National Agro Technology Extensions and Service Center

Beijing, China

National Agro Technology Extensions and Service Center

Beijing, China
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Deng W.,China Agricultural University | Yongwang G.,National Agro Technology Extensions and Service Center | Dazhao S.,China Agricultural University
Journal of Applied Animal Research | Year: 2011

To evaluate the antifertility effects of crude ethanol extracts of Tripterygium hypoglaucum (Levl.) Hutch in Mongolian gerbils. Crude ethanol extracts of T. hypoglaucum root (ETHR) were administrated orally at a dose of 160 mg/kg for 30 days. Sperm density, sperm motility levels and the percentage of misshapen sperm in the cauda epididymides were assessed. The fertility rate of mated female gerbils was calculated. The results indicate that ETHR has effect in Mongolian gerbils. Oral administration of ETHR caused an increase of the percentage of misshapen sperm significantly. Testis and epididymis weights, the sperm density and motility were significantly reduced. Compared to the control group, there was a distinct reduction in the number of litters produced, and the average number of pups per male decreased from 3.4 to 0.87. Reversibility tests showed that testis and epididymis weights, sperm indices and fertility started to gradually recover after 30-days cessation of medication.ETH R brought a significant decrease in birth rate of Mongolian gerbils. © 2011 Taylor & Francis.

Wang D.,China Agricultural University | Li Q.,China Agricultural University | Li K.,China Agricultural University | Guo Y.,National Agro Technology Extensions and Service Center
Crop Protection | Year: 2017

A trap barrier system (TBS) is widely used to manage rodents in farming areas of China. Traditional TBSs are constructed as a rectangle around crops on the principle that rodents are attracted to the enclosed trap-crop (TC) which maximizes the number of rodents captured. This study evaluated the efficiency of capturing rodents using rectangular TBS with and without a trap-crop (R-TBS + TC and R-TBS), and linear TBS (L-TBS) for rodent control in maize fields in Northeastern China. The overall number of rodents captured by R-TBS + TC and R-TBS were not significantly different, but the peak number of rodents trapped by R-TBS occurred later in time in comparison to that of R-TBS + TC. There was no difference in the community composition of the captured rodents by R-TBS and R-TBS + TC. The numbers, age structures and sex ratios of Apodemus agrarius Pallas, the rodent species most commonly trapped by R-TBS + TC and R-TBS were uniform. Thigmotactic movement of a rodent is a more likely explanation for rodent capture than the attraction of trap-crops in R-TBS. The efficacy of L-TBS in capturing rodents was not significantly different compared with R-TBS. The community composition of captured rodents and the characteristics of A. agrarius population (population size, age structures and sex ratios) trapped by R-TBS and L-TBS were similar. L-TBS could be more practical for farmers and appears to provide similar levels of rodent control compared to the traditional R-TBS in this farming system. © 2017 Elsevier Ltd

Zhang M.,CAS Institute of Subtropical Agriculture | Li B.,CAS Institute of Subtropical Agriculture | Wang Y.,CAS Institute of Subtropical Agriculture | Jiang F.,Plant Protection Station of Sichuan Province | And 6 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2010

To provide information on population dynamics and community succession of disease vectors (including Insectivora and Rodentia) after the 2008 earthquake in Wenchuan China, we conducted regular surveys of small mammals. Small mammals in farmland and residential areas were collected with snap-traps every month in Dujiangyan, Pengzhou,Shifang, Mianzhu, Beichuan and Wenchuan, areas near the earthquake epicenter and that sustained serious damage. From 15933 traps, we collected 1171 small mammals in farmland for 13 months after June 2008. The animals trapped belonged two categories: Rodentia (the trap success was 1. 49%) and Soricidae of Insectivora (the trap success was 5. 86%). Anourosorex squamipes was the dominant species in Dujiangyan, Pengzhou, Shifang and Mianzhu. Apedomus agrarius was the dominant species in Beichuan and Wenchuan. Rattus norvegicus, Rattus nitidus, Rattus tanezumi, Mus musculus, Micromys minutes, Niviventerfulvescens and Suncus murinus were also trapped. From 1696 traps set in residential areas, we trapped 212 animals, (the trap success was 12. 50%). A. squamipes was also the dominant species (the trap success was 10.02%), followed by R. tanezumi, M. musculus, R. norvegicus and R. nitidus. Because of intense application of rodenticide after the earthquake, the densities of Rodentia both in farmland and in residential areas were low. However, the densities of Soricidae were still high. Moreover, the numbers of pregnant females of two dominant species (A. squamipes and A. agrarius) were high, especially A. squamipes. According to these and other surveys, which show short-term effects of the earthquake and of intensive application of anticoagulant on rodent populations, surveys will likely need to be carried out for more than three years in the earthquake area.

Shen W.,China Agricultural University | Guo Y.,National Agro Technology Extensions and Service Center | Shi D.,China Agricultural University | Wang D.,China Agricultural University | Hai S.,China Agricultural University
Acta Theriologica Sinica | Year: 2011

In this study, Mongolian gerbils were randomly divided into multi-dose treated group (MDT group), one-dose treated group (ODT group) and control group (CK group) to explore effects of quinestrol on reproductive organs and reproduction. The epididymides, seminal vesicles and semen quality, fertility were assessed at 15, 30, 60 and 90 days after treatment. Histopathological changes of epididymides were observed by H. E stain. Results showed that the coefficient of testes, epididymides, and seminal vesicles were significantly decreased (P<0.01) at 15 or 30 days after treatment. The normal function of the sex gland was impaired, which led to significant decrease in the density and amount of live spermatozoa and reproductive rates (P <0.01), as well as a significant increase of abnormal spermatozoa (P <0.01) in both MDT group and ODT group. Compared with the OUT group, the damage for gerbil reproduction in MDT group was more severely at 15 or 30 days after treatment (P <0.01). After 60 days of treatment withdrawal, the sex gland in treated group was normalized except for gerbil epididymides in the MDT group, while semen quality and reproductive rates were still lower than those in the control group (P < 0.01). The physiological indicators were recovered by 90 days of treatment withdrawal. This indicates that quinestrol shows certain effects on reducing the fertility of male gerbil with a reversible effect after 90 days' treatment and multi-dose treatment has more effects to infertility compared with one-dose treatment.

Wang T.,China Agricultural University | Guo Y.,National Agro Technology Extensions and Service Center | Wang D.,China Agricultural University | Hai S.,China Agricultural University
Acta Theriologica Sinica | Year: 2015

It is critical to confirm the optimum dose and the active duration of the sterilization by quinestrol on rodents for some studies and practices. We fed female and male Brandt's voles 5 doses of 0.5 mg/kg, 1.0 mg/kg, 2.0 mg/kg, 3.0 mg/kg, or 6.0 mg/kg quiestrol for 7 consecutive days. We then assessed their anti-fertility effects on the voles by analyzing reproduction indices including birth date, reproductive rate and reproductive capacity. Results showed that quinestrol delayed the breeding of Brandt's voles in the lab, but the effect was not significant due to the small sample size. In 90 days, some doses of quinestrol decreased the reproductive rate and average litter size of female and male, however, the inhibitory effect still was not significant, again possibly due to small sample size; some doses of quinestrol decreased markedly the reproductive capacity of Brandt's voles. The suppression effects were not significantly correlated with the doses of quinestrol. The optimum doses of quinestrol causing sterility were below 2.0 mg/kg for male and 1.0 mg/kg for female. The dose applyed for Brandt's vole should be below 2.0 mg/kg, which can reduce total litter size of Brandt's vole obviously within 90 days. ©, 2015, Science Press. All right reserved.

Shen W.,China Agricultural University | Shi D.,China Agricultural University | Wand D.,China Agricultural University | Guo Y.,National Agro Technology Extensions and Service Center | And 2 more authors.
Experimental Animals | Year: 2011

The hypothesis that quinestrol exerts testicular damage via oxidative stress was investigated in male gerbils using a daily oral gavage of 3.5 mg/kg body weight for 2 weeks (the multidose-treated group) or 35 mg/kg body weight (the single-dose-treated group). The testicular histological morphology, antioxidant capacity and malondialdehyde (MDA) concentration in testicular tissue and plasma were assessed at 15, 30, and 60 days following treatment. The results showed that the activity of the antioxidant enzymes, including superoxide dismutase (SOD) and glutathione peroxide (GSH-Px), and total antioxidant capacity (T-AOC), at 15 days after treatment in testicular tissue decreased, which led to the MDA concentration increasing while at the same time germ cells were rarefied and showed an irregular distribution in seminiferous tubules of quinestrol-treated gerbils. At 30 days, the testicular weight and antioxidant capacity continued to decrease, while the MDA concentration continued to increase, and testicular histopathological changes were more pronounced. Single-dose and multidose drug treatment had a similar effect on the antioxidant enzymes and MDA, but testicular damage was relatively severe at 15 and 30 days after multidose treatment. By 60 days of treatment withdrawal, however, the above parameters recovered to control levels. The results show that quinestrol causes reversible damage to gerbil testes that might be caused by the oxidative stress and that multidose treatment has more effects on testicular damage compared with one-dose treatment.

Wang D.,China Agricultural University | Guo Y.,National Agro Technology Extensions and Service Center | Shi D.,China Agricultural University
Conservation Genetics | Year: 2011

Brandt's vole (Lasiopodomys brandtii) distribution is discontinuous in Inner Mongolia with some populations isolated from others. Recently, some isolated populations have suffered extinction, and the factors responsible remain elusive. Genetic drift is one of the processes affecting population genetic differentiation, and can play a substantial role in the divergence of small, isolated populations. Using seven microsatellite markers, we genotyped four geographically isolated populations of Brandt's vole, all of which exhibit episodic fluctuations in population density. The results showed a strong genetic differentiation among the geographically distinct populations (total FST = 0.124) and in particular, one population (Zhengxiangbaiqi) was isolated from all others (FST values were greatest between Zhengxiangbaiqi and other populations). Furthermore, high levels of inbreeding (FIS values ranged from 0.205 to 0.290) within each distinct population suggest that inbreeding has and is likely occurring in Brandt's vole populations. These processes can decrease average individual fitness and consequently increase the risk of extinction of the species. © 2010 Springer Science+Business Media B.V.

Xiao-Li B.,China Agricultural University | Da-Zhao S.,China Agricultural University | Yong-Wang G.,National Agro Technology Extensions and Service Center | Xin-Ping W.,Chinese Institute for the Control of Agrochemicals
International Journal of Pest Management | Year: 2010

The aim of this study was to develop a quick, simple and inexpensive anticoagulant rodenticide resistance test method. The blood clotting response (BCR) test for resistance to chlorophacinone-Na in Mongolian Gerbils was prepared using small-volume blood samples. The normal Prothrombin time for Mongolian Gerbils was 9.92 ± 0.96 s using MDC Haemostasis thromboplastin-s (ISI: 1.86) reagent. Percent coagulation activity (PCA) calibration curves fitted the S curve and the PCA of 17% was found to correspond to a coagulation time International Normalized Ratio of 2.5. Dose-response baselines for BCR were obtained using susceptible Mongolian Gerbils and the ED99 values estimated for a quantal response were 0.27710 mg kg-1 for males and 0.26228 mg kg-1 for females. Based on the BCR test for resistance in wild Mongolian Gerbils from Zhenglanqi, Zhengxiangbaiqi, Kezhen in the Inner Mongolia Autonomous Region, we found that the populations of three areas have developed chlorophacinone-Na resistance populations with resistance ratios (%) of 34.0, 30.0 and 40.9, respectively. © 2010 Taylor & Francis.

Yang Z.,Guizhou Yuqing Plant Protection Station | Jin X.,Guizhou Plant Protection Station | Guo Y.,National Agro Technology Extensions and Service Center | Long G.,Guizhou Dafang Plant Protection Station | Liu J.,Guizhou Plant Protection Station
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2010

In The population dynamics and abundance of Apodemus chevrieri, a primary pest rodent, were studied in Dafang County, Guizhou, from 1996 -2008 using toe-clipping, surveys, and modelling from monthly capture rates. Apodemus chevrieri represents 62% of all farmland rats and is stable among years, ranging from 49%-79% of captured rodents. Over the last ten years, the average annual capture rate was 2. 58% 1. 27%. From 1996 to 1999, the population density was high and the annual average capture rate exceeded 3%. However, population density from 2001 to 2008 was low, and the annual average capture rate was less than 2%. Populations of Apodemus chevrieri showed significant variation with year, month, and season. The highest annual average capture rate of 4. 99% was five times higher than the lowest annual average rate. Monthly average catch rates varied by a factor of 39, and average catch rates in the summer were 2. 3 times higher than those in winter. Population changes throughout the year typically showed a single peak in June, and were essentially similar among different years. A classification standard was formulated for integration with local rodent control targets, taking into account population fluctuations and damage caused in previous years. Correlations were obtained among capture rate, reproductive parameters, sex ratio, pregnancy rate, litter size, testis growth, monthly reproductive index, and population density in the peak month of June. Using regression analysis, population levels in April can be used to forecast accurately the June population density and maximum numbers. The average match rates for value prediction and magnitude prediction were 92. 84% and 100. 00%, respectively. This high accuracy indicates practical and feasible forecasting for pest rodent populations and its use in control.

Wan X.,CAS Institute of Zoology | Liu L.,CAS Institute of Zoology | Wang G.,Mississippi State University | Guo Y.,National Agro Technology Extensions and Service Center
Mammalian Biology | Year: 2015

Litter size and body size of animals may coevolve under the concomitant pressures of sexual selection, fecundity selection, and viability selection. Studies have demonstrated the positive relationship between body size and litter size, consistent with Darwin's fecundity advantage of large body size. However, the counterbalancing selection hypothesis predicts fecundity selection would result in a positive correlation between litter size and body size initially, whereas the opposite pressure by viability selection would decrease litter size with further increasing body size beyond a threshold size. Moreover, the reproduction senescence hypothesis predicts that litter size of old, large females would decline with deteriorating body conditions. In this study, we tested the predictions of the counterbalancing selection hypothesis and the reproduction senescence hypothesis concerning the quadratic relationship between body size and litter size in Daurian ground squirrels (Spermophilus dauricus). Litter size increased initially with increasing carcass weight of females, and then decreased with further increases in carcass weight, supporting the prediction of the counterbalancing hypothesis. However, litter size was not related to body condition index of females, and body conditions improved with increasing body weight, suggesting that the reproduction senescence hypothesis alone cannot explain the observed quadratic relationship between litter size and carcass weight of female S. dauricus. © 2014 Deutsche Gesellschaft für Säugetierkunde.

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