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1.
Market-age broiler chickens from flocks infected with Salmonella typhimurium were killed after being placed in crates and subjected to simulated shipping conditions for five, 19 or 24 hours. The cloacal feces, ceca and exteriors of the birds were cultured for salmonellae to identify shedders, cecal carriers and external carriers respectively, and the results compared with those obtained from pen-mates killed at the time the tested birds were put into the crates. Carriage of S. typhimurium was significantly higher among birds placed in clean crates than among the uncrated controls, mainly due to an increase in cecal carriers (from 23.5% to 61.5%). This increase was not related to the time spent in the crate. Twenty-four chickens were placed in crates contaminated with Salmonella alachua and all 24 became carriers of this organism: 22 (91.5%) of these were cecal carriers and 18 (75%) were shedders. This contamination also spread to 15/24 chickens placed in clean crates and "shipped" in the same truck: six of these became cecal carriers and seven were shedders. These results indicated that chickens in shipping crates which are exposed to salmonellae under transport conditions may readily become infected and begin to shed salmonellae within 24 hours.  相似文献   

2.
Cultural monitoring was used to determine the incidence and sources of salmonellae in a 4160-bird broiler flock raised on litter in 32 pens. Twenty-five of the pens remained apparently free of salmonellae during the 49-day growing period. Salmonella johannesburg, first detected in the meat meal component of the starter ration, was recovered from the litter of seven pens and from the intestines of dead or culled chicks from two pens. Salmonella alachua was also recovered from two of these pens. Culture of swabs collected from the plastic crates used to transport this flock for processing showed that 97/112 (86.6%) were contaminated with salmonellae (15 serovars) before the birds were loaded. The crate washer at the plant did not remove salmonellae from these crates: 97/132 (73.5%) crates sampled after washing yielded salmonellae. Eleven serovar were recovered, including S. johannesburg and S. alachua introduced by the infected flock. Twelve of 31 chickens (38.7%) collected when the birds were unloaded at the processing plant were intestinal carriers of S. johannesburg and/or S. alachua and 29 (93.5%) were external carriers. Salmonella johannesburg, S. alachua and four other serovars were isolated from the feathers of these birds. Eleven of 25 (44%) carcasses tested from this flock yielded salmonellae. Salmonella johannesburg or S. alachua, first isolated from the infected flock, were recovered from five carcasses and S. haardt and S. Typhimurium, first isolated from the transport crates were recovered from six carcasses.  相似文献   

3.
Three flocks raised for broiler or roaster performance tests were studied to determine the incidence and sources of salmonellae during the growing period, transport and processing and to relate these to contamination of processed carcasses. Day old chicks in two of the tests, (tests IV and V), were treated with a culture of intestinal anaerobes derived from mature chickens. The incidence of salmonellae during the growing period was too low to permit any conclusions about the efficacy of this culture in preventing Salmonella infection, but it had no adverse effect on flock performance. Carcasses from all three flocks were contaminated with salmonellae. Although the test IV flock was raised free of salmonellae, 46% of the carcasses tested from this flock were contaminated. The apparent source was the transport crates, 99% of which yielded salmonellae before the flock was loaded. In test V, 92% of the carcasses tested yielded salmonellae. The apparent sources were: flock infection (apparently originating from the parent flock), contaminated crates, spread during transport, and plant contamination. The flock of test VI was infected with Salmonella albany, and 54% of the carcasses tested were contaminated with this serovar. Carcasses of chicks infected early in life were more likely to be contaminated than those of chickens which contacted salmonellae later in the growing period.  相似文献   

4.
Cultural monitoring was used to study the incidence and sources of salmonellae in a 4160 bird broiler flock during the growing period, transport and processing in a commercial plant. No salmonellae were isolated from any of 132 litter samples of 189 chickens cultured during the seven-week growing period, even though nest litter samples from four of the eight parent flocks yielded salmonellae and Salmonella worthington was isolated from the meat meal component of the grower ration. On arrival at the plant, 2/23 birds sampled carried S. infantis on their feathers, although intestinal cultures failed to yield salmonellae. Three of 18 processed carcasses samples yielded salmonellae (S. infantis, S. heidelberg, S. typhimurium var copenhagen). The most likely source of these salmonellae was the plastic transport crates, since 15/107 sampled before the birds were loaded yielded salmonellae (S. infantis, S. typhimurium). The crate washer at the plant did not reduce the incidence of Salmonella-contaminated crates, since 16/116 sampled after washing yielded salmonellae (S. infantis, S. typhimurium, S. heidelberg, S. schwarzengrund, S. albany).  相似文献   

5.
Carcass contamination during processing is an expensive problem for poultry processors. Feed withdrawal (FW) is commonly used to reduce the amount of gut contents prior to slaughter, thereby reducing the probability of contamination. The present study used market aged mixedsex broilers to evaluate the effect of FW time on the incidence of fecal spillage and contamination of broiler carcasses at processing. In order to develop a more simple research protocol for FW, the effects of live haul and holding in stationary crates were compared. Broilers were subjected to 1 of 4 FW times (4, 8, 12, and 16 h) prior to slaughter at a commercial processing plant, in which the incidence of carcass contamination was recorded. Carcass yield and clearance of contents from 8 gut sections were determined. Moisture content of the pooled gut contents was assessed.Shrink increased from 2.1 to 3.3% of pre-FW BW after 4 and 16 h, respectively. Gut weights decreased significantly with every additional 4 h of FW. The incidence of processing plant inefficiencies decreased with increasing FW time. Gut moisture was not correlated with FW time, although moisture of the gut contents was reduced in birds subjected to live haul. Twelve hours of FW resulted in an optimal combination of gut clearance and carcass yield.  相似文献   

6.
Effects of different crating periods on selected biochemical indices were monitored in a group of unsexed ROSS 308 broiler chickens aged 42 days. 120 randomly selected chickens were weighted and placed in 15 heavy duty plastic crates with reduction in floor space approx. 160 cm2/kg of body weight of broilers (average body weight was 2.75 kg). Five crates were kept for 4 hours (Group 4h), another five crates for 8 hours (Group 8 h) and another five crates for 12 hours (Group 12h). After tested periods of crating the broilers were released and blood samples were withdrawn from Vena bosilico in 24 randomly selected birds from each group (Groups 4 h, 8 h, 12 h respectively) and also in other 24 randomly selected non-crated control birds. The results of our experiment proved that duration of crating significantly influenced the stress response in broiler chickens. The duration of crating period was positively correlated with the plasma corticosterone level and negatively correlated with the lactate dehydrogenase, cholesterol, triglycerides, glucose and lactate levels in the blood of broiler chickens.  相似文献   

7.
Campylobacter is recognized as one of the leading cause of gastroenteritis worldwide, and is frequently isolated from the small intestines and ceca microflora of chickens. Twenty-one out of 81 Campylobacter-positive poultry flocks were selected to evaluate the genetic diversity of Campylobacter isolates and to study the distribution of genotypes among flocks. Campylobacter isolates recovered from chicken carcasses and ceca were analyzed by pulsed-field gel electrophoresis (PFGE). Little diversity was found among Campylobacter strains isolated from a given carcass, with a maximum of 2 different genotypes being present. However, at flock level, as many as 4 different profiles were observed. Typing of strains showed that most strains isolated from ceca were similar to those isolated from corresponding broiler carcasses. A total of 39 different macrorestriction profiles were observed, with evidence of Campylobacter cross-contamination among broiler flocks in Quebec slaughterhouses. Surprisingly, some flocks shared related genotypes both with and without sharing similar rearing practices. Existence of such cross-contamination must be considered to in developing strategies to control Campylobacter in chickens, and to avoid bacteria contamination of noncolonized flocks. Further typing studies of Campylobacter found in hatcheries, farm environment, and crates or trucks in Quebec might be helpful in elucidating the kinetics of broiler chicken Campylobacter contamination.  相似文献   

8.
Donor chickens given feed medicated with one or two levels of decoquinate or given non-medicated feed were infected with oocysts of Eimeria tenella or E. maxima per os. Twelve hours after inoculation with oocysts liver, mid-intestine or ceca homogenates were fed to previously uninfected recipient chickens. The results showed that continuous medication with decoquinate was effective in preventing the transfer of sporozoites from the intestine to the liver. Oocysts were detected in the feces of all recipients of tissue from non-medicated donors, showing that some sporozoites of E. maxima and E. tenella are normally transferred to liver. Young broiler chickens were immunized by oral inoculation of E. maxima oocysts. The immune status of similar chickens inoculated with sporozoites of the same species directly into the liver or spleen were assessed. During the experimental period half of the chicks were provided with non-medicated food and the remainder were given feed supplemented with decoquinate; decoquinate was effective in arresting the development of the sporozoites. Two weeks after initial infection the birds were challenged with oocysts of E. maxima per os. Injection of sporozoites into the spleen did not protect against challenge. Birds inoculated with sporozoites into the liver were unable to develop a significant level of immunity. When the drug pressure was removed from these birds, parasitism of the intestine occurred and immunity developed.  相似文献   

9.
OBJECTIVE: To determine whether stress associated with transportation or feed withdrawal increased fecal shedding of Salmonella Typhimurium among pigs experimentally infected with the organism. ANIMALS: 86 healthy pigs. PROCEDURE: Pigs were challenge exposed with Salmonella Typhimurium at 4 weeks old and reared conventionally. When pigs reached market weight, they were assigned to groups and subjected to various combinations of transportation and feed withdrawal. Ileocecal contents were collected after slaughter and tested for Salmonella Typhimurium. RESULTS: Salmonella Typhimurium was not detected in feces collected from pigs just prior to slaughter. When feed was withheld for 24 hours prior to slaughter, the proportion of transported pigs with Salmonella Typhimurium in ileocecal contents at the time of slaughter was not significantly different from the proportion of nontransported pigs. However, when feed was not withheld prior to slaughter, the proportion of transported pigs with Salmonella Typhimurium in ileocecal contents at the time of slaughter was significantly higher than the proportion of nontransported pigs. CONCLUSIONS AND CLINICAL RELEVANCE: When carrier pigs remained on feed, transportation stress increased the proportion positive for Salmonella sp. On the basis of results reported here, it is suggested that producers withhold feed from pigs for 24 hours prior to transportation to a slaughter plant.  相似文献   

10.
Oral salmonella antigens for the control of salmonella in chickens   总被引：4，自引：0，他引：4  
Multivalent antigen preparations of sonicated lyophilized cells derived from up to 6 different salmonella serotypes were added in decreasing levels to broiler feed throughout the broiler's life. Several preliminary experiments challenging chicks via contaminated feed with some of the homologous serotypes showed that salmonellae were cleared more rapidly from treated chicks than from untreated controls and that fewer isolations of salmonellae were made from their ceca.  相似文献   

11.
The intestines from 124 dead, sick and normal broiler chickens from 24 cases of necrotic enteritis were subjected to histological examination. Tissue sections from the duodenum, jejunum, ileum and ceca from each broiler were examined histologically for lesions of necrotic enteritis and the presence of coccidia. Lesions of necrotic enteritis were present in one or more areas of the intestine in all but six of 94 dead or sick birds and they were most common and severe in the jejunum. Coccidia were found in only small numbers in both diseased and normal birds.

Brown and Brenn stained sections showed Gram-positive bacilli intimately associated with early necrotic lesions on the tips of villi. Tissue sections from the intestines of sick birds permitted a proposed pathogenesis for this disease with the lesion starting at the tips of villi.

The similarity in pathogenesis and pathological lesions in this disease of broilers and Clostridium perfringens type C enteritis in baby pigs is discussed.

  相似文献   

12.
Feed withdrawal management has significant effects on contamination of commercial broiler chickens. The effect of a cue (short period of feed withdrawal) on broiler behavior, carcass yield, and carcass quality (carcass scratches, trimming, condemnations, and fecal contamination) was evaluated using 2,400 female broilers. Cues were applied for 3 consecutive days prior to slaughter by lifting the feeders in each pen for 0, 1, 2, or 4 h. Bird behavior was monitored to determine the effect of the cue on feeding patterns. The effect of the cue on carcass yield and quality (carcass scratches, trimming, condemnations, and internal contamination) at the time of processing was determined.Cueing for 1 (CUE1), 2 (CUE2), and 4 (CUE4) h resulted in an increase in activity at the feeders compared with the control treatment (CUE0); higher activity resulted from longer cues. During the cue, live BW loss was greatest in the CUE4 treatment at 24.8 g. Birds in the CUE1 treatment gained 11.3 g during application of the cue. Uniformity of cecal contents was improved in the CUE4 treatment. No differences in carcass yield among cueing treatments were observed. The incidence of new scratches, a possible entry point for cellulitis infections, was lowest in the CUE0 and CUE4 treatments. Contamination scores were highest in the CUE1 treatment and lowest in the CUE0 and CUE4 treatments.The data suggest that feeding cues of up to 4 h may be used without compromising processing yield or carcass quality. Benefits may be limited to improved uniformity of cecal emptying.  相似文献   

13.
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   

14.
An experiment was carried out to study the effects of vaccination with Paracox, a live, attenuated vaccine against avian coccidiosis, on broilers isolated from extraneous Eimeria parasites. The study involved 3200 broiler chickens raised in floor pens similar to commercial conditions, but in an initially Eimeria-free environment. Forty percent of the chickens were vaccinated at 3 days of age and given either a basal unmedicated feed or a feed supplemented with the feed antibiotic virginiamycin. Unvaccinated birds were given either the basal feed or feed supplemented either with virginiamycin or the anticoccidial ionophore narasin. At slaughter at 36 days of age vaccinated birds had a lower live weight than non-vaccinated birds. The difference was 4.6% in unmedicated, and 6.0% in virginiamycin medicated chickens. Feed conversion ratio at slaughter was 2.5% higher for unmedicated vaccinated birds, and 1.3% higher for virginiamycin medicated vaccinated birds, compared to respective non-vaccinated groups. There was no significant difference in overall performance of unvaccinated birds given narasin as compared to virginiamycin. At 10 days post vaccination vaccinated birds had a higher number of Clostridium perfringens in the caeca, but there was no difference thereafter. Throughout the experiment, caecal clostridial counts were considerably higher in vaccinated unmedicated birds than in unvaccinated birds given narasin. The number of oocysts shed in the vaccinated groups was very low, but during a subsequent challenge with E. maxima and E. tenella the birds' immunity was found to be satisfactory.  相似文献   

15.
Campylobacter spp. are present in organs and tissues of broiler chickens but the dissemination route is unclear. The aim of the current study was to determine Campylobacter prevalence within circulating blood of commercial broilers. Broilers were acquired from 19 flocks originating from three commercial poultry processing companies. Using aseptic blood collection techniques, 5 ml of circulating blood was collected from each bird and the sample analyzed for Campylobacter. The Campylobacter colonization status of each bird was determined by aseptically sampling and analyzing the ceca. Campylobacter was recovered from 58% (11/19) of flocks sampled. From the 248 total birds sampled, 12% and 46% of the birds had Campylobacter in the blood and ceca, respectively. This study documents Campylobacter prevalence in the circulating blood of commercially raised broilers. Campylobacter presence in the circulatory system may indicate the path used by the organism for rapid dissemination to organs and tissues. From a processing viewpoint, Campylobacter presence in circulating blood of market-age broilers may increase the likelihood of cross-contamination between birds during slaughter.  相似文献   

16.
The objective of this study was to compare the effects of 3 diet formulations containing different protein sources (animal, plant, and a combination of animal and plant) on the colonization of Campylobacter jejuni in the gastrointestinal tract of broiler chickens. A freshly isolated strain of C. jejuni (biotype IV, serotype HS O:21, O:29, HL untypable) from a broiler chicken was used to infect 3-day-old chicks that had been free of C. jejuni; 0.5 mL of an inoculum containing 108 colony-forming units was administered orally. Shedding of the organism was studied, and C. jejuni in the ceca, jejuni, and crop were enumerated by quantitative culture. The isolates recovered from the birds during the study period of 35 d were characterized and confirmed as C. jejuni by the use of standard methods and underwent biotyping, serotyping, antimicrobial susceptibility testing by disk diffusion and the E-test, and flagellin gene typing. A cyclical pattern of shedding of C. jejuni was observed in all the birds. Colonization was highest in the ceca. The ceca of birds receiving plant-protein-based feed had significantly less colonization then the ceca of birds receiving the other types of feed, whereas the differences in colonization of the jejuni and crops were not significant. Characterization by biotyping, serotyping, and flagellin gene typing showed that 95% of the recovered isolates were identical to the strain used for infecting the chicks. However, with the Lior-HL typing scheme, 74% of the recovered isolates were HL untypable. Antimicrobial resistance testing did not reveal significant differences between the infecting strain and the recovered isolates among the different feed groups.  相似文献   

17.
Meat production with minimum animal suffering is a humanitarian concern. Thus, the objective of this work was to observe the performance of Cobb broiler chickens from 7 to 46 days of age when raised under different installations: dark house system (DHS), conventional yellow system (CYC) and conventional blue system (CBC). The feed conversion ratio for the birds raised on the DHS was 3.8% and 2.7% lower than those for the CYC and CBC systems, respectively. Compared with the CYC and CBC systems, average daily gain under the DHS was 11.4% and 9.3% higher, respectively, and body weight at 46 days was 11.4% and 9.3% higher, respectively (P ≤ 0.05). The birds' welfare was assessed based on their stress by determining the amount of pale, soft and exudative (PSE) meat in the breast fillets. The CYC and CBC birds had 24.3% and 25.3% PSE meat, respectively, whereas the DHS birds had 37.0%. We concluded that the DHS has a greater potential to produce broiler chickens, with superior performance to conventional systems, despite the higher stress faced by the birds during the maneuvers just before slaughter.  相似文献   

18.
Avian reovirus was isolated from intestines of 3-to-7-day-old broiler chickens with enteritis from broiler houses where osteoporosis was a problem. The virus was purified in a cesium chloride gradient (buoyant density 1.37 gm/ml) and identified as a reovirus by electron microscopy. Specific-pathogen-free (SPF) chickens and commercial broiler chickens with anti-reovirus maternal antibodies inoculated at 1 day of age with the reovirus isolate developed lesions of femoral head fractures and/or osteoporosis; reovirus could be reisolated from the bone marrow and intestinal tracts of experimentally infected SPF birds. The reovirus isolate, although isolated from intestines, induced development fo tenosynovitis lesions in SPF and commercial broiler chickens.  相似文献   

19.
1. An experiment was conducted with 98 male and 98 female broiler chickens (Ross 308) to study the effect of growth rate, induced by different dietary means, sex and live weight (1500?g and 2000?g) at slaughter on production parameters, bone strength and sensorial characteristics of the breast meat.

2. The birds were divided into four groups and individually fed a standard commercial diet, a high energy diet or low energy diet from d?11 to slaughter at between d 28 and 39. Three groups were fed ad libitum and a further group was fed a restricted amount of the high energy feed. Half of the birds in each group were slaughtered at approximately 1500?g and the other half at 2000?g live weight.

3. The diets resulted in different growth rates. The chickens fed the high energy and the commercial diet had the highest growth rate at both live weights at slaughter. The restricted fed chickens had lower bone strength than the chickens fed the low energy diet.

4. Breast meat from male broilers was juicer, more tender and less hard than breast meat from females. Chickens slaughtered at 2000?g live weight were juicer than those slaughtered at 1500?g. Chickens given the high energy feed ad libitum and restricted had different growth rates, but the sensory parameter related to texture showed no difference.

5. It was concluded that an increased slaughter weight might improve meat quality due to improved juiciness.  相似文献   

20.
The paper presents two cases of malabsorption syndrome in broiler chickens. The results indicate that the etiological factor appears to be the virus agent which causes necrosis in extra-excretional parts of the pancreas. During the course of the disease disorders in the enzymatic activity of gammaglutamyltransferase, leucylaminopeptidase and alanylaminopeptidase were observed. It consequently leads to the deterioration of intestines digestion and resorption of feed components. Application of Selcewet-Polfa to the diseased birds improved the health of the birds, morphological picture of peripheral blood and mineralisation of thigh bones. No radical improvement in the compensation of the final body weight was recorded.  相似文献   

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