共查询到20条相似文献，搜索用时 593 毫秒
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C. O. Bwanga 《Acta veterinaria Scandinavica》1991,32(4):431
The present review summarizes information concerning the methods available to cryopreserve boar semen, covering the historical background, cryobiology and cryoprotecting considerations, technological developments and recent advances in cryopreservation methodologies. Successful methods for cryopreservation of boar semen have not been achieved despite numerous efforts world wide. Improvements in semen preservation technologies have been deterred by lack of in vitro methods that can accurately predict in vivo fertilizing capacity of frozen boar semen. The cell membrane is of crucial importance with regard to freeze-thaw survival of spermatozoa. It is important to optimize the survival of the plasma membrane as this is a non homogenous entity both in structure and function. The boar sperm membrane exhibits extreme sensitivity to freezing treatment. Freezing and thawing results in considerable changes in electrolyte dynamics and damages have mainly been associated with alterations in the head membranes especially at thawing. To date fruitless efforts have been carried out to find a cryoprotectant for the spermatozoa membranes and glycerol still continues to be used despite its harmful effects to the membranes. 相似文献
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Bates G 《Journal of the American Veterinary Medical Association》2007,231(2):197; author reply 197-197; author reply 198
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Martinez M Mahmood I Hunter RP 《Journal of veterinary pharmacology and therapeutics》2006,29(5):425-432
Interspecies scaling is a useful tool for the prediction of pharmacokinetic parameters from animals to humans, and it is often used for estimating a first-time in human dose. However, it is important to appreciate the mathematical underpinnings of this scaling procedure when using it to predict pharmacokinetic parameter values across animal species. When cautiously applied, allometry can be a tool for estimating clearance in veterinary species for the purpose of dosage selection. It is particularly valuable during the selection of dosages in large zoo animal species, such as elephants, large cats and camels, for which pharmacokinetic data are scant. In Part I, allometric predictions of clearance in large animal species were found to pose substantially greater risks of inaccuracies when compared with that observed for humans. In this report, we examine the factors influencing the accuracy of our clearance estimates from the perspective of the relationship between prediction error and such variables as the distribution of body weight values used in the regression analysis, the influence of a particular observation on the clearance estimate, and the 'goodness of fit' (R(2)) of the regression line. Ultimately, these considerations are used to generate recommendations regarding the data to be included in the allometric prediction of clearance in large animal species. 相似文献
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G. W. CRIGHTON 《The Journal of small animal practice》1968,9(9):463-472
Abstract— Defects in thermal regulatory mechanisms of the new-born dog are described with particular reference to the relative absence of true chemical regulation of body temperature during the first 2–3 days of life. This deficiency is partly compensated by the ability to absorb heat from external sources. Some of the clinical signs of health of the day-old puppy are given together with signs of progressive hypothermia which can develop under natural conditions. 相似文献
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W.B. Ley DVM. MS J.L. Hoffman T.N. Meacham Ph.D T.L. Sullivan R.L. Kiracofe M.L. Wilson 《Journal of Equine Veterinary Science》1989,9(2)
Fifty-six mares of lighthorse breeding were utilized in a controlled management scheme for induced daytime foaling. All mares had pre-foaling mammary secretions sampled for evaluation of water hardness (ppm) or calcium carbonate content (ppm). Sampling began 10 days prior to expected foaling date for each mare and was performed once daily for 3 days followed by twice daily until foaling occurred. Samples were diluted 1:6 in distilled water and tested by each of 3 methods: Sofchek™ Test Strips4, Predict-A-Foal™ Test Kit5 and Titrets™ Calcium Hardness Test Kit6. Mares were then either induced (i) to foal (no.= 33) according to a decision point of readiness for birth as indicated by pre-foaling mammary secretion testing (≥250 ppm water hardness by Sofchek™ test, ≥ 250 ppm calcium carbonate content by Titrets test, ≥ 4 color bar changes by Predict-A-Foal test), or allowed to foal spontaneously (s) (no.=23). There were no differences (p>0.05) in the mean pre-foaling mammary secretion test values (μi=293ppm, μs=329ppm; μi=4.1, μs=4.2; and μi=281ppm, μs=298ppm; for Sofchek, Predict-A-Foal and Titrets, respectively) between mare groups at the time of foaling (time=0) for any of the 3 testing methods employed. Mean intervals to foaling after reaching decision points of readiness for birth were different (p<0.05) between Sofchek and Titrets test for both mare groups, but only in the induced-to-foal group between Sofchek and Predict-A-Foal tests. Probabilities of 79%, 53% and 59% were calculated for mares foaling spontaneously within 24 hours of reaching the decision points used in this trial of readiness for birth on the initial occasion for Sofchek, Predict-A-Foal and Titrets™ tests, respectively. Each test was determined to have the ability to predict readiness of approaching parturition and found to be easily applicable to field use. The Titrets test was found to be least variable in its response to measurement of pre-foaling mammary secretion hardness changes both within and between mares. 相似文献
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Buchanan DS 《Journal of animal science》2008,86(12):3640-3646
Teaching has a long and varied history in the life of departments of animal science and the American Society of Animal Science. Some of the earliest reports from meetings of the society have strong indication that planning the curriculum was a prominent feature of the meetings. Teaching symposia were also included almost from the beginning. The society went through a lengthy period from the 1940s through most of the 1960s when teaching was not a prominent focus, but a symposium in 1968 appeared to be a catalyst for change, and, since that date, teaching has again been an important part of the meetings. In recent years, outstanding symposia and contributed papers have made the teaching section a vibrant entry. Departments of animal science have changed considerably since the early days in which "men taught boys" and the primary goal was to produce farmers. More female students, more urban students, interest in a wide variety of animals, and greatly diversified career goals have been emerging during the last few decades. Departments of animal science and the American Society of Animal Science are positioning to be able to respond to change and face the challenge of providing excellence in teaching during the next century. 相似文献
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绿色荧光蛋白（GFP）基因和新霉素磷酸转移酶（NPTⅡ）基因被广泛应用于植物的遗传转化中。为了研究融合标记基因NPTⅡ::GFP在柑橘遗传转化中的筛选效率，本实验将CaMV35S组成型启动子驱动的nptⅡ∷GFP融合标记基因表达载体pNGM和由CaMV35S启动子分别驱动NPTⅡ、GFP两个基因的表达载体pNPTII-GF经农杆菌介导法转化锦橙上胚轴。GFP绿色荧光检测结果显示，GFP在转NPTⅡ∷GFP融合基因植株中强烈表达，荧光强度与非融合GFP转基因植株的表达水平相当。NPTⅡ∷GFP融合标记基因对锦橙的转化效率为10.8%，与非融合NPTⅡ基因的转化效率（11.0%）没有明显差异。研究结果表明，NPTⅡ∷GFP融合标记基因是一个有效的柑桔遗传转化筛选标记基因。 相似文献
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M. M. Brosnahan 《Equine Veterinary Education》2020,32(11):590-602
Interpretation of eosinophilia in body fluids or tissues is often not straightforward. Eosinophil counts vary among clinically healthy individuals, and considerable overlap can occur between normal and affected animals in conditions such as allergic airway disease. Parasite exposure is a confounding factor when counts are increased, and in cases where very high counts and dramatic clinical signs make another disease process obvious, the underlying pathology may be uncertain and treatment difficult. Eosinophils are a component of the immune response in many diseases of the horse, but their specific role is often unknown and likely multifactorial. In helminth infections, eosinophils are assumed to be part of the normal host response to a pathogen, whereas in multisystemic eosinophilic epitheliotropic disease (MEED), the predominance of eosinophils likely represents a wildly dysregulated response, or an abnormal response altogether. This distinction is still not clear for other diseases. Understanding the pathways involved in recruitment, activation or suppression of eosinophils is required for more accurate diagnostics, effective therapeutics, and successful strategies for prevention of eosinophil associated diseases. Eosinophils of the horse: Part II reviews published observations on the eosinophil in clinical diseases of the horse. The behaviour of eosinophils in three common and relatively well-studied conditions is presented first, including gastrointestinal helminth infections, non-infectious respiratory disease, and insect bite hypersensitivity. The less common eosinophil-associated diseases such as eosinophilic disease confined to the intestine (EDCI) and MEED are considered, followed by a brief summary of the eosinophil in phycomycosis and neoplasia. In conclusion, a panoramic view of the equine eosinophil as presented in Parts I and II is placed in the larger context of current eosinophil research, and areas of study are identified that may improve our understanding of eosinophil biology in equine health and clinical disease. 相似文献
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Suijkerbuijk A 《Tijdschrift voor diergeneeskunde》2006,131(14-15):543
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James J England 《Veterinary Clinics of North America: Food Animal Practice》2002,18(3):373-8, v
Biosecurity is the management practice that reduces the opportunities for infectious agents to gain access to, or spread within, a food animal production unit. As the public's concern for food safety continues to be directed toward the producer, a well-defined and well-documented biosecurity plan will be a significant factor in ensuring that animal products are safe, wholesome, and acceptable. Veterinarians are the initial control point for biosecurity and therefore are expected by their clientele and the general public to assist in establishing, defining, refining, and practicing biosecurity programs. 相似文献
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M W Miller K W Knauer D S Herring 《Seminars in veterinary medicine and surgery (small animal)》1989,4(1):58-76
Doppler echocardiography allows the serial, noninvasive collection of quantitative hemodynamic information. When coupled with the results of physical examination, thoracic radiographs, ECG, and routine cross-sectional and M-mode echocardiogram, DE helps identify the nature as well as the severity of cardiac disease. As more experience is gained with DE, more applications will be discovered and the indications for more invasive diagnostic tests including cardiac catheterization will diminish. 相似文献
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Peter F. Kasigwa 《African Zoology》2013,48(4):154-162
The habitats and patterns of vertical migration of the shell banding morphs of the snail Sitala jenynsi (Pfeiffer) were studied in Dar es Salaam and Wazo regions of central coastal Tanzania Both dimorphic and trimorphic populations were arboreal throughout the year. The snails occurred randomly within mid-heights 180 to 360 cm. without apparent morph differences in micro-distribution. The pattern of circadial vertical distribution consisted of upward migrations during mornings and downward shifts during late evenings. These oscillations regressed negatively on relative humidity (RH), a unit advance in RH representing an eight-fold descent of snails on daytime height. Variations in RH accounted for much of the total variance in the mean vertical distance. During high RH, however, temperature and mating behaviour probably exerted major influences on snail micro-distribution. The effects of arboreality on snail survival and initiation of differentiating subpopulations are proposed 相似文献
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AN Bruere 《New Zealand veterinary journal》2013,61(1)
Abstract The article which appeared in the Jubilee Issue of the New Zealand Veterinary Journal (Marshall and Manktelow 2002) reviewed one of this country's most important zoonotic diseases. I wish to add three important references concerning its first recognition in livestock and humans in New Zealand. 相似文献