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1.
Five commercial formulations ofBacillus thuringiensis (Berliner) were found to be effective for control of larvae of the red-humped caterpillar,Schizura concinna (Smith & Abbot), an important defoliator of broad-leaved trees in California. The formulations tested were Biotrol® BTB 183 25 W, Biotrol® XK, Dipel®, Thuricide® HPC, and Thuricide® 90TS 950T. As a result of these trials,B. thuringiensis replaced chemical insecticides for the control of this pest in 1970, and has provided effective control as part of an operational pest management programme for four years.  相似文献   

2.
The contact toxicity of eight insecticides to adults of four parasitoids of the sweetpotato whiteflyBemisia tabaci was evaluated in the laboratory. Two common Texas species,Eretmocerus sp. andEncarsia pergandiella Howard, and two exotic species,Eretmocerus mundus Mercet from Spain andEncarsia formosa Gahan from Greece were tested. Insecticides, applied as sprays to greenhouse-grown cotton plants at recommended rates were amitraz (Ovasyn®), azinphosmethyl (Guthion®), bifenthrin (Capture®), buprofezin (Applaud®), cypermethrin (Ammo®), methyl parathion and thiodicarb (Larvin®), with a water control. Parasitoid adults were confined on discs cut from leaves (1) sprayed the same day and (2) sprayed two days previously. Survival in both treatments was measured two and four days following exposure. Significant differences in toxicity were detected among the insecticides. Buprofezin was not toxic to any of the four parasitoids. When caged on leaves sprayed two days previously, only amitraz of the remaining compounds allowed significant general parasitoid survival after two days.E. mundus exhibited the greatest overall tolerance to insecticides, with 40% or more surviving 48 hr after confinement on leaves sprayed with amitraz, thiodicarb and cypermethrin. Survival was generally much reduced after 96 hr. In a separate test, fresh residues of endosulfan (Thiodan®) were highly toxic at the two rates tested, but two day old residues at the lower rate allowed 76.7% survival ofE. mundus and 35% survival ofE. pergandiella after 48 hrs.  相似文献   

3.
The wide-range transformation/expression platform, Xplor®2, was employed for the assessment of Schwanniomyces occidentalis as a potential producer of the recombinant proteins human IFNα2a (IFNα2a) and S. occidentalis fructofuranosidase (SFfase), and its efficiency was compared to that of Arxula adeninivorans. ADE2 and URA3 genes from both yeast species were isolated, characterized and used as selection markers in combination with the IFNα2a and SFfase expression modules, which used the strong constitutive A. adeninivorans-derived TEF1 promoter. Yeast rDNA integrative expression cassettes and yeast integrative expression cassettes equipped with a selection marker and expression modules were transformed into auxotrophic S. occidentalis and A. adeninivorans strains and a quantitative comparison of the expression efficiency was made. Whilst IFNα2a was mainly accumulated extracellularly (>95 %) in A. adeninivorans, extracellular SFfase (>90 %) was detected in both yeast species. The DNA composition of the selection marker modules and expression modules, especially their open reading frame codon usage, affects auxotrophy recovery as well as protein expression. Auxotrophy recovery was only achieved with selection marker modules of the homologous gene donor yeast. The concentration of recombinant IFNα2a was fivefold higher in A. adeninivorans (1 mg?L?1), whereas S. occidentalis accumulated 1.5- to 2-fold more SFfase (0.5 Units ml?1). These results demonstrate the extension of the use of the wide-range expression platform Xplor®2 to another yeast species of biotechnological interest.  相似文献   

4.
Proteins containing the BTB (Bric-à-brac, tramtrack, and Broad Complex) domain typically share low sequence similarities and are involved in a wide range of cellular functions. We previously identified two putative and closely related BTB genes, BTB1 and BTB2, in the genome of the predatory mite Metaseiulus occidentalis. In the current study, full-length BTB1 and BTB2 cDNAs were cloned and sequenced. BTB1 and BTB2 encode proteins of 380 and 401 amino acids, respectively. BTB1 and BTB2 proteins each contain an N-terminal BTB domain and no other identifiable domains. Thus, they belong to a large category of BTB-domain proteins that are widely distributed in eukaryotes, yet with largely unknown function(s). BTB1 and BTB2 gene knockdowns in M. occidentalis females using RNAi reduced their fecundity by approximately 40% and 73%, respectively, whereas knockdown had no impact on their survival or the development of their offspring. These findings suggest these two proteins may be involved in processes related to egg production in this predatory mite, expanding the list of functions attributed to these diverse proteins.  相似文献   

5.
Abstract: The side‐effects of six pesticides used on peaches in Brazil were tested on the hymenopteran egg parasitoid Trichogramma cacoeciae using four laboratory tests: (a) adult parasitoid exposure to fresh pesticide residue on glass plates (worse case); (b) direct spray of host eggs enclosing the parasitoid egg, larvae or pupae (less‐exposed life stages); (c) exposure of adults to pesticide residues on plant leaves at different intervals after application (persistence); (d) Dose–response pesticide exposures of adults on glass plates. Two dose rates were used: (1) The highest recommended field dosage (FD) and (2) the predicted initial environmental concentrations (PIEC). The results showed that the preparations greatly differed in their initial toxicity and persistence. The insecticide Valient® (methoxyphenozide) and the fungicide Venturol® (dodine) were considered harmless to T. cacoeciae adults as they fell into the class 1 category according to the guidelines of the International Organization for Biological Control (IOBC) when parasitoids were directly exposed to chemical residues. The insecticide/acaricide Assist® (mineral oil) was slightly harmful at the rate of PIEC 0.4 (40% of FD) and moderately harmful at FD. Pesticides in the categories harmless and moderately harmful can be considered for use in integrated pest management (IPM). The fungicide/acaricide Kumulus DF® (sulphur) and the insecticides Dipterex® 500 (triclorfon) and Lebaycid® 500 (fenthion) were harmful at both concentrations. In the persistence test, Assist® was short lived and therefore may in special cases (i.e. reduced direct contact) be considered for use in IPM, but Kumulus® DF, Dipterex® 500 and Lebaycid® 500 constantly reduced parasitism between 77 and 100% and were rated as persistent (more than 30 days). The direct spray of parasitized host eggs at intervals after parasitism showed that Assist® and Kumulus® DF were harmless to the parasitoid egg, larvae and pupae within the host eggs. Dipterex® 500 was slightly harmful when sprayed one day after parasitism (parasitoid egg) and moderately harmful to the other two stages (larvae and pupae). Lebaycid® 500 was harmful to the parasitoid egg and larvae and moderately harmful to the pupae. The dose–response test showed that Kumulus® DF and Dipterex® 500 were toxic to T. cacoeciae. Kumulus® DF was harmful from 1 PIEC 0.4 to 0.125 PIEC 0.4 dosages and was slightly harmful with 0.0625 PIEC 0.4 dosage. Dipterex® 500 was harmful to T. cacoeciae in all the dosages tested.  相似文献   

6.
Recently, most foodborne illness outbreaks of salmonellosis have been caused by consumption of contaminated fresh produce. Yet, the mechanisms that allow the human pathogen Salmonella enterica to contaminate and grow in plant environments remain poorly described. We examined the effect of feeding by phytophagous insects on survival of S. enterica on lettuce. Larger S. enterica populations were found on leaves infested with Macrosteles quadrilineatus. In contrast, pathogen populations among plants exposed to Frankliniella occidentalis or Myzus persicae were similar to those without insects. However, on plants infested with F. occidentalis, areas of the infested leaf with feeding damage sustained higher S. enterica populations than areas without damage. The spatial distribution of S. enterica cells on leaves infested with F. occidentalis may be altered resulting in higher populations in feeding lesions or survival may be different across a leaf dependent on local damage. Results suggest the possibility of some specificity with select insects and the persistence of S. enterica. Additionally, we demonstrated the potential for phytophagous insects to become contaminated with S. enterica from contaminated plant material. S. enterica was detected in approximately 50% of all M. quadrilineatus, F. occidentalis, and M. persicae after 24 h exposure to contaminated leaves. Particularly, 17% of F. occidentalis, the smallest of the insects tested, harbored more than 102 CFU/F. occidentalis. Our results show that phytophagous insects may influence the population dynamics of S. enterica in agricultural crops. This study provides evidence of a human bacterial pathogen interacting with phytophagous insect during plant infestation.  相似文献   

7.
The selectivity of five entomopathogens and a chemical insecticide (positive control) to pupae and adults of the egg parasitoid Telenomus remus (Nixon) was evaluated in the laboratory under controlled environmental conditions according to protocols established by the International Organization for Biological Control. Baculovirus anticarsia (Baculovirus AEE®), Bacillus thuringiensis var. kurstaki (Thuricide®), Bacillus thuringiensis var. aizawai (Agree®), Beauveria bassiana (Boveril®), Metarhizium anisopliae (Metarril®) and Trichoderma harzianum (Trichodermil®) are harmless to T. remus pupae, and adults. Thus, our results suggest that the insect control strategies applied here are compatible since entomopathogens were classified as harmless to T. remus in most examined cases and therefore facilitate a joint application to control different pests. Bacillus thuringiensis var. kurstaki (Dipel®), despite being classified as slightly harmful in some of the evaluations, can still be considered compatible for use together with T. remus, especially when compared with chemical insecticides such as chlorpyrifos that might be considered harmful to the parasitoid survival.  相似文献   

8.
Low back pain is a major public health issue in the Western world, one main cause is believed to be intervertebral disc (IVD) degeneration. To halt/diminish IVD degeneration, cell therapy using different biomaterials e.g. hydrogels as cell carriers has been suggested. In this study, two different hydrogels were examined (in vitro) as potential cell carriers for human mesenchymal stem cells (hMSCs) intended for IVD transplantation. The aim was to investigate cell-survival and chondrogenic differentiation of hMSCs when cultured in hydrogels Puramatrix® or Hydromatrix® and potential effects of stimulation with growth hormone (GH). hMSCs/hydrogel cultures were investigated for cell-viability, attachment, gene expression of chondrogenic markers SOX9, COL2A1, ACAN and accumulation of extracellular matrix (ECM). In both hydrogel types, hMSCs were viable for 28 days, expressed integrin β1 which indicates adhesion of hMSCs. Differentiation was observed into chondrocyte-like cells, in a higher extent in hMSCs/Hydromatrix® cultures when compared to hMSCs/Puramatrix® hydrogel cultures. Gene expression analyses of chondrogenic markers verified results. hMSCs/hydrogel cultures stimulated with GH displayed no significant effects on chondrogenesis.In conclusion, both hydrogels, especially Hydromatrix® was demonstrated as a promising cell carrier in vitro for hMSCs, when directed into chondrogenesis. This knowledge could be useful in biological approaches for regeneration of degenerated human IVDs.  相似文献   

9.
Greenhouse experiments were conducted on various crops (cucumber, tomato, eggplant, green bean) to ascertain the effects of Break-thru® (polyether-polymethylsiloxane-copolymer, a silicone surfactant) and an oil emulsion, on Beauveria bassiana (Balsamo) Vuillemin (Bb) applications for the control of the two spotted spider mite, Tetranychus urticae Koch. The objectives were to compare a) the efficacy of Bb control when applied in aqueous Break-thru® or an oil emulsion; b) the effects of various concentrations of Bb conidia, as affected by each surfactant; and c) the effects of Break-thru® on the activity of the fungus. Conidia were suspended either in an aqueous Break-thru® or an emulsifiable formulation at different conidial concentrations (1.05 × 106, 2.1 × 106 and 4.2 × 106 conidia ml?1) and sprayed onto leaves 2 weeks after artificial pest inoculation. Two sprays were performed, with an interval of one week from one spray to another, and T. urticae population counts (both motile and egg stages) were made on plant leaves 7 days after each spray. Bb conidia in Break-thru® were more efficacious than conidia in emulsifiable formulation. With the highest rate of conidia (4.2 × 106 conidia ml?1), mortality of adult mites ranged from 60 ± 4.2 (mean ± SE) to 85.7 ± 4.3% in the Break-thru® suspension and 39.4 ± 7 to 61.3 ± 6% in the oil emulsion. Leaf damage index was also substantially reduced from 70% in the unsprayed control to 40% by the application of Bb conidia at the highest rate with Break-thru®. Break-thru® can be combined with Bb in the integrated management of T. urticae and Isolate R444 is a promising candidate for the control of the pest.  相似文献   

10.
The influence of five different crops (beans, cucumber, eggplant, maize, and tomato) on persistence and the control efficacy of Beauveria bassiana (Balsamo) Vuillemin to Tetranychus urticae Koch was investigated. Plants were artificially infested with T. urticae. B. bassiana conidia were suspended in Break-thru® solution (0.01%) at three different concentrations (0.5, 1, 2 g l?1) and sprayed once onto plants. Plants in the control treatment were sprayed with Break-thru® solution alone. The number of conidia and levels of mite mortality were evaluated. Colony forming unit counts of conidia recovered from plant leaves declined over time regardless of the concentrations of B. bassiana applied. The rate of decline was different among crops and significantly higher on maize. However, more than 50% of the initial population of conidia were still viable on crops three weeks after application. The longer persistence of B. bassiana on crops did not result in better control of mites. Rather, mortality was positively correlated to the amount of inoculum deposited on leaves immediately after spraying. Mortality of mites was concentration-dependent and influenced by the host crop, with less control observed on maize and tomato than eggplant, beans and cucumber. Results were consistent between trials conducted and confirmed the hypothesis that the type of crop can influence the efficacy of B. bassiana against T. urticae.  相似文献   

11.
The effect of leaves of Quercus agrifolia, Cercis occidentalis, Eucalyptus globulus, and Juglans regia on the initial deposit and subsequent rate of decay of viable spores of Bacillus thuringiensis was investigated. Significant differences in the size of the initial viable spore deposit were found between the various species, with E. globulus markedly lower than the others. The viable spore decay patterns of the various species were analyzed using a segmented linear model and significant differences in initial rates of decay were also measured. Thus it appears that the characteristics of the leaves of the treated plants may have an effect on the coverage and field persistence of viable B. thuringiensis spores. Some possible mechanisms for these effects are discussed.  相似文献   

12.
不同杀虫剂对西花蓟马的室内毒力及田间药效   总被引:1,自引:0,他引:1       下载免费PDF全文
【目的】西花蓟马是一种世界性的危险性入侵害虫,筛选防治西花蓟马的有效药剂可为生产中科学用药提供依据。【方法】通过室内毒力测定和田间药效试验,测定了2种化学药剂和8种生物药剂对西花蓟马成虫的致死中浓度(LC_(50))和药后不同时期的防治效果。【结果】室内毒力测定依据LC_(50)值将各药剂对西花蓟马的敏感性由高到低依次排序为乙基多杀菌素(0.1958 mg·L~(-1))、印楝素(0.9399 mg·L~(-1))、苦参碱(1.2483 mg·L~(-1))、阿维菌素(1.8096 mg·L~(-1))、高效氯氰菊酯(4.4458 mg·L~(-1))、藜芦碱(10.7628 mg·L~(-1))、鱼藤酮(18.1898 mg·L~(-1))、吡虫啉(46.3964 mg·L~(-1))、松脂酸钠(131.5214 mg·L~(-1))、苏云金杆菌(446.2318 mg·L~(-1));田间药效试验发现,乙基多杀菌素和吡虫啉防治西花蓟马均表现出较强的速效性和持效性,药后1~14 d的防效分别可达84%和73%以上;其次是藜芦碱,药后1~14 d的防效可达48.15%~61.37%;高效氯氰菊酯的防效较低,药后14 d的防效为46.22%;生物药剂阿维菌素、苏云金杆菌、苦参碱、印楝素的速效性均较低,但防效随施药后时间的延长而逐渐上升;鱼藤酮持效性最低。【结论】乙基多杀菌素和吡虫啉可推荐为生产中防治西花蓟马的首选药剂,植物源药剂藜芦碱和生物药剂阿维菌素可作为交替使用药剂。  相似文献   

13.
Susceptible coffee plants (Coffea arabica cv. ‘Mundo Novo’) treated with a suspension of Bacillus thuringiensis or with three of commercial products (Thuricide HD, Bactimos and Bactospeine PM) of B. thurngiensis were protected against a later inoculation with Hemileia vastatrix, the causal agent of coffee leaf rust. Thuricide HD was effective at concentrations from 5 to 20 mg/ml; at this concentration, protection reached 90 %, lasted for at least 5 weeks, and was systemic. Induced resistance was determined by the reduction of the average number of lesions per leaf in treated leaves when compared with non-treated controls. A decrease in lesion size as well as a delay in sporulation time were also observed in protected plants treated with Thuricide HD.  相似文献   

14.
Pathogenicity ofHeliothis nuclear polyhedrosis virus (HSNPV) to the corn earworm,Heliothis armigera, was studied using 3 different inoculative methods. The LD50 values of 4th-instar larvae inoculated with corn-fed, diet-fed and inoculum-imbiding method were 1.85×106, 2.55×105 and 1,22×103 PIBs/larva, respectively. The inoculum-imbiding is more sensitive and convenient for inoculatingH. armigera with HSNPV. The HSNPV product, Elcar®, was highly pathogenic toH. armigera, the LD50 values of 2nd-, 3rd- and 4th-instar larvae being 27, 83 and 1,221 PIBs/larva, respectively, as measured by the inoculum-imbiding method. The mortality of 4th-instar larvae caused by HSNPV was increased, but the incubation period was shortened with higher incubation temperatures. However, the high temperature at 35°C caused a lower mortality, and a prolongation of the median lethal time (LT50). Stability and persistence of HSNPV preparations were better in January–February and April–May than in June–July and October–November periods when sprayed on corn silks under field conditions. The HSNPV was inactivated by weak alkaline dew (pH 8.1) collected from soybean leaves, but it remained active on those from corn, tomato and asparagus with pH 7.2–7.3. The artificial heavy rainfall of 242 mm/h for 30 min did not wash off HSNPV preparations sprayed on the corn silks.  相似文献   

15.
Abstract

In this study, Metarhizium anisopliae TR 106 and Beauveria bassiana TR 217 was tested against fourth instar larvae of Thaumetopoea pityocampa. The LT50 and LT90 of 1?×?106 concentration of M. anisopliae against T. pityocampa were 3.60 and 4.11 for direct application, while these were 2.87 and 3.60?days, respectively in leaves application. The LT50 and LT90 of the 1?×?108 concentration of the same isolate were 2.50 and 2.95?days for direct application, and 2.98 and 3.74?days for leaves application. The LT50 of insect and leaves application for 1?×?106 of B. bassiana were 3.75 and 3.49?days, respectively. The LT90 of same concentration for insect application was 4.48?days, while LT90 for leaves application was 4.63?days. Similarly, LT50 of insect and leaves application for 1?×?108 of B. bassiana were 3.03 and 3.31?days, while LT90 were 3.68 and 4.29?days, respectively. Approximate 100% mycosis was observed in all treatments.  相似文献   

16.
This laboratory study examined the lanthanum modified clay Phoslock® for its effectiveness to bind soluble reactive phosphorus (SRP), release of nutrients from this modified clay, its influence on water quality variables (pH, oxygen saturation %, conductivity and turbidity), effects on phytoplankton growth (green alga Scenedesmus obliquus, cyanobacteria Microcystis aeruginosa and Anabaena sp.), and, lastly, its effect on the population growth of the rotifer Brachionus calyciflorus. A clear dose–response for SRP binding by the modified clay was observed. A small amount of ammonium is released from Phoslock®. We found no effect of Phoslock® on pH or oxygen saturation. Conductivity increased with the increasing concentration of Phoslock®. An application of Phoslock® caused a transient increase of turbidity up to 211 NTU. However, due to rapid settlement, turbidity fell below 13 NTU (~1 m Secchi depth), after 6 h. Phoslock® addition caused a reduction in growth of all phytoplankton species tested that we attribute to the combined effects of light limitation, flocculation with the bentonite and binding of SRP to Phoslock®. We estimated the EC50 of Phoslock® on the population growth of rotifer B. calyciflorus to be 0.15 g Phoslock® l?1. Overall, the results of our study indicate Phoslock® seems to be suitable for field applications.  相似文献   

17.
Among 28 isolates of Beauveria bassiana tested for virulence against F. occidentalis in laboratory bioassays, we found strain SZ-26 as the most potent, causing 96% mortality in adults at 1×107 mL−1conidia after 4 days. The effect of the strain SZ-26 on survival, longevity and fecundity of the predatory mite Neoseiulus (Amblyseius) barkeri Hughes were studied under laboratory conditions. The bioassay results showed that the corrected mortalities were less than 4 and 8% at 10 days following inoculation of the adult and the larvae of the predator, respectively, with 1×107 conidia mL−1 of SZ-26. Furthermore, no fungal hyphae were found in dead predators. The oviposition and postoviposition durations, longevity, and fecundity displayed no significant differences after inoculation with SZ-26 using first-instar larvae of F. occidentalis as prey in comparison with untreated predator. In contrast, the preoviposition durations were significantly longer. Observations with a scanning electron microscope, revealed that many conidia were attached to the cuticles of F. occidentalis at 2 h after treatment with germ tubes oriented toward cuticle at 24 h, penetration of the insect cuticle at 36 h, and finally, fungal colonization of the whole insect body at 60 h. In contrast, we never observed penetration of the predator''s cuticle and conidia were shed gradually from the body, further demonstrating that B. bassiana strain SZ-26 show high toxicity against F. occidentalis but no pathogenicity to predatory mite.  相似文献   

18.
β-1,3-glucanase and chitinase activities were induced locally and systemically 4–25 and 11–25 days, respectively, after spraying the surface of the third pair of coffee leaves from the apex of 8-month-old plants with a 50 mg/ml aqueous suspension of Bacillus thuringiensis in a commercial formulation (Thuricide HP-Sandoz). The treatment also induced local and systemic resistance against Hemileia vastatrix after the application of the inducer. Within 14–18 days of application of the Thuricide inducer, the β-1,3-glucanase activity in the locally and systemically-protected unchallenged leaves reached maximum levels of 226% and 279% higher levels respectively, than in control plants. The chitinase activity reached maximum levels of 224% and 181% respectively, within 18–21 days after treatment with the inducer. Two β-1,3-glucanase bands were detected by native PAGE electrophoresis in extracts from locally-and systemicallyprotected unchallenged coffee leaves.  相似文献   

19.
A field experiment was conducted to observe the effect of TS amendments on soil enzymes and phytoremediation potential of two economically important cultivars of geranium. Different doses of TS were applied in soil to examine threshold limit of HMs where geranium cultivars can be grown successfully in contaminated sites. Treatment variation significantly affected pH, EC, OC, N, P, K and HM content in soil after 50 days of incubation. After harvest, both cultivars were examined to assess the impact of various treatments on their fresh herb, dry matter, essential oil yield and HM accumulation. C/G ratio close to 1 was observed at 50 tha?1 sludge treatment in both cultivars. Urease and β-glucosidase activities in soil were maximum at 50 tha?1 whereas dehydrogenase and phosphatase activities were maximum at 100 tha?1 in both cultivars. β-glucosidase, acid and alkaline phosphatase, urease and dehydrogenase activities were relatively high after 85 days over 45 days in both cultivars. Maximum metal uptake was found in roots of cv. Bourbon followed by leaves. Geranium was observed to be a good candidate for phytoremediation as it mitigates metal toxicity by root absorption and cv. Bourbon is better candidate for the same.  相似文献   

20.
《Small Ruminant Research》2010,92(2-3):219-224
Four experiments were conducted to evaluate the effectiveness of a new controlled drug releasing device containing 0.3 g progesterone (DICO®) on ovarian control in sheep. In experiment 1, serum progesterone concentrations induced by a 14 days treatment of DICO® (n = 9) and CIDR-G® (n = 9) were compared in ovariectomized ewes. Both devices induced similar responses and no differences were recorded. In experiment 2, the onset of oestrus and the time of ovulation obtained after 14 days treatment with DICO® (n = 8) and CIDR-G® (n = 7) were compared in cyclic ewes. Both devices induced oestrus and ovulation in all of the ewes. The onset of oestrus (34.5 ± 2.8 and 30.0 ± 7.7 h), the time of ovulation (60.0 ± 9.1 and 54.9 ± 6.4 h), the ovulation rate (1.3 ± 0.5 and 1.4 ± 0.5), the follicular diameter at ovulation (7.0 ± 0.8 and 7.3 ± 1.1 mm), and the lifespan of the ovulatory follicles (8.6 ± 2.2 and 10.0 ± 2.9 days) were similar for the DICO® and CIDR-G® devices, respectively. In Experiment 3, the re-utilization of DICO® devices inserted for 6 days (i.e. short-term protocol) was evaluated in ovariectomized ewes. The females received a re-used (previously used for 6 days; n = 11) or a new DICO® (n = 11) for a period of 6 days. The re-used DICO® devices induced a lower serum progesterone concentration than the new devices (P < 0.05). However, the re-used DICO® device maintained serum progesterone concentrations above 7.1 nmol/L (i.e. >2 ng/ml) throughout treatment. In Experiment 4, the administration of eCG treatment at DICO® withdrawal was evaluated in cyclic ewes. The short-term protocol using DICO® devices for 6 days was applied with (n = 8) or without (n = 7) 300 IU eCG at the time of device withdrawal. The administration of eCG advanced ovarian follicular development, synchronizing the onset of oestrus at 36 h and the time of ovulation at 60 h from device withdrawal. In conclusion, data from these experiments show the use of DICO® or CIDR-G® devices containing 0.3 g of progesterone to have a similar efficiency in controlling serum progesterone concentrations, follicular development and the time of ovulation in sheep. The re-use of the devices, associated with the short-term protocol for 6 days is possible, although further studies on induced fertility rates are warranted.  相似文献   

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