Stakeholder position paper: food animal veterinarian     

Burkgren T  Vogel L 《Preventive veterinary medicine》2006,73(2-3):177-179

Food animal veterinarians practice in a variety of settings with considerable differences between the settings. Due to variability, aggregate data from surveillance of antimicrobial use is not very useful to practitioners unless correlated information is provided, such as the relative disease status, ages of animals, and purpose of use. Of greater utility is use data as it relates to a specific farm or production system. Of greater importance to clinical practitioners is a meaningful surveillance system that tracks trends in antimicrobial resistance in common pathogens causing animal diseases.  相似文献   

Effect of Cryopreservation on Bovine Sperm Viability as Determined by Dual DNA Staining     

DL Garner  CA Thomas  CH Allen  PL Senger  RG Sasser 《Reproduction in domestic animals》1997,32(6):279-283

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Long toe, low heel, short toe, no foot     

Bruce Lyle DVM 《Journal of Equine Veterinary Science》2003,23(6):276-277

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The differential genetic signatures related to climatic landscapes for jaguars and pumas on a continental scale     

Marina ZANIN  Noa GONZALEZ-BORRAJO  Cuauhtémoc CHÁVEZ  Yamel RUBIO  Bart HARMSEN  Claudia KELLER  Pablo VILLALVA  Ana Carolina SRBEK-ARAUJO  Leonora Pires COSTA  Francisco PALOMARES 《Integrative zoology》2021,16(1):2-18

Modern and paleoclimate changes may have altered species dynamics by shifting species’ niche suitability over space and time. We analyze whether the current genetic structure and isolation of the two large American felids, jaguar (Panthera onca) and puma (Puma concolor), are mediated by changes in climatic suitability and connection routes over modern and paleoclimatic landscapes. We estimate species distribution under 5 climatic landscapes (modern, Holocene, last maximum glaciations [LMG], average suitability, and climatic instability) and correlate them with individuals’ genetic isolation through causal modeling on a resemblance matrix. Both species exhibit genetic isolation patterns correlated with LMG climatic suitability, suggesting that these areas may have worked as “allele refuges.” However, the jaguar showed higher vulnerability to climate changes, responding to modern climatic suitability and connection routes, whereas the puma showed a continuous and gradual transition of genetic variation. Despite differential responsiveness to climate change, both species are subjected to the climatic effects on genetic configuration, which may make them susceptible to future climatic changes, since these are progressing faster and with higher intensity than changes in the paleoclimate. Thus, the effects of climatic changes should be considered in the design of conservation strategies to ensure evolutionary and demographic processes mediated by gene flow for both species.  相似文献   

The Effect of Post-Ovulatory Artificial Insemination on Sow Reproductive Performance     

CD Castagna  CH Peixoto  FP Bortolozzo  I Wentz  F Ruschel  GB Neto 《Reproduction in domestic animals》2003,38(5):373-376

In order to increase reproductive performance, sows are usually inseminated several times during oestrus. In practice, this results in a significant number of sows receiving one or more post‐ovulatory inseminations. This study was carried out to determine the percentage of sows that receive one or more post‐ovulatory inseminations and the effect of such treatment on reproductive performance. The results were analysed from a total of 1298 sows on two farms. It was observed that more than 70% of the sows received at least one post‐ovulatory insemination and approximately 20% received two or more. There was no observed effect on the rate of return to oestrus, farrowing rate or litter size (p > 0.05).  相似文献   

Effect of a Single Injection of Long-acting Progesterone on the First Ovulation in Early and Late Spring Transitional Mares     

Simon A. Staempfli  Sarah Clavier  Don L. Thompson  Patrick J. Burns  Sara K. Lyle  Angus O. McKinnon 《Journal of Equine Veterinary Science》2011,31(12):744-748

Since 1966, exogenous progestins have been used in equine practice for pregnancy maintenance, estrous suppression, and control of erratic sexual behavior. This study was designed to investigate the use of a new compounded controlled-release progesterone preparation (BioRelease P4 LA 300) in early and late spring transitional mares. In the first experiment, the pharmacodynamic properties of the preparation were studied in five geldings. In the second experiment, the use of a single intramuscular injection (600 mg) was tested in 68 embryo-recipient mares maintained under natural photoperiod in the Southern Hemisphere. Experiment 1 demonstrated elevated serum concentrations of progesterone (>1 ng/mL) for 7.6 ± 2.2 days. In experiment 2, there was no effect of treatment in mares that were treated on September 18, independent of their follicular status at day of treatment (10 to 15 mm; 20 to 25 mm, respectively). When mares with a follicular size of 20 to 25 mm were treated on October 14, significantly more progestin-treated mares (10/12; 83%) ovulated between 10 and 24 days after treatment than untreated controls (3/12; 25%) (P < .05). Additionally, there was a trend in mares treated on October 14 for a shorter treatment to ovulation interval (mean ± SD, 18.6 ± 8.7 days) compared with untreated controls (mean ± SD, 26.7 ± 14.7 days) (P = .07). Administration of one single injection of long-acting progesterone is a simple and effective method of controlling the first ovulation of the season in late transitional mares.  相似文献   

Smooth Brome (Bromus inermis Leyss) and Soil Chemical Response to Concrete Grinding Residue Application     

Tom DeSutter  Patricia Goosen-Alix  Lyle Prunty  Paul White Jr.  Frank Casey 《Water, air, and soil pollution》2011,222(1-4):195-204

Concrete grinding residue (CGR) is a by-product created by concrete pavement maintenance operations. The application of CGR to roadside soils is not consistently regulated by state agencies across the USA, which is partially due to the lack of science-based information on its impacts to soils and plants. The objectives of this research were to determine the impact of CGR additions to soil on both smooth brome (Bromus inermis L.) biomass and plant and soil chemical parameters. In a greenhouse study, two soils were treated with two CGR by-products at 8% and 25% by weight. Shoot biomass was significantly influenced by the main effects (Soil, CGR, and Rate) and by all two-way interactions, but not consistently positively or negatively correlated. Trace metal concentrations in the shoot biomass were variable, but 68% of these metals had the same concentration or lower in the 25% CGR treatments compared with the controls. Soil pH and electrical conductivity were significantly influenced by the main effects and two-way interactions of Soil × Rate and CGR × Rate, and soil pH was significantly greater in the CGR-treated soils. Calcium, Na, Mg, Al, and S concentrations in soils were all influenced by additions of CGR, but trace metal levels in the treatments were all within the range for uncontaminated soils. Ecosystem impact of applying CGR will be dependent upon the quality of CGR and soil characteristics. Controlling the liming potential of CGR should be considered a best management practice.  相似文献   

Implications of Age, Size and Region on Mercury Contamination in Estuarine Fish Species     

Jeremy J. Verdouw  Catriona K. Macleod  Barbara F. Nowak  Jeremy M. Lyle 《Water, air, and soil pollution》2011,214(1-4):297-306

This study investigated the effects of age and length on mercury contamination in four fish species; yellow-eye mullet (Aldrichetta forsteri), black bream (Acanthopagrus butcheri), sand flathead (Platycephalus bassensis) and sea-run brown trout (Salmo trutta) from the Derwent Estuary, Tasmania, Australia, and examined the implications of these findings for public health monitoring. Mean mercury levels exceeded the Food Standards Australia and New Zealand maximum permitted level (0.5?mg?kg^?1) for all species except yellow-eye mullet. Mean levels in black bream were significantly higher (p?<?0.05) than other species and consequently are a particular concern for human health. Regional differences (p?<?0.05) in mercury levels in sand flathead were not obviously correlated with metal levels in the sediments. However, age and length significantly (p?<?0.05) influenced mercury levels in brown trout and sand flathead, with age being more strongly related to intraspecies differences. In addition, movement and distribution within the estuary and trophic status appeared to be important factors in contribution to interspecific variation. Consequently, a sound understanding of fish life history and biology is important in identifying species which may be susceptible to accumulating mercury and hence pose a potential threat to human health.  相似文献   

The Nature of the 660-Kilometer Upper-Mantle Seismic Discontinuity from Precursors to the PP Phase   总被引：2，自引：0，他引：2  

CH Estabrook  R Kind 《Science (New York, N.Y.)》1996,274(5290):1179-1182

Global Seismic Network data were used to image upper-mantle seismic discontinuities. Stacks of phases that precede the PP phase, thought to be underside reflections from the upper-mantle discontinuities at depths of 410 and 660 kilometers, show that the reflection from 410 kilometers is present, but the reflection from 660 kilometers is not observed. A continuous Lame's constant lambda and seismic parameter at the 660-kilometer discontinuity explain the missing underside P reflections and lead to a P-wave velocity jump of only 2 percent, whereas the S-wave velocity and density remain unchanged with respect to previous global models. The model deemphasizes the role of Lame's constant lambda with regard to the shear modulus and constrains the mineralogical composition across the discontinuity.  相似文献   

Life history traits and conservation actions for the Maugean skate (Zearaja maugeana), an endangered species occupying an anthropogenically impacted estuary     

Cynthia A. Awruch  Justin D. Bell  Jayson M. Semmens  Jeremy M. Lyle 《水产资源保护:海洋与淡水生态系统》2021,31(8):2178-2192

1. The Maugean skate, Zearaja maugeana, is endemic to two isolated western Tasmanian (Australia) estuaries. The species' persistence in one of these estuaries (Bathurst Harbour) is uncertain, while the other estuary (Macquarie Harbour), potentially the remaining stronghold for the species, is an anthropogenically impacted system.
2. Key life-history parameters were studied to inform conservation actions for this species. Reproductive information was obtained using non-lethal methodologies, circulating concentrations of sex steroids and ultrasonography. Growth and age parameters were estimated based on vertebral sections from a small sample of individuals.
3. Females and males reached 870 and 760 mm total length, respectively. The species reached a maximum age of at least 10 years. Females and males attained 50% sexual maturity at 665 and 633 mm total length, respectively, probably maturing somewhere between four and six years of age. Females displayed an asynchronous, discontinuous reproductive cycle, being able to reproduce throughout the year, with a probable decline in reproductive activity during summer. No egg cases were observed in-utero. Males produce sperm all year round, with a peak in testosterone production during spring–autumn.
4. Conservation strategies for Z. maugeana will need to focus on reducing anthropogenic impacts on the environmental health, the primary impacts being altered river flows associated with the production of hydroelectricity and increased nutrient load associated with salmonid aquaculture. There is a need to better understand how reproductive success, egg survival and recruitment are affected by these environmental challenges if the future well-being of this species is to be secured.

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