December 2018 Newsletter

Treasurer's Report

I must start this short report by congratulating Dr. Estella Prukner-Radovcic (Croatia), first for her organization of a most successful European Poultry Conference (EPC) in Dubrovnik. It has been reported that this was the largest agricultural conference ever held in that part of Europe. She and her colleagues worked as if they were a veteran conference organizing team and even had to turn away many, who waited too late to register. Second, Dr. Prukner-Radovcic is the newly elected President of the European Federation and is our newest member on the WPSA Board.

The Board met in Dubrovnik before the EPC and we were joined by another new member, Dr. S. Sriboonsue (Thailand). He was elected several months ago as the new President of the Asian Pacific Federation. The Board met for 1.5+ days and worked through the long agenda. I presented the Treasurer’s Report on the 2017 financial records. Included in that report were positive details on payments from the Journal’s Sponsors and Advertisers, as well as the payment of dues from Branches. While we are still experiencing problems with some of our service providers who do not bill promptly, there is NO issue with WPSA having the ability to pay all its obligations. WPSA had a gain in terms of its continuing operations, that is Income exceeded Expenses. The Association’s portfolio of investments also performed very well, providing a healthy balance as we entered 2018.

I just returned last week from the USA’s 4-H National Poultry and Egg Conference in Louisville, Kentucky. The United States of American Branch of WPSA is a sponsor of this event. For those of you unfamiliar with 4-H, it is the official youth programme of the Land Grant Universities in the United States. Children across the country, who sign up for ‘4-H Poultry’ are involved in raising all types of exhibition and/or exhibition poultry, as well as studying many aspects of poultry science. While I have been an official at this Conference for over 30 years, I never cease to be impressed with the quality of the youth and their enthusiasm for poultry. A big ‘salute’ to my home WPSA Branch for fostering the growth of this valuable programme.

As we look at the final page of the 2018 calendar, I send my wishes to all of you that you end the year in good health and remain active in your local Branches throughout 2019.

Dr Francine Bradley, Treasurer

WG4

Eggs and Egg Quality

European Working Group 4 (Egg Quality) has two new chairpersons: Cristina Alamprese (University of Milan, Italy) and Joël Gautron (INRA, France). They took over the leadership of WG4 from Maureen Bain just after the European Poultry Conference that was held in Dubrovnik (Croatia) in September 2018. We would like to thank Maureen for her work on behalf of WG4 and for her attention related to research topics on egg quality.

It is our intention to continue the work of WG4 while increasing the networking activities among all the Group’s members, in order to create a strong team that is able to answer any new challenges for the egg sector at both a scientific and industrial levels, without forgetting the importance of good communication with the society. The network will continue to provide support to the organizers of WPSA events in order to develop scientific programmes about eggs and egg quality, and to identify possible speakers. Moreover, we believe in the importance of identifying research funding possibilities in order to boost research in the egg and egg product fields.

As usual, there is much work to do but we trust in the cooperation of all the members!

WG4 currently has representatives from 21 countries and meets every 2 years at a key WPSA event. Every other year the group holds its own joint ‘EGGMEAT’ symposia with WG5 (Poultry Meat Quality). The aim of these symposia is to bring like-minded people together to discuss hot topics in the field of egg and meat quality.

Cristina ALAMPRESE
		Associate Professor in Food Science and Technology at the Department of Food, Environmental and Nutritional Sciences of the University of Milan (Italy). Research interests: Quality of fresh eggs; Technological treatment of egg products; Functional properties (gelling, whipping, and emulsifying capacity; rheological behaviour) of eggs and egg products; Influence of egg ingredients on food product quality; and Technological properties of poultry meat. E-mail:
Joël GAUTRON
		Research Director, Biology of birds and Poultry research Unit UR0083, head of the team «Egg Defences, valorisation, evolution», Institut National de la Recherche Agronomique, Nouzilly, France.  Research interests: Biochemistry and molecular biology related to egg formation and its quality; High-throughput methodology to identify and characterize biological activities related to natural egg defences; Physiology of chicken egg formation; and, Mechanisms of eggshell biomineralisation. E-mail:

Cristina Alamprese & Joël Gautron, Co-Chairs WG4

WG5

Poultry Meat Quality

The ‘XXIV European Symposium on the Quality of Poultry Meat’ will be conjointly held with the ‘XVIII European Symposium on the Quality of Eggs and Egg Products’ in Çeşme, İzmir, Turkey between 23 -26 June 2019. Visit http://www.eggmeat2019.com to keep you updated. Special reduced registration fees are available for WPSA members and students.

Massimiliano Petracci

WG6

Incubation and Fertility Research Group (IFRG)

2018 IFRG Meeting – Edinburgh, Scotland

October 4th – October 5th

For 2018, the IFRG meeting was held at the 5th floor of the Holiday Inn hotel in Edinburgh. The scenic view over Pink Hill Park and Edinburgh Zoo offered all 57 participants a sunny atmosphere during the two days of the meeting. We all experienced a friendly and informative meeting not least because we met several colleagues with similar interests, as became clear during coffee breaks, lunches and the conference dinner.

This 43rd IFRG meeting offered an interesting programme, including a workshop and presentations related to the biology of avian reproduction and the practice of incubation technology. The programme was the result of the combined efforts of Glenn Baggott (IFRG board, ed. British Poultry Science, London, UK) and Marleen Boerjan (President IFRG, WPSA WG 6, Pas Reform). This year we were able to organise the lectures offered by participants into sessions opened by 3 invited speakers.

Thanks to the talent for improvisation of the complete Aviagen incubation team, we were able to organize a workshop ‘embryo-staging’ led by invited speaker Murray Bakst, a recognized experienced consultant in fertility and early embryonic development of poultry. With the practical help of Ampai Nangsuay and Serdar Őzlü, embryos were collected from fresh eggs. Thereafter Murray Bakst and Guo Jun discussed the embryonic stage, according to the Eyal-Gyladi staging system.

A second invited speaker Professor Maureen Bain (Glasgow University) presented an overview and new insights into the ultrastructure of the eggshell. In addition, she focused on the importance of the cuticle to protect the egg content from vertical contamination by E.coli or Salmonella. Finally, she advised us to include routinely the staining of cuticle in egg quality control practices.

Hatchery managers encounter more and more influences of incubation conditions on the quality and performance of day old chicks and poults. The positive as well as negative effects of high and low incubation temperatures are known and are discussed often. Professor Warren Burggren from the University of North Texas, USA, was invited to speak about the epigenetic implications of incubation on the embryonic and foetal development. In his intriguing presentation, he showed how the developing embryo responds, in a critical phase, to environmental conditions by (1) complete phenotypic adaptations (developmental plasticity), (2) programming/training of the foetus and (3) epigenetic alterations of gene expression. In commercial incubation practice, these different but related phenomena are often unknown or ignored. From the presentation, we learned how the level of RH during certain critical phases of development influences the development of glomeruli in the primordial kidney.

In Session 1: Embryo quality, egg handling and egg storage four speakers showed how the genetic background, age of the parents and treatment of fresh eggs affects the stage of the embryo and, consequently, early mortality during incubation. Ewa Łukaszewicz (University of Wroclaw, Poland) researching the stage of development in different goose breeds and flock ages reported the interesting observations that the stage of embryonic development at oviposition was dependent on laying season and breed. Also the need for a correct and routine staging of the embryos in fresh or stored eggs after short period of incubation (SPIDES, heat-treatments) was clear from the three presentations related to egg handling in the farm and hatchery.

Ampai Nangsuay (Aviagen, Asia Pacific) presented data on embryo stage in eggs collected under field conditions in a tropical climate. It was observed and concluded that the local environmental conditions (transport and temperature) influenced the rate of embryo development during storage. The eggs from prime flocks had to be transported over a long period and distance at temperatures above 22 °C. As a consequence the embryos developed from an average stage 10.3 to stage 11.7 during prolonged transport at high temperatures. The eggs from an old flock were cooled below 22 °C within 5 ½ h and did not show any development after transport.

Okan Elibol from Ankara University, Turkey, concluded that the hatchability differences between eggs from young and old flocks induced by rapid cooling might depend on the differences in embryonic development at oviposition. He presented data on the effect of the profile of egg cooling after oviposition on stage of embryo and finally hatchability. The stage of embryonic development was advanced by controlled cooling compared to rapid cooling and in the eggs from the older flock. The rapid cooling resulted in a lower hatchability because early mortality and the number of second class chicks were increased especially for eggs derived from younger flocks (28 weeks).

Tolga Erkus (Aviagen, UK) presented results of 3 or 5.5 hours exposure above 32°C at day 5 of a total storage period of 14 days of eggs from two grandparent flocks (34 wks and 54 wks). After the treatment the stage of the embryos (n=15) was evaluated and the longer period of treatment resulted in, as expected, an advanced stage of development and resulted in a better hatchability compared to the 3.5-hr treatment.

Joanna Rosenberger, a PhD student from Wroclaw University is studying the behavioural aspects of Capercaillie (Tetrao urogallus) during incubation. In her first presentation, she discussed whether improper turning might explain the high levels of early mortality during artificial incubation. In her second lecture, she discussed how knowledge of female behaviour and egg storage in the nests might help to improve artificial incubation results.

In Session 2: Egg quality, more basic aspects of egg quality were discussed before the presentation of Professor Maureen Bain. Utilising new research on embryonic development during egg formation in the hen (South-Korean University), Marleen Boerjan (Pas Reform, the Netherlands) discussed pre-gastrulation embryonic development in the hen as it has been shown that gastrulation gene expression might be initiated in the oocyte during yolk development. In short, without the pre-gastrulation development in the uterus of the hen, the gastrulation-related cell movements cannot occur, with increased rates of early mortality as a consequence.

Roger Banwell (Petersime, Belgium) presented new hatchability data in experiments related to specific gravity of eggs, egg weight loss and RH levels and concluded that hatchability of eggs in the medium (1.070- 1.085 gm/cm3) specific gravity class is highest compared to ‘low’ and ‘high’ specific gravity eggs. Specific gravity was found to be a better predictor for hatchability than percentage egg weight loss.

Session 3: Epigenetics, incubation and chick vitality was introduced by the lecture of Prof. Warren Burggren and followed by five presentations addressing several aspects of incubation technology and chick quality.

Incubation temperature

Juan Lopez (Hendrix Genetics, Canada) and Roos Molenaar presented new data on incubation temperatures measured and controlled as eggshell temperature (EST). Lopez showed that incubation of turkey eggs at low (99.2- 99.6 °F) eggshell temperatures compared to high (99.8-101 °F) resulted in higher hatchability, higher body weights at hatch and higher yolk free body mass.

Roos Molenaar (Adaptation Physiology Group, Wageningen University, the Netherlands) studied the effects of a combination of high EST (38.9 °C) during second week of incubation and low EST (36.7 °C) in the third week on body weight and selected bone characteristics; hatch results were not addressed. In these experiments, no effect on body weight and length of the tibia at slaughter age was found. The high temperature during the second week resulted in a slightly thicker bone and higher bone strength. A lower temperature in the third week resulted in a 5 hr-longer incubation duration and lower bone strength.

Early feeding

Keith Bramwell (Jamesway Incubators, Canada) presented the results of experiments related to feed and water in hatcher baskets. The hatch window was divided in four periods and chicks received water and feed immediately when all chicks of the specific period had hatched. From this research it is concluded that access to feed and water prior to chick placement at the farm had no influence on final body weight, feed conversion and mortality overall.

Serdar Őzlű (Ankara University, Turkey) studied the influence of hatching time and post-hatch holding time on yolk sac weight and live performance. The whole hatch window was divided in (1) early hatch (471-474 h), (2) middle hatch (483-486 h) and late hatch (493-496 h) and from all hatch periods, half of the chicks were held for 18 h and 30 h before they received feed. The chicks stored post hatch for 30 h consumed more feed the first 7 days and had a higher 7 days body weight but at day 35 all chicks had a similar body weight.

Development of the microbiome in day old chicks

Jean de Oliveira summarized the research at R&D Cargill, Belgium, on the origin of the intestinal microbiome in day old broiler chicks held under commercial conditions. The results showed that in 5 out the 6 flocks studied there was a strong link, similarity, between microbiota of the parent breeder and offspring in an integrated poultry operation. As a result of vertical transmission from breeder to offspring Salmonella was found in one of 6 flocks.

Posters

Two posters from a research consortium of the University of Pisa (Italy) and INRA- Centre Val de Loire (France) were presented on genetic selection on meat traits of broilers and consequences induced on reproductive performances. From the research presented in both posters it can be concluded that genetic selection for high ultimate pH of the meat measured 24 hr after slaughter results in lower reproductive performance as shown by poorer quality hatching eggs, higher embryo mortality and lower hatchability.

The INRA research group also presented a poster on multigenerational effects of heat manipulation on body temperature and growth in broiler chicks. The study addressed the effects of heat treatments during incubation on body temperature and growth in the two following generations. The thermal manipulation used during embryonic development consisted of increasing the incubation temperature of eggs up to 39.5 °C and relative humidity to 65% for 12 h/d between days 7 and 16 of incubation. The results showed for the first time evidence of a multigenerational effect of heat stimulation during embryogenesis on growth and thermoregulation in fast-growing chickens. It seems that the responses to thermal manipulations are sex-dependant.

Julia George and David Clayton (Queen Mary University, London, UK) presented a poster about the DNA methylation pattern in zebra finch embryos exposed briefly to vocal signals. It was confirmed that the zebra finch embryos react to environmental signals by epigenetic changes, which can be detected by altered DNA-methylation pattern.

Ewa Łukaszewicz and colleagues (University of Wrocław, Poland) presented a poster addressing the enrichment of broiler sperm extender, diluent, for broiler sperm by organic additives. It was concluded that the implementation of organic additives had a positive effect on broiler sperm quality. However, the positive effects lasted for only 6 hours, thereafter the number of live sperm decreased.

Sylvian Briere and colleagues (Hendrix Genetics Turkeys and INRA Nouzilly) presented a poster related to the collection of data for genetic selection strategies. It is concluded that the application of CT-scans technology generates data not only on adipose tissue and bone composition but also about egg, yolk and albumen weights and composition.

Marleen Boerjan (President IFRG, WPSA WG 6 (10/2018)

WG6 Incubation and Fertility Research Group (IFRG)
&
WG12 Fundamental Physiology & Perinatal Development (PDP) in Poultry

The French Branch of WPSA is dedicated to promote knowledge and understanding of all aspects of poultry science and poultry production. It will organize the Combined Meeting of the ‘Incubation and Fertility Research Group’ (IFRG/WPSA Working Group 6) and the ‘Fundamental Physiology and Perinatal Development in Poultry’ (PDP/WPSA Working Group 12) in Tours, August 2019.

On behalf of the French Organizing Committee and the WG-6 and 12 working Groups of the European Federation of WPSA branches, we are pleased to invite you to attend the IFRG - PDP 2019. This congress will take place in Tours, France, on August, 28 to 30, 2019, at hotel ‘Univers’. The Website is currently under construction

Barbara Tzschentke

WG10

Turkeys

The 10th ‘Hafez’ International Symposium on Turkey Production will be held in Berlin, Germany; May/June 2019. I hope to see you in Berlin.

Prof. Dr H. M. Hafez
Chair of Working Group 10
World’s Poultry Science Association
Federation of European Branches
Institute of Poultry Diseases, Free University Berlin
Königsweg 63
14163 Berlin, Germany

Summaries

The role of Astragalus membranaceus as immunomodulator in poultry

M.R. FARAG and M. ALAGAWANY

Astragalus membranaceus (AM) is a member of the family Leguminosae which has been widely used as immunomodulatory agent. Astragalus polysaccharides (APS) possess promising biological activities like immune enhancing, anti-oxidant, anti-viral, anti-microbial and anti-parasitic activities. Researchers have studied the immune enhancing activities of AM in birds and reported that APS and sulphated APS (4 or 8 mg/kg of body weight) showed immunomodulatory effects broiler chicks infected with lipopolysaccharide and modulated the resulting negative effects. AM powder supplementation in broiler feed at levels of 0, 100, 200 and 300 mg /kg diet increased the immune organs weight and IgG level and improved the liver and kidney functions and antioxidant status. Dietary APS (10 g/kg) promoted the growth rate and the histology of jejunum of offspring chickens. The addition of crude AM at 0.5% in laying hen feed for 21 days was able to improve the composition of faecal microorganisms. The following review describes the structure and chemical composition of AM and its immunomodulatory role in improving the health status of poultry and its mechanisms of action.

Phenotypic characteristic of junglefowl and chicken

T.T. DESTA

Junglefowl display adaptive characters like seasonal breeding, well-established social hierarchy, explorative behaviour, territoriality, aggression and short ranged flight, however, they are smaller, produce less and mature later than commercial breeds. Non-green junglefowl cocks display eclipse plumage – a reliable indicator of genetic purity and a trait that has been disappeared from chickens. Junglefowl show high sexual dimorphism, however, intra-sex level variation is considerably limited. There are conflicting reports on viability of hybrids from junglefowl, however, red junglefowl crossed with chickens invariably produce fertile offspring. Although junglefowl and chickens share common parasites and diseases, junglefowl exhibit high variability in natural immunity and are relatively resilient to infection. Junglefowl prefer secondary forests and village environs, demonstrating their propensity for human landscapes. Habitat preference and historical, ritual and leisure activities of ancient man might have resulted in junglefowl being recruited for domestication. Particularly, native chickens share a number of phenotypic characters with junglefowl, however, cosmopolitan chickens have experienced high phenotypic input from world-wide dispersal and adaptation to a wide range of management and breeding regimes. Based on morphological scores and behavioural ecology, red junglefowl resembles chickens and amongst the junglefowls, red and Ceylon junglefowl are closely related, whereas grey and green junglefowl have been found to be distant.

Health promoting and pharmaceutical potential of ferulic acid for the poultry industry

M. SAEED, M. ALAGAWANY, S.A. FAZLANI, S.A. KALHORO, M. NAVEED, N. ALI, KIFAYAT-ULLAH, M.A. ARAIN and S. CHAO

Ferulic acid is (FA) is a phenolic compound found in vegetables, fruits, cereals and coffee. It exists in both a free form and covalently conjugated to polysaccharides in the plant cell wall, polyamines, hydroxyl fatty acids, lignin, and glycoproteins. It has exhibited many vital biological properties, such as growth enhancing, antioxidant, antibacterial and immunomodulatory effects. It can be used as a food preservative and has a wide range of applications. FA has been reported to be a potent antioxidant and anti-inflammatory agent and is considered as part of a promising strategy for improving vascular cell-compatibility and blood compatibility as well. Additionally, dietary FA could improve the antioxidant capacity and, hence, meat quality in poultry. Supplementation of FA at 40 mg/kg or 80 mg/kg diet reduced the formation of hepatic MDA in case of carbon tetrachloride toxicity. The susceptibility of meat to oxidation in broiler chickens receiving oats at 200 g/kg diet as a source of FA was higher compared to the stability of meat in chickens receiving 200 ppm vitamin E. After examining the literature, it became apparent that the research on promising therapeutic effects of FA in poultry, in particular, is limited. So, the aim of this review was to indicate the importance of FA and its beneficial effects. In addition, this review includes information on the use of FA as a natural phenolic compound in poultry nutrition and its different applications in the poultry industry.

Chicken processing: impact, co-products and potential

A.R. SEIDAVI, H. ZAKER-ESTEGHAMATI and C.G. SCANES

Processing poultry results in considerable waste and/or by-products. Assuming a 70% yield during processing, the aggregate of waste from processing chickens for meat globally is 45.9 million tons. The nitrogen in processing waste and by-products globally is 1.3 million metric tons; equivalent to 49% of nitrogen in poultry excreta globally. If yield increased to 80%, as seen in the USA, there is a concomitant reduction in processing waste. If this were extended globally, there would be a 19.1 million metric ton reduction in processing waste. The global cost of processing chicken has been calculated as 51.3 x 109 MJ (equivalent to 0.06% of agricultural/food energy usage). The environmental costs of processing include energy, high quality (potable) water usage (estimated at about 30 litres per bird) and large quantities of organic solids and ‘dirty’ water as by-products together with contamination of surface and of ground water. There is a case for viewing poultry waste as a resource. These co-products could be used as human foods, high protein animal feed ingredients (after rendering), high value health related products (e.g. collagen, hyaluronic acid and chondroitin sulphate), bioenergy (e.g. biodiesel) and other products. The following review focuses on estimating the amount of processing waste and approaches to reduce processing waste, such as increasing yield and considering waste as a resource or, at least potential, co-product.

Flavonoids supplementation - An ideal approach to improve quality of poultry products

A.A. KAMBOH, R.A. LEGHARI, M.A. KHAN, U. KAKA, M. NASEER, A.Q. SAZILI and K.K. MALHI

Supplementing flavonoids in poultry diets has shown the potential to progress the nutritional, sensorial and microbiological quality of poultry meat and eggs. In the last decade, several studies have determined the benefits of flavonoids for inhibition of lipid oxidation and microbial growth, check any pH-dependent deterioration and improve the colour stability of meat and related products. Flavonoids are typically absorbed in the ileum where pH is between 5-6.8. The various flavonoids vary in effective dose levels in poultry, but are typically included in levels ranging from 0.05-0.2%. Furthermore, flavonoid supplementation in the chicken diet has been reported to positively alter the fatty acid profile of meat and eggs by reducing the cholesterol and triglyceride content. Meat colour, in terms of lightness, can be improved by up to 5%. The aim of this review is to evaluate the use of various plant flavonoids as a substitute for synthetic feed additives in the poultry feed industry to satisfy consumer demands in terms of quality and safety of animal products. The results have stimulated interest in more research on the various flavonoid classes to determine the most effective compounds and their optimal doses for both broilers and laying hens.

Wood-based litter in poultry production: a review

M.T. MUNIR, C. BELLONCLE, M. IRLE and M. FEDERIGHI

Bedding material is an important factor for floor-based poultry production systems as it can affect bird health and welfare. Bedding can be made of organic materials like wood or plant-based material or inorganic materials like clay and sand, and should generally have good absorbency, be easily available, comfortable and non-toxic to birds. Wood is an organic renewable resource having good humidity regulation and antimicrobial properties and its by-products are commonly used as poultry litter in many countries. In France, wood-based bedding is used in 80% of turkey production. This litter has approximately 50% lower NH3 production compared to other materials like sand and hulls, and has multiple environment-friendly disposal options. Moreover, the birds grown on such litter show better health and welfare and are more likely to exhibit natural behaviour on this material, which is helpful for the amelioration of physiological status and reduction of locomotory injuries. Moreover, birds can show between 5-7% improvements in different performance parameters. In addition, the antimicrobial potential of wood may help to counter the load of certain pathogens in environment of birds. This review describes the physiochemical properties of wood-based bedding materials and their role in production and welfare of poultry.

Outlook on EU and Croatian poultry meat market - Partial equilibrium model approach

D. KRANJAC, K. ZMAIĆ, A. CRNČAN and M. ZRAKIĆ

The European Union poultry meat market is the subject of numerous research studies due to its importance in the EU's total agricultural production, exports and food security. With 14.5 million tons of poultry meat production in 2016, the EU-28 is one of the world's leading producers of this kind of meat (approximately 12%). The Old Member States (EU-15) and the New Member States (EU-13) generate 73.8% and 26.2% of the total EU poultry meat production, respectively. The average poultry meat consumption in the EU-28 is currently approximately 24 kg per capita. In the last decade, the EU's poultry meat market has seen structural changes in production, consumption and trade that are the subject of the partial equilibrium model analysis. Results of mid-term projections for the poultry meat market through to the year 2030 showed a decrease in production volume in the EU-15, along with a slowdown of domestic and per capita consumption and a change of status from net exporters to net importers of poultry meat. Meanwhile, in the EU-13 there has been a steady growth in the volume of production and domestic and per capita consumption of poultry meat. The EU-13 Member States will remain net exporters through 2030, with a strong trend in export growth. Croatia, the youngest member state, follows trends in the domestic poultry meat market that are similar to the rest of the EU-13. Until 2030, Croatian poultry meat production is expected to increase by 43.02%, the domestic consumption by 29.37% and per capita consumption for 39.89%. Although Croatia will remain a net importer by the end of the 2030, the gap in net trade deficit is expected to decrease by 31.31%.

Behaviour and meat quality of chicken under different housing systems

A. EL-DEEK and K. EL-SABROUT

Chicken housing systems have been an interesting subject of research for many years and remains a topic of debate. The information detailed in the literature provides opposing views on recommended housing systems (indoor or outdoor) for chickens, and thus, producers are searching for more precise information in terms of animal welfare, productive performance, chicken behaviour and meat quality. Approximately 80% of customers worldwide prefer chicken products with perceived higher quality derived from free-range (organic) systems with increased welfare standards. Based on published literature, the majority (approximately 70%) of intensive production systems that are currently used do not usually support the natural behavioural needs of poultry. However, mortality rate of broilers can reach more than 10% in outdoor production systems due to cannibalism. Suitable housing systems that focus on the animals’ well -being translate into better behavioural activities and higher productive performance. The present review provides the critical information detailed in the existing literature on different housing systems and their effect on chicken behaviour and meat quality. It can be concluded that the housing system, as a non-genetic factor, directly affects the welfare of the birds and can impact their behaviour and certain meat quality traits. Thus, the free-range production system might be considered favourable alternative housing system.

The implication of lighting programmes in intensive broiler production system

M.A. AROWOLO, J.H. HE, S. HE and T.O. ADEBOWALE

Lighting, amongst other factors, is a potent and critical micro-climatic component in broiler houses as it influences many behavioural, physiological and metabolic processes in birds. To optimise the intensive system for broiler production, various lighting programmes (regarding light duration and its distribution, light colour/wavelength and light intensity) have been explored. This review compares the effects of different elements of lighting regimen on the growth performance, health, and welfare and carcass characteristics of broilers. Considering this, various degrees of intermittent photo-period (i.e. mixing photo- and scoto- periods within 24 hours) rather than one continuous photoperiod have been proven to significantly improve broilers’ weight gain by 3.4-5.8%, feed to gain ratio up to 7.3%, mobility up to 46.5%, decrease mortality rate ranging between 0.43% and 0.72%, and finally, increase carcass yield. Short wavelength lights and light intensity of ≥5 lux after the initial brooding period are said to stimulate birds’ metabolism and growth thereby, enhancing the production system. In conclusion, the lighting programme, apart from improving broiler productivity, could reduce cost expended on energy in an intensive production system.

Present and potential impacts of waste from poultry production on the environment

A.R. SEIDAVI, H. ZAKER-ESTEGHAMATI and C.G. SCANES

Poultry production is associated with greenhouse gas (GHG) emissions but at a much lower extent than other livestock. Global production of nitrogen from poultry excreta has been estimated at about 3.29 million metric tons for meat type chickens (the average of two estimates with different assumption of 2.65 and 3.94 million metric tons) and 2.36 million metric tons for laying hens. These estimates are markedly below earlier estimates, suggesting that the issues related to loading are of a markedly smaller magnitude than previously envisioned. However, if it is assumed that 2% of the nitrogen is lost as nitrous oxide with a global warming potential (GWP) of 298 CO2 equivalents (eq.) per unit as GHG, poultry waste is contributing 33.7 million metric tons of CO2 eq./year or 0.0337 gigatons (Gt) CO2 eq./yr. This represents only 0.64% of agricultural GHG emissions. The preferred method for the disposal of poultry excreta is land application as a fertiliser with the aggregate of livestock and poultry excreta being applied to 0.3 million hectares in the USA. The environmental consequences of excreta in litter include the release of ammonia and nitrous oxide (a GHG) together with contamination of ground and surface water with nitrate, phosphate and pathogens. Alternative approaches to utilise used litter are the following: combustion, gasification, digestion and feeding to ruminants. There is scope to reduce the environmental impact of poultry production on the environment.