向日葵野生二倍体种组织和原生质体培养的形态发生能力     

Boko.  NE 张义 《国外农学:向日葵》1991,(2):6-9

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草原的生物多样性   总被引：1，自引：0，他引：1  

West  NE 张维 《国外畜牧学(草原与牧草)》1993,(3):14-28

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Efficacy of bovine herpesvirus-1 inactivated vaccine against abortion and stillbirth in pregnant heifers     

Zimmerman AD  Buterbaugh RE  Herbert JM  Hass JM  Frank NE  Luempert Iii LG  Chase CC 《Journal of the American Veterinary Medical Association》2007,231(9):1386-1389

OBJECTIVE: To evaluate the efficacy of an inactivated bovine herpesvirus-1 (BHV-1) vaccine to protect against BHV-1 challenge-induced abortion and stillbirth. DESIGN: Prospective study. ANIMALS: 35 beef heifers. PROCEDURES: Before breeding, heifers were vaccinated with a commercially available BHV-1 inactivated vaccine SC or IM. The estrous cycle was then synchronized, and heifers were artificially inseminated 30 to 60 days after vaccination. Heifers (n = 21) were challenge inoculated IV at approximately 180 days of gestation with virulent BHV-1. Fourteen control heifers were not vaccinated. Clinical signs of BHV-1 infection were monitored for 10 days following challenge; serologic status and occurrence of abortion or stillbirth were evaluated until time of calving. RESULTS: 18 of 21 (85.7%) heifers that received vaccine were protected from abortion following challenge, whereas all 14 control heifers aborted. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that an inactivated BHV-1 vaccine can protect against abortion resulting from a substantial challenge infection, with efficacy similar to that of modified-live BHV-1 vaccines.  相似文献   

Ionophore toxicity in turkeys     

Horrox NE 《The Veterinary record》2001,148(7):219

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Initial lung lesions in two calves experimentally infected with Haemophilus somnus     

Tegtmeier C  Bloch B  Jensen NE  Jensen HE 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1999,46(8):517-523

The initial lung lesions in two calves intrabronchially inoculated with Haemophilus somnus are described. The animals were euthanized within 7 h after challenge. The in situ location of H. somnus and accompanying lesions were examined by light microscopy, immunohistochemistry and transmission electron microscopy (TEM). Inoculation with H. somnus resulted in the development of acute pulmonary lesions within 3.5 h. H. somnus antigen was demonstrated only within the luminal spaces of the airways and in one area of bronchio-associated lymphoid tissue (BALT). As observed by TEM, the bacteria were phagocytized by both neutrophils and alveolar macrophages. Antigen was never demonstrated in the pulmonary intravascular macrophages.  相似文献   

Rabies in two privately owned domestic rabbits     

Karp BE  Ball NE  Scott CR  Walcoff JB 《Journal of the American Veterinary Medical Association》1999,215(12):1824-7, 1806

Two privately owned domestic rabbits (Oryctolagus cuniculus) in Maryland were found to be infected with the raccoon variant of the rabies virus in 1998. Both rabbits had an acute onset of anorexia and paralysis or paresis of the left forelimb; 1 also developed head tremors and a head tilt. One of the rabbits became ill 25 days after being attacked by a raccoon (Procyon lotor) and was euthanatized 3 days after onset of illness. The other rabbit, which was housed in an outdoor hutch, died 4 days after onset of clinical signs; the source of infection in that rabbit remains unknown. Currently, there is not a rabies vaccine approved for use in rabbits; thus, the only way to prevent the infection in rabbits is to prevent exposure. Veterinarians in rabies-enzootic areas should be familiar with the clinical signs of rabies in rabbits and should caution rabbit owners about the need to protect their pets from contact with wildlife.  相似文献   

Feasibility of using total purines as a marker for ruminal bacteria     

Obispo NE  Dehority BA 《Journal of animal science》1999,77(11):3084-3095

A procedure for measuring total purine content of mixed ruminal bacteria was adapted for use in the determination of purines in pure cultures of ruminal bacteria. Recovery of adenine and guanine, alone or in mixture, was quite variable. The problem was traced to solubility of the silver salt of adenine in the acid wash solution. When the precipitating solution was used as the wash, recovery of the purines was over 97%. Recovery of a 1:1 mixture of adenine and guanine added to yeast RNA was 100.6+/-3.2%. Purine, protein, and bacterial concentrations were determined for 10 pure cultures of ruminal bacteria: Butyrivibrio fibrisolvens, D16f, H10b, and H17c; Fibrobacter succinogenes B21a; Lachnospira multiparus D25e; Lactobacillus lactis ARD26e; Prevotella ruminicola H15a; Ruminococcus albus 7; Ruminococcus flavefaciens B34b; and Streptococcus bovis ARD5d. The CV for the most-probable-number (MPN) assay (bacterial concentrations), purine analysis, and protein analysis were 55.86, 5.25 and 6.52%, respectively. Considerable variation was found among bacterial species and strains when purine and protein concentrations were compared as the amount per individual cell. More consistent values were obtained when these components were expressed on a dry matter basis. Purine:protein ratios for the 10 pure cultures ranged from .023 to .1299, with a mean value of .0883. For samples of mixed bacteria separated from ruminal fluid, this ratio was found to average .0306, which is approximately one-third of the value for the pure cultures. The value determined for the mixed bacterial sample is similar to previously reported values. Based on the ratio obtained with the pure cultures, the microbial protein flow out of the rumen has probably been overestimated in most previous reports. Limited studies suggest that the samples of mixed ruminal bacteria used as a standard are probably contaminated with feed particles containing protein, which results in lower purine:protein ratios.  相似文献   

A pharmacokinetic study including some relevant clinical effect of medetomidine and atipamezole in lactating dairy cows     

Ranheim B  Arnemo JM  Ryeng KA  Søli NE  Horsberg TE 《Journal of veterinary pharmacology and therapeutics》1999,22(6):368-373

Medetomidine is the most potent and selective alpha2-agonist used in veterinary medicine and its effects can be antagonized by the alpha2-antagonist atipamezole. The pharmacokinetics of medetomidine and atipamezole were studied in a cross-over trial in eight lactating dairy cows. The animals were injected intravenously (i.v.) with medetomidine (40 microg/kg) followed by atipamezole i.v. (200 microg/kg) or saline i.v. after 60 min. Drug concentrations in plasma were measured by HPLC. After the injection of atipamezole, the concentration of medetomidine in plasma increased slightly, the mean increment being 2.7 ng/mL and the mean duration 12.1 min. However, atipamezole did not alter the pharmacokinetics of medetomidine. It is likely that the increase in medetomidine concentration is caused by displacement of medetomidine by atipamezole in highly perfused tissues. The volume of distribution at steady state (Vss) for medetomidine followed by saline and medetomidine followed by atipamezole was 1.21 and 1.32 L/kg, respectively, whereas the total clearance (Cl) values were 24.2 and 25.8 mL/min x kg. Vss and Cl values for atipamezole were 1.77 mL/kg and 48.1 mL/min x kg, respectively. Clinically, medetomidine significantly reduced heart rate and increased rectal temperature for 45 min. Atipamezole reversed the sedative effects of medetomidine. However, all the animals, except one, relapsed into sedation at an average of 80 min after injection of the antagonist.  相似文献   

Effect of histamine on lung contractile elements in growing cattle     

Jolly S  Robinson NE  Desmecht DJ 《American journal of veterinary research》2003,64(7):819-822

OBJECTIVE: To determine the effect of histamine on the contractile elements of the respiratory tract in neonatal calves and young adult cattle. SAMPLE POPULATION: Samples of trachealis muscle, bronchi, and intrapulmonary arteries and veins dissected from the respiratory tracts of healthy bovids (2 to 8 days and 16 to 20 months old). PROCEDURE: Histamine cumulative concentration-effect curves (10(-6) to 10(-3) M) were constructed in duplicate smooth muscle samples mounted in organ baths. Contractile responses to histamine were compared with reference contractions elicited by methacholine (10(-5) M) for airways or KCl (127 mM) for vessels. RESULTS: In young adult cattle, trachealis muscle had a substantial contractile response to histamine (84% of methacholine-induced contraction), whereas bronchi reacted slightly (15 and 20% for large and small bronchi, respectively). Although contractile responses to KCl were comparable in arteries and veins, histamine-induced contractions were greater for intrapulmonary veins than for arteries (202 vs 48% of KCl-induced contraction). In neonatal calves, histamine-induced contraction of veins also exceeded that of arteries (230 vs 54% of KCl-induced contraction); however, unlike in young adult cattle, histamine produced notable contraction of large and small bronchi (48 and 60% of methacholine-induced contraction, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: Compared with intrapulmonary arteries, intrapulmonary veins have greater contractile responses to histamine in neonatal and young adult cattle. Data suggest loss of histamine responsiveness in bronchial smooth muscle as neonatal calves grow to young adults. Venodilation may be useful in treatment of lung edema in cattle.  相似文献   

Cross-sectional study of serum antibodies against Sarcocystis neurona in cats tested for antibodies against Toxoplasma gondii     

Rossano MG  Murphy AJ  Vrable RA  Vanzo NE  Lewis SK  Sheline KD  Kaneene JB  Mansfield LS 《Journal of the American Veterinary Medical Association》2002,221(4):511-514

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