Microbial cross-contamination during air chilling of poultry

1. Cross-contamination during air chilling of poultry carcases was investigated using a nalidixic acid-resistant strain of Escherichia coli K12 as a marker organism. 2. Experiments were carried out on 2 types of commercial chiller, with and without the use of water sprays (evaporative cooling), and a pilot-scale chiller in which conditions could be varied as required. 3. In the commercial chillers, the marker was dispersed in all directions from a single inoculated carcase and transmission was increased by the use of chlorinated water sprays. 4. Similar results were obtained with the pilot-scale chiller, where the marker was recovered from 45/54 uninoculated carcases; cross-contamination was not prevented by spraying carcases with water containing 50 mg/l of free available chlorine. 5. Despite the ease of microbial transmission from inoculated carcases, cross-contamination during air chilling is likely to be less than that occurring at earlier stages of poultry processing, when carcases are more heavily contaminated.     

Simulation model for Campylobacter cross-contamination during poultry processing at slaughterhouses

Broiler meat is regarded as the most common source of Campylobacter infection and risk management measures are required to reduce broiler meat contamination. Among the quantitative risk assessments for Campylobacter in broiler meat, evaluation of the poultry processing stage is particularly important for predicting the contamination level of broiler meat and the effects of control measures. In this study, we built a simulation model for cross‐contamination during poultry processing focusing on Campylobacter contamination at the individual carcass level. Using this model, we examined changes in the prevalence of contaminated carcasses and the number of Campylobacter per carcass after processing. As a result, it was found that the prevalence and number of Campylobacter after processing were largely influenced by the number of Campylobacter on the contaminated carcasses before processing. In the baseline model, where it was assumed that the mean number of Campylobacter on contaminated carcasses before processing was 4.7 log₁₀ cfu per carcass, the prevalence after processing was less than that before processing. Although the median value of Campylobacter on contaminated carcasses was reduced after processing, the distributions after processing became wider and the upper limit of the 95% credible interval of Campylobacter on contaminated carcasses remained elevated. The individual‐based simulation model can trace individual level changes considering discrete interactions, while models tracing mean values cannot handle these interactions in detail. The individual‐based approach is considered useful for modelling cross‐contamination among individual carcasses during poultry processing.     

Effects of defeathering and insulative jackets on production by laying hens at low temperatures

1. Exposure to a temperature of 5 °C compared with 20 °C resulted in a 20.5% increase in food consumption and an 18.8% decrease in efficiency of food utilisation with intermediate values resulting from exposure to 10 °C and 15°C.

2. Removal of feathers from the neck, back and (or) breast resulted in a 5 to 6% increase in food consumption.

3. The effects of feather removal and temperature on food consumption were additive.

4. Cloth jackets effectively insulated the back and breast areas when feathers had been removed but also resulted in increased food intake and lower efficiency.     

Quantification of water as a potential risk factor for cross-contamination with Salmonella,Campylobacter and Listeria in a poultry abattoir

1. Water used in a modern poultry processing line was tested from October 2005 to June 2006 to determine the level of bacteria in an abattoir in Germany.

2. A total of 420 water samples were taken from 14 processing sites (PSs), at 10 times, and from three different hours of the working shift at three sampling hours (SHs) at 5:00 a.m. (SH 1), 9:00 a.m. (SH 2) and 12:00 a.m. (SH 3). Each sample was assessed for the aerobic plate count (APC) and the prevalence of Salmonella, Campylobacter, Listeria and Yersinia over 30 sampling weeks. The APC numbers of each PS from three SHs were compared, and the prevalence of Salmonella, Campylobacter, Listeria and Yersinia from each PS of three SHs was determined as well as change from the initial PS to the end of the processing line.

3. A total of 46 water samples were positive for Salmonella, 120 positive for Campylobacter and 4 positive for Listeria. None of the water samples was found to be positive for Yersinia. During the course of the day, the APC increased. Salmonella was mostly found during SH 1 (5 a.m.) in water from all PSs. A high number of Campylobacter were observed at SH 2 (9 a.m.) and SH 3 (12 a.m.) from all PSs.

4. The results show that water, which is still used in substantial amounts in present poultry processing technology, can serve as a carrier for Salmonella and Campylobacter.

5. The findings indicate that birds might progressively contaminate the equipment and become contaminated via the same equipment, that water at every processing position of the line constitutes a risk and that more attention should be paid to effective water management in the processing plan.     

接种沙门氏菌苗可使新生雏鸡和强制换羽母鸡得到免疫保护

过去人们常认为,由于刚出壳雏鸡的免疫系统尚未发育成熟,同时肠道内缺乏有益的微生物,因而处于高度的敏感期,此时接种沙门氏菌苗产生的保护作用很有限。然而,最新的研究表明,在这些敏感期接种疫苗,可诱发产生保护作用。     

Animal welfare relevant issues during the killing of poultry during epidemics

In this article firstly the standards of the killing methods of poultry because of animal diseases and the parameter for the choice of a method are described. The following part deals with the effects of the different killing methods. Finally the most important control points during the killing of poultry are discussed.     

Campylobacter spp. in broiler flocks at farm level and the potential for cross-contamination during slaughter

Screening of broiler flocks for their Campylobacter carriage on farm level and consequently the spread of Campylobacter spp. during slaughtering can help to identify hygiene control points. Therefore, between December 2001 and August 2002 in total 51 broiler flocks from three farms of different geographical regions in Germany were analysed for thermophilic Campylobacter. Campylobacter spp. were isolated from 45% of the broiler flocks examined. Subsequently, 1101 samples were taken from 22 flocks during different stages of processing. Samples were collected from: transport crates before and after cleaning/disinfection, evisceration, post-scalded and post-chilled carcasses and endproducts. Additionally, 45 selected Campylobacter isolates of droppings were genotyped by pulsed-field gel electrophoresis (PFGE). Campylobacter carriage of flocks showed seasonal variation, with the highest contamination rate during the period of June to August. No evidence was found for a horizontal transmission from one broiler flock to the next via a persistent house-contamination. In each positive flock, one to three different genotypes were found. One or two clones dominated isolations obtained from the farm level. The fact that in different flocks indistinguishable isolates of clonal origin were detected during the same rearing period suggested a transmission between the broiler flocks or an intermittent common external source. In one case, isolates of clonal origin were detected in various farms during different rearing periods. Sampling during processing confirmed that the entrance of a positive flock resulted in contamination of the abattoir environment. Campylobacter spp. were isolated from all sampling stages along the processing line, with a percentage of 91.1-100 of isolates at different stages of slaughtering.     

高成本时代家禽业的发展方向

据报道称．目前世界各地．特别是西方发达国家的消费者在选择肉类蛋白时．对鸡肉的兴趣正在超过牛肉．在澳大利亚这个以牛羊肉为动物蛋白质主要来源的国家．2007年鸡肉的年人均消费量已经达到了37．4kg;在美国．鸡肉的年人均消费量高达53．3kg．占肉类消费的40％．超过了牛肉和猪肉的消费水平;日本人均鸡肉年消费量达40kg以上,占肉类的47％;     

ZZMZ菌剂在牛粪堆肥过程中对微生物群落的影响

[目的]为了提高牛粪堆肥中分解纤维素的微生物含量.[方法]以人工接种灭活ZZMZ堆肥微生态调节剂堆肥处理(JSM 堆肥)和未接种ZZMZ堆肥微生态制剂处理作为对照,按40 L/40 t(1‰)添加灭活ZZMZ堆肥微生态调节剂.[结果]表明:接种ZZMZ菌剂可以使牛粪便堆肥细菌数量提高4.53%,放线菌数量提高6.37%...     

Animal welfare and workers' protection during electric stunning of poultry for slaughter

Every slaughter process involves problems as to animal welfare as well as safety aspects and the protection of workers. With poultry these are basically concentrated on electrical stunning. Electrical currents and voltages suitable for stunning slaughter animals are principally also hazardous for man in what respect body resistance is of crucial importance. Potential hazards have to be looked upon as present in spite of existing safety regulations. Comparatively high stunning voltages for poultry recently proposed because of animal welfare considerations have met objections not only from the viewpoint of meat hygienic but workers' safety regulations as well. While the former meanwhile could be overcome the latter still has to be investigated, especially as a regulation on the electrical stunning of poultry is currently being prepared. In this respect the question whether adequate stunning efficiency can be obtained by reducing the voltage and prolonging the time of exposure is of special interest. First preliminary results of such investigations are presented. To ensure workers' safety other related aspects should also be taken into account and examined for improvements.     

Digestion of poultry manure by Musca domestica

Larvae of the house fly (Musca domestica) grew and developed normally in fresh poultry manure where the proper environmental conditions were maintained. A temperature of 27 °C and a moisture content ranging from 60 to 75% in fresh poultry manure was determined to be optimum for larval development. A moisture content of 80% or greater created anaerobic problems for larvae.

Optimum production of house fly pupae was obtained by inoculating 0.50 to 0.75 g of fly eggs per kg of fresh poultry manure. Five to eleven days were required for the eggs to be converted to pupae depending on the environmental conditions. After digestion, the poultry manure, was reduced to about half and was granular in texture. The digested residue readily dried, had less odour and contained approximately 15% protein.     

Results of salmonella isolation from poultry products, poultry, poultry environment, and other characteristics

Five hundred sixty-nine Salmonella were isolated out of 4745 samples from poultry products, poultry, and poultry environment in 1999 and 2000 from the Pacific northwest. These Salmonella were identified to their exact source, and some were serogrouped, serotyped, phage typed, and tested for antibiotic sensitivity. Food product samples tested included rinse water of spent hens and broilers and chicken ground meat. Poultry environment samples were hatchery fluff from the hatcheries where eggs of grandparent broiler breeders or parent broiler breeder eggs were hatched and drag swabs from poultry houses. Diagnostic samples were of liver or yolk sac contents collected at necropsy from the young chicks received in the laboratory. Of these samples tested, 569 were Salmonella positive (11.99%). Ninety-two Salmonella were serogrouped with polyvalent somatic antisera A-I and the polymerase chain reaction. Somatic serogroups B and C comprised 95.25% of all the Salmonella. Out of a total of 569 positive samples, 97 isolates of Salmonella were serotyped. A total of 16 serotypes and an unnamed Salmonella belonging to serogroup C1 were identified. The Salmonella serotypes were heidelberg (25.77%); kentucky (21.64%); montevideo (11.34%); hadar and enteritidis (5.15% each); infantis, typhimurium, ohio, and thompson (4.12% each); mbandaka and cerro (3.09% each); senftenberg (2.06%); berta, istanbul, indiana, and saintpaul (1.03% each); and an unnamed monomorphic Salmonella (2.06%). Ninety-two Salmonella were tested for drug sensitivity with nine different antimicrobials. All of the 92 Salmonella were resistant to erythromycin, lincomycin, and penicillin except one sample (S. berta), which was moderately sensitive to penicillin. All of the tested Salmonella were susceptible to sarafloxacin and ceftiofur. The percentages of Salmonella susceptible to sulfamethoxazole-trimethoprim, gentamicin, triple sulfa, and tetracycline were 97.83%, 92.39%, 86.96%, and 82.61%, respectively.     

Persistence of salmonella enteritidis in poultry units and poultry food

1. Studies on the survival of Salmonella enteritidis in poultry units and food were carried out over a two‐year period.

2. The organism persisted for at least one year in an empty trial house at the laboratory in which naturally‐infected broiler breeder birds had previously been housed. A similar survival period was seen in a building which had housed an infected layer breeder flock, although infection was not detected in a subsequent pullet flock.

3. Salmonella enteritidis was also frequently found surviving outside poultry houses in small pockets of litter and fan dust which had been left after cleansing and disinfection of the site. On some poultry units S. enteritidis was also found in wild bird droppings.

4. Salmonella contamination appeared to persist preferentially in association with dust particles swept from the floor and in food troughs and S. enteritidis survived at least 26 months in artificially contaminated poultry food.     

Evidence of cross-contamination by Campylobacter spp. of broiler carcasses using genetic characterization of isolates

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.     

Rapeseed napin and cruciferin are readily digested by poultry

Rapeseed proteins have been considered as being poorly digestible in the gut of non‐ruminants. The aim of the study was to assess the digestibility of napin and cruciferin in ileal digesta of broiler chickens, testing sixteen samples of rapeseed co‐products with protein levels ranging from 293 g/kg to 560 g/kg dry matter. Each sample was included into a semi‐synthetic diet at a rate of 500 g/kg and evaluated with broiler chickens in a randomised design. Dietary and ileal digesta proteins were extracted and identified by gel‐based liquid chromatography–tandem mass spectrometry (LC‐MS/MS). Three isomers of napin (a 2S albumin) and nine cruciferins (an 11S globulin) were identified in the rapeseed co‐products, whereas six endogenous enzymes such as trypsin (I‐P1, II‐P29), chymotrypsin (elastase and precursor), carboxypeptidase B and α‐amylase were found in the ileal digesta. It is concluded that as none of the rapeseed proteins were detected in the ileal digesta, rapeseed proteins can be readily digested by broiler chickens, irrespective of the protein content in the diet.     

The incidence of clostridia in poultry carcasses and poultry processing plants

An investigation of the incidence and types of clostridia was carried out as part of a bacteriological examination of poultry carcasses and plant swabs. From 19 per cent to 35 per cent of chicken carcasses from four processing plants were contaminated with clostridia in the “total” differential reinforced clostridial medium count whereas 27–5 per cent to 83–5 per cent were contaminated with clostridial spores. Swabs of equipment and personnel (hands and aprons) in three of the plants showed that from 15 per cent to 75 per cent of the samples were positive for “ total” clostridia, and from 33 per cent to 85 per cent positive for clostridial spores. Clostridium welchii was recovered from all poultry plants but the incidence varied widely between the four plants sampled. The organisms isolated were Cl. bifermentans, Cl. histolyticum, Cl. butyricum, Cl. sporogenes and Cl. welchii. The majority of Cl. welchii isolates were from spore counts.     

Behavioural responses of poultry during kosher slaughter and their implications for the birds' welfare

Measurements were made during Shechita (kosher) slaughter of 692 meat chickens, including the behaviour of the birds during the procedure and the times from their removal from the crate, to neck cutting, bleed-out and shackling. Four of 100 birds showed a mild physical response to neck cutting but the others showed no response. Approximately 60 per cent of the birds showed a physical response to touching the eye or eyelid at up to 5 seconds after neck cutting, but by 15 seconds none showed this response. The birds became unable to retain their posture and suffered involuntary muscular contractions at 12 to 15 seconds after neck cutting and had lost approximately 40 per cent of their total blood volume by 30 seconds after neck cutting.     

Detection and identification of food-borne pathogens of the genera Campylobacter, Arcobacter and Helicobacter by multiplex PCR in poultry and poultry products

The objective of this study was to develop a multiplex polymerase chain reaction (PCR) to detect and differentiate food-borne pathogens of the three genera Campylobacter, Arcobacter and Helicobacter in a single step procedure. One common reverse primer and three genus-specific forward primers were designed by hybridizing to the 16S rRNA of selected reference strains. Besides the species with significance as food-borne pathogens isolated from poultry meat--Campylobacter jejuni, Campylobacter coli, Arcobacter butzleri and Helicobacter pullorum--several other members of these genera were tested to determine the specificity of the designed multiplex PCR. In total, 20 ATCC and NCTC reference strains of Campyobacter, Arcobacter and Helicobacter were used to evaluate the PCR. Specific amplificates were obtained from all thermophilic species of Campylobacter as well as from species of Arcobacter and Helicobacter. No amplification product was obtained from the non-thermophilic Campylobacter, C. hyointestinalis and C. fetus. Furthermore, a total of 43 field strains of the three genera isolated from poultry, pigs, cattle and humans were investigated using this PCR. To confirm the classification of 10 H. pullorum strains the 16S rRNAs were sequenced. The developed PCR is a helpful diagnostic tool to detect and differentiate Campylobacter, Arcobacter and Helicobacter isolated from poultry and poultry products.