Efficacy and safety of an infectious bursal disease virus intermediate vaccine in ovo.     

M Coletti  E Del Rossi  M P Franciosini  F Passamonti  G Tacconi  C Marini 《Avian diseases》2001,45(4):1036-1043

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Landscape change under indirect effects of human use: the Savanna of Central Chile     

Eduardo R. Fuentes  Reinaldo Avilés  Alejandro Segura 《Landscape Ecology》1989,2(2):73-80

The Chilean Intermediate Depression to the north of Santiago has experienced a physiognomical transformation from a Prosopis chilensis woodland to an Acacia caven savanna. Today P. chilensis trees are scarce and belong mostly to the larger size classes. By contrast A. caven seems to reproduce frequently and its populations consist of individuals of all size classes. In this paper we document these changes and report the results of tests aimed at determining the causes of these physiognomical changes. We found that livestock, leporids, introduced Mediterranean forbs and agriculture account for differences in seed dispersal and survival of A. caven and P. chilensis, which can explain the documented changes in the Chilean landscape.  相似文献   

A model estimating the risk of Fusarium head blight on wheat*     

V. Rossi  S. Giosu  E. Pattori  F. Spanna  A. Del Vecchio 《EPPO Bulletin》2003,33(3):421-425

A dynamic simulation model for the risk of Fusarium head blight on wheat was elaborated based on systems analysis. The model calculates a daily infection risk based on sporulation, spore dispersal and infection of host tissue of the four main species causing the disease (Gibberella zeae, Fusarium culmorum, Gibberella avenacea, Monographella nivalis). Spore yield and dispersal are calculated as functions of temperature, rainfall and relative humidity, while the main factors affecting the infection rate are temperature, wetness and the host growth stage. The model also calculates a risk for mycotoxin production by G. zeae and F. culmorum in the infected head tissue. First validations against field data, collected in some wheat‐growing areas in northern Italy and not used in model elaboration, produced satisfactory results.  相似文献   

Evaluation of sampling methods and assessment of the sample size to estimate the weed seedbank in soil, taking into account spatial variability   总被引：1，自引：0，他引：1  

L Ambrosio  L Iglesias†  C Marín  & J P Del Monte‡ 《Weed Research》2004,44(3):224-236

As field sampling is time consuming, it is necessary to develop efficient sampling techniques to obtain accurate estimates of the weed seedbank in soil. The relative efficiency between sampling schemes depends on the spatial variability in weed seed density across agricultural fields. Spatial variability of the weed seed density was characterized by theoretical correlograms. A systematic sampling (square grill) scheme was considered and it was found that, taking into account spatial variability, this sampling scheme was more efficient than simple random sampling. As a result, the sample size can be reduced in comparison with that given in previous studies, where spatial correlation was ignored. The reduction depends on the correlation structure defined as a function of the ratio, τ, between the nugget effect and the sill of the variogram. The maximum reduction of the sample size, without loss of either precision or confidence level corresponds to the case where there is no nugget effect, τ = 0. The opposite extreme case, where the reduction is nil, corresponds to the case of a pure nugget effect τ = 1. The abaci based on given expressions are provided to determine the sample size in species whose spatial pattern can be fitted either to a Poisson or to a negative binomial distribution.  相似文献   

<Emphasis Type="SmallCaps">d</Emphasis>-Cloprostenol enhances estrus synchronization in tropical hair sheep     

Alejandro Alavez Ramírez  Victor Manuel Meza Villalvazo  Emmanuel Sosa Arredondo  Hugo Alonso Ramírez Ramírez  Héctor Magaña Sevilla 《Tropical animal health and production》2018,50(5):991-996

To compare the effects of PGF2α (dinoprost tromethamine) and d-cloprostenol in a two-dose protocol for estrus synchronization in hair sheep during breeding season in Yucatán, México, two experiments were conducted. In experiment 1, 61 cyclic hair sheep were divided into two groups: G1 (control n?=?30), two doses of 50 μg of dinoprost tromethamine IM with 12 days between applications, and G2 (n?=?31), two doses of 50 μg of d-cloprostenol IM at the same time interval. For determination of progesterone levels, 16 ewes from each group were randomly selected. In experiment 2, 70 cyclic hair sheep were assigned at the same treatments (G1 and G2, n?=?35) and 48 h after the second application, the ewes in estrus were detected by two vasectomized rams. Sheep with detected estrus were inseminated, and 45 days after, pregnant animals were identified by ultrasonography. An exact Fisher’s test was performed for the analysis of ewes in estrus (experiments 1 and 2) and number of pregnant ewes (experiment 2); for the comparison of time between end of treatment-estrus presentation, a survival analysis was used. Duration of estrus in hours was analyzed using a generalized mixed model (GLM) ANOVA whereas plasma progesterone concentrations were analyzed by non-linear regression. There were significant differences (P?<?0.05) in the proportion of ewes in estrus upon treatments (G1, 57% vs G2, 87% and G1, 37.1% vs G2, 65.7% in experiments 1 and 2, respectively), and between the end of treatment-onset estrus interval (P?<?0.01), survival curves showed the highest number of sheep in estrus between 40 and 48 h (G1, 43.7?+?8.05 h vs G2, 42.9?+?6.7 h, experiment 1). There were no significant differences (P?>?0.05) in duration of estrus (G1, 42?+?6.1 h, vs G2, 41.1?+?11.2 h, experiment 1) and pregnancy in the ewes that presented estrus, and were inseminated (G1, 38.4% vs 52.1%, experiment 2). With regard to concentrations of progesterone, significant differences (P?<?0.01) were found between treatments, and progesterone levels before the second application of d-cloprostenol were higher. In consideration of the results, it can be concluded that in a two-dose protocol of a luteolytic agent, more ewes presented estrus in response to d-cloprostenol compared to dinoprost tromethamine with similar pregnancy rates.  相似文献   

Hand-assisted laparoscopic cystotomy for cystic calculus removal in male horses (3 cases)     

Alejandro Merchan  Elizabeth J. Barrett  Dwayne H. Rodgerson 《The Canadian veterinary journal. La revue veterinaire canadienne》2021,62(1):22

A technique for hand-assisted laparoscopic removal of cystic calculi in male horses is described. Three cystic calculi ranging from 5 to 10 cm in diameter were removed successfully using bilateral para-inguinal laparoscopic portals assisted by a human hand within the abdomen, effectively sealing the midline incision. Long-term follow-up information obtained from referring veterinarians and owners indicated that the patients returned to their previous activity level and had no recurrence of clinical signs in the following 6 to 12 months.Key clinical message:Hand-assisted recumbent laparoscopy is a satisfactory surgical technique for removal of cystic calculi in horses which cannot be operated on standing or whose body condition would make the parainguinal approach difficult.  相似文献   

Comparative pharmacokinetics and pharmacokinetic/pharmacodynamic analysis by nonlinear mixed‐effects modeling of cefquinome in nonpregnant,pregnant, and lactating goats after intravenous and intramuscular administration     

Nicols Javier Litterio  Augusto Matías Lorenzutti  María del Pilar Zarazaga  Martín Alejandro Himelfarb  Manuel Ignacio San Andrs‐Larrea  Juan Manuel Serrano‐Rodríguez 《Journal of veterinary pharmacology and therapeutics》2021,44(1):68-78

Cefquinome is a fourth‐generation cephalosporin that is used empirically in goats. Different physiologic factors like pregnancy or lactation could determine the pharmacokinetic behavior of drugs in the organism. The objectives of this study are to (a) compare the pharmacokinetics of cefquinome after intravenous and intramuscular administration in adult nonpregnant (n = 6), pregnant (n = 6), and lactating goats (n = 6), at a dose of 2 mg/kg, with rich sampling by nonlinear mixed‐effects modeling, (b) conduct a pharmacokinetic/pharmacodynamic analysis to evaluate the efficacy of the recommended posology in goats with different physiological states, and (c) determine the optimal posology that achieve a PTA value ≥ 90%, taking into account a T > MIC ≥ 60% of a MIC value ≤ 0.25 µg/ml, in the different subpopulations of goats for both routes. Gestation significantly increased Ka and V1, while reduced F0, Cl, and Q. On the other hand, lactation significantly increased V1 and reduced Tk0. Cefquinome concentrations achieved in placental cotyledon, amniotic fluid, and fetal serum indicate a minimal penetration across the placental barrier. Moreover, milk penetration of cefquinome was minimal. The total body clearance of cefquinome for goats was 0.29 L kg^?1 hr^?1, that is apparently higher than the reported for cows (0.13 L kg^?1 hr^?1) and pigs (0.16 L kg^?1 hr^?1). So, the optimal dose regimen for cefquinome after intravenous and intramuscular administration required higher dose and frequency of administration compared with recommendations for cows or pigs. Therefore, 2 mg kg^?1 8 hr^?1 and 5 mg kg^?1 12 hr^?1 could be used for IV and IM routes, respectively, for the treatment of respiratory infections caused by P. multocida and M. haemolytica, but only 5 mg kg^?1 12 hr^?1 by both routes should be recommended for Escherichia coli infections.  相似文献   

Ocular teratoid medulloepithelioma in a northern red-shouldered macaw: case report and literature review     

Jeann Leal de Araújo  Alice C. A. M. Arruda  Nayadjala T. A. Santos  Glenison F. Dias  Thiago F. L. Nery  Fabio Del Piero  Richard Ploeg  Brian F. Porter  Ingeborg M. Langohr 《Journal of veterinary diagnostic investigation》2021,33(3):600

A 4-mo-old northern red-shouldered macaw (Diopsittaca nobilis) was admitted to the veterinary hospital of the Arruda Câmara Zoo, in the State of Paraiba, Brazil, for investigation of an orbital mass. Given rapid progression and lack of response to treatment, the bird was euthanized, and an autopsy was performed. Histologically, the mass consisted of a retrobulbar invasive tumor characterized by tubular and rosette-like structures, with interspersed heteroplastic tissues, such as aggregates of neuroglial cells and islands of hyaline cartilage. The tumor was immunopositive for pancytokeratin, GFAP, NSE, and S100. These findings were compatible with an ocular teratoid medulloepithelioma, a neoplasm best described in humans but also reported rarely in young cockatiels and African Grey parrots.  相似文献   

Socio-spatial organization reveals paternity and low kinship in the Honduran white bat (Ectophylla alba) in Costa Rica     

Edgar G. GUTIÉRREZ  Isabela VIVAS-TORO  Daniela CARMONA-RUÍZ  David VILLALOBOS-CHAVES  Bernal RODRÍGUEZ-HERRERA  Melina Del REAL-MONROY  Gloria LEÓN-AVILA  Jorge ORTEGA 《Integrative zoology》2021,16(5):646-658

Ectophylla alba is a tent-making bat that roosts in mixed-sex clusters comprising adults and offspring. Our goal was to determine the genetic identity of individuals belonging to different roosting groups. We tested the hypothesis of kin selection as a major force structuring group composition. We used 9 microsatellites designed for E. alba to determine the genetic identity and probability of parentage of individuals. We analyzed parentage and kinship using the software ML-Relate, GenAIEx, and Cervus. The obtained relationship probabilities (0.5) revealed a clear maternal relationship between female adults and offspring with allele compatibility, and at least 5 relationships between male adults and pups. We found a low degree of relatedness within roosting groups. Between roosting groups at different sites, the mean probability of a half-sibling relationship ranged from 0.214 to 0.244 and, for full-sibling relationship, from 0.383 to 0.553. Genetically, adult individuals were poorly related within clusters, and kinship as an evolutionary force could not explain group membership.  相似文献   

Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study—A Randomized Clinical Trial          下载免费PDF全文

A. Boswood  J. Häggström  S.G. Gordon  G. Wess  R.L. Stepien  M.A. Oyama  B.W. Keene  J. Bonagura  K.A. MacDonald  M. Patteson  S. Smith  P.R. Fox  K. Sanderson  R. Woolley  V. Szatmári  P. Menaut  W.M. Church  M. L. O'Sullivan  J.‐P. Jaudon  J.‐G. Kresken  J. Rush  K.A. Barrett  S.L. Rosenthal  A.B. Saunders  I. Ljungvall  M. Deinert  E. Bomassi  A.H. Estrada  M.J. Fernandez Del Palacio  N.S. Moise  J.A. Abbott  Y. Fujii  A. Spier  M.W. Luethy  R.A. Santilli  M. Uechi  A. Tidholm  P. Watson 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2016,30(6):1765-1779

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