or treated with trypsin. Treatment of RBC with trypsin or neuraminidase enhanced hemagglutination. Possible surface lectin activity in M hyopneumoniae was evaluated by use of carbohydrates in a blocking assay; hemagglutination was not inhibited by any of 13 carbohydrates evaluated. Mycoplasma hyopneumoniae convalescent porcine serum and monoclonal antibodies against 2 M hyopneumoniae immunogens of molecular weights of 64,000 and 41,000 inhibited hemagglutination.  相似文献   

PRELIMINARY FINDINGS FOLLOWING THE USE OF A CONTINUOUS INFUSION OF XYLAZINE,GGE AND KETAMINE TO MAINTAIN GENERAL ANAESTHESIA IN 40 HORSES UNDERGOING A WIDE VARIETY OF SURGICAL PROCEDURES     

L.E. Young  D.H. Bartram  M. Diamond  A. Gregg  R.S. Jones 《Veterinary anaesthesia and analgesia》1991,18(Z1):171-174

  相似文献