AUSTRALIAN POULTRY CRC - Poultry Hub

More documents

Recommendations

Info

© 2008 Australian Poultry CRC Pty LtdAll rights reserved.ISBN 1 921010 26 6Pilot trial – Mortality in free range flocksProject No. 05-13The information contained in this publication is intended for general use to assist publicknowledge and discussion and to help improve the development of sustainable industries.The information should not be relied upon for the purpose of a particular matter. Specialistand/or appropriate legal advice should be obtained before any action or decision is taken onthe basis of any material in this document. The Australian Poultry CRC, the authors orcontributors do not assume liability of any kind whatsoever resulting from any person's use orreliance upon the content of this document.This publication is copyright. However, Australian Poultry CRC encourages widedissemination of its research, providing the Centre is clearly acknowledged. For any otherenquiries concerning reproduction, contact the Communications Officer on phone 02 67733767.Researcher Contact DetailsTanya NagleRedlands Research Centre,QDPI&FCleveland, Queensland 4163Phone: 07 3824 9534Fax: 07 3286 3094Email: Tanya.Nagle@dpi.qld.gov.auIn submitting this report, the researcher has agreed to the Australian Poultry CRC publishingthis material in its edited form.Australian Poultry CRC Contact DetailsPO Box U242University of New EnglandARMIDALE NSW 2351Phone: 02 6773 3767Fax: 02 6773 3050Email: poultrycrc@une.edu.au.Website: http://www.poultrycrc.com.auPublished in September 2008ii
Executive SummaryFree-range is the poultry housing system most actively supported by welfare groups. Currently thereare 1.69 million free range hens in Australia (11% of total laying hens in Australia) with an estimatedgrocery market share of 14.5%. Free range eggs are worth 23% of the value of the Australian eggindustry, which is more than $71 million a year. Mortality in free range flocks can be caused bynumerous factors including feather pecking and/or cannibalism, disease, predators and management(diet, housing, strain, rearing, light levels, vaccinations, flock size and density). There is limitedscientifically sound information on causes of mortality in free range flocks in Australia and we willstart to address this. This pilot study provides survey data on what producers believed were the causesof mortality and preliminary epidemiological data on causes of mortality in an intensive, albeit oflimited geographical range, survey.A survey of all free-range producers in Australia was undertaken to indicate causes of mortality in theindustry and to tailor the epidemiological survey to ensure temporal/locality issues were covered.Fourteen free range producers replied to the nationwide survey, five from Queensland, one from NewSouth Wales, and four each from South Australia and Victoria. Fowl cholera was named as the mostimportant cause of mortality in Queensland. New South Wales and Victoria recorded spotty liver asone of their most important causes of mortality with South Australia giving it a low rank andQueensland producers not considering it a problem at all. It is to be thought that, similar symptomsshown by both fowl cholera and spotty liver might have confused producers in their presumption.Queensland and Victoria had problems with predators (foxes/crows and dogs/hawks, respectively)with Victoria also recording heat stress as an important cause of mortality. Egg peritonitis, prolapse/protusion, cannibalism and vent pecking were all seen as important causes of mortality in all states.In 2006, five flocks of birds from free range farms in Southeast Queensland undertook an intensiveepidemiological survey which included a detailed survey, serology and faecal samples of the flock,ongoing mortality records and gross pathology of all mortalities. Flock sizes of the five farms rangedfrom 1500 – 3500 with all hens (Bond Brown, Bond Black and Hyline Brown) allowed to range indaylight hours regardless of weather conditions. All farms had conventional sheds fixed in onelocation and fitted with individual nest boxes and perches. All farmers reported that they hadvaccinated their flocks for infectious bronchitis (IB), Newcastle disease virus (NDV) and egg dropsyndrome (EDS). Overall, all flocks had a positive average NDV, IB and EDS titre throughout thesurvey; however farms 4 and 5 did not have a uniform distribution of the titres and therefore not agood protection for their flocks. Reproduction tract lesions such as oophoritis, salpingitis, eggperitonitis, and salpingoperitonitis were the most frequently encountered necropsy findings,presumably causing death of laying hens. Cannibalism was the second most common cause ofmortality. A follow-up investigation was carried out in 2008 to collect sterile samples from freshsacrificed birds showing similar symptoms to previous trial for further microbiological tests. It wasshown that 85% of birds sacrificed had similar reproductive tract problems. From samples collected(61 in total), 20 did not show presence of any bacteria; gram positive cocci were found in 30 (or 49%)of all samples, while 11 (or 18%) of isolates were gram negative cocci or rods. It is common incommercial poultry that egg laying can be interrupted by stress or an infectious disease. The frequencywith which Staphylococcus spp. was isolated suggests an aetiological relationship with encounteredlesions. However, only S. aureus is considered to be pathogenic in poultry. To date isolates from livebirds have not been associated with human infections or food intoxications. Economic losses occur toproducers because egg production drops and mortality increases. Bird welfare could also becompromised.The nationwide survey questionnaire return rate was disappointing with only fourteen producersreturning completed surveys. The survey was developed in consultation with free range producers andan opportunity for the industry itself to have a major input into the direction of free-range research inAustralia. Apparently, the survey caused concern that we were unfairly targeting the free rangeindustry and therefore in turn helping the cage layer industry. Recommendations include improvementiii
Page 1: AUSTRALIAN POULTRY CRCFINAL REPORTP
Page 5 and 6: Table of ContentsEXECUTIVE SUMMARY
Page 7 and 8: TablesTABLE 1: DISTRIBUTION OF NATI
Page 9 and 10: IntroductionIndustry ProfileFree-ra
Page 11 and 12: Avian influenzaIn domestic poultry,
Page 13 and 14: ManagementThis includes factors suc
Page 15 and 16: ObjectivesThe objective of this pro
Page 17 and 18: Figure 1: Appropriate restraint of
Page 19 and 20: ResultsNationwide SurveyGeneralFour
Page 21 and 22: Table 5: Measures taken in between
Page 23 and 24: The similar symptoms shown by both
Page 25 and 26: inactivated vaccination should be l
Page 27 and 28: Initial Final Initial Final Initial
Page 29 and 30: Start Finish Start Finish Start Fin
Page 31 and 32: Figure 7: Chronic peritonitis: peri
Page 33 and 34: Figure 13: Pecking around the vent
Page 35 and 36: Figure 19: Head injuries associated
Page 37 and 38: act as mechanical vectors of other
Page 39 and 40: Appendix AFree-range layer mortalit
Page 41 and 42: 4. MANAGEMENTa) Are birds beak trim
Page 43 and 44: Appendix BPublicity LetterThe Austr
Page 45 and 46: Appendix DPublicity flyer (P.I.X.)M
Page 47 and 48: Appendix FSurvey reminder letterDea
Page 49 and 50: 2. HOUSING OF SURVEY FLOCKa) Shed t
Page 51 and 52: Appendix HExample of mortality reco
Page 53 and 54:
3. Further recordsa. Sample collect
Page 55 and 56:
15 Found dead. Liver white foci and
Page 57 and 58:
Repro organs atrophied; intestinesm
Page 59 and 60:
ReferencesAllen, J. and Perry, G.C.
Page 61 and 62:
Sommer, F. and Vasicek, L. 2000. Ma
show all

AUSTRALIAN POULTRY CRC - Poultry Hub

Create successful ePaper yourself

Delete template?

Save as template?