共查询到19条相似文献，搜索用时 631 毫秒
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禽流感严重影响着全世界养禽业的发展,也造成了巨大的经济损失,因此,快速而准确地诊断技术对禽流感的防控极为重要。近年来,在禽流感病毒传统诊断技术基础上,又出现了一些新兴的诊断技术,本文主要针对禽流感病毒的鉴别诊断、传统诊断技术及分子生物学诊断技术等情况进行了综述,为禽流感的有效防控提供必要的技术参考。 相似文献
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禽流感诊断和预防研究进展 总被引：2，自引：0，他引：2
综述了近年来禽流感流行的特征、对养禽业的危害、对人类健康的影响，总结了禽流感诊断技术如单克隆抗体诊断技术、竞争性ELISA法、rNP-ELISA法、RT－PCR法、RFLP亚型分型法等的最新研究进展，分析了全病毒灭活禽流感佐剂疫苗预防禽流感的效果和缺点，概述了在禽流感基因工程亚单位疫苗、核酸疫苗等的实验研究突破和临床使用效果。 相似文献
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禽流感检测方法研究进展 总被引：6，自引：0，他引：6
禽流感不仅对世界养禽业带来巨大的经济损失，而且可以感染人，公共卫生意义重大。由于其病毒亚型众多，抗原性变异极快，毒株的致病性也相差很大，早期快速诊断和血清学检测就成为预防和控制禽流感的前提条件。禽流感病毒的传统诊断方法是分离病毒和检测抗体。近年来，又相继建立了血凝抑制试验、神经氨酸酶抑制试验、酶联免疫吸附试验等血清学诊断技术及分子诊断技术。文章对禽流感检测方法快速诊断进行了概述。 相似文献
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禽流感的快速诊断方法 总被引：1，自引：0，他引：1
最近一些亚洲国家相继报道有禽流感发生，首先报道的是韩国、日本、越南，其次为柬埔寨、印度尼西亚、巴基斯坦和中国。越南是在联合国协助之下做出诊断，柬埔寨是将病料送往法国作出的诊断，泰国最初被误诊为禽霍乱，印度尼西亚则被误诊为新城疫，目前仍可听到某些地区有疑似禽流感 相似文献
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Piechotta M Bollwein J Friedrich M Heilkenbrinker T Passavant C Branen J Sasser G Hoedemaker M Bollwein H 《The Journal of reproduction and development》2011,57(1):72-75
The objective of the present study was to compare two commercially available blood-based pregnancy tests, namely BioPRYN, an ELISA for pregnancy-specific protein B (PSPB), and an ELISA for pregnancy-associated glycoprotein (PAG), for early pregnancy diagnosis in dairy cattle using transrectal ultrasonography as a gold standard. Transrectal ultrasonography was conducted 26-58 days after artificial insemination (AI) in 197 cattle from 19 farms. Concurrently, a blood sample was collected for determination of serum PSPB and PAG. Transrectal palpation was performed approximately 120 days after AI to verify that pregnancy was maintained. For PSPB and PAG, there were no significant differences (P>0.05) in sensitivity (98.0 and 97.8%), specificity (97.1 and 91.2%), positive predictive values (99.3 and 97.8%), negative predictive values (91.9 and 91.2%) and accuracy (97.8 and 96.4%). In conclusion, the two blood pregnancy assays were equally efficacious and were highly accurate (based on transrectal ultrasonography as the gold standard). 相似文献
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M Russo D Vecchio G Neglia C Pacelli A Prandi B Gasparrini L Zicarelli MJ D’Occhio G Campanile 《Reproduction in domestic animals》2010,45(6):988-991
The aim in this study was to investigate corpus luteum function and embryonic loss in buffaloes mated by artificial inseminations (AI) during the transitional period from breeding to non‐breeding season. The study was carried out using 288 multiparous Italian Mediterranean Buffalo cows at 110 ± 4 days in milk. The buffaloes were mated by AI after synchronization of ovulation by the Ovsynch‐TAI protocol 25 days after AI buffaloes underwent trans‐rectal ultrasonography to assess embryonic development. Pregnancy diagnosis was confirmed on Days 45 and 70 after AI by rectal palpation. Buffaloes pregnant on Day 25 but not on Day 45 were considered to have undergone late embryonic mortality (LEM), whilst buffaloes pregnant on Day 45 but not on Day 70 were considered to have undergone foetal mortality (FM). Corpus luteum size and blood flow were determined by real‐time B‐mode/colour‐Doppler on day 10 after AI in 122 buffaloes. The resistive index (RI) and pulsatility index (PI) were recorded at the time. Milk samples were collected on Days 10, 20 and 25 after AI in all inseminated buffaloes for the assay of whey P4 concentrations. Data were analysed by anova . Pregnancy rate on Day 25 after AI was 48.6% (140/288) and declined to 35.4% (102/288) and 30.6% (88/288) by Day 45 and Day 70 respectively. The incidences of LEM and FM were respectively 27.1% (38/140) and 13.7% (14/102). Pregnant buffaloes had greater (p < 0.01) whey concentrations of P4 from Day 20 onwards than buffaloes which showed LEM, whilst P4 in buffaloes that showed FM did not differ from the other two groups on Day 10 and Day 20. Corpus luteum blood flow on Day 10 after AI showed higher RI (p < 0.05) and PI (p = 0.07) values in buffaloes that subsequently were not pregnant on Day 25 compared with pregnant buffaloes. Buffaloes that were not pregnant on Day 45 also had a higher (p = 0.02) RI value on Day 10 than pregnant buffaloes, whilst PI values on Day 10 did not differ for the two groups of buffaloes. It was concluded that blood flow to the corpus luteum on Day 10 after AI influences corpus luteum function as judged by P4 secretion and also embryonic development and attachment in buffaloes. 相似文献
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Avian influenza - diagnosis 总被引：1，自引：0，他引：1
Alexander DJ 《Zoonoses and public health》2008,55(1):16-23
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Cost-benefit evaluation of artificial insemination for genetic improvement of wool-producing sheep 总被引：1，自引：0，他引：1
KA ABBOTT 《Australian veterinary journal》1994,71(11):353-360
SUMMARY The financial costs and benefits associated with the use of artificial insemination (AI) in commercial flocks are evaluated. Benefits are calculated in terms of net present values after summing the discounted value of benefits over 20 years. Two breeding strategies are evaluated. With the first, AI is used to produce flock ewes and wethers. The method is unlikely to be profitable unless high breeding value rams are available for AI programs with fresh semen. With the second, AI is used to produce home-bred rams, which in turn sire flock ewes and wethers. This approach is more likely to be profitable. The cost of AI per lamb weaned from laparoscopic AI programs is about $100. Benefits exceed this cost for rams of very high merit when wool prices are moderate or higher. Flock structure has a significant effect on the benefits. Flocks with low wether retention rates have benefits half that of flocks that retain most wethers to 6 years of age. AI with purchased semen also provides benefits to risk management for owners of commercial flocks who wish to breed their own replacement flock rams. 相似文献
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Kanokporn Kanthavichit Auraiwan Klaengkaew Chutimon Thanaboonnipat Damri Darawiroj Kumpanart Soontornvipart Nan Choisunirachon 《Journal of veterinary science (Suw?n-si, Korea)》2021,22(4)
BackgroundThe morphometry of the acetabulum is one source of information that assists in the clinical diagnosis of the hip and influences the proper selection of a prosthesis, reducing post-operative complications such as those seen in total hip replacement (THR). However, acetabular parameters in small-breed dogs are rarely reported.ObjectivesTo investigate acetabular parameters using radiography and computed tomography (CT) in small-breed dogs with Maltese and Shih Tzu dogs used as model breeds.MethodsStandard calibrated, extended hip radiographs and CT images were obtained. Subsequently, acetabular width (AW) in various directions was measured using radiography and CT, whereas acetabular depth (AD) was obtained by CT. Acetabular index (AI) is a ratio calculated from AD and AW.ResultsThe values of AW and AD were much higher in Shih Tzu than in Maltese dogs. Male Shih Tzus showed higher values of these parameters than females, while sex-based differences in most of the parameters could not be detected in Maltese. Body weight, but not age, influenced AWs and ADs. While AWs and ADs were influenced by several factors, AI was comparable among the assessed factors and between Maltese and Shih Tzu dogs (p = 0.172; 31.42 ± 1.35 and 32.60 ± 1.80, respectively). Also, AI did not vary with breed, sex, or body size.ConclusionsThe obtained radiographic and CT acetabular parameters could be useful as guidelines for evaluating the acetabulum of small-breed dogs in clinical practice. 相似文献
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AIM: To describe the accuracy of transrectal ultrasonography for predicting calving dates in dairy cows under typical New Zealand conditions and to assess potential risk factors for differences between predicted and actual calving dates.METHODS: Data were collected from 116 seasonally calving herds over 2 years in a retrospective single cohort study. Transrectal ultrasonography was undertaken by experienced veterinarians (n=12) to determine if cows were pregnant, and if so to estimate fetal age. Predicted calving date was calculated by adding 282 days to the estimated conception date. Accuracy was assessed using differences between predicted and actual calving dates for each animal. Potential risk factors for animals calving >10 days before or after their predicted calving date were assessed using multinomial logistic regression models.RESULTS: The study population comprised 83,104 cows over the 2 years of the study; 75,037 (90.3%) cows calved within 10 days of their predicted calving date, 3,683 (4.4%) calved >10 days earlier, and 4,384 (5.3%) >10 days later, than predicted. Risk factors for calving >10 days before or after the predicted calving date included having >1 artificial insemination (AI) before pregnancy diagnosis (p=0.03), where the cow’s most recent AI was <21 days before the end of the herd’s AI period (p<0.01), and where the diagnosis was made at the second or third herd-visit (p<0.01). The probability of calving being >10 days later than predicted also increased when the fetus was ≥13 weeks old at pregnancy diagnosis (p<0.01).CONCLUSIONS AND CLINICAL RELEVANCE: In this study, >90% of cows diagnosed pregnant by veterinarians using transrectal ultrasonography calved within 10 days of the predicted calving date. In herds where herd reproductive performance is high, it would be expected that more cows would conceive to their first AI, and potentially fewer cows would have AI close to the end of the herd’s AI period, which would increase diagnostic accuracy. Where herd managers rely on accurate predicted calving dates they should be informed about realistic expected accuracy. For greatest accuracy, a complete AI history should be made available to the person performing the pregnancy diagnoses and cows at most risk of having inaccurate predicted calving dates should be identified. 相似文献
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The objectives of the current study were to evaluate the correlation between reproductive status and steady-state levels of Myxovirus resistance gene (MX2) mRNA in peripheral blood leukocytes (PBL) of dairy heifers and the reliability of using change in MX2 messenger RNA (mRNA) for identification of nonpregnant heifers 18 to 19 d after AI. Holstein heifers (n = 266), 13 +/- 1 mo of age, were assigned randomly to be inseminated (BRED; n = 214) or not (NONBRED; n = 52). Estrous cycles of all heifers were synchronized with an intravaginal insert containing progesterone for 7 d. At insert removal, heifers received an injection of PGF2alpha. Heifers in the BRED group were inseminated on detection of estrus or at a fixed time, 72 h after insert removal concomitant with a GnRH treatment. Heifers in the NONBRED group received an injection of GnRH 48 h after insert removal. Blood samples collected on d 0 (d of AI or estrus) and 18 were used to determine steady-state levels of MX2 mRNA. Samples collected on d 0, 7, 14, and 21 were analyzed for progesterone concentration. Pregnancy was determined retrospectively by progesterone concentration on d 21 and was diagnosed at 30 +/- 1 and 60 +/- 3 d after AI. The fold change in levels of MX2 mRNA from d 0 to 18 was greater for heifers classified and diagnosed as pregnant on d 21 (P < 0.05) and 30 +/- 1 (P < 0.05) and 60 +/- 3 (P < 0.05) d after AI compared with nonpregnant (bred but not pregnant) and NONBRED heifers. Heifers that experienced pregnancy loss from 21 to 30 +/- 1 (P = 0.11) or 21 to 60 +/- 3 (P = 0.08) d of gestation tended to have smaller fold increases in MX2 mRNA expression than those that maintained pregnancy. The sensitivity (range 57.1 to 65.6%) and negative predictive values (range 47.9 to 57.1%) of determining reproductive status on d 18 according to the change in the level of MX2 mRNA expression in PBL were low, and the correlation between diagnosis of pregnancy by fold change in MX2 mRNA expression and other methods was small (r = 0.20 to 0.36). The current study indicates that increased expression of MX2 mRNA in PBL is related to pregnancy approximately 21, 30, and 60 d after AI in dairy heifers and that losses that occurred later in pregnancy were associated with lower fold increases in MX2 mRNA. However, using the change in MX2 mRNA expression was not a reliable method for diagnosis of pregnancy at 18 d after AI because of the low sensitivity and negative predictive value. 相似文献
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Piles M Garreau H Rafel O Larzul C Ramon J Ducrocq V 《Journal of animal science》2006,84(7):1658-1665
The objective of the study was to analyze the reproductive longevity of 2 selected lines of rabbits. The first one was the Prat line, a line selected in Spain on litter size at weaning, and raised in overlapping generations. The second one was a French line, the A1077 line, selected on litter size at birth and individual weight at 63 d of age, managed in batches, and artificially inseminated with discrete generations. Reproductive longevity was measured beginning at the first successful mating, assessed by a pregnancy diagnosis in the Prat line, and at the first kindling in the A1077 line. In the A1077 line, culling for infertility occurred after 3 unsuccessful artificial inseminations. The trait analyzed, defined as the doe length of productive life (LPL), was the time in days between date of the first positive pregnancy diagnosis and date of culling or death in the Prat line. In the A1077 line, the trait was the number of AI after the first kindling. Effects included in the model were year-season, litter size at birth, reproductive cycle or physiological status x cycle interaction, age at first mating, batch (only for the A1077 line), and additive genetic value of the animal as a random effect. Survival analyses were carried out with a Cox model for the Prat line and a discrete model for the A1077 line. The estimated heritability values for LPL were around 0.16 in the Prat and A1077 lines with a model including physiological status x cycle interaction effect. Removing this effect from the model led to an increase in estimated genetic variance with h2 = 0.24 and 0.19 in the Prat and A1077 lines, respectively. Including the traits LPL and number of AI from first fertile mating or AI in selection programs could increase reproductive longevity and decrease the replacement rate. 相似文献