An investigation of the common causes of death in chicken around Arusha Municipality area, Tanzania

E S Swai, P N Sanka* and J E Kaaya*

Ministry of Livestock and Fisheries Development, PO Box 9152, Dar-es-Salaam, Tanzania
ESswai@gmail.com
* Veterinary Investigation Centre, PO Box 1068 Arusha, Tanzania

Abstract

A retrospective study covering a period of 5 years (1998-2002) was carried out using post mortem records at the zonal veterinary investigation centre laboratory to determine the major and probable causes of poultry deaths in and around Arusha Municipality. During this period, a total of 2216 avian commercial (broiler & layer) poultry carcasses of different ages and from different sources were examined and 2027 (91.5%) died as a result of a variety of causes.

No cause of death could be identified from 189(8.5%) cases. Protozoan disease problem namely coccidiosis (1016) was the most important cause of deaths (45.5%). The other problems occurred in the following frequencies; Management related problems 16.3%; Viral diseases 12.5%; Helminthiasis 6.8%; Bacterial diseases 4.5. % and Egg bound peritonitis 5.5%. No seasonality pattern of the diseases could be elucidated, however, it was concluded that coccidiosis, and management related diseases and viral diseases namely Infectious Bursal Disease (IBD) were the most important disease of commercial chicken in the area of study. The recurrence of these diseases perhaps suggests the level of their endemicity and highlights the need for sustained surveillance and intensive control measures.

Key words: Arusha, poultry diseases, Tanzania

Introduction

The main objective of chicken industry is to produce meat and eggs efficiently and economically (Melewas and Rwezaula 1988; Whyte 2002; URT 2006; 2010; Rushton 2009). Several factors either acting singly or in combination may hamper chicken production (Minga and Nkini 1989; Jordan and Pattison 1996, Calnek et al 1997; Sonaiya and Swan 2004).

Besides poor feeding, housing and management, diseases are one of the most important constraints to poultry industry worldwide (Minga et al 1996; Yongolo et al 2011; Knueppel et al 2010; Msoffe et al 2010). Diseases reduce chicken production by reducing productivity and causing economic losses as a result of sub-optimal productivity, high veterinary expense, culling as well as actual chicken mortality. Broadly, continued persistency of diseases exert severe impacts on food security, nutrition, health and financial costs at various level from producer, local, regional and national economy.

The continued surveillance of the major diseases of poultry and those which might have hitherto been considered to cause significant morbidity and mortality is desirable.

The purpose of this paper is to review the various causes of avian (poultry) mortality as diagnosed at the post mortem facility in the Veterinary Investigation Centre, Arusha, during a five year period (1998 to 2002).

Materials and Methods

Area and coverage

This study was conducted at Arusha zonal Veterinary Investigation Centre (AZVIC), which is located within Arusha Municipality, the second largest municipality in Tanzania. Geographically, the municipality is situated at the foot of Mount Meru (Lat 03’16S and 03’20S and Longt 36’37 and 36’50 E) and intersect the Great North Road from Cape Town to Cairo and is the hub of the northern tourist circuit of Tanzania. Currently the human population is estimated at 1,288,008 with a growth rate of 3.2% as opposed to the national of 2.8% per annum (URT 2002). AZVIC support and undertake animal disease surveillance and laboratory services covering four administrative regions (comprising 27 local administrative authorities/districts) of northern Tanzania. The area elevation ranges from 1200-1900 metres above sea level, average bimodal rainfall ranges from 700 to 2000 millimetres and diurnal temperature range of 15 to 32°C (Mhita and Venalinen 1992). Poultry keeping is widely practiced in most urban and peri-ubarn of Arusha municipality and other adjacent districts main towns.

Source and retrieval of post mortem data

Carcases or live sick birds submitted to the AZVIC-laboratory section that originated from different farm sources mainly Arusha Municipality and occasionally from other neighbouring local government authorities (Meru, Monduli, Hai, Moshi and Karatu) were used for the study. A five-year post mortem record (January 1998 - December 2002) of the AZVIC was utilised for this study. Post mortem data recorded in the study period were extracted from case files/registers and post-mortem reports. The diagnosis were based mainly on the gross pathological changes and in some cases, however, few, on microbiological findings. In cases where the pathological changes were found to affect more than one system or organ, only the primary pathological changes have been considered in this report. Other data extracted include data on season of carcase submission, year and classes (broiler or layers). The following season were considered: Dry season (January to March), Wet season (April to June), Pre-wet season (July-September) and Pre-dry season (October to December). Descriptive statistics and graphical illustration was generated in Micro Soft Excel (Microsoft Inc., USA). For description purposes, diseases were categorized into bacterial, viral, coccidiosis, helminthiasis, management related and egg bound peritonitis based on history and gross post mortem lesions.

Results

A total of 2,216 cases of poultry deaths were submitted and recorded during the five year period of the study, giving an average of about 443.2 cases annually (Table 1). On yearly distribution, highest submission of cases was observed in 1998 (24.6%), followed by 1999 with (19.8%) and the least of (18.3%) was recorded in 2000 and 2002, respectively (Table. 1). Of the examined chicken, 189(8.5%) no diagnosis could be made. Two thousands and twenty seven of 2216(91.5%) chicken were affected by one or more of the disease condition described below (Table 1).

Coccidiosis

One thousands and sixteen (45.6%) were considered to have died due to protozoan Eimeria spp parasite infection. The condition was reported in all months and years under review except during the month of February 1998 and 2001, respectively.

Management complex

Management related disease condition affected 363 of 2216(16.3%) cases. Of these, chilling accounted for 218(60%) cases. Chilling was more common observed in rain season (April–June). Other conditions were distributed as follows: vitamin deficiency, 63 of 363(17.3%), starvation, 36 of 363 (9.9%), cannibalism, 24 of 363 (6.6%) and injuries due to various cause 22 of 363(6.0%).

Viral diseases

Viral disease was encountered in 276 of 2216(12.4%) cases. Of the viral disease, Infectious bursa disease (IBD) was encountered in higher frequency 175 of 276(63.4%) followed by New castle disease (NCD) 63 of 276(22.8%) and visceral lymphomatosis, 38 of 276(13.7%).

Bacterial diseases

Ninety nine of 2216 (4.4%) chicken were diagnosed as having died of bacterial associated infections. These were distributed as follows: Omphalitis, 26 of 99 (26.2%), Collibacillosis, 21 of 99 (21.2%), Salmonellosis, 18 of 99 (18.1%), Pasterellosis, 18 of 99 (18.1%) and infectious coryza, 16 of 99(16.6%).

Helminthiasis

One hundred and fifty one of 2216(6.8%) were emaciated and massively associated with both endo- and ectoparasites. Five chicken of 151(3%) had severe lice and flea infestation. Of the endo-parasites, 122 of 146(83.5%) were roundworm namely, Ascaridia and Hetarakis spp and 23 of 146(15.7%) was tapeworm, Taenia spp.

Figure 1. Seasonal distribution of reported chicken carcasses during 1998-2002

Discussion

The results show that the number of cases received each year decreased by 25% in the last year of consideration. The reason for this decrease in the number of cases can possibly be attributed to the post mortem cost recovering exercise which was introduced since 1998 or the re-surgence of private veterinary delivery centres in the light of liberalised veterinary service delivery (Melewas and Rwezaula 1988) or that the owners were no longer interested in their chicken being examined at post-mortem.

• Of the 2216 chicken carcasses examined, 2027(91.5%) died of specific causes while in 189(8.5%) no specific condition could be identified. Not unexpectedly, however, the cause of death varied widely. Such a wide variety of causes of mortality in chicken have been described by various authors (Minga et al 1996; Matovelo et al 1987). Diseases of the alimentary tract caused by protozoan coccidial spp were found to be the most important causes of mortalities accounting for 45% deaths. This finding disagrees with retrospective study surveys in Morogoro, Coast, Dar-es-salaam and Iringa regions, where Fowl Typhoid was noted to be important chicken disease than coccidiosis (Matovelo et al 1987). The climate of Arusha is cold and wet throughout the year, such climate variables; tend to favour multiplication of Eimeria spp.
  
  
• Poor management like feeding with low quality or the wrong growers mash to broilers and the rearing of chicken on a built-up deep litter with no history of anti-coccidian medication, poor aeration due to inadequate building space for urban farms, can be postulated to have led to the persistency evidence of re-ccurrence of coccidiosis in these farms, such practices required to be discouraged amongst farmers.

The second and third most frequent group of diseases were those associated with management (chilling, nutrition, cannibalism, mechanical injuries etc) and viral (IBD, New Castle Disease, Visceral lymphomatosis) infection. These accounted for 16.3% and 12.4% respectively, of all deaths. This means that less than 30% deaths were attributed by various other causes as listed in Table 1. No firm evidence of seasonality pattern could have been elucidated from the death trends noted over years under review, suggesting disease challenge in the area have no seasonality trend.

• Since most of the commercial chickens are reared in confinement, various aspects of management would play an important role in prevention and control of diseases. It is well acknowledged that management varies from one chicken farm to another (Mwalusanya et al 2002; FAO 2008). A majority of the disease or condition described in this paper could have been avoided by applying proper management procedure. Therefore it would seem that there were failures in one or more aspects of management in the farms of origin of the chicken in this report. This could only have been confirmed if complete histories of the farms were obtained or the farms were visited to asses and advises on various aspects of management.
  
  
• The avian carcasses submitted do not represent and reflect the true picture of the chicken diseases in the Northern zone. The proportion of the farms that submitted carcases are those close to the centre. Un-reported or un–attended and attended post mortem in other areas beyond AZVIC are on increase and it was not possible to get access to the data. However, the significant finding noted and gathered from this survey does suggest the diseases status and impact in this farming system. It is therefore concluded that the recurrence of these diseases perhaps suggests the level of their endemicity and highlights the need for sustained surveillance and intensive control measures.

Conflict of interest statement

None of the authors of this paper has a financial or personal relationship with other people or organization that could inappropriately influence or bias the content of the paper.

Acknowledgment

The authors are very grateful to the AZVIC technical staff that performed the post mortem, keep the records and for their cooperation and help. This paper is published with the permission from the Director of veterinary services in Tanzania.

References

Calnek B W, Barnes H J, Beard C W, Mcdougald L R and Saif Y M 1997 Diseases of Poultry. Iowa State University Press, Ames, Iowa, USA pp.1080

FAO, Food Agriculture Organisation 2008 Tanzania Poultry Sector Country Review, FAO Animal Production and Health division, pp. 3-29

Jordan F T W and Pattison M 1996 Poultry Diseases. W.B. Saunders Company Ltd, London, pp 546

Knueppel D, Cardona C, Msoffe P, Demment M, Kaiser L 2010 Impact of vaccination against chicken Newcastle disease on food intake and food security in rural households in Tanzania, Food and Nutrition Bulletin 31(3): 436-45.

Matovelo J A, Semunguruka W D, Meela P N P and Mwamengele G L M 1987 Some indications on the animal diseases status in Tanzania. In: proceedings of the 5th Tanzania Veterinary Association Scientific Conference held in Arusha, 1-3rd December, 1987, 1: 151-163.

Melewas J N and Rwezaula D 1988 Contribution of the animal industry to poverty alleviation, household income and national economy. Tanzania Veterinary Journal 18(4): 270 – 284.

Mhita M S and Venalinen A 1992 The variability of rainfall in Tanzania. INNIDA/SATCC/WMO-Meteorology project. Finnish Meteorol Institute, Helsinki.

Minga U M, Katule A, Yongolo M and Mwanjala T 1996 The rural chicken industry in Tanzania: Does it make sense?. Tanzania Veterinary Journal 16(2): 25–32.

Minga U M and Nkini R P 1989 Disease as a major constraint to chicken production in Tanzania. In: Proceedings of the 13rd Tanzania Society of Animal Production Conference held at Arusha International Conference Centre (AICC), November, 1989 pp: 284-292.

Msoffe P L, Bunn D, Muhairwa A P, Mtambo M M, Mwamhehe H, Msago A, Mlozi M and Cardona C J 2010 Preparation for the prevention and control of highly pathogenic avian influenza in rural Tanzanian village settings. Avian Diseases 54(1): 768-71

Mwalusanya N A, Katule A M, Mutayoba S K, Mtambo M M, Olsen J E and MingaU M 2002 Productivity of local chickens under village management conditions. Tropical Animal Health and Production 34(5): 405-16.

Rushton J 2009 The Economics of Animal Health and Production. CABI Publishing, Wallingford, UK.

Sonaiya E B and Swan S E J 2004 Small-Scale Poultry Production. Technical guide FAO Animal Production and Health Manual, Rome, Italy.

URT, United Republic of Tanzania 2002 Population and household census. Available at http: // www.tanzania.go.tz/cencus/table5.htm.2002; Accessed August, 2013

URT (United Republic of Tanzania) 2006 Livestock Policy. Ministry of Livestock and Fisheries Development, Government Printers, Dar-es Salaam, pp: 12-27

URT, United Republic of Tanzania 2010 Budget speech, 2010/211. Government Printer, Dar-es-Salaam.

Whyte M 2002 Poultry Studies and Anthropological Research Strategies. Characteristics and parameters of family poultry production in Africa. (IAEA, Vienna), 187–192.

Yongolo M G, Christensen H, Handberg K, Minga U and Olsen J E 2011 On the origin and diversity of Newcastle disease virus in Tanzania. Onderstepoort Journal of Veterinary Research 78(1): E1-8.

Received 30 August 2013; Accepted 10 October 2013; Published 1 November 2013

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