Impact of Probing the Reproductive Tract During Early Pregnancy on Fertility of Beef Cows

This short communication reports the impact of endometrial biopsies, uterine flushings and follicular fluid aspiration procedures at day 6 post artificial insemination (AI) on pregnancy rates. In Experiment 1, cows were timed AI (TAI) and assigned to the following treatment groups: control (n = 37), uterine flushing (n = 35) and endometrial biopsy (n = 38). On day 30 post AI, pregnancy rates were 40.5%, 33% and 28.5%, respectively (p > 0.1). Pregnancy rate on day 60 was lower (p < 0.004) in flushed cows than in the controls. In Experiment 2, oestrus was detected and cows were assigned to flushing (n = 32) or biopsy (n = 33) treatments 6 days after AI, which resulted in pregnancy rates of 31% and 36%, respectively (p > 0.1). In Experiment 3, cows were, 6 days after TAI, randomly assigned to the following treatments: control (n = 84) or aspiration of the largest follicle (n = 73). Pregnancy rates on day 30 post AI were 63.5% for the control group and 53% for the aspirated group (p > 0.1). In conclusion, uterine flushing and endometrial biopsy negatively affect pregnancy rates, but neither procedure can be considered to be incompatible with pregnancy maintenance. Follicular aspiration during pregnancy does not interact with pregnancy success. The amount and quality of samples obtained are compatible with the use of cellular and molecular analysis of uterine variables from cows that failed or succeeded on maintaining pregnancy.     

Antigenic relationships of Moraxella bovis isolates recovered from outbreaks of infectious bovine keratoconjunctivitis in Argentina, Brazil, and Uruguay between 1983 and 2000

Cross-reactivity indices (CRIs) of 28 isolates of Moraxella bovis recovered from outbreaks of infectious bovine keratoconjunctivitis in Argentina (A, 11 isolates), Brazil (B, 7), and Uruguay (U, 10) between 1983 and 2000 were estimated. Hyperimmune sera were produced in rabbits and antibody titres determined with each isolate. Isolates showing CRIs³ 70 were placed in the same group. Group I had 13 isolates (A, 1; B, 6; U, 6); group II had 6 isolates (A, 4; U, 2); groups III, IV, and V had 2 isolates each, recovered in Argentina; group VI had 2 isolates, from Uruguay; and group VII had 1 isolate, from Brazil. The CRIs³ 70 between vaccine strains and isolates recovered before and after 1990 were 58% and 42%, 50% and 50%, and 33% and 67% with vaccine strains 2419, 2358, and 2439, respectively. Isolate 273, from Uruguay, showed CRIs > 70 with 78% of the isolates and is recommended as the vaccine strain.     

Bayesian estimation of Tritrichomonas foetus diagnostic test sensitivity and specificity in range beef bulls

Accuracy of culture for diagnosis of Tritrichomonas foetus was investigated in 2832 naturally exposed range beef bulls from 124 herds. Preputial fluid samples were inoculated into the culture medium, incubated at 37 degrees C, and daily examined. Diagnostic test was evaluated using Bayesian techniques to estimate sensitivity and specificity without a gold standard. Median posterior test sensitivity was 72.04% (95% probability interval: 58.07-86.38%) and specificity was 95.37% (95% probability interval: 94.07-96.65%). Low diagnostic test accuracy may have resulted from host and/or diagnostic test procedure related factors. Under natural range conditions, more accurate methods for T. foetus diagnostic and repeated preputial samplings of bulls may be necessary on trichomonosis control programs.     

畜牧兽医行政执法中证据收集应注意的问题

针对当前畜牧兽医行政执法中出现的突出问题,阐述了执法中证据收集应注意的问题并提出了改进措施。     

荒漠区不同干扰下三趾跳鼠种群数量动态

在内蒙古阿拉善荒漠区选择过牧和禁牧两种不同干扰条件下的样地,运用标志重捕法和Jolly-seber模型,于2005年～2007年,对三趾跳鼠(Dipus sagitta)种群数量动态进行了连续3年的专门研究.结果表明:3年中三趾跳鼠种群数量的波动较大,其变动经历了低谷-上升-高峰-下降4个时期,该种的数量变动存在一定规律;同一年中不同干扰条件的种群数量差异明显,3a中种群第1次数量高峰均为过牧区>禁牧区,其种群年平均数量及第2次数量高峰均为禁牧区>过牧区.     

Comparative histopathology and antibody responses of non-Tritrichomonas foetus trichomonad and Tritrichomonas foetus genital infections in virgin heifers

The potential pathogenicity of non-Tritrichomonas foetus trichomonads (NTfTs) recently isolated from the prepuce of virgin bulls is not known. The purpose of this study was to determine the ability of these NTfTs to cause disease in the female reproductive tract relative to T. foetus. Forty-four virgin heifers were experimentally infected intravaginally with either one of two NTfTs (Pentatrichomonas hominis or Tetratrichomonas spp.), T. foetus, or sterile media and cultured weekly from 0 time until slaughter at 8 weeks. Serum and vaginal antibody responses during infection were assessed, and the reproductive tracts were histologically examined, scored, and compared based on numbers of neutrophils, eosinophils, lymphocytes, and plasma cells as well as the qualitative appearance of the reproductive tract. The NTfTs did not persist in the reproductive tract, while T. foetus persisted for at least 6-8 weeks. Further, no vaginal IgA response to infection was found in NTfT-infected and control heifers, but a vaginal IgA response was present in the T. foetus-infected group. Heifers infected with NTfT or controls showed little mucosal inflammatory response compared to T. foetus-infected heifers. Among the trichomonads studied, persistent infection by T. foetus alone seems responsible for uterine inflammatory lesions usually associated with pregnancy loss. The NTfTs studied in this work only transiently infected the vagina and were associated with strictly mild inflammatory changes, which probably do not cause significant disease, i.e., pregnancy loss.     

Inclusion body disease in two captive Australian pythons (Morelia spilota variegata and Morelia spilota spilota)

Two captive Australian pythons, one carpet and one diamond python, presented with signs of central nervous system dysfunction. The carpet python was agitated. Its head was tilting and it was incoordinated and had convulsions. It was treated with antibiotics and anthelmintics but was eventually euthanased after failing to respond to therapy. The diamond python had flaccid paralysis of the caudal half. It was not treated and became disoriented and died. Hepatocytes from both pythons contained irregular 2 to 10 m m eosinophilic intracytoplasmic inclusion bodies. The brain of the diamond python was not available for examination. Occasional neurones in the carpet python brain contained similar inclusion bodies and other changes suggestive of viral infection. The clinical signs and histopathological findings in both pythons were consistent with boid inclusion body disease.     

RZWQM2模型模拟地膜覆盖时间对棉田氮素迁移特征和氮肥利用效率的影响

[目的]地膜覆盖时间影响着棉田养分的迁移及氮素利用效率,我们尝试利用根区水质模型(root?zone water?quality?model-version?2,?RZWQM2)评估新疆绿洲棉田不同地膜覆盖时间下土壤氮素迁移特征和作物吸收利用率,为优化地膜覆盖方法提供理论依据.[方法]于2017—2018年在新疆进行了...     

Failure to establish infection with Tetratrichomonas sp. in the reproductive tracts of heifers and bulls

Experimental infection of the reproductive tracts of heifers and bulls with Tetratrichomonas sp. isolated from preputial smegma of virgin bulls was attempted. Nine heifers and four bulls were challenged by inoculation of 7 x 10(6) Tetratrichomonas sp. into the vaginal lumen and preputial cavity, respectively. Vaginal mucus and preputial smegma samples were collected and cultured for Tetratrichomonas sp. Heifers were slaughtered in groups of three at 2, 9 and 21 days after inoculation. Two heifers and two bulls infected with Tritrichomonas foetus and two uninfected heifers were used as controls for the model infection. Tetratrichomonas sp. were only isolated in vaginal mucus of 7/9 inoculated heifers at 6h post-inoculation, and genital secretions taken at slaughter time from vagina, uterus and oviduct were cultural negative. Bulls challenged with Tetratrichomonas sp. remained cultural negative. Since Tetratrichomonas sp. survived only a few hours in the female genitalia and did not survive in the male genitalia after experimental challenge, Tetratrichomonas sp. did not colonize the genital tract. These were likely trichomonads from the digestive tract. Collection of clean samples without fecal contamination from the reproductive tract is proposed as a measure to avoid Tetratrichomonas sp. transitory genital infection.     

单宁酶的研究进展

详细介绍了单宁酶的来源、生产、提取、纯化及其物理化学和生物学性质,并概述了它的固定化技术。