Factors Affecting Plasma Pregnancy-associated Glycoprotein 1 Concentrations Throughout Gestation in High-producing Dairy Cows     

B Serrano  F López-Gatius  P Santolaria  S Almería  I García-Ispierto  G Bech-Sabat  J Sulon  NM de Sousa  JF Beckers  JL Yániz 《Reproduction in domestic animals》2009,44(4):600-605

This study was designed to establish the factors, if any, which could affect plasma pregnancy-associated glycoprotein-1 (PAG-1) expression in a study population of 87 pregnant, high-producing dairy cows. The factors examined were: semen providing breed (Holstein-Friesian vs Limousin), outcome of gestation (male vs female newborn, and singleton vs twin pregnancies), lactation number, milk production at pregnancy diagnosis, plasma progesterone concentration, season of gestation (warm period, March–November vs cool period, December–February), and day of gestation (40, 90, 120, 150, 180 and 210). Pregnancy was diagnosed by transrectal ultrasound on day 40 post-insemination and by palpation per rectum on days 90, 120, 150, 180 and 210. Blood samples were collected from each animal immediately before each pregnancy diagnosis. The relative contributions of the different factors on PAG-1 concentrations were evaluated by GLM repeated measures analysis of variance. No significant effects of the herd, foetal sex, milk production, lactation number and plasma progesterone concentrations were observed. In contrast, twin pregnancy, the use of Limousin semen and conception during the cool period were correlated with significantly increased plasma PAG-1 concentrations throughout gestation. Our data indicate that both cow well-being during early placental development, determined in our conditions by reduced heat stress when conception occurred in the cool season, and crossbreed pregnancies lead to improved PAG-1 production throughout the gestation period.  相似文献   

The Influence of Oxygen Tension on Cumulus Cell Viability of Canine COCs Matured in High-Glucose Medium     

AEF Silva  P Rodriguez  LF Cavalcante  BA Rodrigues  JL Rodrigues 《Reproduction in domestic animals》2009,44(S2):259-262

High in vitro oxygen (O₂) tensions are associated with enhanced levels of reactive oxygen species and cumulus oocyte complex (COC) apoptosis. The objective of this study was to determine the influence of O₂ tension on cumulus cell (CC) viability from canine oocytes. Cumulus oocyte complexes were distributed into three groups (CG, T20 and T5) and two O₂ tension levels (20% and 5%). The control group (CG) was matured in vitro in a humidified atmosphere with 5% CO₂ in air in TCM199 with 26.19 m m sodium bicarbonate, 10% (v/v) foetal calf serum (FCS), 0.10 m m gentamicin, 0.20 m m pyruvic acid, 20 μg/ml oestradiol, 0.5 μg/ml follicle-stimulating hormone, 0.03 IU/ml human chorionic gonadotropin, and 1.0 μg/ml human somatotropin. Groups T20 and T5 were matured under 20% or 5% O₂ tensions respectively in a high-glucose medium, without FCS. T20 and T5 were as CG, and supplemented with 0.1% Polyvinyl Alcohol, and 5.5 m m glucose. After 48 h of IVM, CCs from COCs were stained with propidium iodide (1.50 m m ). The results showed that viability of CCs (cytoplasmic features and nuclear morphological integrity) was different for the three groups. Rates of apoptosis were at 57.9% (521/900) for CG, 54.4% (490/900) for T20 and 38.9% (350/900) for T5 (p < 0.001). Predominant features in apoptotic cells (n = 1361) were DNA nuclear fragments (94.0%). It was concluded that CCs of canine COCs cultured in high-glucose medium showed significantly less apoptosis than those cultured in medium with FCS. Low O₂ tension was efficient in reducing apoptosis in canine CCs.  相似文献   

Changing trends in mastitis     

RN Zadoks  JL Fitzpatrick 《Irish veterinary journal》2009,62(Z4):S59

The global dairy industry, the predominant pathogens causing mastitis, our understanding of mastitis pathogens and the host response to intramammary infection are changing rapidly. This paper aims to discuss changes in each of these aspects. Globalisation, energy demands, human population growth and climate change all affect the dairy industry. In many western countries, control programs for contagious mastitis have been in place for decades, resulting in a decrease in occurrence of Streptococcus agalactiae and Staphylococcus aureus mastitis and an increase in the relative impact of Streptococcus uberis and Escherichia coli mastitis. In some countries, Klebsiella spp. or Streptococcus dysgalactiae are appearing as important causes of mastitis. Differences between countries in legislation, veterinary and laboratory services and farmers' management practices affect the distribution and impact of mastitis pathogens. For pathogens that have traditionally been categorised as contagious, strain adaptation to human and bovine hosts has been recognised. For pathogens that are often categorised as environmental, strains causing transient and chronic infections are distinguished. The genetic basis underlying host adaptation and mechanisms of infection is being unravelled. Genomic information on pathogens and their hosts and improved knowledge of the host's innate and acquired immune responses to intramammary infections provide opportunities to expand our understanding of bovine mastitis. These developments will undoubtedly contribute to novel approaches to mastitis diagnostics and control.  相似文献   

Use of antiviral medications against equine herpes virus associated disorders     

D. M. Wong  L. K. Maxwell  P. A. Wilkins 《Equine Veterinary Education》2010,22(5):244-252

Numerous types of equine herpesviruses (EHV) continue to afflict horses resulting in a variety of clinical manifestations. While many of the clinical manifestations of EHV are self‐limiting or require only supportive care, some clinical expressions of EHV infections cause severe risk to the horse's overall health and can result in abortion, long‐term deficits or death. Antiviral medications are infrequently utilised therapeutics in equine medicine and their exact efficacy is largely unknown. However, the use of antiviral medications may potentially decrease convalescent time and improve outcome in horses with EHV‐related diseases. Thus, equine practitioners should consider the potential use of antiviral medications in the future. The purpose of this article is to familiarise the equine practitioner with current information in regard to antiviral medications and their potential uses in equine medicine.  相似文献   

Signal detection theory clarifies the concept of perceptual range and its relevance to landscape connectivity     

Robert J. Fletcher Jr.  Christopher W. Maxwell Jr.  John E. Andrews  Wendy L. Helmey-Hartman 《Landscape Ecology》2013,28(1):57-67

Understanding functional connectivity is critical for several issues in ecology and conservation. When animals actively search for habitat across landscapes, their perceptual range of habitats can profoundly influence connectivity. Nonetheless, conceptual development and estimation of perceptual ranges and their influence on connectivity have been limited. Signal detection theory (SDT) has a long tradition in several disciplines to address the problem of detecting stimuli in noisy and uncertain environments. SDT is particularly useful for understanding perceptual ranges because it acknowledges uncertainty in the detection process and distinguishes between two key parameters that have previously been confounded when interpreting the perceptual range of animals: signal detectability and response bias of individuals. Here we extend SDT to the concept of perceptual range, provide approaches for estimating patch detectability and response bias, and apply this framework to interpreting the perceptual range of cactus bugs (Chelinidea vittiger). We find that signal detectability of habitat by C. vittiger, and thus their perceptual range, is between 1 and 2 m, based on generalized linear models aimed at estimating signal detection parameters. SDT provides new insights into perceptual ranges and functional connectivity, which may help understand intra and interspecific variation in animal responses to modified landscapes.  相似文献   

Terraclor (PCNB) for control ofRhizoctonia solani. II. PCNB residues in tubers     

G. D. Easton  R. C. Maxwell  C. R. Oldenburg  P. D. Anderson 《American Journal of Potato Research》1970,47(11):430-434

Terraclor (PCNB) applied to soils by broadcast and row slightly reduced the incidence ofRhizoctonia solani but did not increase yield or per cent of U. S. No. 1 tubers either by weight or numbers. Residues of PCNB in tubers grown in treated soils increased as the rate per acre of PCNB increased. Almost all of the residues were in the tuber peel.  相似文献   

The implications of controlling grazed sward height for the operation and productivity of upland sheep systems in the UK. 5. The effect of stocking rate and reduced levels of nitrogen fertilizer     

A. R. Sibbald  T. J. Maxwell  A. J. I. Dalziel  & R. D. M. Agnew 《Grass and Forage Science》2002,57(1):33-47

The implications for UK upland sheep systems of reducing nitrogen fertilizer application to perennial ryegrass/white clover swards were studied over 3 years. Sward height (3·5–5·5 cm) was controlled for ewes with lambs until weaning using surplus pasture areas for silage; thereafter, ewes and weaned lambs were grazed on separate areas, and sward height was controlled by adjusting the size of the areas grazed and using surplus pasture areas for silage if necessary. Combinations from three stocking rates [10, 6 and 4 ewes ha⁻¹ on the total area (grazed and ensiled)] and four nitrogen fertilizer levels (150, 100, 50 and 0 kg ha⁻¹) provided six treatments that were replicated three times. Average white clover content was negatively correlated with level of nitrogen fertilizer. The proportion of white clover in the swards increased over the duration of the experiment. Control of sward height and the contribution from white clover resulted in similar levels of lamb liveweight gain on all treatments. All treatments provided adequate winter fodder as silage. It is concluded that the application of nitrogen fertilizer can be reduced or removed from upland sheep pastures without compromising individual animal performance provided that white clover content and sward height are maintained. Resting pastures from grazing by changing ensiled and grazed areas from year to year sustained white clover content over a 3-year period.  相似文献   

Response of Thawed Epidi dymal Red Deer Spermatozoa to Increasing Concentrations of Hydrogen Peroxide,and Importance of Individual Male Variability     

AE Domínguez‐Rebolledo  F Martínez‐Pastor  AF Bisbal  JL Ros‐Santaella  O García‐Álvarez  A Maroto‐Morales  AJ Soler  JJ Garde  MR Fernández‐Santos 《Reproduction in domestic animals》2011,46(3):393-403

Oxidative stress represents a challenge during sperm manipulation. We have tested the effect of increasing hydrogen peroxide (H₂O₂) levels on red deer spermatozoa after cryopreservation, and the role of male‐to‐male variation in that response. In a first experiment, eight thawed samples were submitted to 0, 25, 50, 100 and 200 μm H₂O₂ for 2 h at 37°C. Intracellular reactive oxygen species (H₂DCFDA‐CM) increased with H₂O₂ concentration, but we only detected a decrease in sperm function (motility by CASA and chromatin damage by sperm chromatin structure assay) with 200 μm . Lipoperoxidation assessed by the thiobarbituric acid reactive substance (TBARS) method increased slightly with 50 μm H₂O₂ and above. In a second experiment, samples from seven males were submitted to 0 and 200 μm H₂O₂ for 2 h, triplicating the experiment within each male. Males differed at thawing and regarding their response to incubation and H₂O₂ presence. We found that the kinematic parameters reflected male‐to‐male variability, whereas the response of the different males was similar for lipid peroxidation and viability. A multiparametric analysis showed that males grouped differently if samples were assessed after thawing, after incubation without H₂O₂ or after incubation with H₂O₂. Red deer spermatozoa are relatively resilient to H₂O₂ after thawing, but it seems to be a great male‐to‐male variability regarding the response to oxidative stress. The acknowledgement of this individual variability might improve the development of optimized sperm work protocols.  相似文献   

Computed tomographic findings,surgical management and postoperative outcomes of large intermuscular lipomas in the hindlimb of 11 dogs     

JD Crowley  G Hosgood  NV Crawford  JL Richardson 《Australian veterinary journal》2020,98(4):135-139

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Incidence and new records of Mycosphaerella species within a Eucalyptus globulus plantation in Western Australia     

S.L. Jackson  A. Maxwell  T.I. Burgess  G.E.StJ. Hardy  B. Dell   《Forest Ecology and Management》2008,255(12):3931-3937

Eucalyptus globulus is the predominant exotic hardwood plantation species in Western Australian (WA), and is often planted adjacent to native eucalypt forests. The increase in number of Mycosphaerella species associated with Mycosphaerella leaf disease (MLD) in E. globulus plantations in WA in the past decade has raised concern about the possible movement of pathogens between the native forests and plantations. In order to determine whether the introduction of new E. globulus genetics into WA may have further exacerbated this situation, juvenile and adult foliage were taken from a genetics trial near Albany, WA consisting of 60 full-sib families and Mycosphaerella species identified using morphological and molecular tools. Eleven species of Mycosphaerella were identified from one plantation: Mycosphaerella fori (Pseudocercospora fori) and Mycosphaerella ellipsoidea are new records for Australia; Mycosphaerella tasmaniensis (Passalora tasmaniensis) and Mycosphaerella suttoniae (Kirramyces epicoccoides) are new records for WA; and Mycosphaerella nubilosa, Mycosphaerella cryptica, Mycosphaerella marksii, Mycosphaerella molleriana, Mycosphaerella lateralis, Mycosphaerella aurantia and Mycosphaerella parva, previously recorded for WA. The most frequently isolated species from juvenile foliage was M. marksii (77%) followed by M. nubilosa (33%). M. nubilosa was most frequently isolated from adult leaves (88%) followed by M. parva (7.5%). Three species, M. molleriana, M. lateralis and M. cryptica, were only isolated from adult leaves while M. ellipsoidea was only isolated from juvenile leaves. These records increase the number of known Mycosphaerella species from eucalypts in WA from 10 to 13. The increase in the number, distribution and impact of Mycosphaerella species contributing to MLD in WA is of concern both to the potential productivity of the plantations and the biosecurity of native WA Eucalyptus species. Continued monitoring of the plantation estate is required to understand the dynamics of the host–pathogen interactions.  相似文献