The unilateral avian oviduct is divisible into five functional regions which, moving distally, include the infundibulum, magnum, isthmus, tubular shell gland and shell gland pouch. Each region subserves a variety of functions, which through their interaction give rise to the multilayered albumen, shell membranes and the organic/norganic complex, which comprises the shell. The sequential activity of these structurally diverse regions is a necessary prerequisite for ′normal′ egg formation. The reproductive effort can be influenced by a number of disease processes either directly by virtue of the fact that they alter the ability of the lining cells to synthesise their integral components or indirect by generally compromising bird health. Notable amongst the former are Infectious Bronchitis, Newcastle Disease and Egg Drop Syndrome. All change the quality of the final product in terms of the shape and texture of the shell. In recent years it has become evident that environmental stress has an equally, if not more, important role to play in oviduct disfunction. In the absence of large areas of functional surface epithelium, the eggs laid were structurally defective at all levels from the mammillary layer outwards. As the epithelial layers regenerated, shell quality approximated normality, but never returned to the pre-stress condition.

The process of candling signals amongst other internal defects a variety of inclusions variously classified as blood and meat spots. They are quite specific in their locations; thus blood spots originating from the rupture of ovarian blood vessels at ovulation, are invariably confined to the periphery of the yolk mass, while meat spots now classified according to their composition are confined to albumen. Within the latter they are recognised as tissue rich deposits, the result of oviduct breakdown and/or calcium rich fragments. The latter implies a breach in the barrier provided by the soft shell membranes.

Although thermophilic campylobacters have sometimes caused disease in poultry, both in challenge studies and under field conditions, the organisms are usually carried asymptomatically in the alimentary tract of infected individuals. There is, however, a significant association between campylobacters in poultry and human enteritis. Properties of Campylobacter jejuni that are associated with intestinal colonisation in the bird are discussed. The organism is morphologically and physiologically well adapted to its ecological niche in the mucus-filled crypts of villi, but establishment and maintenance of colonisation involve a complex interaction between bacterium and host that has yet to be fully elucidated. Bacterial factors include the possession of intact, functional flagella and the type of flagellin expressed. Also, colonisation has been shown to depend on the expression of certain stress-response and virulence genes.

Attempts to prevent or reduce campylobacter colonisation by establishing a competitive or antagonistic microflora in chicks have not always been successful, and possible reasons are considered. Some protection was obtained with bacteria such as mucin-utilising coliforms, but the protective potential of these organisms appears to be limited. In other studies, the natural occurrence of colonisation resistance has been demonstrated in broilers and its development followed. Experience suggests that the phenomenon depends on the presence of strictly anaerobic bacteria that have yet to be isolated and identified.

Laying hens have physiological responses that affect their productive performance when given different ambient temperatures. The objectives of this study were, first, to quantitatively describe the relationship between different constant environmental temperatures and egg production characteristics of laying hens by a statistical analysis and assessment of the published literature. Second, to compare the effect of different cycling environmental temperatures on the egg production characteristics of laying hens. Twenty-nine experiments were selected that had compared different constant temperatures and that included 21°C within their range. Differences in egg production were expressed as a proportion of the treatment group given 21°C within that experiment. An exponential curve with the addition of a linear trend gave the best (P<0.001) description of egg numbers, weight and mass, feed intakes and egg composition variables. There was a linear decrease (P<0.001) in measures of shell strength with increasing temperature. A second statistical analysis compared eight published experiments that had described the egg laying responses of laying hens kept in daily fluctuating temperatures and had been compared to a treatment group kept at 21°C within the same experiment. The results indicated that the egg laying responses of the hens were best predicted by computing the mean of the predicted responses to each of the temperatures that occurred during the day. However, information on the low temperature, the proportion of the day at the low temperature and the amplitude of the temperature cycle were required to give a precise prediction of the egg laying responses.

Phosphorus (P) is receiving considerable attention with regard to poultry litter in the United States. Litter, a combination of bedding material and excreta, contains valuable nutrients and has been historically applied as fertilizer on pasture and row crop lands. Compared to commercial fertilizers, broiler litter has a low nitrogen to phosphorus ratio. Poultry litter application rates have been based on the nitrogen needs of crops resulting in a gradual build-up of Pin the soil. Phosphorus runoff into nearby water bodies can be detrimental to aquatic life. Proper management of litter is critical to maintaining the farmer's environmental stewardship. Many researchers are investigating best management practices to alleviate potential problems related to over application of P. However, gaps exist among the researchers due to their specialty and training.

Communication across groups (nutritionists verses soil scientists) is the key for making progress. For example, the agronomist's plan for utilization of litter should coincide with the nutritionist's specifications for P requirements. This article identifies some of the more commonly used terms that define the forms of P in an effort to unite the different perspectives. The purpose is to convey the complexity of the xisting efforts for P analysis, identifying factors that influence changes in chemical forms such as dietary Plevel, Psource and characteristics, the use of dietary phytase in rearing conditions, subsequent litter handling, and conditions of litter application. The end result should create a “cause and effect” type thinking among the groups working on the broiler industry P issues.

Poultry meat and eggs are important sources of human pathogens. Salmonella is a major cause of human foodborne infections following consumption of poultry products. The original ambition of the EU to eradicate zoonotic agents from the animal production chain has been tempered to reducing the infection pressure of specified zoonotic agents at all levels of the production chain. This can be done by a combination of pre-harvest, harvest and post-harvest measures. Feed additives constitute an important group of pre-harvest measures which can help in controlling Salmonella on the farm. Feed additives used for the control of Salmonella can be of different types, including antibiotics, prebiotics, probiotics and synbiotics. Public concerns regarding possible antibiotic resistance transfer lead to the ban of antibiotics as growth promoters in monogastric diets within the EU. Experimental and practical use of pre-, pro- and synbiotics, as well as volatile fatty acids as feed additives are discussed in this review. The effects of these additives on resistance to infection, on the extent of excretion and on the persistence of infection are reviewed. Attention is paid also to possible undesirable effects of some of these products. Taking into consideration the underestimated high level of contamination of poultry, the feed additives reviewed in this article can certainly play a valuable part in control strategies during the pre-harvest phase aiming at reducing the infection pressure and thus limiting the risk of contamination of poultry products.

Selenium (Se) has a special place among the feed-derived natural antioxidants, being an integral part of selenoproteins participating in the regulation of various physiological processes in the body. As a part of glutathione peroxidase (GSH-Px) Se belongs to the first and second major levels of antioxidant defence in the cell. There are two major sources of Se for poultry organic selenium, mainly in the form of selenomethionine (SeMet), which can be found in any feed ingredient in varying concentrations and inorganic selenium, mainly selenite or selenate, which are widely used for dietary supplementation. There is a principal difference in metabolism and efficiency of these two forms of selenium, with SeMet being more effective. In fact SeMet possesses antioxidant properties, however, in some conditions selenite can be a pro-oxidant. Se deficiency and excess in modern poultry production are very rare. In general, adequate Se supplementation is considered to be a crucial factor in maintaining the high productive and reproductive characteristics of commercial poultry.

A review is presented of results from research and commercial production of two alternative keeping systems – furnished cages and aviary systems. These systems have gradually evolved through criticism of conventional cage keeping of layers, mainly in North Western Europe, due to the lack of possibilities for birds to perform natural behaviours and to restricted space. They provide birds with nests to lay eggs in, perches to rest on, and litter material to manipulate and dust-bathe in. Experience and development of the aviary are longer than that of furnished cages, the latter existing in wide spread commercial production only in Sweden as yet. However, according to a new EU-directive in 1999, conventional cages may not be used as a new investment from 2003 and not at all from 2012. Birds in both systems may produce well but the aviaries are less predictable due to irregular outbreaks of flock cannibalism, especially in non beak-trimmed medium heavy brown birds, despite offering the birds litter and plenty of space. The furnished cages try to combine advantages of small group size in cages and reduce disadvantages of poor air condition, and sometimes inferior hygiene, in floor-kept hens. They are still subjected to extensive improvements in details of design e.g. to enhance egg quality. Hence, results may vary considerably between models. In order to maintain a stable social order it is probably vital to retain a moderate group size in furnished cages.

This paper gives a detailed description of the working method of dissection of the turkey carcase into its parts and additionally, the cutting of the breast and leg (thigh and drumstick) to obtain the proportions of tissues. The particular cuts during the dissection are explained step by step by means of twenty-eight colour photos. The paper is completed with a definition of terms concerning the carcase and with anatomical illustrations. The objective of the description is to establish a recommended standard for the dissection of the turkey carcase in order to allow comparisons of results.

This paper discusses materials used as bedding or litter for the rearing of broilers and turkeys in the U.S.A. The U.S. poultry industry has historically used pine shavings as the litter of choice for many years. Sawdust has replaced pine shavings in many areas, however, not by choice, but because pine shavings have become increasingly difficult to obtain. Regionally, rice hulls, straw, and peanut hulls can be found in use by poultry producers for litter. Re-cycled paper products have received a lot of research and development, but have not had a great deal of acceptance by the poultry industry. Sand is another alternative bedding that is currently being tested in southern climates. Alternative litter materials for poultry will continue to be researched and evaluated, and pine shavings or sawdust will probably continue to be used as the benchmark comparison. However, while bird performance will always be a threshold criterion, cost and availability will ultimately determine the adoption of new or alternative litter materials by poultry growers and the poultry industry.

The relationships between phenotype and genotype were first described by Mendelian genetics in the case of genes with a major phenotypic effect. The remarkable improvement of biochemical and molecular tools has now made it possible to identify the molecular nature of major genes, and to understand better their mode of action. From a functional point of view, mutations of a given gene can be classified into three groups: loss of function, interference and dominant negative action, and gain of function. From a structural point of view, a large diversity of molecular polymorphisms can be found, the consequences of which depend rather on their position than on their nature. Genetic abnormalities or mutations with obvious morphological effects provide the most didactic examples to understand the genotype-phenotype relationships. The example of sex-linked dwarfism in chicken is described in detail and the present state of knowledge on the molecular identification of major genes in the chicken is reviewed. Finally, a general discussion, based upon examples taken from human genetics and mouse genetics, draws lessons from the study of major genes in order to approach the study of complex phenotypes or genotype x environment interactions.

Poultry can be managed under different feeding systems, depending on the husbandry skills and the feed available. These systems include the following: (1) a complete dry feed offered as a mash ad libitum; (2) the same feed offered as pellets or crumbles ad libitum; (3) a complete feed with added whole grain; (4) a complete wet feed given once or twice a day; (5) a complete feed offered on a restricted basis; (6) choice feeding. Of all these, an interesting alternative to offering complete diets is choice feeding which can be applied on both a small or large commercial scale. Under choice feeding or ‘free-choice feeding’ birds are usually offered a choice between three types of feedstuffs: (a) an energy source (e.g. maize, rice bran, sorghum or wheat); (b) a protein source (e.g. soyabean meal, meat meal, fish meal or coconut meal) plus vitamins and minerals and (c), in the case of laying hens, calcium in granular form (i.e. oyster-shell grit). This system differs from the modern commercial practice of offering a complete diet comprising energy and protein sources, ground and mixed together. Under the complete diet system, birds are mainly only able to exercise their appetite for energy. When the environmental temperature varies, the birds either over- or under-consume protein and calcium. The basic principle behind practising choice feeding with laying hens is that individual hens are able to select from the various feed ingredients on offer and compose their own diet, according to their actual needs and production capacity. A choice-feeding system is of particular importance to small poultry producers in developing countries, such as Indonesia, because it can substantially reduce the cost of feed. The system is flexible and can be constructed in such a way that the various needs of a flock of different breeds, including village chickens, under different climates can be met. The system also offers a more effective way to use home- produced grain, such as maize, and by-products, such as rice bran, in developing countries. Because oyster-shell grit is readily available in developing countries at lower cost than limestone, the use of cheaper oyster-shell grit can further benefit small-holders in these countries. These benefits apart, simpler equipment suffices when designing and building a feed mixer on the farm, and transport costs are lower. If whole (unground) grain is used, the intake of which is accompanied by increased efficiency of feed utilisation, the costs of grinding, mixing and many of the handling procedures associated with mash and pellet preparation are eliminated. The choice feedstuffs can all be offered in the current feed distribution systems, either by mixing the ingredients first or by using a bulk bin divided into three compartments.

The main aim of nutrition is to optimise productive efficiency, but this is usually only achieved when health is also optimised. Thus health and consequent welfare are major priorities in modern nutritional practices. The dietary contents of energy, protein and amino acids can be varied to alter specific production outputs, for example, growth rate, body composition, egg weight, usually without any adverse welfare impact. Genetic predispositions to specific disorders affecting the skeletal or cardiopulmonary systems associated with selection of broilers for fast growth can be partially overcome by changes to diet composition or feed supply aimed at suppressing growth rate. Vitamin and mineral deficiencies or imbalances can lead more directly to specific lesions and welfare problems. Metabolic disorders affecting poultry may not always be caused by nutrition, but good nutrition can often alleviate their impacts. Nutritional modifications can also help poultry to cope with stresses. The ban on the use of antibacterial feed additives is putting increasing pressure on the correct formulation of diets and the introduction of novel additives to optimise bird performance and health.

This paper describes the feed resource bases for the different chicken production systems and its utilisation potentials in Ethiopia. Past attempts made to improve the production and productivity of birds through better utilisation of locally available feed resources are assessed. The merits and demerits of the different feed types through chemical and animal evaluation are reviewed. Finally, future areas of research on the available feed resource base and feeding of chicken are suggested to aid the rational utilisation of locally available feed resources.

The work comments on the results of four experiments on biological responses of growing turkeys to fresh or oxidized fat applied in a concentrate mixture in amounts from 2% at the beginning (1–4 weeks) to 5% in the end period of fattening (13–16 weeks). The content of fat with a high peroxide value (50–150 meq O2/kg), which contained simultaneously a higher content of selenium (0.3 mg/kg), vitamin E (30–40 mg/kg) and vitamin A (1200–15000 IU/kg) caused reduction in body weight gain of turkeys, mainly as a result of lowered feed intake. Enriching diets with fat of a very high degree of oxidation (100–150 meq O2/kg) did not result in worsening of the turkeys' health condition, but considerably lowered their vitamin E reserves. Symptoms of muscular dystrophy and changes in biochemical and enzymatic indices in serum and liver were not observed. However, a decrease in the activity of lactic dehydrogenase in liver lesion of hepatocytes was noted, that was partially confirmed in microscopic assay and ultrastructural characteristics of liver. The rise in temperature (from 23°C to 30°C) in the rearing pens reduced the effect of the turkey feeding, while not, at the same time increasing a negative effect of oxidized fat on the fattening results. Products of fat oxidation increased the birds' susceptibility to virus infections causing haemorrhagic intestinal inflammation.

From primary production and on through the whole processing line, the poultry house microflora will be transferred into the processing plant, and further on in the process, onto exterior parts of the birds as well in their gut microflora. This is particularly true for Salmonella. In this paper, the major stages of poultry processing are considered with regard to the potential spread of Salmonella. Most of the data referred to in this review applies to broiler chickens.

Cross contamination occurs especially during scalding, defeathering, head pulling, evisceration and chilling. The poultry meat processing line does not have any killing capability for Salmonella. At present, effective barriers that might be able to control Salmonella do not exist. It would be useful to develop more techniques and procedures than are presently available.

Several other options for intervention to control Salmonella already exist. Although generally known, these have not yet been incorporated into the production sequence. They include the implementation of other processing actions such as flaming; changes of machinery design for example in scalding tanks and transport containers. It would also be helpful to base operational designs of machinery for scalding and crate washing more on scientific data such as time-temperature-relations in calculation of Salmonella death rates.

However, none of these actions alone would be able to solve the problem, an integrated approach is needed.

More data on flock Salmonella status is needed at critical stages during broiler growout. Also requirements for special products such as minimally processed meat must be examined, and more quantitative data are needed to calculate time-temperature relations more precisely.

The level of a single essential amino acid that is either deficient or in excess of requirement may result in a diet that does not optimise the economic efficiency of a laying hen production system. The objectives of this study were, first, to quantitatively describe the effect of increasing the dietary levels of a single limiting amino acid on the egg production characteristics of laying hens by a statistical analysis and assessment of the published literature. Second, to compare three methods of describing the dietary amino acid concentration; as a proportion of the diet (g/kg of feed), as a proportion of the crude protein (g/kg crude protein) or as a proportion of the ideal crude protein (g/kg ideal crude protein). Sufficient published experiments were available to give statistically valid comparisons of lysine (42 experiments), methionine (77 experiments), methionineplus cystine (77 experiments) and tryptophan (21 experiments). Amino acid concentration was described by three different methods; concentration in diet (g/kg of feed), concentration in the crude protein (g/kg crude protein) or concentration in the ideal crude protein (g/kg ideal crude protein). An exponential curve gave the best fit to these data sets for almost all variables. The exceptions were egg weights with tryptophan (no relationship (p>0.05)) and egg weights and egg mass output with methionine plus cystine (linear relationship only). Expressing the egg production responses as a proportion of the crude protein, as compared to a proportion of the diet, gave a reduction in the residual standard deviation and increased the proportion of explained variation for all variables examined. The results indicated that expressing amino acid supply as a proportion of crude protein is preferable in laying hen nutrition.

Resulting from EU-wide initiatives of animal welfare organizations, the Council of the European Union has approved stricter legal standards for keeping laying hens in battery cages (Council Directive 1999/74/EC). The economic impacts of this legislative review can be summarized as follows:

1. The current trade protection in favour of EU-producers versus imports from non-member countries amounts to approximately 0,01 Euro/egg. Hence, there is little scope for passing increased costs on to consumers.

2. Competitive disadvantages for the EU-producers, caused by increasing legal standards for keeping laying hens will become even more critical if future WTO-agreements cause further reduction in tariffs. As a whole, this will lead to a drastic cut in EU egg production.

3. Due to their cost advantages, countries with less stringent standards for keeping laying hens will extend their share of the EU- egg market. Thus, looking at the global picture, stricter legal standards within the EU will not lead to an improvement of animal welfare, but to a regional shift of the problems.

4. The fall in egg production in the EU will result in heavy losses to net value-added and employment. Given a decline in production of 10 billion eggs, it can be estimated that

- net value-added will decrease by approximately 270 million Euros.

- employment will lower by approximately 12,000 jobs.

Family poultry production (FP), which is still important in low-income food-deficit countries, is an appropriate system to supply the fast-growing human population with high quality protein. It can also provide additional incorne to the generally resource-poor small farmers, especially women. Although requiring low levels of inputs, FP contributes significantly to food security, poverty alleviation and ecologically sound management of natural resources. FP is also a source of employment for underprivileged groups in many local communities. However, constraints facing FP production systems include poor management conditions and poorly developed marketing structures for the products. The skills of small farmers in all aspects of poultry management must be improved through training and education. Poultry farmers should also be provided with credits or loans, taking into account the economic circumstances and socio-cultural context in which the beneficiaries live. In addition, the marketing system must be improved, for the benefit of both FP keepers and consumers.

Due to public demands for enhanced water quality, American poultry producers are being subjected to increased regulation by both the federal and state governments. Under the authority of the US Clean Water Act, concentrated animal feeding operations, including some poultry producers, must secure a discharge permit and adopt comprehensive nutrient management plans. State regulations concerning the closure of operations are also affecting producers. Depending on the state regulation, private insurance, guarantees, surety bonds, letters of credit, or payments may be required. A few states and a proposed federal regulation seek to expand the operations covered by discharge permits. Under this concept, co-permitting regulations would hold integrators responsible for permit violations. With these proposals, the poultry industry is presented with a number of opportunities to help structure regulations that help achieve improved water quality while preserving the economic viability of producers' business enterprises.