Showing papers in "Worlds Poultry Science Journal in 2008"

Poultry meat consumption trends in Europe

Abstract: 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 ...

Qualitative attributes and consumer perception of organic and free-range poultry meat

Abstract: The effect of the organic production (OP) system on the qualitative characteristics and consumer perception of poultry meat is reviewed in the following paper. Age at slaughtering, genetic strains (fast- and slow-growing), physical activity, and pasture intake are key factors in determining meat quality. In conventional farming, fast-growing chicks are generally used, but these are not suitable for OP, since they may develop health and welfare problems, the most recurrent of which are leg disorders and lameness. Conversely, use of slow-growing strains in OP has positive repercussions on both animal welfare and product qualitative characteristics (eating quality and appearance) perceived by consumers. From the published data it can be concluded that organic poultry can be a viable production method, especially if suitable changes in EU Regulation. 1804/99 are made. The market opportunity for both organic and free range poultry products does not yet seem to be fully developed. We suggest that structured integration between production and consumption stages could resolve this problem.

The use of distillers dried grains with solubles (DDGS) in poultry nutrition

Abstract: Distillers dried grains with solubles (DDGS) is a by-product of the ethanol industry produced by dry mill ethanol plants. During the fermentation process starch from the grain is converted to ethanol and CO2, concentrating the remaining nutrients in DDGS by 2-3 times. In the European Union the favoured use of renewable energy sources has encouraged increased production of biofuels. The increase of bio-ethanol production has resulted in large quantities of DDGS entering the feed raw material market. Because of its high nutrient quality, related to the typically gentle drying and processing it receives, DDGS obtained from the modern ethanol industry may be used as a feed for monogastric animals with good results. The main problem in the use of DDGS for poultry is its high variability of nutrient content and availability.Results from different laboratories on the use of DDGS as feed component for poultry are discussed in the article. Based on the results presented, DDGS obtained from the modern ethanol plants is an acceptable ingredient of poultry diets and can be safely fed at 5-8% in starter diets for broilers and turkey, and 12-15% in grower-finisher diets for broiler and turkey and diets for laying hens.

Important metabolic pathways in poultry embryos prior to hatch

Abstract: Growth performance and meat yield of commercial broilers and turkeys has improved linearly each year during the past four decades (Havenstein et al., 2003b; Havenstein et al., 2003a; Havenstein et al., 2007), and this trend is likely to continue in the future as new technologies in genetics, biotechnology and developmental biology are adopted by the poultry industry. As the time it takes meat birds to achieve market size decreases, the period of embryonic development becomes a greater proportion of a bird's productive life. Therefore, incubation and embryonic development towards hatch is of greater relative importance to the successful rearing of meat poultry than ever before (Hulet 2007; Foye et al., 2007b). Consequently, anything that supports or limits growth and development during the incubation period will have a marked effect on overall growth performance and health of modern strains of meat poultry. Many poultry researchers now realize that future gains in genetic and production potential of poultry will come from advancements made during the incubation period and embryogenesis (Elibol et al., 2002; Peebles et al., 2005; Christensen et al., 2007; Collin et al., 2007; Leksrisompong et al., 2007). The urgent need to explore and understand the biology of incubation has been emphasised by several symposia: two held at the annual conference of the U.S. Poultry Science Society (July 2006-Edmonton, Alberta, Canada “Managing the embryo for performance”, and July 2007-San Antonio, TX Informal Nutrition Meeting “The impact of imprinting on biological and economical performance in animals”), and one held by the European Federation of World Poultry Science Society (October 2007-Berlin, Germany “Fundamental physiology and perinatal development in poultry), which were specifically devoted to demonstrating the importance of the embryonic period on poultry performance. This review will summarise the metabolic events and pathways in four of the most active tissues of embryos during the period just prior to hatch, and the hormonal control that coordinates the marked changes as the embryo prepares for its post-hatch life.

Bacterial contamination of table eggs and the influence of housing systems

Abstract: 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.

Significance of phytic acid and supplemental phytase in chicken nutrition: a review

Abstract: Phytic acid is an anti-nutritional constituent of plant derived feeds As a reactive anion, it forms a wide variety of insoluble salts with minerals including phosphorus, calcium, zinc, magnesium and copper Phytic acid is also known to form complexes with protein and proteolytic enzymes (pepsin and trypsin) Because of the lack of endogenous phytase enzymes that hydrolyze phytic acid; phosphorus, calcium, protein and other phytic acid bound nutrients are less available to poultry Commercially-available microbial phytase has great nutritional significance and ecological importance Poultry diets supplemented with microbial phytase result in improved growth performance and increased digestibility and availability of phytate bound phosphorous, calcium, zinc and copper Microbial phytase supplementation has also been shown to increase ileal digestibility of crude protein and amino acids The efficacy of supplemental microbial phytase depends on its rate of inclusion, dietary calcium and phosphorus ratio, vitamin D3, nature of diet, age and genotype of birds Thus, microbial phytase can be used to exploit the inherent nutritional potential of feedstuffs for more economic and environmentally-friendly poultry production

Poultry production profile and expected future projection in Bangladesh

Abstract: 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...

Animal welfare in poultry production systems: impact of EU standards on world trade

Abstract: 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 E...

The chicken embryo and its micro environment during egg storage and early incubation

Abstract: When egg storage periods are prolonged (>7 days), hatchability and chick quality declines. The reason for this decline has been investigated, but is still not completely understood. At oviposition the developmental stage of the chicken embryo varies and so do the total number of viable cells. During storage, changes can occur in the embryo. Embryo viability at the end of storage seems to be dependent on the number of viable cells and the developmental stage of the embryo at oviposition. When the hypoblast is completely formed (during the quiescent developmental stage), the embryo seems to be more able to endure prolonged storage periods than embryos that are less or more advanced. During storage, changes also occur in egg characteristics such as albumen viscosity, albumen pH and yolk pH. There appears to be an interaction between albumen pH and embryo viability during early incubation and perhaps also during storage. An albumen pH of 8.2 seems to be optimal for embryo development. Albumen pH may influence embryo viability, but embryo viability may in turn, affect albumen pH. It has been hypothesised that an embryo in which the hypoblast is completely formed is better able to provide an effective barrier between the internal embryo and the exterior (yolk and albumen) and/or is better able to produce sufficient amount of carbon dioxide, which will reduce the pH level in the micro environment of the embryo to the optimal pH of 8.2. It appears that, to maintain hatchability and chick quality after prolonged storage periods, embryonic development should be advanced to the stage in which the hypoblast is completely formed or the atmosphere during storage and early incubation should be altered in such a way that albumen pH is maintained at the optimal level of 8.2.

Relationship between hatchling length and weight on later productive performance in broilers

Abstract: Hatchling length and weight are used as tools to measure hatchling quality. However, the relationship between these parameters and later performance are not well known. This review evaluates the relationship between hatchling length or weight and slaughter weight, breast meat yield and feed conversion ratio (FCR) in both male and female broilers. Datasets from two trials were compared. In the first, hatchling length and weight of 100 male and 100 female broilers were measured and body weight and breast meat yield were determined at 38 days of age. In experiment 2, hatchling length of 187 female and 230 male broilers was measured and body weight was determined at 21 and 42 days of age. Feed intake was determined between 21 and 42 days of age. In both experiments, male broilers showed a positive relationship between hatchling length and slaughter weight or breast meat yield, but no relationship was found with hatchling weight. The relationship between hatchling length and performance in female broilers differed between the two experiments. In female broilers, a negative relationship between hatchling weight and breast meat yield was found. No relationship between hatchling length and FCR in both male and female broilers was found. From this limited dataset, it can be concluded that hatchling length seems to be a better parameter to predict subsequent chick performance, excluding FCR, than hatchling weight, but gender needs to be taken into account

Standard European footpad dermatitis scoring system for use in turkey processing plants

Abstract: A standard scoring system for turkeys at slaughter that consists of 5 categories based on the size of the lesion was adopted as the recommended classification scheme for FPD in slaughter plants at ...

Eggshell factors influencing eggshell penetration and whole egg contamination by different bacteria, including Salmonella Enteritidis

Abstract: Trans-shell infection routes and whole egg contamination of 7 selected bacterial strains; Staphylococcus warneri, Acinetobacter baumannii, Alcaligenes sp., Serratia marcescens, Carnobacterium sp., Pseudomonas sp. and Salmonella enteritidis, recovered from egg contents, were studied. The first objective was to correlate bacterial eggshell penetration with various eggshell characteristics and bacterial strains. An agar approach was used to assess the eggshell penetration. The second objective was to assess the contamination of whole eggs with the bacterial strains; whole intact eggs were used in this case. The intact shells of agar-filled and whole eggs were inoculated with 10 3 –10 4 cfu of the selected strains. During 3 weeks storage at 20 °C and 60% relative humidity, the bacterial eggshell penetration was regularly monitored. The whole egg contamination was only analyzed after 3 weeks. The eggshell characteristics such as area eggshell, shell thickness and number of pores did not influence the bacterial eggshell penetration. For each individual bacterial strain the mean cuticle deposition was lower for penetrated compared to non-penetrated eggshells. For the individual strain Carnobacterium sp. and for the global results of all strains this difference was statistical significantly. The whole egg contamination was not influenced by neither the area of the eggshell nor the porosity of the eggshell. The results of the agar approach indicate that the Gram-negative, motile and non-clustering bacteria penetrated the eggshell most frequently; Pseudomonas sp. (60%) and Alcaligenes sp. (58%) were primary invaders followed by S. enteritidis (43%). All selected strains were able to penetrate; penetration was observed most frequently after ca. 4–5 days. Particularly S. enteritidis was a primary invader of whole eggs: the membranes and/or the content of 32% of the whole eggs was contaminated. The remaining bacterial eggshell contamination with the selected strain was determined after 3 weeks storage. Penetrated eggshells and contaminated whole eggs showed a significantly higher bacterial contamination on the eggshell compared to non-penetrated eggshells and non-contaminated whole eggs respectively (global results of all strains). The influence of hen age on bacterial eggshell penetration and egg content contamination was not significant. While the agar approach is suitable to study the influence of the eggshell characteristics on the bacterial eggshell penetration, the intact egg approach gives an estimation of the penetration of the shell followe db y the probability of survival and migration in whole eggs.

Variability in wheat: factors affecting its nutritional value

Abstract: 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.

Producing specialist poultry products to meet human nutrition requirements: Selenium enriched eggs

Abstract: 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.

The application of zeolite in poultry production

Abstract: 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 cha...

Epidemiology, challenges and prospects for control of Newcastle disease in village poultry in Nigeria

Abstract: 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.

Indigenous breeds, crossbreds and synthetic hybrids with modified genetic and economic profiles for rural family and small scale poultry farming in India

Abstract: Approximately 110 million birds from nineteen documented indigenous, heavier and lighter bodied chicken breeds and numerous non-descript types are bought and sold at unorganized meat markets in Ind...

Genetics and selection of mule ducks in France: a review

Abstract: Duck breeding in France is directed mainly towards ‘foie gras’ (duck fatty liver) production. Nowadays the roasted duck, produced from the pure Muscovy, is economically a less important industry. A...

Controlling reproductive seasonality in the geese: a review

Abstract: The following paper reviews the breeding seasonality and its control in the domestic geese. Geese breeds can be classified into 3 types according to their breeding season: Type 1 inhabits higher latitude (40 to 45o N) temperate zones, and breeds during the longer days in spring and early summer. Types 2 inhabits mid-latitude (30 to 40o N) temperate regions, and start their breeding season in autumn and end in the following spring - early summer. Type 3 are the short-day breeding geese, located in subtropical areas (22 to 25o N), which breed from late summer to the following spring. Differences in breeding seasonalities are attributed to adaptations to environment conditions, enabling geese to fully utilize these conditions to achieve maximal reproductive performance and survival. Divergent breeding seasons are caused by the different pituitary secretions of gonadotrophins and prolactin in response to annual changes in photoperiod. In practical goose production, laying seasons can be controlled by imposing artificial photoperiods, with almost opposite photo-programmes for long or short day breeding geese, respectively. In addition, genetic selection and other animal husbandry measures such as timing of gosling stocking and nutritional intake levels can modify, to various degrees, the goose breeding seasonality.

Approaches to determine the sex prior to and after incubation of chicken eggs and of day-old chicks

Abstract: Domestic chickens produce eggs that contain at almost equal proportions female and male embryos. For many centuries, domestic chickens were bred as dual-purpose birds for both egg and meat producti...

Involvement of the hypothalamic-pituitary-thyroid axis and its interaction with the hypothalamic-pituitary-adrenal axis in the ontogeny of avian thermoregulation: a review

Abstract: The emergence of thermoregulation in avian species is a complex matter in which neural as well as hormonal processes are involved. In a previous paper, the neural aspects of primary avian thermoregulation were discussed. In this paper the role of the hypothalamus-pituitary-thyroid axis (HPT-axis) and the hypothalamus-pituitary-adrenal axis (HPA-axis) in the ontogeny of avian thermoregulation is evaluated. The regulatory mechanisms and different important hormones of both axes, which have stimulatory or inhibitory effects, are discussed. Because the onset of functionality of the thermoregulatory system is of great interest, the ontogeny and functionality of the hormonal axes are clarified. There is a great difference between precocial and altricial birds in hormonal events as well as in neural processes which are involved in the emergence of thermoregulation. In precocial avian species the HPT-axis becomes functional during the mid- to late embryonic period while the same axis only becomes fully functional during the first week post-hatch in altricial avian species. As early as the sixties, the emergence of homeothermy in chickens was investigated. It was concluded that the thyroid gland plays an important role in the thermoregulatory mechanisms of newly hatched chicks. More recent studies however were not able to show any direct effect of the thyroid hormones on the thermoregulation of day-old chicks, although blocking the conversion of T4 to T3 caused a decrease in body temperature in young chicks. Thyrotropin releasing hormone (TRH) is known to act in thermoregulation in mammals and several authors have found an effect of TRH on the metabolism of young and older chicks. However, the exact mechanism still remains unclear. Because the HPT- and the HPA-axis show close relationships, the role of the HPA-axis in the ontogeny of thermoregulation is also taken into consideration in this review. In mammals as well as in birds, corticotropin releasing hormone (CRH) is involved in the primary thermoregulation. We conclude that the HPT-axis has an important role in the ontogeny of avian thermoregulation. The exact role of the HPA-axis remains largely unclear although at least CRH is definitely of some importance.

Avian influenza in poultry

Abstract: Influenza A viruses that infect poultry can be divided into two groups. Very virulent viruses cause highly pathogenic avian influenza (HPAI), with flock mortality as high as 100%. These viruses have been restricted to subtypes H5 and H7, although not all H5 and H7 viruses cause HPAI. All other viruses cause a milder, primarily respiratory, disease (LPAI), unless exacerbated. Until recently, HPAI viruses were rarely isolated from wild birds, but for LPAI viruses extremely high isolation rates have been recorded in surveillance studies. Influenza viruses may infect all types of domestic or captive birds in all areas of the world. The frequency with which primary infections occur in any type of bird usually depends on the degree of contact there is with feral birds. Secondary spread is typically associated with human involvement, either by birds or bird product movement or by transferring infective faeces from infected to susceptible birds, but potentially wild birds can be involved. In recent years the frequency of HPAI outbreaks appears to have increased and there have been particularly costly outbreaks of HPAI in densely populated poultry areas in Italy, The Netherlands and Canada. In each outbreak millions of birds were slaughtered to bring the outbreaks under control. Since the 1990s, AI infections due to two subtypes have been widespread in poultry across a large area of the World. LPAI H9N2 appears to have spread across the whole of Asia in that time and has become endemic in poultry in many of the affected countries. However, these outbreaks have been overshadowed by the H5N1 HPAI virus, initially isolated in China that has now spread in poultry and/or wild birds throughout Asia and into Europe and Africa, resulting in the death or culling of hundreds of millions of poultry and posing a significant zoonosis threat. To date control methods seem to have been unsuccessful on the larger scale and HPAI H5N1 outbreaks continue to be reported.

Review of the initial validation and characterization of a 3K chicken SNP array

Abstract: In 2004 the chicken genome sequence and more than 2.8 million single nucleotide polymorphisms (SNPs) were reported. This information greatly enhanced the ability of poultry scientists to understand chicken biology, especially with respect to identification of quantitative trait loci (QTL) and genes that control simple and complex traits. To validate and address the quality of the reported SNPs, assays for 3072 SNPS were developed and used to genotype 2576 DNAs isolated from commercial and experimental birds. Over 90% of the SNPs were valid based on the criterion used for segregating, and over 88% had a minor allele frequency of 2% or greater. As the East Lansing (EL) and Wageningen University (WAU) reference panels were genotyped, 1933 SNPs were added to the chicken genetic map, which was used in the second chicken genome sequence assembly. It was also discovered that linkage disequilibrium varied considerably between commercial layers and broilers; with the latter having haplotype blocks averaging 10 to 50 kb in size. Finally, it was estimated that commercial lines have lost 70% or more of their genetic diversity, with the majority of allele loss attributable to the limited number of chicken breeds used.

Identification of new chicken egg proteins by mass spectrometry-based proteomic analysis

Abstract: The chicken egg and foods containing egg components are an important part of human nutrition. Furthermore, eggs are a potential source of bioactive molecules and a potential delivery system for therapeutic proteins, explaining the continuing scientific interest in eggs and their components. Using mass spectrometry-based high-throughput proteomic techniques, 119 proteins in egg yolk, 78 proteins in egg white, and 528 proteins in the decalcified eggshell organic matrix have recently been identified. Most of these proteins were identified in their respective egg compartment for the first time. Some of these proteins were already known from chicken tissues or other egg compartments, but many were novel. In the eggshell soluble matrix 39 phosphoproteins containing more than 150 different phosphorylation sites were identified. Twenty-two of the identified phosphoproteins had not been recognized as phosphoproteins previously.

Evaluation of prevalence and seasonality of Newcastle disease in chicken in Kaduna, Nigeria

Abstract: Newcastle disease is a major constraint to poultry production in Africa, in both commercial and village rearing systems. A ten-year review (January, 1996-December, 2005) of case reports in respect ...

Breeding for feed efficiency and adaptation to feed in poultry

Abstract: The following paper reviews the current data regarding the physiological origins of variations in feed efficiency, and the effects of genetic selection on energy balance parameters. Effects of diet composition on response to genetic selection are considered by focusing on three feed factors: protein concentration, energy concentration and utilisation of specific ingredients. Analyses of effects of genetic selection on responses to diet composition highlight the problems associated with the increased dietary protein concentrations needed by the latest commercial broilers as a result of genetic selection. The advantages and disadvantages in producing lean birds are discussed from the point of view of feed efficiency and adaptation to feed variation. Lastly, the problems of variation in digestibility resulting from broiler selection are discussed.

Long term selection for reduced or increased pecking behaviour in laying hens

Abstract: Feather pecking in laying hens is an important issue in animal welfare. Four studies in laying hens were selected which investigated increased or reduced pecking behaviour using direct or indirect ...

A projection of the regional development of egg production until 2015.

Abstract: In contrast to detailed projections for the development of plant and animal production, as published by the United States Department of Agriculture (USDA) or the Food and Agricultural Policy Research Institute (FAPRI), for a great number of commodities, there are hardly any projections for the development of hen egg production. The OECD publishes projections for the coming decade annually, but the data cover all poultry eggs, the EU Commission gives data only for EU member states. In this paper, a projection for the development of hen egg consumption and hen egg production between 2005 and 2015 is presented. It is based on an analysis of the development between 1995 and 2005 as well as on basic population and socio-economic data, such as population development, age structure of the population, urbanisation of a society, development of the gross national product and the per capita national income. Based on these data, the development of the per capita consumption of shell eggs was calculated for the decade until 2015. These data were then used in combination with the predicted development of the population to calculate the additional egg demand in 2015. It is estimated that the additional egg demand will be as high as 12 million metric tonnes. This will result in a total production volume of 70.9 million tonnes. About 67% of this demand will arise in Asia, 12% in Africa, and 11% in Latin America. These continents will gain shares in global egg production, North America and Europe will lose shares. Whether the required volume of 70.9 million tonnes can be reached, will depend on several factors, e.g. outbreaks of Avian Influenza, higher feed costs because of the booming bio-energy production, and political decisions ( e.g. banning of conventional cages in the EU).

Molecular genetics in a modern poultry breeding organization

Abstract: Molecular genetics is providing the tool box of the 21st century for the modern poultry breeding company. These tools allow for rapid and accurate identification and selection at the gene level of those individuals with better performance traits. Genetic selection can be done before traits are expressed, molecular genetics testing can be applied to males for female limited traits, and it can be done on chicks shortly after hatch. They also allow for rapid diagnosis of genetic deficiencies and pathogen contamination, and allow excellent quality control and brand identification methods. This tool box will continue to improve as new methods and more rapid and less expensive methodologies are developed.

History, changing scenarios and future strategies to induce moulting in laying hens

Abstract: 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 indu...