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Ohnishi Y Nishimura K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(7):797-800
Reticulocytes, known as late polychromatic erythrocytes, were induced in blood of chickens infected with Leucocytozoon caulleryi by bleeding when the second-generation merozoites were released into the blood from the second-generation schizonts. The second-generation merozoites preferentially invaded into reticulocytes and developed to stage II gametocytes. Enhanced development of stage II gametocytes to mature gametocytes was observed in the reticulocytes in vivo and in vitro in the bleeding group. Nevertheless, invasion of reticulocytes by the second-generation merozoites was not considered to be absolutely necessary for the development of gametocytes. 相似文献
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Robert L. Lott 《Canadian journal of veterinary research》1962,26(2):36-38
Two nitrofuran feed additives, 0.011% nihydrazone and a combination of 0.0055% nitrofurazone and 0.0008% furazolidone, improved weight gains and feed conversions in chickens with “air sac infection.” Both nitrofurans caused a significant reduction in the total chickens condemned at the dressing plant from this disease, but nihydrazone gave the best results.
Nihydrazone*, a new nitrofuran feed additive for chickens, was found by Wolfgang et al. (1) to be effective against coccidiosis due to Eimeria tenella and E. necatrix. In chickens nihydrazone was shown by Edgar et al. (2) to result in fewer chickens condemned from “air sac infection” than with any other drug used. Rosenberg et al. (3) found nihydrazone caused significant reduction in condemnations due to this disease. Cosgrove (4) showed that nihydrazone prevented an outbreak of cecal coccidiosis, reduced the incidence of “air sac infection,” improved weight gains, feed conversions and livability. Bierer (5) found nihydrazone active against fowl typhoid.
Harwood et al. (6) reported bifuran** effective against E. tenella and E. necatrix coccidiosis and it has been used commercially for this purpose. Bierer (5) (7) found Bifuran*** active in prevention of pullorum disease and fowl typhoid in chicks.
The mode of action of nihydrazone and nitrofurazone against E. tenella coccidiosis was shown by Johnson and Van Ryzin (8).
This production efficiency study was undertaken to evaluate nihydrazone and bifuran in the presence of “air sac infection” and concomitant diseases under field conditions. Camden (9) states that the only satisfactory test of a drug is the performance it gives under field conditions.
Nihydrazone (1) (5) and Bifuran (5) (6) have both antibacterial and antiprotozoal activity and under field conditions, normal densities of bacterial and other parasitic organisms are encountered (9). Thus a coccidiostat having antibacterial and antiprotozoal properties is desirable (7).
相似文献5.
The possibility that bacteremia and toxemia were the causes of death in cases of cecal coccidiosis was investigated. Germ-free and ordinary chickens with microflora were inoculated with sporulated oocysts of Eimeria tenella. At 5 days postinoculation, cecal lesions in ordinary chickens were more severe than those in germ-free ones. Cardiac blood, spleen, and liver were examined in ordinary chickens for bacteremia and endotoxemia, and small numbers of bacteria were recovered from both infected and uninfected birds. Endotoxin levels in plasma of E. tenella-infected birds were low and not different from the levels of uninfected controls. To examine unknown toxic factors, a large volume of serum from infected chickens was injected intravenously into uninfected birds. No significant clinical signs were observed. It is concluded that the intestinal bacteria increase the severity of coccidial lesions without bacteremia and toxemia. 相似文献
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Susceptibility to disease and the subclass-specific antibody response to Eimeria tenella, E. acervulina, and E. maxima were compared in two inbred strains of chickens, FP (B15B21) and SC (B2B2). FP strain was more susceptible to coccidiosis than SC chickens based on oocyst production, lesion score, and clinical signs. FP chickens infected with E. tenella had more severe cecal lesions and a significantly lower hematocrit level than SC chickens. FP chickens infected with E. acervulina excreted five times as many oocysts at 6 days postinfection as SC and showed a 71% reduction in plasma carotenoid level compared with controls (56% reduction in SC chickens). Body-weight change did not correlate with other signs of disease. Both SC and FP chickens produced high levels of serum IgM and IgG and biliary IgA. Although SC chickens had a slightly higher antibody response than FP chickens at 7 days postinoculation, both strains maintained high levels of IgM, IgG, and IgA for a prolonged period post primary inoculation. Although SC and FP chickens show different disease susceptibility to coccidiosis, they demonstrate similar antibody response. 相似文献
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V.E. Berezin A.P. Bogoyavlenskyi S.S. Khudiakova P.G. Alexuk E.S. Omirtaeva I.A. Zaitceva G.B. Tustikbaeva R.C. Barfield R.H. Fetterer 《Veterinary parasitology》2010
Immunostimulating complexes (ISCOMs) are unique multimolecular structures formed by encapsulating antigens, lipids and triterpene saponins and are one of the most successful antigen delivery systems for microbial antigens. In the current study, both the route of administration and the antigen concentration of ISCOMs, containing Eimeria tenella antigens and saponins from native plants, were evaluated in their ability to stimulate humoral immunity and to protect chickens against a challenge infection with E. tenella. Broiler chickens were immunized with ISCOM preparations containing E. tenella antigens and the purified saponins Gg6, Ah6 and Gp7 isolated from Glycyrrhiza glabra, Aesculus hippocastanum and Gipsophila paniculata, respectively. The effects of the route of administration, dose of antigen and type of saponin used for construction of ISCOMs were evaluated for ability to stimulate serum IgG and IgM and to protect chickens against a homologous challenge. A single intranasal immunization was the most effective route for administering ISCOMs although the in ovo route was also quite effective. Dose titration experiments demonstrated efficacy after single immunization with various ISCOM doses but maximum effects were observed when ISCOMs contain 5–10 μg antigen. Immunization of birds by any of the three routes with E. tenella antigens alone or antigens mixed with alum hydroxide adjuvant resulted in lower serum antibody and reduced protection to challenge relative to immunization with ISCOMs. Overall the results of this study confirm that significant immunostimulation and protection to challenge are achieved by immunization of chickens with ISCOMs containing purified saponins and native E. tenella antigens and suggest that ISCOMs may be successfully used to develop a safe and effective vaccine for prevention of avian coccidiosis. 相似文献
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Inclusion of Bacillus amyloliquefaciens strain TOA5001 in the diet of broilers suppresses the symptoms of coccidiosis by modulating intestinal microbiota 
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下载免费PDF全文 Takamitsu Tsukahara Ryo Inoue Keizo Nakayama Takio Inatomi 《Animal Science Journal》2018,89(4):679-687
Coccidiosis is an intestinal parasitic infection and one of the most prevalent and economically damaging diseases of chickens. Furthermore, coccidia‐induced mucogenesis promotes secondary colonization by Clostridium perfringens, a major pathogen of chickens that causes necrotic enteritis. Our previous work found that supernatant of a culture of Bacillus amyloliquefaciens strain TOA5001 (BA) inhibited the growth of C. perfringens on Gifu anaerobic broth medium. Accordingly, we evaluated the effectiveness of dietary BA administration in inhibiting C. perfringens colonization of the intestine in broilers that were experimentally infected with coccidia. Ten healthy broilers from a BA‐supplemented (2 × 105 colony‐forming units/g of feed) broiler group and 10 from a non‐treated group were challenged with Eimeria tenella and E. maxima (5000 oocysts of each species/chick) at 28 days old. At 36 days old, five chicks from each group were slaughtered, whereas the remaining five in each group were killed at 49 days old. Dietary BA administration into Eimeria‐challenged birds reduced coccidial symptoms such as intestinal lesions. It also modified the cecal microbiota through suppressing C. perfringens and E. coli colonization, and inducing domination of Faecalibacterium prausnitzii, the Lactobacillus group and unknown Lachnospiraceae genera by bacterial DNA‐based metagenome analyses. B. amyloliquefaciens TOA5001 supplementation suppressed the symptoms of coccidiosis by modulating cecal microbiota in Eimeria‐challenged broilers. 相似文献
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Drug resistance in coccidia: a robenidine-resistant strain of eimeria tenella. 总被引：3，自引：0，他引：3 下载免费PDF全文
下载免费PDF全文 Tests for resistance to a recently introduced anticoccidial drug, robenidine, were performed on a strain of Eimeria tenella recovered from broiler chickens infected with acute cecal coccidiosis. The strain was identified previously and again confirmed by the timing of mortality of the infected chickens (five to six days postinfection), the appearance of lesions and parasites in ceca only, and the measurements (21.6 +/- 1.9 micron X 19.8 +/- 2.4 micron) of the oocysts. The tests showed that the strain of E. tenella could establish infections in chickens medicated with fourfold the recommended level of robenidine in feed but no oocysts could be recovered from the feces of infected chickens when the level of drug was increased to eightfold. The decrease in mortality, in the severity of lesions and oocyst output and the increase in the average weight gain of infected chickens followed closely the increase in the level of robenidine in feed. In contrast, no infections were found in chickens infected with a sensitive strain of E. tenella and maintained on feed mixed with the recommended level of robenidine. This and other findings discussed here show that resistance to robenidine is developing in coccidia commonly found in broiler houses. 相似文献
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Shola David Ola-Fadunsin Isaiah Oluwafemi Ademola 《Tropical animal health and production》2013,45(6):1423-1428
Avian coccidiosis is one of the most important diseases of poultry and it is responsible for a large number of all broiler mortalities worldwide. The control of this disease relies mainly on the use of anticoccidial drugs. However, herbal preparations could be an alternative for the treatment against coccidiosis in chickens. The direct effects of Moringa oleifera acetone extracts on broiler chickens naturally infected with mixed Eimeria species was investigated to determine the relative efficacy of the extracts against coccidiosis in birds. The investigations were carried out in seven groups (ten chickens per group). The birds were given various doses (1.0, 2.0, 3.0, 4.0 and 5.0 g/kg body weight) of acetone extract of leaves of M. toltrazuril® (positive control) and untreated (negative control). The extract was evaluated for anticoccidial activity by means of inhibition of oocyst output in faeces, faecal score, weight gain and mortality. Haematological indices were evaluated by standard methods. The group treated with 1.0 g/ kg body weight Moringa oleifera extract produced the least inhibitory effect on oocyst shed in the faeces (96.4 %), while the groups treated with 2.0 g/kg, 3.0 g/kg, 4.0 g/kg and 5.0 g/kg body weight of the extract produced 97.4, 98.7, 99.1 and 99.8 %, respectively. Body weight gains of infected chickens treated with the extract significantly improved (p?<?0.05), and faecal scores were milder. Packed cell volume, haemoglobin concentration and red blood count of the treated birds were significantly (p?<?0.05) higher than those of the infected untreated group. Moringa oleifera leaves could find application in the treatment of avian coccidiosis in veterinary practice. 相似文献
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Fredrick Kaingu Dandan Liu Lele Wang Jianping Tao Rebecca Waihenya Helen Kutima 《Tropical animal health and production》2017,49(4):823-828
Anticoccidial effects of Aloe secundiflora crude leaf extract was tested in broiler chickens following oral infection with Eimeria tenella. Sixty 22-day-old birds were divided into six groups of ten birds each. Three treatment groups A, B, and C were fed with the extract (100, 250, and 500 mg/day, respectively) mixed in feed for 10 days, and three control groups: group D (drug control) administered 300 mg/l of sulfachloropyrazine sodium soluble powder in drinking water for 5 days, group E (infected/non-medicated positive control), and group F (uninfected/non-medicated negative control). Except for group F, all groups were orally inoculated with 75,000 sporulated oocysts of E. tenella. The effects of the extract on E. tenella infection were evaluated by severity of bloody diarrhea, body weight (BW) gain, oocyst output, and lesion score. No bird in the treated groups died of coccidiosis, and severity of bloody diarrhea was milder than in the positive control group. BW gains in the treated groups were significantly higher than in group E (p < 0.05). The lesion scores of the treated groups were significantly lower than that of group E. Oocyst output in groups A, B, and C were 11.23, 8.24, and 6.82 × 106, respectively. As compared with the negative control group (12.84 × 106), the reductions in oocyst production were 12.54, 35.83, and 46.88%, respectively. Oocyst output significantly reduced with an increase in Aloe dosage. The findings of this study suggest that Aloe secundiflora extract presents an alternative anticoccidial agent for the control of avian coccidiosis. 相似文献
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A.K. Bera D. Bhattacharya D. Pan B. Manna S. Bandyopadhyay S.K. Das 《Research in veterinary science》2010,89(2):196-199
The objective of this study was to evaluate the immunotherapeutic potential of heat killed Mycobacterium phlei in broiler chicken against experimentally produced Eimeria tenella infection. The selected dose of E. tenella oocyst (5 × 103 sporulated oocysts per bird) was capable of producing a mild form of caecal coccidiosis as observed by significant difference in body weight gain, clinical findings and caecal lesion score. Heat killed M. phlei was fed orally at 10 mg per bird with sterile PBS vehicle at alternate day for four doses. Our study reveals that per day body weight gain was significantly (p < 0.01) higher for healthy control compared to coccidia infected group. The group fed M. phlei along with coccidial challenge showed significantly (p < 0.05) higher body weight gain than infected control group. Heat killed M. phlei feeding also found effective to reduce the caecal lesion score significantly (p < 0.05) in comparison to E. tenella infected untreated group. IgA concentrations in serum and bile at 7-day post challenge of coccidial oocyst was also significantly (p < 0.01) higher in M. phlei fed group when compared to coccidia infected and healthy control group. We concluded that use of heat killed M. phlei has a beneficial role as an immunostimulant against caecal coccidiosis in broiler chicken. 相似文献
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The effect of concurrent cecal coccidiosis infections on severity of Histomonas meleagridis (blackhead disease) in chickens was investigated in a series of experiments. Cecal lesions from H. meleagridis were severe in all inoculated control groups and did not appear to be affected by the introduction of Eimeria tenella infection. However, the severity of liver lesions and number of birds positive for liver lesions of H. meleagridis increased significantly with the presence of E. tenella. The increase was similar when 10(3) or 10(4) oocysts of E. tenella were given and was the same when oocysts were given at the same time as H. meleagridis or 4 days prior. The liver lesions increased directly as doses of H. meleagridis increased from 7.5 x 10(3) cells to 30, 100, or 300 x 10(3) when E. tenella was given along with H. melelagridis but not when H. meleagridis was given alone. Administration of a live coccidiosis vaccine containing very low levels of E. tenella also gave a significant boost to liver lesions but at a much lower level than that observed with larger doses of E. tenella. The positive relationship between infections of cecal coccidiosis and H. meleagridis in chickens suggests that such dual exposure may contribute to increased clinical outbreaks of blackhead disease in chickens under field conditions. 相似文献
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The study was designed to evaluate the anticoccidial activity of the methanolic extract of Musa paradisiaca root in chickens. The chickens were divided into six groups of 12 chickens each. Each chicken in five groups was infected
with 8,000 infective coccidia (Eimeria tenella) oocysts at day 28 of age while one group served as uninfected control. At day 7 post-infection, two chickens remaining in
each group were sacrificed for postmortem examination to confirm coccidiosis. Also at day 7 post-infection, each chicken in
four infected groups was given graded doses (250, 500 and 1,000 mg/kg b.w.) of the extract or amprolium (conventional drug).
Two groups (an infected and uninfected group) did not receive treatment. Parameters used to assess progress of infection and
response to treatment included clinical signs typical of coccidiosis, oocyst count per gramme of faeces (OPG) and packed cell
volume (PCV). Treatment of previously infected chickens with M. paradisiaca root extract resulted in a progressive decrease in severity of observed clinical signs, marked reductions in OPG and a gradual
increase in PCV. In each case, the changes were dose dependent. There was no significant difference in mean OPG and mean PCV
of the extract (at 1,000 mg/kg b.w.) and amprolium-treated groups at termination of the study (at day 50 of age). In the acute
toxicity study, the extract was found to be non-toxic to the chickens even at the highest dose of 4,000 mg/kg b.w. The results
of this study demonstrated that the extract has anticoccidial activity in a dose-dependent manner and at a dosage of 1,000 mg/kg
b.w. had similar efficacy with amprolium in the treatment of chicken coccidiosis. 相似文献
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R. B. Williams 《Veterinary research communications》1992,16(2):147-152
Experiments were carried out to investigate why the anticoccidial ionophore monensin is more potent against the coccidiumEimeria tenella in chickens fed on a maize-based diet (as in the USA) than in chickens fed on a wheat-based diet (as in the UK). The explanation seems to be that the pathogenicity ofE. tenella is lower in maize-fed chickens than in wheat-fed chickens, whether monensin is present in the diet or not. Possible reasons for this are suggested. The better survival of maize-fed birds may be partly due to protective effects of the higher concentrations of vitamins A and E derived from their diet. Furthermore, the higher concentrations of niacin and riboflavin in wheat than in maize may enhance coccidial pathogenicity. These opposing factors might combine to cause equivalent infection levels to produce more severe coccidiosis in chickens fed on a wheat-based diet than on a maize-based diet. 相似文献
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Liviu Dr?gan Adriana Gy?rke Jorge FS Ferreira Ioan A Pop Ioan Dunca Maria Dr?gan Viorica Mircean Iosif Dan Vasile Cozma 《Acta veterinaria Scandinavica》2014,56(1):22