Review Article
Bacterial contamination of table eggs and the influence of housing systems
- K. DE REU, W. MESSENS, M. HEYNDRICKX, T.B. RODENBURG, M. UYTTENDAELE, L. HERMAN
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- Published online by Cambridge University Press:
- 07 May 2008, pp. 5-19
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With the introduction of alternative housing systems for laying hens in the EU, recent research has focussed on the bacterial contamination of table eggs, e.g. eggshell and egg content contamination. Contamination of eggshells with aerobic bacteria is generally higher for nest eggs from non-cage systems compared to nest eggs from furnished cages or eggs from conventional cages. Studies indicate limited or no systematic differences in eggshell contamination with aerobic bacteria between eggs laid in the nest boxes of furnished cages and eggs laid in conventional cages. The major differences found in experimental studies between cage- and non-cage systems are less pronounced under commercial conditions. The effect of housing system on eggshell contamination with specific groups of bacteria is variable. Limited information is available on the influence of housing system on egg content contamination. Recent research does not indicate large differences in egg content contamination between eggs from cage- and non-cage systems (ignoring outside nest and floor eggs). The microflora of the eggshell is dominated by Gram-positive bacteria, whereas Gram-negative bacteria are best equipped to overcome the antimicrobial defences of the egg content. Much of the research on eggshell and egg content contamination focuses on Salmonella, since infection with Salmonella enteritidis, resulting from the consumption of contaminated eggs or egg products, is still a major health problem. Observed Salmonella prevalence on the eggshell and in the egg content vary, depending on the fact whether investigations were based on randomly sampled table eggs or on eggs from naturally infected hens. The limited information available on other pathogens shows that they are exclusively isolated from the eggshell and not from the internal contents.
Variability in wheat: factors affecting its nutritional value
- A. GUTIÉRREZ-ALAMO, P. PÉREZ DE AYALA, M.W.A. VERSTEGEN, L.A. DEN HARTOG, M.J. VILLAMIDE
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- Published online by Cambridge University Press:
- 07 May 2008, pp. 20-39
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Wheat is a common raw material used to provide energy in broiler diets. Its apparent metabolisable energy and its influence on broiler performance varies between wheat samples. Reasons for that variability can be classified as intrinsic (variety, chemical composition) and extrinsic factors (growing conditions, storage, etc.), both of which affect nutrient digestibility and availability. However, these factors are not always considered when formulating the diets for broiler chickens. Moreover, research through the years has questioned the relation between wheat AME and animal performance. This review aims to describe factors that influence the observed variability in wheat nutritive value for broiler chickens by considering origin (variety, growing conditions and post-harvest storage), chemical composition of the grain (carbohydrates and protein) and the broiler chicken.
Animal welfare in poultry production systems: impact of EU standards on world trade
- P.L.M. VAN HORNE, T.J. ACHTERBOSCH
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- Published online by Cambridge University Press:
- 07 May 2008, pp. 40-52
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Animal welfare receives more legislative attention in the European Union (EU) than in many other regions of the world. Animal welfare standards for poultry are generally taken to be higher in the EU than in producing countries exporting to the EU, particularly developing countries. The recent action plan for animal welfare introduced by the European Commission aims to further expand the body of regulatory standards. In broiler production worldwide, birds are mainly kept on litter. Recently the EU agreed on a new Directive to set standards for maximum bird density. However, this is not considered likely to have a great impact on global trade. At present, the difference in animal conditions, including bird density, in Brazil and Thailand is limited compared to the EU. In egg production the majority of commercial layers are kept in laying cages. There is wide variation in space allowance per bird from 300 to 400 cm2 in Brazil, Ukraine and India towards the current minimum of 550 cm2 per hen in the EU. After 2012, hens in the EU will be kept in enriched cages with a minimum space allowance of 750 cm2 per hen. It is expected that this will have an impact on world trade in egg products and especially egg powder. Trade in table eggs will continue to be limited to the local region. The EU is considering the use of labelling to provide consumers with more information concerning the standard of production. Another option could be to use financial mechanisms such as taxes or tariffs to prevent imports from other countries with lower standards. The likelihood of a measure being challenged would depend on how difficult it was for exporters outside the EU to meet the requirements.
Poultry meat consumption trends in Europe
- P. MAGDELAINE, M.P. SPIESS, E. VALCESCHINI
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- 07 May 2008, pp. 53-64
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What are the main factors affecting consumption of poultry meat? Can buying behaviour and consumption attitudes be altered by a context that seems to be lastingly affected by the presence of avian influenza? This paper proposes some answers to these questions by taking into account the geographical diversity of consumption and its recent evolution in Europe. Relatively low and competitive pricing of poultry compared to other meat, the absence of cultural or religious obstacles, and dietary and nutritional (protein) qualities are the main factors explaining its attractiveness. Others factors underly consumers' attraction to poultry. Firstly, during the various health crises consumers' attention has been focused on production methods (feed, animals' well-being, etc.) and on reliability of information. Interest in 'approved local' products, whose appeal is based on the credibility-taste combination, has consequently spread in Europe. Secondly, consumption has developed around more elaborate products incorporating two types of service: a saving of preparation time ('ready-to-eat' food) and a diversification of places of consumption (catering outside the home).The main trends within poultry's consumption have not been changed by the avian influenza episode. Tendencies noted during the last decade and described in the article are anticipated to remain the same.
History, changing scenarios and future strategies to induce moulting in laying hens
- M. YOUSAF, A.S. CHAUDHRY
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- 07 May 2008, pp. 65-75
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Moulting is a natural phenomenon in birds during which they replace old plumage with new feathers, reduce feed intake, lose body weight and suspend reproduction. Moulting in laying hens can be induced by using photoperiods, feed deprivation or restriction or diets containing minerals or variable amounts of other ingredients. Induced moulting can result in higher egg production and improved quality. It reduces mortality, production costs and investments in new farms and hatcheries. While feed withdrawal has been a most effective way to induce moult in poultry birds, it is illegal on welfare grounds in the UK and Europe. This may have implications for the global poultry industry. Therefore, efforts to find a non feed removal method as a desirable alternative to induce moulting in poultry birds are underway in different countries. This paper reviews the history of induced moulting and its future implications by examining different methods that have been tested in the past and their potential to become a more acceptable alternative to feed removal method of inducing moulting in laying hens.
The application of zeolite in poultry production
- F. SHARIATMADARI
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- 07 May 2008, pp. 76-84
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Zeolites are crystalline, hydrated aluminosilicates of alkali and alkaline earth cations which have infinite, three dimensional structure. Among many properties attributed to zeolites, two most characteristics that relates to their effectiveness in animal nutrition are their ability to lose and gain water reversibly and being capable of exchanging selectively a variety of cations in their structure without much major changes of structure. However the effect of zeolites on food intake, weight gain, growth rate, egg production, egg weight, shell thickness and internal egg characteristic are in dispute. While some of the experiments report beneficial effect due to inclusion of zeolite in the diet of birds, others show no changes and yet there are results that indicate the negative effects. Reasons such as level of usage, type of zeolite (natural vs. synthetics) and even within natural ones, the levels of impurities, are to be blamed for discrepancies reported from the experiments. On the other hand there has been evidence that zeolites has beneficial effect on feed efficiency ratio, water consumption, nutrient utilization, manure and litter condition and more importantly on aflatoxicosis.
Producing specialist poultry products to meet human nutrition requirements: Selenium enriched eggs
- V.I. FISININ, T.T. PAPAZYAN, P.F. SURAI
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- Published online by Cambridge University Press:
- 07 May 2008, pp. 85-98
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During the last decade it has become obvious that, while our lifestyle, including diet, stress, smoking, medical issues, exercise, and genetics are major determinants of human health status, it is diet that plays a central role. The effect of nutrition on human health has received substantial attention, and even ‘traditional’ medicinal philosophies that state that diet and nutrients play only limited roles in human health is being revised. In most developed countries nutritional practices have changed the focus from combating nutrient deficiencies to addressing nutrient requirements for maintaining good health throughout life. The role of selenium (Se) in human health and diseases has been discussed in detail in several recent reviews, with the main conclusion being that Se deficiency is recognised as a global problem which needs solving urgently. Analysing recent publications that relate human health to useful poultry products, it is evident that Se-enriched eggs can be used as an important delivery system of this trace mineral for humans. In particular, developments and commercialisation of organic forms of selenium has initiated a new era in the availability of selenium-enriched products. It has been shown that egg selenium content can be easily manipulated to give increased levels, especially when organic selenium is included in hen's diet at levels that provide 0.3-0.5 ppm Se in feed. As a result, technology for the production of eggs delivering ~50% (30-35 μg) of the human selenium RDA have been developed and successfully tested. Currently companies all over the world market Se-enriched eggs including the UK, Ireland, Malaysia, Thailand, Australia, Turkey, Russia and Ukraine. Prices for enriched eggs vary from country to country, typically being similar to free-range eggs. The scientific, technological and other advantages and limitations of producing designer/modified eggs as functional foods are discussed in this paper.
Small-Scale Family Poultry Production
Poultry production profile and expected future projection in Bangladesh
- S.C. DAS, S.D. CHOWDHURY, M.A. KHATUN, M. NISHIBORI, N. ISOBE, Y. YOSHIMURA
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- Published online by Cambridge University Press:
- 07 May 2008, pp. 99-118
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The aim of this paper is to review the current status of poultry production and its future prospects in Bangladesh, covering both rural and commercial poultry production. As an important sub-sector of livestock production, the poultry industry in Bangladesh plays a crucial role in economic growth and simultaneously creates numerous employment opportunities. The poultry industry, as a fundamental part of animal production, is committed to supplying the nation with a cheap source of good quality nutritious animal protein in terms of meat and eggs. Two main systems of poultry production are common in Bangladesh nowadays: commercial poultry production – where birds are kept in total confinement, and traditional scavenging or semi-scavenging poultry production. Approximately 20% of the protein consumed in Bangladesh originates from poultry. With the exception the dip in production due to the recent Avian Influenza outbreak, the growth of this industry in terms of standards of commercialization, is very rapid. A gap still exists between the requirement and supply of poultry meat and eggs within the recent frame-work of the informal marketing system that is currently used. Among poultry species, the chicken population is dominant over others, at almost 90%, followed by ducks (8%) and a small number of quail, pigeons and geese. Free range ‘backyard’ and scavenging poultry, that are traditionally reared by rural women and children, still play an important role in generating family income, in addition to improving the family's diet with eggs and meat. Productive and reproductive performance of indigenous birds is relatively very low (35-40 eggs and 1-1.5 kg meat per bird per year), but genetic improvements by selective breeding, along with adequate nutrition and proper management, looks promising and quite possible. Commercial poultry production in Bangladesh, is conducted on an industrial scale and is growing tremendously in spite of recent difficulties but is expected to make a significant contribution to the economic development of the country. A national poultry policy is expected to be approved by the government shortly, which, when implemented, will improve the organization of production and marketing, allowing increased stability and security of output throughout the year. In addition, efforts should be taken to ensure safety standards of poultry meat and eggs for human consumption. Experts from the government, research institutes, universities, NGOs and other relevant sectors need to work in a collaborative manner in order to allow sustainable production and fight challenges jointly when they appear from time to time. Corresponding attention to research and development will allow the poultry sector to flourish in Bangladesh. As government funding is limited, industrialists need to come forward either to establish their respective research facilities or to provide funds to universities and research institutes in order to undertake research works of national and international importance.
Epidemiology, challenges and prospects for control of Newcastle disease in village poultry in Nigeria
- J.A. NWANTA, P.A. ABDU, W.S EZEMA
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- 07 May 2008, pp. 119-127
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Newcastle disease is a viral and often fatal disease that has been reported to affect a wide range of avian hosts, irrespective of age and sex. It is reported to be a major constraint to the development, survival and productivity of village poultry. This paper is a review of the epidemiology of Newcastle disease in village poultry in Nigeria, with emphasis on the susceptibility of species, types and ages. Also examined are the challenges and prospects of Newcastle disease control in this village poultry sector in Nigeria. This was conducted for the purpose of formulating effective strategies for controlling the disease in the rural areas of Nigeria.