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1.
Broilers deriving from a parent flock, which had been effected in the 6th. month of hatching egg production, show arthritis beginning with the 12th day of life. The tarso-metatarsal joint has been affected. Birds show stunting. Body weights at slaughter and feed conversion of the affected flocks were reduced. The percentage of condemned birds before slaughter was highly increase and came up to 3-5%. Chickens of other breeder flocks, which were reared with the diseased birds, showed viral arthritis at an age of 18-20th day of life. The boilers derived from parent flocks which had been vaccinated twice during the with a 1133 reo live vaccine and before laying with an oil based vaccine of the antigen type WVU. A reovirus has been isolated (isolate K 171/87), which caused viral arthritis in 1133-immune day old chicks after parenteral and oral application. Infection of these chickens with the pathogenic reovirus of the antigen type 1133 didn't cause a disease. Also by serological examinations it was shown, that the reo-isolate K 171/87 possesses a different antigenicity. The kind of occurrence indicates, that this reovirus infection has been transmitted vertically from one parent flock and it spread laterally to chickens of other parent flocks in broiler farms.  相似文献   

2.
The increasing number of clinical cases of inclusion body hepatitis (IBH) associated with fowl adenoviruses (FAdVs) is a growing concern in different parts of the world, including Canada. After an outbreak of IBH in a 10-d-old pullet broiler breeder flock, we serologically monitored the flock from 8 to 46 wk of age, using the agar gel precipitation test (AGPT) offered by diagnostic laboratories and an FAdV group-specific enzyme-linked immunosorbemt assay (ELISA) developed earlier. In addition, we tested 1-d-old progeny for possible vertical transmission of FAdV when the breeder flock approached the peak of egg production by performing virus isolation and polymerase chain reaction (PCR) procedures on target organs. As in previous studies comparing the 2 tests, ELISA was more sensitive than AGPT. With ELISA, a few birds had weakly positive results at 8 wk of age, and all the birds had strongly positive results from 12 wk of age until the end of the study. This group-specific ELISA is therefore a sensitive and practical way to monitor FAdV antibodies in commercial flocks. None of the 1-d-old chicks tested were positive by PCR, nor was FAdV isolated from the same tissues, indicating an absence of transmission of infectious virus to the progeny. The lack of virus production and transmission could be due to the presence of high antibody titers in the layers.  相似文献   

3.
A survey of antibodies against infectious bursal disease virus (IBDV), infectious bronchitis virus (IBV), Newcastle disease virus (NDV), and reovirus (RV) was conducted in broiler-breeder flocks and selected progeny broiler flocks utilizing the enzyme-linked immunosorbent assay. Marked differences in antibody titers between different breeder flocks were related to differences in vaccination programs. Poor performance in some progeny broiler flocks was related to low antibody titers against IBDV in the source breeder flocks. Progeny broiler flocks in which there was a high incidence of condemnations for airsacculitis had elevated antibody titers against IBV. A few progeny broiler flocks that experienced high mortality due to gangrenous dermatitis had no antibody titers against IBDV at processing. Antibody titers against RV were very variable and could not be related to any production problems.  相似文献   

4.
In the period from 1985 to 1987, 24 broiler crops (12 houses; one integration and 3 farms) and 9 pullet flocks (9 houses, 4 farms) were examined for parasites. Intestinal lesion scores and the number of parasites in the intestinal lumen (semiquantitative estimation) were recorded, and the Eimeria species determined when possible (broilers crops: 3rd and 5th week, pullet flocks 4th, 8th, 12th and 18th week). Additionally, the quantity of parasites in litter or faecal samples was examined in regular intervals. Clues for economic damage were only found in broiler crops with increased numbers of coccidial oocysts per gram litter in the 5th week of the fattening period. Eimeria tenella and E. acervulina were the dominating species in broiler chickens and also pullets, E. maxima oocysts however were only casual findings. No ectoparasites, helminths or other protozoa than Eimeria were observed. With regard to the intestinal lesions and the quantities of parasites in the intestine no significant differences were seen when comparing selected broiler chicks and birds taken at random. In pullet flocks the examination of random samples was the superior method, because only freshly dead bodies, collected in insufficient numbers, were suitable for diagnostics. In 3 broiler crops and one flock of replacement pullets kept on a wired floor no Eimeria were diagnosed.  相似文献   

5.
The plaque neutralization test and the agar gel precipitation test were used to detect neutralizing and precipitating antibody to avian reovirus strain WVU2937 in sera from 14 commercial broiler breeder flocks and eight progeny flocks. Ten breeder flocks (71%) possessed positive agar gel precipitation reactors (598 sera tested) and 12 (86%) possessed plaque neutralization reactors (114 serum pools tested). All broiler flocks possessed agar gel precipitation reactors, but these were not examined for neutralizing antibody. As no avian reovirus vaccine had been used in Canada prior to this survey these reactions were presumably due to natural infection. Clinical evidence suggested that such infection was asymptomatic in most cases.The development and persistence of antibody to reovirus strain WVU2937 was followed in chicks exposed to the virus by oral inoculation or by contact. Neutralizing antibody was demonstrated in all birds by postinoculation day 17 and this persisted for at least six months. Precipitating antibody was also demonstrated in most chicks by postinoculation day 17, but by six months only 12% of the chicks were still agar gel precipitation positive.  相似文献   

6.
Due to its low nutrient density, cottonseed meal (CSM) may be a potential alternative feed ingredient for soybean meal (SBM) in broiler breeder pullet diets to improve flock BW uniformity. A major concern when utilizing CSM in poultry diets, however, is the presence of gossypol. It was determined in an initial experiment that when broiler breeder hens are fed a diet containing CSM, gossypol accumulates in the liver. When CSM is removed from the diet, however, hepatic gossypol levels dissipate within a few weeks. In a subsequent study, in order to achieve the breeder guideline ideal weight, broiler breeder pullets reared with a diet containing CSM from 2 to 18 wk of age had to be fed a larger amount than birds consuming a standard SBM diet. The CV of bird weight was significantly lower during the rearing period for birds reared with the corn and CSM diet. This difference in uniformity was maintained as the hens entered the breeding period. Egg weight, hatchability, and fertility were equivalent for hens reared with a diet containing CSM and those reared with a standard diet throughout the growing period. The results suggest that broiler breeder pullets reared on a diet containing CSM as the major protein source have improved flock BW uniformity and normal subsequent reproductive performance.  相似文献   

7.
Coarse-spray (CS) administration of a commercial S1133 reovirus vaccine was evaluated in 1-day-old specific-pathogen-free broilers for prevention of clinical infection induced by intratracheal challenge with two enteric reovirus isolates. In Expt. 1, chickens were challenged at 4 days of age with either the 2408 or CO8 isolate. In Expt. 2, chickens were challenged at 7 days of age with either isolate. In Expt. 3, chickens were challenged at 3, 5, or 7 days of age with the 2408 isolate. In Expt. 1, vaccinated birds showed significant protection against challenge with either isolate at 4 days of age as measured by morbidity, mortality, gross lesions, and body weight. In Expt. 2, vaccinated birds showed greater protection against challenge at 7 days of age. In Expt. 3, resistance in vaccinated birds increased with time between vaccination and challenge. Vaccinated birds challenged at 3 days of age showed no significant protection, whereas vaccinated birds challenged at 5 or 7 days of age had increased resistance. This vaccine did not induce a drop in weight gain, morbidity, mortality, or microscopic lesions in the tendons.  相似文献   

8.
Breeder and broiler flocks were serologically evaluated using a multiple enzyme-linked immunosorbent assay (M-ELISA). The serologic status of two commercial broiler-breeder flocks and their progeny was monitored, and 840 sera were promptly assessed for antibodies against six infectious agents using the M-ELISA. Breeder flocks were sampled at lay, and broiler chicks were hatched from fertile eggs collected on the scheduled lay date of the breeders. The broiler chicks were placed for growout as eight separate flocks (four from each breeder), and the serologic survey of broilers included sequentially sampling each flock five times between 1 day of age and market. Association of broiler vaccination schedules, mortality, and condemnation data with the temporal serologic data obtained indicated that the earlier appearance of active antibody against infectious bursal disease (IBD) in some unvaccinated flocks was associated with subsequent higher growout mortality and with the poorer overall performance that these flocks experienced. The results of this serologic survey also demonstrated that if a constant, well-timed monitoring program had not been used, major serologic differences between flocks would not have been detected. Serologic profiles of selected broiler flocks by virus-neutralization (VN) tests for infectious bronchitis virus (IBV) and reovirus or by hemagglutination-inhibition (HI) tests for Newcastle disease virus (NDV) compared favorably with the serologic profiles obtained by M-ELISA. Comparison of vaccination histories with serologic results derived from M-ELISA, VN or HI tests indicated that response to vaccination for IBV and NDV at 1 day was either blocked or significantly delayed by moderate levels of maternal antibody and/or were suppressed by an apparent field outbreak of IBD that occurred in all eight broiler flocks.  相似文献   

9.
Serum samples from 1120 layers from 56 flocks and 400 pullets from 20 flocks were tested by an indirect sandwich ELISA to investigate the prevalence of antibodies to Histomonas meleagridis in chickens kept in alternative husbandry systems. The overall prevalence of antibodies to H meleagridis in layers was 37.3 per cent, and positive birds were identified in 50 flocks. This was significantly higher than in pullets, where only 8.3 per cent of the birds tested positive. Optical density (OD) values obtained from pullet sera were much lower than the OD values from layers; however, positive birds were detected in half of the pullet flocks. In particular, all birds from an organic pullet flock were found to be positive, with high OD values. Overall, the highest prevalence of positive sera was obtained from birds kept in free-range flocks. Attempts to reisolate live histomonads from birds in 18 layer flocks were unsuccessful.  相似文献   

10.
We examined the utility of baculovirus-expressed infectious bursal disease virus (IBDV) proteins to act as antigens in the enzyme-linked immunosorbent assay (ELISA). The three IBDV protein antigens tested included 1) a truncated VP2, 2) whole VP2, and 3) the polyprotein products VP2, VP3, and VP4. Serum samples from 2-wk-old commercially reared broilers were collected and tested in the three ELISAs. Serum samples were obtained from 34 different commercial broiler flocks. An average of 14 serum samples (range = 11-17) were tested for each flock. The ELISA results were compared with the percentage of protection of these birds following challenge with IBDV. Fifty 2-wk-old chicks from each of the 34 broiler flocks were challenged with STC classic virus or Del-E variant virus. At 7 days postchallenge, the bursa from each of the birds was removed and bursa/body weights were recorded. Percentage of protection was determined by the number of birds in each challenge group that had normal relative bursal weights compared with unchallenged controls. No evidence was found of a relationship between ELISA data generated with the polyprotein antigen (VP2, VP3, VP4) and percentage of protection observed in the STC and Del-E challenged birds. A significant relationship was found between ELISA data and percentage of protection to STC and Del-E when the truncated VP2 or whole VP2 antigens were used in the ELISA. The results of this study indicate that predicting the percentage of protection against classic or variant IBDV strains in broilers from vaccinated breeder flocks can be improved when VP2 is used as the only antigen in the ELISA.  相似文献   

11.
Antibody response was rapid and high in broiler breeder chickens receiving 1 or 2 vaccinations with oil-emulsion vaccine against Newcastle disease at 23 or at 23 and 26 weeks old. The antibody titers remained high during the 41-week experimental period. At 64 weeks old, about 41 weeks after vaccination, the geometric mean hemagglutination-inhibition antibody titer was 67 from the single vaccination, and 103 from the double vaccination. The immune response to live-virus vaccine given at 2, 9, 20, 30, 42, or 54 weeks of age via the drinking water was high, but uniformity was lacking in the antibody response in the breeders and maternal antibody response in the progeny. Maternal antibody levels in one-day-old chicks were related to the titers of antibody in the dams. Maternal antibody titers of chicks originated from breeder flocks that were vaccinated with the oil-emulsion vaccine remained high for all hatches.  相似文献   

12.
Eight 22-week-old broiler breeder replacements were presented from a flock experiencing a mild mortality problem. Approximately 2-3% of the birds were not getting onto the slats to eat or drink. The birds had been reared in dark-out houses under an experimental lighting schedule. Upon examination, several birds appeared blind or partially blind; others exhibited a photophobic response. Two birds lacked a unilateral menace reflex. No other gross abnormalities or lesions were noted. Histopathologic sections of the eyes revealed retinal degeneration and detachment with early degenerative lesions in one lens. The breeder flock came into production normally but peaked below average. Light intensity in the pullet house was measured at 0.3 footcandles (3.2 lux). Although the lighting program under which the pullets were grown is suspect, the etiology of the disorder remains unclear.  相似文献   

13.
In 40 cases salmonellae of the serovar Salmonella (S.) gallinarum were culturally isolated from domesticated gallinaceous birds submitted for diagnostic purposes in the period of 1979-1989. On the basis of the cultural and biochemical features found 35 of them could be assigned to the biovar Pullorum and 5 to the biovar Gallinarum. Of 35 isolates of the biovar Pullorum, 29 were isolated from pure bred chickens of small fancy-exhibition type flocks, 4 from floor-housed adult brown hybrid laying hens and one each from broiler chicks and pheasant chicks (Phasianus colchicus). Acute to subacute courses of the pullorum disease were observed in the 4 flocks of brown hybrid hens. Of 5 isolates of the biovar Gallinarum, 4 were isolated from adult brown hybrid laying hens kept in battery cages and one from floor-housed brown hybrid pullets of the laying type. First cases of fowl typhoid occurred early in the summer of 1988. The disease was characterized by a peracute course in the 4 flocks of brown laying hens and by a more acute course in the pullet flock. The primary source of the fowl typhoid producing organisms was not elucidated.  相似文献   

14.
An outbreak of anemia dermatitis syndrome caused by chicken anemia agent (CAA) occurred in 15 broiler flocks. An average of 29% of chickens in these flocks were derived from a common breeder flock. The breeder flock had no antibody to CAA at 20 weeks of age but had seroconverted by 31 weeks. Diseased broiler flocks were derived from eggs laid by the breeder flock between 25 and 30 weeks of age. CAA infection in the breeder flock was subclinical, with no apparent effects on mortality or performance. A strategic program of therapeutic and/or prophylactic antibiotic therapy was begun in affected broiler flocks as soon as the disease was diagnosed. Nevertheless, when the cost of therapy was taken into account, affected broiler flocks had a net income 17.3% to 19.6% lower than normal flocks. Average bird weights were 3.3% to 3.5% lower in affected flocks than in unaffected flocks, and affected flocks had a significantly greater proportion of lighter birds. Average mortality in affected flocks was 2.0% to 2.3% higher than in normal flocks, with peak mortality occurring in the third week of life. There was no apparent effect on feed-conversion ratio.  相似文献   

15.
An integrated broiler company experienced a major outbreak of pullorum disease during 1990. The outbreak resulted in the distribution of Salmonella pullorum-infected birds to more than 150 roaster flocks in five states. Twenty-two parent (multiplier) breeder flocks became infected. An epizootiological investigation uncovered a grandparent male line breeder flock as the index flock supplying males to the affected parent flocks. Transmission apparently occurred vertically through the egg and horizontally by contact in the hatcheries and by placement of chicks on contaminated litter.  相似文献   

16.
Previous evidence for the presence of chicken anemia virus (CAV) in the gonads of immune specific-pathogen-free chickens raised the question whether this occurs also in commercial breeders. The presence of CAV was investigated by nested PCR in the gonads and spleens of hens from two 55- and 59-week-old, CAV-vaccinated (flocks 2 and 3), and two 48- and 31-week-old non-vaccinated broiler breeder flocks (flocks 1 and 4). In addition, lymphoid tissues of 20-day-old embryos from these hens were also investigated for the presence of CAV. CAV was detected in the gonads and of 5/6 and 11/22 of the vaccinated hens and in some hens also in the spleen alone. Embryos from 7/8 and 5/18 of these hens were positive. In the non-vaccinated flocks, CAV was detected in the gonads of 11/34 and 10/10 hens in flocks 1 and 4, respectively. In addition, 11 birds in flock 1 had positive spleens. CAV DNA was detected in 3/11 and 2/10 of their embryos. CAV-positive gonads and embryos were detected in samples from hens with moderate as well as high VN antibody titers. Vaccinated chickens positive for CAV in the gonads and in their embryos had VN titers ranging from >1:512 to <1:2048. In non-vaccinated chickens, the VN titers of CAV positive chickens ranged from 1:128 to 1:4096. These results demonstrate that CAV genome can remain present in the gonads of hens in commercial broiler breeder flocks even in the presence of high neutralizing antibody titers that have been associated with protection against CAV vertical transmission. It also suggests that transmission to the progeny may occur irrespectively of the level of the humoral immune response in the hens.  相似文献   

17.
Disseminated Aspergillus flavus infection in broiler breeder pullets   总被引：1，自引：0，他引：1  
Increased morbidity and mortality occurred in a 5-wk-old broiler breeder replacement pullet flock. The affected broiler pullet flock was housed on the first floor of a two-story confinement building. Mortality increased to 0.1%/day compared to the flock on the second floor, which had mortality levels of less than 0.01%/day. Clinical signs in the affected chickens included inactivity, decreased response to stimuli, and anorexia. No respiratory or neurologic signs were observed. On necropsy, affected pullets were dehydrated and emaciated and had disseminated variably sized single or multiple heterophilic granulomas that contained intralesional septate and branching fungal hyphae. Lesions were extensive around the base of the heart in the thoracic inlet and in the kidneys. Other affected organs included eyelid, muscle, proventriculus, ventriculus, intestine, liver, spleen, lung, and heart. Aspergillus flavus was cultured from the visceral granulomas. The source of flock exposure to the organism was not determined.  相似文献   

18.
Infectious anemia of poultry is a disease of high economical significance. Connatal infection of chicks with the chicken anemia agent (CAA) via the embryonated egg causes anemia along with severe immunosuppression, thus rendering the chicken susceptible for secondary infections. In order to prevent infection of young chicks, it is necessary to induce immunity against CAA in parent flocks, with the aim to prevent connatal spread of the infection and provide maternal protection for baby chicks. In this publication, the efficacy and use of a live CAA vaccine is reported. From autumn 1986 until summer 1990, 3 experimental vaccine charges were applied in 85 broiler parent flocks with totally 3.1 million chickens. In addition, totally 293,000 broiler breeder and 171,000 layer breeder chicken were vaccinated in 1989/90. The vaccine was administered between the 13th and 19th week of life by drinking water without adverse effect to the birds. Chicken anemia symptoms were observed only at the begin of laying period in two parent flocks. These flocks had been vaccinated in the 17th and 19th week, respectively. The offsprings of all other vaccinated parent flocks remained free of chicken anemia. Day-old chicks derived from vaccinated parent flocks were protected against CAA challenge infection. It is emphasized, that vaccination should be performed within the 13th to 15th week of life, because according to our observations, this will lead to an immediate seroconversion.  相似文献   

19.
D J King 《Avian diseases》1986,30(4):724-727
Newcastle disease virus (NDV) hemagglutination-inhibition (HI) titers were determined for serum samples from eight commercial broiler breeder flocks and their progeny. The chickens sampled had been vaccinated and reared by different producers in different regions of the United States. Breeder flocks had the highest number of NDV-positive HI titers (greater than or equal to 1:10). Eighty percent or more of the samples from six of eight breeder flocks were positive; the geometric mean titers (GMTs) for those six breeder flocks ranged from 19 to 92. Only 3 of 8 broiler flocks had an increased frequency of positive titers and higher GMTs after vaccination. The frequency of positive titers was greater than 80% in only 2 of 8 of the oldest broiler flocks. The number of NDV-negative titers (less than 1:10) increased with age in most broiler flocks, even though all had been vaccinated once or more with live NDV vaccines.  相似文献   

20.
D J King 《Avian diseases》1986,30(4):719-723
Serum samples were collected from broiler breeders and their 1-day-old, 2-week-old, and 5-week-old progeny from different regions of the United States. Individual samples were tested by hemagglutination-inhibition (HI) against six infectious bronchitis virus (IBV) strains: Massachusetts 41 (Mass), H52, Connecticut 46 (Conn), Arkansas 99, SE17, and JMK. The use of multiple strains to test broiler flocks resulted in the detection of seroconversions to Conn and JMK vaccination that were not detected with the IBV Mass HI test. Further, HI titers were detected to IBV strains not used for flock vaccination. In some cases, those titers could be due to cross reactions to antigens common to each of the virus strains. In two breeder flocks, the highest HI titers were to heterologous strains.  相似文献   

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