A review of the financial impact of production diseases in poultry production systems
P. J. Jones A D , J. Niemi B , J.-P. Christensen C , R. B. Tranter A and R. M. Bennett AA School of Agriculture, Policy and Development, University of Reading, PO Box 237, Whiteknights, Reading, RG6 6AR, UK.
B Natural Resources Institute Finland (Luke), Bioeconomy and Environment Unit, Kampusranta 9, FI-60320 Seinäjoki, Finland.
C Department of Veterinary and Animal Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Stigbøjlen 4, 1870 Frederiksberg C, Denmark.
D Corresponding author. Email: p.j.jones@reading.ac.uk
Animal Production Science 59(9) 1585-1597 https://doi.org/10.1071/AN18281
Submitted: 5 May 2018 Accepted: 31 August 2018 Published: 29 October 2018
Abstract
While the academic literature widely asserts that production diseases have a significant financial impact on poultry production, these claims are rarely supported by empirical evidence. There is a risk, therefore, that the information needs of poultry producers regarding the costs associated with particular diseases are not being adequately met. A systematic literature review of poultry production diseases was undertaken, first, to scope the availability of studies that estimate the financial impacts of production diseases on poultry systems and, second, on the basis of these studies, estimates were generated of the magnitude of these impacts. Nine production diseases, selected by a panel of stakeholders as being economically important in the EU, were examined. The review found that the poultry disease literature has primarily an epidemiological focus, with very few publications providing estimates of the financial impacts of diseases. However, some publications have quantified the physical impacts of production diseases and control interventions, for example, using measures such as output volumes, mortality rates and bacterial counts. Using these data in standard financial models, partial financial analyses were possible for some poultry production diseases. Coccidiosis and clostridiosis were found to be the most common production diseases in broiler flocks, with salpingoperitonitis being the most common in layers. While the financial impact of untreated diseases varied, most uncontrolled diseases were estimated to make flocks loss-making. However, in all cases, interventions were available that signficantly reduced these losses. The review reinforces the concern that the available academic literature is not providing sufficient information for poultry producers to decide on financially optimal disease-prevention and treatment measures.
Additional keywords: poultry diseases, systematic literature review.
References
Abdelrahman W, Mohnl M, Teichmann K, Doupovec B, Schatzmayr G, Lumpkins B, Mathis G (2014) Comparative evaluation of probiotic and salinomycin effects on performance and coccidiosis control in broiler chickens. Poultry Science 93, 3002–3008.| Comparative evaluation of probiotic and salinomycin effects on performance and coccidiosis control in broiler chickens.Crossref | GoogleScholarGoogle Scholar |
Acar N, Sizemore FG, Leach GR, Wideman RF, Owen RL, Barbatio GF (1995) Growth of broiler chickens in response to feed restriction regimens to reduce ascites. Poultry Science 74, 833–843.
| Growth of broiler chickens in response to feed restriction regimens to reduce ascites.Crossref | GoogleScholarGoogle Scholar |
Agro Business Consultants Ltd (2012) ‘ABC budgeting & costings book.’ 83rd edn. November 2016. (Agro Business Concultants Ltd: Melton Mowbray, UK)
Allain V, Mirabito L, Arnould C, Colas M, Le Bouquin S, Lupo C, Michel V (2009) Skin lesions in broiler chickens measured at the slaughterhouse: relationships between lesions and between their prevalence and rearing factors. British Poultry Science 50, 407–417.
| Skin lesions in broiler chickens measured at the slaughterhouse: relationships between lesions and between their prevalence and rearing factors.Crossref | GoogleScholarGoogle Scholar |
Ambrosen T, Petersen VE (1997) The influence of protein level in the diet on cannibalism and quality of plumage of layers. Poultry Science 76, 559–563.
| The influence of protein level in the diet on cannibalism and quality of plumage of layers.Crossref | GoogleScholarGoogle Scholar |
Aminov RI, Mackie RI (2007) Evolution and ecology of antibiotic resistance genes. FEMS Microbiology Letters 271, 147–161.
| Evolution and ecology of antibiotic resistance genes.Crossref | GoogleScholarGoogle Scholar |
Arce J, Berger M, Lopez Coello C (1992) Control of ascites syndrome by feed restriction techniques. Journal of Applied Poultry Research 1, 1–5.
| Control of ascites syndrome by feed restriction techniques.Crossref | GoogleScholarGoogle Scholar |
Arce-Menocal J, Avila-Gonzalez E, Lopez-Cello C, Garibay-Torres G, Martinez-Lemus LA (2009) Body weight, feed-particle size and ascites incidence revisited. Journal of Applied Poultry Research 18, 465–471.
| Body weight, feed-particle size and ascites incidence revisited.Crossref | GoogleScholarGoogle Scholar |
Assured Chicken Production (ACP) Standards (2006) ‘Key health and welfare indicators for broiler production.’ Available at http://www.journals.cambridge.org/ [Verified May 2016]
Balevi T, Ucan US, Coskun B, Kurtoglu V, Cetingul IS (2001) Effect of dietary probiotic on performance and humoral immune response in layer hens. British Poultry Science 42, 456–461.
| Effect of dietary probiotic on performance and humoral immune response in layer hens.Crossref | GoogleScholarGoogle Scholar |
Bell D (2012) US experiences with Lohmann Selected Leghorn (LSL-Lite) layers, part 3: livability. Lohmann Information 47, 22–33.
Bennett R (2012) Economic rationale for interventions to control livestock disease. EuroChoices 11, 5–10.
| Economic rationale for interventions to control livestock disease.Crossref | GoogleScholarGoogle Scholar |
Bilgili SF, Hess JB, Blake JP, Macklin KS, Saenmahayak B, Sibley JL (2009) Influence of bedding material on footpad dermatitis in broiler chickens. Journal of Applied Poultry Research 18, 583–589.
| Influence of bedding material on footpad dermatitis in broiler chickens.Crossref | GoogleScholarGoogle Scholar |
Bisgaard M (1976) The influence of infectious bronchitis virus on egg production, fertility, hatchability and mortality rate in chickens. Nordisk Veterinaermedicin 28, 368–376.
Bisgaard M, Dam A (1981) Salpingitis in poultry II: prevalence, bacteriology and possible pathogenesis in egg laying chickens. Nordisk Veterinaermedicin 33, 81–89.
Burton RW, Sheridan AK, Howlett CR (1981) The incidence and importance of tibial dyschondroplasia to the commercial broiler industry in Australia. British Poultry Science 22, 153–160.
| The incidence and importance of tibial dyschondroplasia to the commercial broiler industry in Australia.Crossref | GoogleScholarGoogle Scholar |
Camacho-Fernandez D, Lopez C, Avilla E, Arce J (2002) Evaluation of different dietary treatments to reduce ascites syndrome and their effects on corporal characteristics in broiler chickens. Journal of Applied Poultry Research 11, 164–174.
| Evaluation of different dietary treatments to reduce ascites syndrome and their effects on corporal characteristics in broiler chickens.Crossref | GoogleScholarGoogle Scholar |
Cengiz O, Hess JB, Bilgili SF (2011) Effect of bedding type and transient wetness on footpad dermatitis in broiler chickens. Journal of Applied Poultry Research 20, 554–560.
| Effect of bedding type and transient wetness on footpad dermatitis in broiler chickens.Crossref | GoogleScholarGoogle Scholar |
Cocsik E, Kortes HE, Oude Lansink AGJM, Saatkamp HW (2014) Effects of different broiler production systems on health care costs in The Netherlands. Poultry Science 93, 1301–1317.
Cook JKA, Orbell SJ, Woods MA, Huggins MB (1999) Breadth of protection of the respiratory tract provided by different live-attenuated infectious bronchitis vaccines against challenge with infectious bronchitis viruses of heterologous serotypes. Avian Pathology 28, 477–485.
| Breadth of protection of the respiratory tract provided by different live-attenuated infectious bronchitis vaccines against challenge with infectious bronchitis viruses of heterologous serotypes.Crossref | GoogleScholarGoogle Scholar |
Craig JV, Lee HY (1990) Beak trimming and genetic stock effects on behavior and mortality from cannibalism in White Leghorn-type pullets. Applied Animal Behaviour Science 25, 107–123.
| Beak trimming and genetic stock effects on behavior and mortality from cannibalism in White Leghorn-type pullets.Crossref | GoogleScholarGoogle Scholar |
Crane R, Davenport R, Laney S, Vaughan R (2014) Poultry production in England: farm business survey 2012/13. Rural Business Research (RBR), February 2014.
de Jong IC, Gunnink H, van Harn J (2014) Wet litter not only induces footpad dermatitis but also reduces overall welfare, technical performance and carcass yield in broiler chickens. Journal of Applied Poultry Research 23, 51–58.
| Wet litter not only induces footpad dermatitis but also reduces overall welfare, technical performance and carcass yield in broiler chickens.Crossref | GoogleScholarGoogle Scholar |
Edwards HM (1990) Efficacy of several vitamin D compounds in the prevention of tibial dyschondroplasia in broiler chickens. The Journal of Nutrition 120, 1054–1061.
| Efficacy of several vitamin D compounds in the prevention of tibial dyschondroplasia in broiler chickens.Crossref | GoogleScholarGoogle Scholar |
Edwards HM, Sorensen P (1987) Effect of short fasts on the development of tibial dyschondroplasia in chickens. The Journal of Nutrition 117, 194–200.
| Effect of short fasts on the development of tibial dyschondroplasia in chickens.Crossref | GoogleScholarGoogle Scholar |
EFSA (2010) Scientific opinion on the influence of genetic parameters on the welfare and the resistance to stress of commercial broilers. EFSA Journal 8, 1666
| Scientific opinion on the influence of genetic parameters on the welfare and the resistance to stress of commercial broilers.Crossref | GoogleScholarGoogle Scholar |
European Food Safety Authority (EFSA), European Centre for Disease Prevention and Control (ECDPC) (2016) The European Union summary report on antimicrobial resistance in zoonotic and indicator bacteria from humans, animals and food in 2014. EFSA Journal 14, 4380
Ekstrand C, Algers B, Svedberg J (1997) Rearing conditions and foot-pad dermatitis in Swedish broiler chickens. Preventive Veterinary Medicine 31, 167–174.
| Rearing conditions and foot-pad dermatitis in Swedish broiler chickens.Crossref | GoogleScholarGoogle Scholar |
El-Lethey H, Aerni V, Jungi TW, Wechsler B (2000) Stress and feather pecking in laying hens in relation to housing conditions. British Poultry Science 41, 22–28.
| Stress and feather pecking in laying hens in relation to housing conditions.Crossref | GoogleScholarGoogle Scholar |
EU (2011) ‘EU action plan against the rising threats from antimicrobial resistance, COM (2011) 748.’ Available at http://ec.europa.eu/dgs/health_consumer/docs/communication_amr_2011_748_en.pdf [Verified May 2016]
European Commission (2015) ‘World food consumption patterns: trends and drivers.’ EU Agricultural markets briefs, no. 6, June 2015. Available at https://ec.europa.eu/agriculture/markets-and-prices/market-briefs_en [Verified May 2016]
EUROSTAT (2016) ‘Agriculural accounts and prices.’ Available at http://ec.europa.eu/eurostat/statistics-explained/index.php/Agricultural_accounts_and_prices [Verified August 2016]
FAO (2016a) ‘Livestock in the balance, change in the livestock sector.’ Available at http://www.fao.org/docrep/005/y4252e/y4252e07.htm [Verified May 2016]
FAO (2016b) ‘Food supply – livestock and fish primary equivalent.’ Available at http://faostat.fao.org/site/610/DesktopDefault.aspx?PageID=610#ancor [Verified May 2016]
FAO (2016c) ‘Livestock production.’ Available at http://www.fao.org/docrep/005/y4252e/y4252e07.htm [Verified May 2016]
Faramarzi S, Bijanzad P, Javaherzadeh V, Moomivand H, Stabraghi E, Dehnavi EN, Ghaedi A, Zarghami A (2014) Evaluation of two different infectious bronchitis vaccination programmes in broiler breeder chickens. International Journal of Biosciences 5, 210–216.
| Evaluation of two different infectious bronchitis vaccination programmes in broiler breeder chickens.Crossref | GoogleScholarGoogle Scholar |
FDA (2005) ‘Withdrawal of enrofloxacin for poultry.’ Available at http://www.fda.gov/AnimalVeterinary/SafetyHealth/RecallsWithdrawals/ucm042004.htm [Verified May 2016]
Fossum O, Hansson DS, Engelsen Etterlin P, Vagsholm I (2009) Causes of mortality in laying hens in different housing systems in 2001 to 2004. Acta Veterinaria Scandinavica 51, 3
| Causes of mortality in laying hens in different housing systems in 2001 to 2004.Crossref | GoogleScholarGoogle Scholar |
Glatz PC (2001) Effect of poor feather cover on feed intake and production of aged laying hens. Asian–Australian Journal of Animal Science 14, 553–558.
Gocsik E, Kortes HE, Oude Lansink AGJM, Saatkamp HW (2014) Effects of different broiler production systems on health care costs in the Netherlands. Poultry Science 93, 1301–1317.
| Effects of different broiler production systems on health care costs in the Netherlands.Crossref | GoogleScholarGoogle Scholar |
Gregersen RH, Christensen H, Ewers C, Bisgaard M (2010) Impact of Escherichia coli vaccine on parent stock mortality, first week mortality of broilers and population diversity of E. Coli in vaccinated flocks. Avian Pathology 39, 287–295.
| Impact of Escherichia coli vaccine on parent stock mortality, first week mortality of broilers and population diversity of E. Coli in vaccinated flocks.Crossref | GoogleScholarGoogle Scholar |
Hagger C, Marguerat C, Steiger-Stafl D, Stranzinger G (1989) Plumage condition, feed consumption and egg production relationships in laying hens. Poultry Science 68, 221–225.
| Plumage condition, feed consumption and egg production relationships in laying hens.Crossref | GoogleScholarGoogle Scholar |
Hassanzadeh M, Gilanpour H, Charkkar S, Buyse J, Decuypere E (2005) Anatomical parameters of cardiopulmonary system in three different lines of chickens: further evidence for involvement in ascites syndrome. Avian Pathology 34, 188–193.
| Anatomical parameters of cardiopulmonary system in three different lines of chickens: further evidence for involvement in ascites syndrome.Crossref | GoogleScholarGoogle Scholar |
Hassanzadeh M, Buyse J, Decuypere E (2008) Further evidence for the involvement of anatomical parmeters of cardiopulmonary system in the development of ascites syndrome in broiler chickens. Acta Veterinaria Hungarica 56, 71–80.
| Further evidence for the involvement of anatomical parmeters of cardiopulmonary system in the development of ascites syndrome in broiler chickens.Crossref | GoogleScholarGoogle Scholar |
Havenstein GB, Ferket PR, Qureshi MA (2003) Growth, livability, and feed conversion of 1957 versus 2001 broilers when fed representative 1957 and 2001 broiler diets. Poultry Science 82, 1500–1508.
| Growth, livability, and feed conversion of 1957 versus 2001 broilers when fed representative 1957 and 2001 broiler diets.Crossref | GoogleScholarGoogle Scholar |
Ignjatovic J, Sapats S (2000) Avian infectious bronchitis virus. Revue scientifique et technique (International Office of Epizootics) 19, 493–508.
| Avian infectious bronchitis virus.Crossref | GoogleScholarGoogle Scholar |
Izadinia M, Nobakht M, Khajali F, Faraji M, Zamani F, Qujeq D, Karimi I (2010) Pulmonary hypertension and ascites as affected by dietary protein source in broiler chickens reared in cool temperature at high altitudes. Animal Feed Science and Technology 155, 194–200.
| Pulmonary hypertension and ascites as affected by dietary protein source in broiler chickens reared in cool temperature at high altitudes.Crossref | GoogleScholarGoogle Scholar |
Jones RC, Worthington KJ, Capua I, Naylor CJ (2005) Efficacy of live infectious bronchitis vaccines against a novel European genotype, Italy 02. The Veterinary Record 156, 646–647.
Jordan FTW, Williams NJ, Jones WT (2005) Observations on salpingitis, peritonitis and salpingoperitonitis in layer breeder flock. The Veterinary Record 157, 573–577.
| Observations on salpingitis, peritonitis and salpingoperitonitis in layer breeder flock.Crossref | GoogleScholarGoogle Scholar |
Kalmar ID, Vanrompay D, Janssens GPJ (2013) Broiler ascites syndrome: collateral damage from efficient feed to meat conversion. Veterinary Journal (London, England) 197, 169–174.
| Broiler ascites syndrome: collateral damage from efficient feed to meat conversion.Crossref | GoogleScholarGoogle Scholar |
Khajali F, Zamani-Moghaddam A, Asadi-Khoshoei E (2007) Application of an early skip-a-day feed restriction on physiological parameters, carcass traits and development of ascites in male broilers reared under regular or cold temperatures at high altitude. Animal Science 78, 159–163.
| Application of an early skip-a-day feed restriction on physiological parameters, carcass traits and development of ascites in male broilers reared under regular or cold temperatures at high altitude.Crossref | GoogleScholarGoogle Scholar |
Lambton SL, Nicol CJ, Friel M, Main DCJ, McKinstry CM, Sherwin J, Weeks CA (2013) A bespoke management package can reduce levels of injurious pecking in loose-housed laying hen flocks. The Veterinary Record 172, 423
| A bespoke management package can reduce levels of injurious pecking in loose-housed laying hen flocks.Crossref | GoogleScholarGoogle Scholar |
Lee JT, Broussard C, Fitz-Coy S, Burke P, Eckert NH, Stevens SM, Anderson PN, Caldwell DJ (2009) Evaluation of live oocyst vaccination or salinomycin for control of field-strain Eimeria challenge in broilers on two different feeding programs. Journal of Applied Poultry Research 18, 458–464.
| Evaluation of live oocyst vaccination or salinomycin for control of field-strain Eimeria challenge in broilers on two different feeding programs.Crossref | GoogleScholarGoogle Scholar |
Leeson S, Morrison WD (1978) Effect of feather cover on feed efficiency in laying birds. Poultry Science 57, 1094–1096.
| Effect of feather cover on feed efficiency in laying birds.Crossref | GoogleScholarGoogle Scholar |
Leeson S, Gonzalo J, Summers JD (1995) ‘Poultry metabolic disorders and mycotoxins.’ (University Books: Guelph, Ontario, Canada)
Li GQ, Kanu S, Xiao SM, Xiang FY (2005) Responses of chickens vaccinated with a live attenuated multi-valent ionophore-tolerant Eimeria vaccine. Veterinary Parasitology 129, 179–186.
Lilburn MS, Lauterio TJ (1989) Relationships among mineral balance in the diet, early growth manipulation and incidence of tibial dyschondroplasia in different strains of meat type chickens. Poultry Science 68, 1263–1273.
| Relationships among mineral balance in the diet, early growth manipulation and incidence of tibial dyschondroplasia in different strains of meat type chickens.Crossref | GoogleScholarGoogle Scholar |
Liverani M, Waage J, Barnett T, Pfeiffer DU, Rushton J, Rudge JW, Loevinsohn ME, Scoones E, Smith RD, Cooper BS, White LJ, Goh S, Horby P, Wren B, Gundogdu O, Woods A, Coker RJ (2013) Understanding and managing zoonotic risk in the new livestock industries. Environmental Health Perspectives 121, 873–877.
| Understanding and managing zoonotic risk in the new livestock industries.Crossref | GoogleScholarGoogle Scholar |
Lovland A, Kaldhusdal M (2001) Severely impaired production performance in broiler flocks with high incidence of Clostridium perfringens-associated hepatitis. Avian Pathology 30, 73–81.
| Severely impaired production performance in broiler flocks with high incidence of Clostridium perfringens-associated hepatitis.Crossref | GoogleScholarGoogle Scholar |
Luo L, Tong J, Huang J (1992) Effects of dietary chloride and magnesium on the incidence of tibial dyschondroplasia in chickens fed on Chinese practical diets. British Poultry Science 33, 603–611.
| Effects of dietary chloride and magnesium on the incidence of tibial dyschondroplasia in chickens fed on Chinese practical diets.Crossref | GoogleScholarGoogle Scholar |
Martland MF (1985) Ulcerative dermatitis in broiler chickens: the effects of wet litter. Avian Pathology 14, 353–364.
| Ulcerative dermatitis in broiler chickens: the effects of wet litter.Crossref | GoogleScholarGoogle Scholar |
Maxwell MH, Robertson GW (1998) UK survey of broiler ascites and sudden death syndromes in 1993. British Poultry Science 39, 203–215.
| UK survey of broiler ascites and sudden death syndromes in 1993.Crossref | GoogleScholarGoogle Scholar |
Mayne RK, Else RW, Hocking PM (2007) High litter moisture alone is sufficient to cause footpad dermatitis in growing turkeys. British Poultry Science 48, 538–545.
| High litter moisture alone is sufficient to cause footpad dermatitis in growing turkeys.Crossref | GoogleScholarGoogle Scholar |
Medina HA (2008) ‘Factors that could indice peritonitis in commercial egg layers.’ Zootechnica, 2 October 2008. Available at http://www.zootecnicainternational.com/article-archive/veterinary/234-factors-that-could-induce-peritonitis-in-commercial-egg-layers-.html [Verified May 2016]
Merle R, Koesters S, Suerie C, Ovelhey A, Kreienbrock L (2009) Mortality in laying hens – a comparison of different housing systems. In ‘Proceedings of the 12th symposium of the International Society for Veterinary Epidemiology and Economics’, 10–14 August 2009, Durban, South Africa. p. 108.
Miguel JA, Asenjo B, Ciria J, del Cacho E, Calco JL (2008) Comparison of control methods for coccidiosis in native Spanish ‘Castellana Negra’ chickens. Spanish Journal of Agricultural Research 6, 531–536.
| Comparison of control methods for coccidiosis in native Spanish ‘Castellana Negra’ chickens.Crossref | GoogleScholarGoogle Scholar |
Miller RW, Skinner EJ, Sulakvelidze A, Mathis GF, Hofacre CL (2010) Bacteriophage therapy for control of necrotic enteritis of broiler chickens experimentally infected with clostridium perfringens. Avian Diseases 54, 33–40.
| Bacteriophage therapy for control of necrotic enteritis of broiler chickens experimentally infected with clostridium perfringens.Crossref | GoogleScholarGoogle Scholar |
Morris MP (1993) National survey of leg problems. Broiler Industry 93, 20–24.
Muneer MA, Halvorson DA, Sivanandan V, Newman JA, Coon CN (1986) Effects of infectious bronchitis virus (Arkansas strain) on laying chickens. Avian Diseases 30, 644–647.
| Effects of infectious bronchitis virus (Arkansas strain) on laying chickens.Crossref | GoogleScholarGoogle Scholar |
Muneer MA, Newman JA, Halvorson DA, Sivanandan V, Coon CA (1987) Effects of avian infectious bronchitis virus (Arkansas strain) on vaccinated laying chickens. Avian Diseases 31, 820–828.
| Effects of avian infectious bronchitis virus (Arkansas strain) on vaccinated laying chickens.Crossref | GoogleScholarGoogle Scholar |
Muneer MA, Chaudhry KM, Khawaja KM (2000) Losses due to infectious bronchitis virus infection in laying and breeding hens. Pakistan Veterinary Journal 20, 64–70.
Nahashon SN, Nakaue HS, Mirosh LW (1996) Performance of single comb White Leghorn fed a diet supplemented with a live microbial during the growth and egg laying phases. Animal Feed Science and Technology 57, 25–38.
| Performance of single comb White Leghorn fed a diet supplemented with a live microbial during the growth and egg laying phases.Crossref | GoogleScholarGoogle Scholar |
Narrod C, Tiongco M, Costales A (2008) ‘Global poultry sector trends and external drivers of structural change.’ Available at http://www.fao.org/AG/againfo/home/events/bangkok2007/docs/part1/1_1.pdf [Verified 25 May 2016]
Nasr MAF, Murrell J, Wilkins LJ, Nicol CJ (2012) The effect of keel fractures on egg-production parameters, mobility and behaviour in individual laying hens. Animal Welfare 21, 127–135.
| The effect of keel fractures on egg-production parameters, mobility and behaviour in individual laying hens.Crossref | GoogleScholarGoogle Scholar |
Nasr MAF, Murrella J, Nicol CJ (2013) The effect of keel fractures on egg production, feed and water consumption in individual laying hens. British Poultry Science 54, 165–170.
| The effect of keel fractures on egg production, feed and water consumption in individual laying hens.Crossref | GoogleScholarGoogle Scholar |
National Chicken Council (2016) ‘U.S. broiler performance.’ Available at http://www.nationalchickencouncil.org/about-the-industry/statistics/u-s-broiler-performance/ [Verified 19 May 2016]
Nicol CJ, Gregory NG, Knowles TG, Parkman ID, Wilkins LJ (1999) Differential effects of increased stocking density, mediated by increased flock size, on feather pecking and aggression in laying hens. Applied Animal Behaviour Science 65, 137–152.
| Differential effects of increased stocking density, mediated by increased flock size, on feather pecking and aggression in laying hens.Crossref | GoogleScholarGoogle Scholar |
Onbasilar EE, Erol H, Cantekin Z, Kaya U (2007) Influence of intermittent lighting on broiler performance, incidence of tibial dyschondroplasia, tonic immobility, some blood parameters and antibody production. Asian–Australian Journal of Animal Sciences 20, 550–555.
Pagazaurtundua A, Warriss PD (2006) Levels of foot pad dermatitis in broiler chickens reared in 5 different systems. British Poultry Science 47, 529–532.
| Levels of foot pad dermatitis in broiler chickens reared in 5 different systems.Crossref | GoogleScholarGoogle Scholar |
Peguri A, Coon C (1993) Effect of feather coverage and temperature on layer performance. Poultry Science 72, 1318–1329.
| Effect of feather coverage and temperature on layer performance.Crossref | GoogleScholarGoogle Scholar |
Petek M, Sonmez G, Yildiz H, Baspinar H (2005) Effects of different management factors on broiler performance and incidence of tibial dyschondroplasia. British Poultry Science 46, 16–21.
| Effects of different management factors on broiler performance and incidence of tibial dyschondroplasia.Crossref | GoogleScholarGoogle Scholar |
Petrik MT, Guerin MT, Widowski TM (2015) On-farm comparison of keel fracture prevalence and other welfare indicators in conventional cage and floor-housed laying hens in Ontario, Canada. Poultry Science 94, 579–585.
| On-farm comparison of keel fracture prevalence and other welfare indicators in conventional cage and floor-housed laying hens in Ontario, Canada.Crossref | GoogleScholarGoogle Scholar |
Reid G, Bocking A (2003) The potential for probiotics to prevent bacterial vaginosis and preterm labor. American Journal of Obstetrics and Gynecology 189, 1202–1208.
| The potential for probiotics to prevent bacterial vaginosis and preterm labor.Crossref | GoogleScholarGoogle Scholar |
Rincon MU (2000) Mild feed restriction and compensatory growth in the broiler chicken. MSc Thesis, University of Guelph, Guelph, Canada.
RSPCA (2016) ‘Laying hens: farming (egg production).’ Available at http://www.rspca.org.uk/adviceandwelfare/farm/layinghens/farming [Verified May 2016]
Sherwin CM, Richards GJ, Nicol CJ (2010) Comparison of the welfare of layer hens in 4 housing systems in the UK. British Poultry Science 51, 488–499.
| Comparison of the welfare of layer hens in 4 housing systems in the UK.Crossref | GoogleScholarGoogle Scholar |
Shini S, Shini A, Blackall PJ (2013) The potential for probiotics to prevent reproductive tract lesions in free-range laying hens. Animal Production Science 53, 1298–1308.
Shirley MW, Bushell AC, Bushell JE, McDonald V, Roberts B (1995) A live attenuated vaccine for the control of avian coccidiosis: trials in broiler breeders and replacement layer flocks in the UK. The Veterinary Record 137, 453–457.
| A live attenuated vaccine for the control of avian coccidiosis: trials in broiler breeders and replacement layer flocks in the UK.Crossref | GoogleScholarGoogle Scholar |
Suo X, Zhang JX, Li ZG, Yang CT, Min QR, Xu LT, Lui Q, And Zhu XQ (2006) The efficacy and economic benefits of Supercox®, a live anticoccidial vaccine in a commercial trial in broiler chickens in China. Veterinary Parasitology 142, 63–70.
| The efficacy and economic benefits of Supercox®, a live anticoccidial vaccine in a commercial trial in broiler chickens in China.Crossref | GoogleScholarGoogle Scholar |
Swayne DE (2013) ‘Diseases of poultry.’ 13th edn. (Ed. DE Swayne; Associate eds JR Glisson, LR McDougald, LK Nolan, DL Suarez, V Nair) (Wiley-Blackwell: New York)
Sykes R (2010) The 2009 Garrod lecture: the evolution of antimicrobial resistance: a Darwinian perspective. The Journal of Antimicrobial Chemotherapy 65, 1842–1852.
| The 2009 Garrod lecture: the evolution of antimicrobial resistance: a Darwinian perspective.Crossref | GoogleScholarGoogle Scholar |
Tactacan GB, Schmidt JK, Miille MJ, Jimenez DR (2013) A Bacillus subtilis (QST 713) spore-based probiotic for necrotic enteritis control in broiler chickens. Journal of Applied Poultry Research 22, 825–831.
| A Bacillus subtilis (QST 713) spore-based probiotic for necrotic enteritis control in broiler chickens.Crossref | GoogleScholarGoogle Scholar |
Taira K, Nagai T, Obi T, Takase K (2014) Effect of litter moisture on the development of footpad dermatitis in broiler chickens. The Journal of Veterinary Medical Science 76, 583–586.
| Effect of litter moisture on the development of footpad dermatitis in broiler chickens.Crossref | GoogleScholarGoogle Scholar |
Tarpey I, Orbell SJ, Britton P, Casais R, Hodgson T, Lin F, Hogan E, Cavanagh D (2006) Safety and efficacy of infectious bronchitis virus used for chicken embryo vaccination. Vaccine 24, 6830–6838.
| Safety and efficacy of infectious bronchitis virus used for chicken embryo vaccination.Crossref | GoogleScholarGoogle Scholar |
Tawfik HI, Salama E, Hassan OM, Ahmed A (2013) Preparation and evaluation of live bivalent bronchitis vaccine in chicken. Researcher 5, 31–35.
Thøfner I, Ladefoged Poulsen L, Bisgaard M, Christensen H, Heidemann Olsen R, Christensen JP (2015) Longitudinal study of mortality observed in four broiler breeder flocks. In ‘19th WVPA Congress’, 7–11 November 2015, Cape Town. p. 148.
Tablante NL, Estevez I, Russek-Cohen E (2003) Effect of perches and stocking density on tibial dyschondroplasia and bone mineralization as measured by bone ash in broiler chickens. Journal of Applied Poultry Research 12, 53–59.
| Effect of perches and stocking density on tibial dyschondroplasia and bone mineralization as measured by bone ash in broiler chickens.Crossref | GoogleScholarGoogle Scholar |
Traill WB, Mazzocchi M, Shankar B, Hallam D (2014) Importance of government policies and other influences in transforming global diets. Nutrition Reviews 72, 591–604.
| Importance of government policies and other influences in transforming global diets.Crossref | GoogleScholarGoogle Scholar |
van Horne PML (2014) Competitiveness of the EU egg sector: international comparison base year 2013. Report LEI 2014-041. LEI Wageningen UR, Wageningen, The Netherlands.
van Horne PLM, Bont N (2014) Competitiveness of the EU poultry meat sector: international comparison base year 2013. LEI report 2013-068. LEI Wageningen UR, The Hague, The Netherlands.
Vermeulen AN, Schaap DC, Schetters TP (2001) Control of coccidiosis in chickens by vaccination. Veterinary Parasitology 100, 13–20.
| Control of coccidiosis in chickens by vaccination.Crossref | GoogleScholarGoogle Scholar |
Vits A, Weitzenburger D, Hamann H, Distl O (2005) Production, egg quality, bone strength, claw length, and keel bone deformities of laying hens housed in furnished cages with different group sizes. Poultry Science 84, 1511–1519.
| Production, egg quality, bone strength, claw length, and keel bone deformities of laying hens housed in furnished cages with different group sizes.Crossref | GoogleScholarGoogle Scholar |
Wang G, Ekstrand C, Svedberg J (1998) Wet litter and perches as risk factors for the development of footpad dermatitis in floor-housed hens. British Poultry Science 39, 191–197.
| Wet litter and perches as risk factors for the development of footpad dermatitis in floor-housed hens.Crossref | GoogleScholarGoogle Scholar |
Weber RM, Nogossek M, Sander I, Wandt B, Neumann U, Gluender G (2003) Investigations of laying hen health in enriched cages as compared to conventional cages and a floor pen system. Wiener Tierärztliche Monatsschrift 90, 257–266.
Wilkins LJ, McKinstry JL, Avery NC, Knowles TG, Brown SN, Tarlton J, Nicol CJ (2011) Influence of housing system and design on bone strength and keel bone fractures in laying hens. The Veterinary Record 169, 414
| Influence of housing system and design on bone strength and keel bone fractures in laying hens.Crossref | GoogleScholarGoogle Scholar |
Williams RB (2002) Anticoccidial vaccines for broiler chickens: pathways to success. Avian Pathology 31, 317–353.
| Anticoccidial vaccines for broiler chickens: pathways to success.Crossref | GoogleScholarGoogle Scholar |
Williams RB (1999) A compartmentalised model for the estimation of the cost of coccidiosis to the world’s chicken production industry. International Journal for Parasitology 29, 1209–1229.
| A compartmentalised model for the estimation of the cost of coccidiosis to the world’s chicken production industry.Crossref | GoogleScholarGoogle Scholar |
Williams RB, Gobbi L (2002) Comparison of an attenuated anticoccidial vaccine and an anticoccidial drug programme in commercial broiler chickens in Italy. Avian Pathology 31, 253–265.
| Comparison of an attenuated anticoccidial vaccine and an anticoccidial drug programme in commercial broiler chickens in Italy.Crossref | GoogleScholarGoogle Scholar |
Williams RB, Carlyle WW, Bond DR, Brown IA (1999) The efficacy and economic benefits of Paracox, a live attenuated anticoccidial vaccine, in commercial trials with standard broiler chickens in the UK. International Journal for Parasitology 29, 341–355.
| The efficacy and economic benefits of Paracox, a live attenuated anticoccidial vaccine, in commercial trials with standard broiler chickens in the UK.Crossref | GoogleScholarGoogle Scholar |
Willis WL, Read L (2008) Investigating the effects of dietary probiotic feeding regimens on broiler chicken production and Campylobacter jejuni presence. Poultry Science 87, 606–611.
| Investigating the effects of dietary probiotic feeding regimens on broiler chicken production and Campylobacter jejuni presence.Crossref | GoogleScholarGoogle Scholar |
Yalcin S, Molayoglu HB, Baka M, Genin O, Pines M (2007) Effect of temperature during the incubation period on tibial growth plate chondrocyte differentiation and the incidence of tibial dyschondroplasia. Poultry Science 86, 1772–1783.
| Effect of temperature during the incubation period on tibial growth plate chondrocyte differentiation and the incidence of tibial dyschondroplasia.Crossref | GoogleScholarGoogle Scholar |
Zhang G, Mathis GF, Hofacre CL, Yaghmaee P, Holley RA, Duranc TD (2010) Effect of a radiant energy-treated lysozyme antimicrobial blend on the control of clostridial necrotic enteritis in broiler chickens. Avian Diseases 54, 1298–1300.
| Effect of a radiant energy-treated lysozyme antimicrobial blend on the control of clostridial necrotic enteritis in broiler chickens.Crossref | GoogleScholarGoogle Scholar |