Husbandry factors causing morphologic abnormalities in poultry meat (broilers)]

Zootechnical events affect the state of slaughtered poultry. Data from the literature are compiled. From this point of view monitoring of environmental parameters and morphological findings observed in the slaughterhouse can help in detecting faults in the fattening period. An approach like this would contribute to quality control in broiler meat production.     

鸡舍环境耐药细菌气溶胶及其向环境传播的研究

通过对舍内粪便、空气和舍外环境(10、50、100m)中的空气分离到的细菌鉴定，包括细菌DNA分子生物学检测及药物敏感实验以及细菌含量统计学分析，证明三者之间存在着内在联系；舍内环境微生物气溶胶包括耐药细菌通过舍内外气体交换排往鸡舍周围环境，舍周边环境在一定范围内受到生物污染。研究显示，在粪便、舍内空气、舍外环境10、50、100m空气中分离的金黄色葡萄球菌和链球菌80％以上对氯霉素(CMP)和对苯唑青霉素(OXA)耐药；粪便和舍内外环境空气中的80％以上的大肠杆菌和沙门氏菌对氨苄青霉素(AMP）、氯霉素(CMP)、头孢唑啉(CFZ)均为抑制。证明该鸡舍曾经使用过这些药物治疗或作为添加剂在饲料中添加，鸡群产生了耐药细菌菌株，并向环境传播。测量数据统计结果指出，十里河鸡场鸡舍内环境空气中的大肠杆菌、沙门氏菌、金黄色葡萄球菌和链球菌与舍外环境中相应菌群含量比较差异显著或极显著(P＜0．05或P＜0．01)，但舍外10、50、100m之间的相应菌群比较差异不显著(P＞0．05)，这说明鸡舍内环境细菌气溶胶含量产生多，含量高，菌源强度大；另一方面，反应了鸡舍内环境微生物气溶胶包括耐药细菌能向舍外环境扩散，位舍外环境在一定的范围内受到动物源性生物污染，影响范围大于100m。通过对鸡舍环境微生物气溶胶来源的探讨发现，粪便中的大肠杆菌、沙门氏菌、金黄色葡萄球菌和链球菌与舍内空气相应菌群数量关系比较，呈现正相关(r=0.99)。这从一个侧面揭示了粪便可能是微生物气溶胶的主要来源。     

Profile of selected bacterial counts and Salmonella prevalence on raw poultry in a poultry slaughter establishment.

The USDA Food Safety and Inspection Service determined populations of bacteria on poultry during processing at a slaughter plant in Puerto Rico in November and December 1987. The plant was selected because of its management's willingness to support important changes in equipment and processing procedures. The plant was representative of modern slaughter facilities. Eight-hundred samples were collected over 20 consecutive 8-hour days of operation from 5 sites in the processing plant. Results indicated that slaughter, dressing, and chilling practices significantly decreased the bacterial contamination on poultry carcasses, as determined by counts of aerobic bacteria, Enterobacteriaceae, and Escherichia coli. Salmonella was not enumerated; rather, it was determined to be present or absent by culturing almost the entire rinse. The prevalence of Salmonella in the study decreased during evisceration, then increased during immersion chilling.     

An investigation of a reported case of white striping in broilers

Market reports of white striping in broiler breast fillets have been increasing, which has generated concerns in the broiler meat industry regarding negative effects on consumer acceptance. This study was conducted to macro- and microscopically characterize the condition of white striping at varying degrees of severity on Cobb 500 broiler breast fillets slaughtered at 42 d of age. Carcasses of 2,512 broilers presenting white striping were slaughtered and macroscopically classified according to the degree of severity of the striations as moderate or severe; further histological microscopic evaluation demonstrated degenerative myopathy in both moderate and severe cases, but 75% of those breast fillets were classified as moderate. Typically, the samples classified macroscopically as moderate showed microscopic necrosis only (65.17%) or moderate multifocal necrosis (9.83%), whereas those classified as severe showed diffuse and strong necrosis (25.00%). The proliferation of connective tissue was not observed for either of the degrees of white striping investigated, characterizing this profile as an acute occurrence.     

Pathogenic effects on domestic poultry of a mycoplasma gallisepticum strain isolated from a wild house finch

Mycoplasma gallisepticum (MG) has been isolated from wild house finches. The pathogenic effects of MG finch strain (K4058) and MG R-strain were compared after exposure of chickens and turkeys. Gross and histologic lesions, reisolation of the organism, serology, and clinical disease were evaluated. Milder histologic and gross lesions, in addition to lower serologic titers, occurred in birds inoculated with the finch strain. Mortality, concurrent with clinical and gross respiratory signs and lesions, was observed only in chickens challenged with R-strain. Both the MG finch strain and MG R-strain were recovered from the respective challenge groups at 14 and 28 days postexposure. The results show that MG isolated from wild house finches may infect domestic poultry species but causes only mild disease and is less virulent than MG R-strain. Commercial enzyme-linked immunosorbent assay kits best detected the serologic response of chickens and turkeys to the MG finch strain.     

The control of Fannia canicularis in a poultry house using a black-light technique

The lesser house fly Fannia canicularis and other species of fly of animal health and public health importance, were shown to be attracted to “ black‐light “ traps in semi‐open poultry houses permitting free access and strong daylight competition. The fly populations were reduced and the number of ovipositions in the droppings pit apparently decreased. It is shown that the use of these traps, normally reserved for indoor insect control, can be extended to include certain farm situations.     

Windrowing poultry litter after a broiler house has been sprinkled with water

In-house windrowing of poultry litter between broiler flocks has been promoted as a management practice to improve the litter condition upon chick placement. Before the onset of the current study, low-pressure sprinklers were used during the grow-out period in a broiler house. Different methods of windrowing were then utilized to determine the effect each had on litter composition. Covered, turned, and static 9 d windrow treatments, and one non-windrowed control were applied to a broiler house containing litter used over multiple flock grow-outs. The house was divided into 16 6 × 6 m plots with each treatment being applied to 4 blocks within the house. Litter from each plot was analyzed for particle size, moisture, N, NH₃, P, K, pH, and temperature over a 20-day period, with d 20 representing 7 d after chick placement. All variables except particle size were statistically different. Of all the treatments, the covered treatment showed the greatest reduction in moisture over the 20-day period. Nitrogen content was lowest in the turned treatment. Ammonia decreased from d 9 to 20. Both the covered and static treatments were able to reach recommended temperatures in both the core and the periphery of the windrows. Conclusively, in-house windrowing after utilizing low-pressure sprinklers did not improve N retention, reduce NH₃ volatilization, or decrease P or K in the litter compared to the control. However, the temperatures obtained in the periphery and core of the covered and static treatments show potential for eliminating pathogens present in the litter.     

Potential of a commercially available water acidification product for reducing Campylobacter in broilers prior to slaughter

1. This study investigated the potential of a commercially available acidified water treatment (PWT) for reducing the number of Campylobacter in vitro and other bacteria in the gut of live broilers.

2. In vitro tests indicated that PWT was highly effective for reducing Campylobacter jejuni and Campylobacter coli at the recommended concentration in water, reducing populations by greater than 7 log₁₀ CFU/ml after 24 h exposure. The decrease in the number of Salmonella serovar Enteritidis and Escherichia coli was not significant.

3. Addition of PWT to the broiler drinking water for the first 7 d, 2 d before and 2 d after each feed change and at feed withdrawal prior to slaughter or only after feed withdrawal had no effect on the number of Campylobacter in caecal samples on farm before thinning and depopulation compared to untreated controls.

4. Although PWT was effective for reducing Campylobacter in water, the results suggest that it does not reduce the number of Campylobacter in the caeca of broilers prior to slaughter under the conditions used in the study.     

Isolation of Escherichia coli from cellulitis and other lesions of the same bird in broilers at slaughter.

Cellulitis results in substantial losses to the broiler industry due to condemnations at slaughter. This study was conducted to clarify the association between Escherichia coli isolated from cellulitis and other lesions caused by E. coli in individual birds. Fourteen flocks were sampled and 118 birds with cellulitis were examined. Escherichia coli was isolated from all but 2 of the cellulitis lesions, and serogroups O78, O1, and O2 predominated. Thirty-six birds had at least 1 other lesion in addition to the cellulitis lesion. Isolation of E. coli from cellulitis and other lesions occurred in 7 of the 14 flocks. Escherichia coli of the same serogroup were isolated from cellulitis and other lesions in some birds, suggesting that a single E. coli may sometimes be responsible for both types of lesions.     

Application of peracetic acid and quarternary ammonium disinfectants as a part of sanitary treatment in a poultry house and poultry processing plant

Hygiene and sanitation play a major role in any effective disease control programme for poultry production and processing premises. Various deficiencies in disinfection may induce that chains of infections are not broken from one stock to another. The present study investigated the efficacy of disinfection on a broiler farm and in a plant processing poultry from the investigated farm. Besides inspection of disinfection, the influence of contamination on broiler carcasses and consequences of this contamination on sanitation of the processing lines were studied. Swabs from surfaces coming into contact with the handled raw material were taken and evaluated. The results obtained by a standard microbiological swab method were evaluated and compared with an ATP-bioluminescence method. The investigations included determination of total counts of microorganisms, coliform bacteria and moulds. When employing the standard plate-count method, the total counts of microorganisms (TCM) reached <1, 1-100 and >100 CFU in 0, 12 and 88% swabs on poultry farm and in 22%, 36% and 42% swabs in the processing plant, respectively. The bioluminescence method was used only in the processing plant and contamination corresponding to <100, 100-300 and >300 relative light units (RLU) was detected in 80%, 10% and 10% swabs respectively.     

Comparison of Staphylococcus aureus recovered from personnel in a poultry hatchery and in broiler parent farms with those isolated from skeletal disease in broilers.

Personnel from one broiler hatchery, and workers on 18 separate broiler parent farms which supply the hatchery, were tested for hand and nasal carriage of Staphylococcus aureus. In both locations, nasal carriage of S. aureus was more common than hand carriage. A total of 63 S. aureus strains were characterised by biotyping, protein A analysis and pulsed field gel electrophoresis (PFGE) typing. Of these, 36 were recovered from broiler hatchery personnel, 14 from broiler parent farm personnel and 13 from cases of skeletal disease in commercial broilers. Biotyping and protein A analysis indicated that none of the strains recovered from hatchery personnel were of the poultry biotype, but that two strains recovered from the hands of two broiler parent farm personnel could be grouped together with 12/13 of strains recovered from skeletal disease in broilers, as poultry biotypes. PFGE-typing could not distinguish 9/13 strains recovered from skeletal disease in broilers and one of the strains from the broiler parent farm personnel from isolate 24 (I. 24), which is the predominant S. aureus strain type associated with clinical disease in N. Ireland broiler flocks. The present study found no evidence of nasal carriage of S. aureus strains of poultry biotype by humans. The finding of hand carriage by broiler parent farm personnel, suggests that handling by personnel may contribute to the dissemination of I. 24 or other S. aureus strains associated with skeletal disease in broilers.