Effects of vitamin E and fish oil inclusion in broiler diets on meat fatty acid composition and on the flavour of a composite sample of breast meat

BACKGROUND: Enriching poultry meat with long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) can increase low population intakes of LC n-3 PUFA, but fishy taints can spoil reheated meat. This experiment determined the effect of different amounts of LC n-3 PUFA and vitamin E in the broiler diet on the fatty acid composition and sensory characteristics of the breast meat. Ross 308 broilers (120) were randomly allocated to one of five treatments from 21 to 42 days of age. Diets contained (g kg−1) 0, 9 or 18 LC n-3 PUFA (0LC, 9LC, 18LC), and 100, 150 or 200 mg LD--tocopherol acetate kg−1 (E). The five diets were 0LC100E, 9LC100E, 18LC100E, 18LC150E, 18LC200E, with four pens per diet, except 18LC100E (eight pens). Breast meat was analysed for fatty acids (uncooked) and sensory analysis by R-index (reheated). RESULTS: LC n-3 PUFA content (mg kg−1 meat) was 514 (0LC100E) and 2236 (9LC and 18LC). Compared with 0LC100E, meat from 18LC100E and 18LC150E tasted significantly different, while 23% of panellists detected fishy taints in 9LC100E and 18LC200E. CONCLUSION: Chicken meat can be enriched with nutritionally meaningful amounts of LC n-3 PUFA, but > 100 mg dl--tocopherol acetate kg−1 broiler diet is needed to protect reheated meat from oxidative deterioration. Copyright © 2010 Society of Chemical Industry

Milk and meat in our diet: good or bad for health?

Foods derived from animals are an important source of nutrients in the diet but there is considerable uncertainty about whether or not these foods contribute to increased risk of various chronic diseases. For milk in particular there appears to be an enormous mismatch between both the advice given on milk/dairy foods items by various authorities and public perceptions of harm from the consumption of milk and dairy products, and the evidence from long-term prospective cohort studies. Such studies provide convincing evidence that increased consumption of milk can lead to reductions in the risk of vascular disease and possibly some cancers and of an overall survival advantage from the consumption of milk, although the relative effect of milk products is unclear. Accordingly, simply reducing milk consumption in order to reduce saturated fatty acid (SFA) intake is not likely to produce benefits overall though the production of dairy products with reduced SFA contents is likely to be helpful. For red meat there is no evidence of increased risk of vascular diseases though processed meat appears to increase the risk substantially. There is still conflicting and inconsistent evidence on the relationship between consumption of red meat and the development of colorectal cancer, but this topic should not be ignored. Likewise, the role of poultry meat and its products as sources of dietary fat and fatty acids is not fully clear. There is concern about the likely increase in the prevalence of dementia but there are few data on the possible benefits or risks from milk and meat consumption. The future role of animal nutrition in creating foods closer to the optimum composition for long-term human health will be increasingly important. Overall, the case for increased milk consumption seems convincing, although the case for high-fat dairy products and red meat is not. Processed meat products do seem to have negative effects on long-term health and although more research is required, these effects do need to be put into the context of other risk factors to long-term health such as obesity, smoking and alcohol consumption.

Long-chain n-3 PUFA: intakes in the UK and the potential of a chicken meat prototype to increase them

With the wide acceptance of the long-chain (LC) n-3 PUFA EPA and DHA as important nutrients playing a role in the amelioration of certain diseases, efforts to understand factors affecting intakes of these fatty acids along with potential strategies to increase them are vital. Widespread aversion to oil-rich fish, the richest natural source of EPA and DHA, highlights both the highly suboptimal current intakes in males and females across all age-groups and the critical need for an alternative supply of EPA and DHA. Poultry meat is a popular and versatile food eaten in large quantities relative to other meats and is open to increased LC n-3 PUFA content through manipulation of the chicken's diet to modify fatty acid deposition and therefore lipid composition of the edible tissues. It is therefore seen as a favourable prototype food for increasing human dietary supply of LC n-3 PUFA. Enrichment of chicken breast and leg tissue is well established using fish oil or fishmeal, but concerns about sustainability have led to recent consideration of algal biomass as an alternative source of LC n-3 PUFA. Further advances have also been made in the quality of the resulting meat, including achieving acceptable flavour and storage properties as well as understanding the impact of cooking on the retention of fatty acids. Based on these considerations it may be concluded that EPA- and DHA-enriched poultry meat has a very positive potential future in the food chain.

Farm business survey 2008/09: poultry production in England

The report provides a commentary on the UK poultry industry focusing on its structure, development and contribution to the UK agricultural economy. It also includes data on the economic performance of poultry businesses in England during 2008/09.

Farm business survey 2009/10: poultry production in England

A commentary on the UK poultry industry focusing on its structure, trends and development. Analysis includes the economic performance of poultry businesses in England during 2009/10.

Consumer perceptions of poultry meat: a qualitative analysis

Consumer studies of meat have tended to use quantitative methodologies providing a wealth of statistically malleable information, but little in-depth insight into consumer perceptions of meat. The aim of the present study was therefore, to understand factors perceived important in the selection of chicken meat, using qualitative methodology. Focus group discussions were tape recorded, transcribed verbatim and content analysed for major themes. Themes arising implied that “appearance” and “convenience” were the most important determinants of choice of chicken meat and these factors appeared to be associated with perceptions of freshness, healthiness, product versatility and concepts of value. A descriptive model has been developed to illustrate the interrelationship between factors affecting chicken meat choice. This study indicates that those involved in the production and retailing of chicken products should concentrate upon product appearance and convenience as market drivers for their products.

Lactobacilli antagonize the growth, motility, and adherence of brachyspira pilosicoli: a potential intervention against avian intestinal spirochetosis

Avian intestinal spirochetosis (AIS) results from the colonization of the ceca and colorectum of poultry by pathogenic Brachyspira species. The number of cases of AIS has increased since the 2006 European Union ban on the use of antibiotic growth promoters, which, together with emerging antimicrobial resistance in Brachyspira, has driven renewed interest in alternative intervention strategies. Probiotics have been reported as protecting livestock against infection with common enteric pathogens, and here we investigate which aspects of the biology of Brachyspira they antagonize in order to identify possible interventions against AIS. The cell-free supernatants (CFS) of two Lactobacillus strains, Lactobacillus reuteri LM1 and Lactobacillus salivarius LM2, suppressed the growth of Brachyspira pilosicoli B2904 in a pH-dependent manner. In in vitro adherence and invasion assays with HT29-16E three-dimensional (3D) cells and in a novel avian cecal in vitro organ culture (IVOC) model, the adherence and invasion of B. pilosicoli in epithelial cells were reduced significantly by the presence of lactobacilli (P < 0.001). In addition, live and heat-inactivated lactobacilli inhibited the motility of B. pilosicoli, and electron microscopic observations indicated that contact between the lactobacilli and Brachyspira was crucial in inhibiting both adherence and motility. These data suggest that motility is essential for B. pilosicoli to adhere to and invade the gut epithelium and that any interference of motility may be a useful tool for the development of control strategies.

Epidemic multidrug-resistant (MDR-AmpC) Salmonella enterica serovar Newport strains contain three phage regions and a MDR resistance plasmid

Multidrug-resistant (MDR-AmpC) Salmonella enterica serovar Newport has caused serious disease in animals and humans in North America, whereas in the UK S. enterica serovar Newport is not associated with severe disease and usually sensitive to antibiotics; MDR S. Newport (not AmpC) strains have only been isolated from poultry. We found that UK poultry strains belonged to MLST type ST166 and were distinct from cattle isolates for being able to utilize D-tagotose and when compared by pulsed-field gel electrophoresis (PFGE), comparative genomic hybridization (CGH) and diversity arrays technology (DArT). Cattle strains belonged to the ST45 complex differing from ST166 at all seven loci. PFGE showed that 19 out of 27 cattle isolates were more than 85% similar to each other and some UK and US strains were indistinguishable. Both CGH and DArT identified genes (including phage-related ones) that were uniquely present in the US isolates and two such genes identified by DArT showed sequence similarities with the pertussis-like (artAB) toxin. This work demonstrates that MDR-AmpC S. Newport from the USA are genetically closely related to pan-susceptible strains from the UK, but contained three extra phage regions and a MDR plasmid.

The Natural History of Slapton Ley Nature Reserve XVIII: nitrogen and phosphorus losses from the catchment - an export coefficient modelling approach

Nitrogen and phosphorus losses from the catchment of Slapton Ley, a small coastal lake in SW England, were calculated using an adaptation of a model developed by Jorgensen (1980). A detailed survey of the catchment revealed that its land use is dominated by both permanent and temporary grassland (respectively 38 and 32% of its total area), and that the remainder is made up of the cultivation of cereals and field vegetables, and market gardening. Livestock numbers in the catchment constitute ca. 6600 head of cattle, 10,000 sheep, 590 pigs, 1700 poultry and 58 horses. The permanent human population of the area is ca. 2000, served by two small gravity-fed sewage treatment works (STWs). Inputs to, and losses from, farmland in the catchment were computed using Jorgensen’s model, and coefficients derived from the data of Cooke (1976), Gostick (1982), Rast and Lee (1983) and Vollenweider (1968). Allowing for outputs from STWs, the total annual external load of N and P upon Slapton Ley is 160 t (35 kg ha-1) a-1 N, and 4.8 t (1.05 kg ha-1) a-1 P. Accordingly to Vollenweider (1968, 1975), such loadings exceed OECD permissible level by a factor of ca. 50 in the case of N, and ca. 5 in that of P. In order to reduce nutrient loads, attention would need to be paid to both STW and agricultural sources.

Restriction fragment length polymorphism of polymerase chain reaction products applied to the differentiation of poultry campylobacters for epidemiological investigations

A technique for subtyping Camplobacter jejuni isolates has been developed by using the restriction fragment length polymorphism (Rnp) of polymerase chain reaction (PCR) products of the fluA and flaB genes. The technique was validated by using strains representing 28 serotypes of C jejuni and it may also be applied to C coli. From these strains 12 distinct RFLP profiles were observed but there was no direct relationship between the RFLP profile and the serotype. One hundred and thirty-five campylobacter isolates from 15 geographically distinct broiler flocks were investigated. All the isolates could be subtyped by using the RFLP method. Isolates from most of the flocks had a single RFLP profile despite data indicating that several serotypes were involved. Although it is possible that further restriction analysis may have demonstrated profile variations in these strains, it is more likely that antigenic variation can occur within genotypically related campylobacters. As a result, serotyping may give conflicting information for veterinary epidemiological purposes. This RFLP typing scheme appears to provide a suitable tool for the investigation of the sources and routes of transmission of campylobacters in chickens.

Bacillus subtilis spores competitively exclude Escherichia coli O78:K80 in poultry

Newly hatched specific pathogen-free chicks were dosed with a suspension of Bacillus subtilis spores prior to challenge with Escherichia coli O78:K80, a known virulent strain associated with avian colibacillosis. 24 h later. A single oral inoculum of 2.5 x 10(8) spores was sufficient to suppress all aspects of E. coli O78:K80 infection. Colonisation of deep organs was reduced by a factor of over 2 log(10) whilst colonisation of the intestine, as measured by direct caecal count, was reduced over 3 log(10). Shedding of E. coli O78:K80 was measured by semi-quantitative cloacal swabbing and was reduced significantly for the: duration of the experiment, 35 days. B, subtilis persisted in the intestine although with decreasing numbers over the same period. Challenge with the same dose 5 days after pre-dosing with spores overcame any suppressive effect of the spores. Crown Copyright (C) 2001 Published by Elsevier Science B.V. All rights reserved.

Diversity of strains of Salmonella enterica serotype Enteritidis from English poultry farms assessed by multiple genetic fingerprinting

Reliable and sufficiently discriminative methods are needed for differentiating individual strains of Salmonella enterica serotype Enteritidis beyond the phenotypic level; however, a consensus has not been reached as to which molecular method is best suited for this purpose. In addition, data are lacking on the molecular fingerprinting of serotype Enteritidis from poultry environments in the United Kingdom. This study evaluated the combined use of classical methods (phage typing) with three well-established molecular methods (ribotyping, macrorestriction analysis of genomic DNA, and plasmid profiling) in the assessment of diversity within 104 isolates of serotype Enteritidis from eight unaffiliated poultry farms in England. The most sensitive technique for identifying polymorphism was PstI-SphII ribotyping, distinguishing a total of 22 patterns, 10 of which were found among phage type 4 isolates. Pulsed-field gel electrophoresis of XhaI-digested genomic DNA segregated the isolates into only six types with minor differences between them. In addition, 14 plasmid profiles were found among this population. When all of the typing methods were combined, 54 types of strains were differentiated, and most of the poultry farms presented a variety of strains, which suggests that serotype Enteritidis organisms representing different genomic groups are circulating in England. In conclusion, geographical and animal origins of Salmonella serotype Enteritidis isolates may have a considerable influence on selecting the best typing strategy for individual programs, and a single method cannot be relied on for discriminating between strains.

Association between cyclohexane resistance in Salmonella of different serovars and increased, resistance to multiple antibiotics, disinfectants and dyes

A panel of 388 salmonellas of animal and human origin, comprising 35 serotypes, was tested for resistance to cyclohexane and to a range of antibiotics, disinfectants and dyes. Cyclohexane resistance was detected in 41 isolates (10.6%): these comprised members of the serovars Binza (1 of 15), Dublin (1 of 24), Enteritidis (1 of 61), Fischerkietz (4 of 5), Livingstone (9 of 11), Montevideo (1 of 32), Newport (4 of 23), Saint-paul (1 of 3), Senftenberg (10 of 24) and Typhimurium (9 of 93). Most (39 of 41) of the cyclohexane-resistant isolates were from poultry. Statistical analysis showed that the cyclohexane-resistant strains were significantly more resistant than the cyclohexane-susceptible strains to ampicillin, chloramphenicol, ciprofloxacin, erythromycin, nalidixic acid, tetracycline, trimethoprim, cetrimide and triclosan. The multiresistance patterns seen,were typical of those caused by efflux pumps, such as AcrAB. The emergence of such resistance may play an important role in the overall antibiotic resistance picture of Salmonella, with particular effect on ciprofloxacin.

Interaction with avian cells and colonisation of specific pathogen free chicks by Shiga-toxin negative Escherichia coli O157:H7 (NCTC 12900)

The prevalence of Escherichia coli O157:H7 infection in birds is low but several deliberate inoculation studies show that poultry are readily and persistently infected by this organism indicating a possible threat to public health. The mechanisms of colonisation of poultry are not understood and the aim is to establish models to study the interaction of E. coli O157:H7, at the cellular and whole animal levels. A non-toxigenic E. coli O157:H7 (NCTC 12900) was used in adherence assays with an avian epithelial cell line (Div-1) and used to inoculate 1-day-old SPF chicks. In vitro, NCTC 12900 induced micro-colonies associated with cytoskeletal arrangements and pedestal formation with intimate bacterial attachment. In the 1-day-old SPF chick, a dose of 1 x 10(5) cfu resulted in rapid and extensive colonisation of the gastrointestinal tract and transient colonisation of the liver and spleen. The number of E. coli O157:H7 organisms attained approximately 10(8) cfu/ml caecal homogenate 24 h after inoculation and approximately 10(7) cfu/ml caecal homogenate was still present at day 92. Faecal shedding persisted for 169 days, ceasing 9 days after the birds came into lay and 6% of eggs were contaminated on the eggshell. Histological analysis of tissue samples from birds dosed with 1 x 10(7) cfu gave evidence for E coli O157:H7 NCTC 12900 induced micro-colonies on the caecal mucosa, although evidence for attaching effacing lesions was equivocal. These models may be suitable to study those factors of E. coli O157:H7 that mediate persistent colonisation in avian species.