Livestock Community and Environment. Proceedings of the 10^th Conference of the Association of Institutions for Tropical Veterinary Medicine, Copenhagen, Denmark, 2001

A SURVEY OF THE DISEASE STATUS OF VILLAGE CHICKEN IN KENYA

Njue S.W., Kasiiti J.L., Macharia J.M., Gacheru S.G., Mbugua H.C.W.

Kabete Central Veterinary Laboratories, P.O. Kabete, Postal code 00602, Nairobi, Kenya. E-mail: sophycate@hotmail.com

Abstract

In Kenya, village chickens constitute 80% of the 29 million poultry population. Despite the large numbers, their potential has not been fully exploited as they only provide 54% of the total eggs and 75% of chicken meat. Diseases continue to be the most limiting factor. This study set out to describe the main poultry diseases of village chickens in agro-ecological zones (ECZ) II and III located in two administrative areas of Kenya, with the aim of developing interventions that would improve the production and hence the livelihoods of poultry rearers. Sampling started in October 1999 and a total of 24 farms were studied across six villages in the two zones. Data collection was by formal and informal interviews as well as direct observation. This was done during the dry and wet seasons through a one-year period to determine the disease status of the poultry population. At the same time, blood and fresh faecal samples were collected. Post mortem examination was done whenever there were sick birds. Management factors influenced the epidemiology of poultry diseases. Predominant diseases in descending order were: Newcastle disease, Salmonellosis, flea infestation, Helminthiasis and Coccidiosis. Helminthiasis was more rampant in ECZ II (P=<0.0565) than in ECZ III. More than half of the farms were infested with fleas for the period of study. Other diseases diagnosed were fowl pox and nutritional deficiencies. Traditional disease control remedies predominated. The productivity of village chickens is likely to be improved through appropriate disease control strategies that involve community participation.

Introduction

Kenya is mainly an agricultural country. However only about 20% of the country is suited to crop production. The remainder is either semi-arid or arid supporting mainly cattle production under pastoral systems. The livestock sector provides 30% of the total agricultural income and employs 50% of the labour force in the agricultural sector. The country is also endowed with a large and diverse wildlife heritage that forms the backbone of the tourism industry. The country’s livestock population is estimated at 14 million heads of cattle, 5.9 million sheep, 7.7 million goats, 820,000 camels and 29 million poultry (Anon., 2000).

The poultry sector in Kenya can be subdivided into commercial and traditional sub-sectors. Each of them has its own peculiarities that make them so special to the level of contribution to the national food security. The commercial sub-sector comprises of layers, broilers, layer parent stock and broiler parent stock. It is confined to the urban and peri-urban areas where the infrastructure necessary for the production and market for produce exists. In contrast, the traditional sub-sector also called rural or backyard production consists of local birds, which have not been classified into breeds, although there are many ecotypes. This subsector is very important for the livelihood of many Kenyans as it is mainly found in the rural areas where 80% of the Kenyan population live. It is a major source of readily available proteins in form of eggs and meat and a source of cash money for 90% of the rural households (Mbugua, P.N., 1990).

With about 80% of the estimated 29 million chickens nation wide, the traditional subsector produces 54% of total eggs and 75% of total poultry meat, but only 10% and 40% of the eggs and poultry meat, respectively, is marketed. These are mainly sold through the open-air market and retail shops (Mbugua, P.N., 1990). Despite all the potentials inherent to the traditional system, the local chicken feeds, houses and protects itself most of the times against all odds. Consequently, birds face hardship due to predators and above all diseases (Kasiiti, J.L., 2000). Disease outbreaks remain the greatest single cause of local chicken mortality and these include both infectious and parasitic diseases. While parasitic diseases appear to be a daily concern, causing little mortality but lower production, Newcastle disease occurs as outbreaks causing mortality as high as 100%. This study was therefore undertaken with the participation of farmers to identify the major diseases affecting village chicken production so as to come up with suitable interventions that would improve the production and hence the livelihoods of poultry rearers.

Materials and methods

Location and description of the study area

The work was done in six villages whose short description is given in the table below. The villages were located in two widely separated districts of Kenya and they were chosen from two agro ecological zones (ECZ). The choice was based on the distribution of female farmers keeping village chicken and their proximity to Kabete Veterinary Research Laboratories (about two hours drive from the station).

Table 1: Features of the six villages selected for the in-depth study

Features	Villages
	Karai	Kabete	Nyathuna	Mbilini	Ngiini	Isinga
Administrative areas	Kiambu			Machakos
Agro ecological zone*	ECZ II			ECZ III
Mean rainfall (mm)*	600-2000 (long rains mid March to end May; short rains mid October-end November)			500-1300(long rains end March to May; short rains October-December)
Annual mean temperatures (^oC)*	14.4^oC-18.9^oC			17^oC-20^oC
Agricultural activities*	Dairy farming; Pig rearing; Commercial poultry (layers & broilers) and village chicken rearing; Cash crop (coffee) and food crops (maize, potatoes, vegetables) farming			Dairy and beef production; Village chicken rearing; food crops (maize, pulses), bananas and cash crops (coffee) farming

*Source: Jaetzold and Schimidt, 1983a & 1983b

Study design

Two cross-sectional baseline farm surveys were conducted during the dry and wet seasons in October 1999 and January 2000 respectively. Concurrently, disease survey was carried out for a one-year period commencing from October 1999.

Study population and sampling procedure

The population of interest consisted of female farmers keeping more than six adult village birds and with intention of improving their production for enhanced household nutrition and additional income. The District Veterinary Officers and Animal Health Assistants (AHAs)-the Veterinary staff in charge of the villages supplied lists of villages and eligible farmers respectively. Random stratified sampling procedure was used to select both the villages and the farms. The sampling process started in October 1999. Twenty-four farms were recruited for this study. They had a total of 443 birds.

Data collection and handling

A structured questionnaire was used to gather information related to village poultry production, during two baseline surveys. To supplement the information so gathered, semi-structured interviews guided by a checklist were conducted along. This allowed for exhaustive harvesting of Indigenous Technical Knowledge (ITK) that was possessed by the farmers with regard to poultry diseases. Further information on disease status in the flock during the one year period was gathered by direct observations and entry into a disease survey form which was administered whenever necessary. The AHAs provided any additional information on disease occurrence in their respective areas throughout the one-year period. Questionnaire derived farm variables and other data were synthesized into appropriate variables and entered into a spreadsheet programme (Microsoft Excel 2000, USA).

Sample collection and handling

Birds were appraised before relevant samples were collected. The samples collected were serum, EDTA blood, fresh faeces and external parasites. Blood was collected from wing vein using disposable sterile syringes (3ml) and needles (21G 1¹/₂). Serum was then harvested and aliquoted into 2ml cryovials for storage at –20^oC and –80^oC until further analysis. Two fresh faecal samples were collected from each farm and put in nylon casings while the external parasites and placed in screw-capped bottles. Where necessary, post-mortem examination was done. All the samples were transported to the laboratory under chilling conditions.

Analysis

Data analysis

Microsoft Excel 2000, programme was used to generate descriptive statistics and frequency distributions of the variables from the questionnaire. A chi-square analysis was used on categorical variables to assess differences and associations. Graphical presentations were used to depict farmer’s perceptions.

Laboratory analysis

Serum samples were examined by Indirect ELISA for antibodies against Newcastle Disease. Test protocols were performed exactly as detailed in the FAO/IAEA manual supplied with the ELISA kit from Seibersdorf Laboratories, Austria. The results were entered in an ELISA data sheet and percent positivity of the sample calculated using the following formula provided in the ELISA Bench Protocol Version – NDV 1.01.

Percent Positivity (sample) =

Mean Optical density of the replicate sample x 100

Median Optical density of the median of C++

Pullorum testing was done by direct agglutination method whereas the external parasites were examined directly under a microscope. For the qualitative analysis of the helminth eggs and coccidial oocysts, flotation method was used whereas concentration McMaster technique was used for the qualitative analysis, Thin blood smears were prepared for the diagnosis of haemoparasites as described by Permin and Hansen (1998).

Results

Baseline survey

All the farmers answered the questions resulting in 100% response rate.

Results of the statistical analysis of the questionnaire derived farm variables – dry and wet season

The results of the statistical analysis of the questionnaire-derived variables obtained from 24 family poultry farms in ECZII and ECZIII are summarised in Table 2. There was no significant statistical difference (P=0.5342) in questionnaire-derived farm variables during the dry and wet season in the two zones. However a significant (P=0.0001) proportion of farmers from ECZ III (82%) cleaned chicken houses more frequently (monthly) than those in ECZ II (10%).

Table 2: Summary results of the analysis of factors influencing disease situation in village poultry production in 24 farms in ECZ II and ECZ III as perceived by farmers.

FACTOR	ECZII		ECZIII		P-VALUE
	FREQ	PERCT	FREQ	PERCT
Housing
Cleaning chicken housing	10/12	83	11/12	92	0.5371
Frequency of cleaning: -
Monthly	1/10	10	8/11	82	0.0010
Chicken exchange patterns
Mating cock from: -
Neighbours	1/12	8.3	4/12	33.3	0.1316
Source of stock: -
Market	1/12	8.3	5/12	41.7	0.0593
Neighbour	3/12	25	2/12	16.7	0.6152
Marketing: -
Same village	4/10	40	3/5	60	0.4522
Neighbouring village/shopping centre/town	3/10	30	4/5	80	0.0641
Tradesman or itinerant trader	6/12	50	3/12	25	0.2059
Access to veterinary and extension services
Animal health assistant/chemist	10/12	83	9/12	75	0.6152
Frequency of visits >month	12/12	100	2/9	22	0.0002
Percentage mortalities
Dry season		59.2		85	0.0001
Chicks		74.5		62.5	0.0677
Growers		15		22.7	0.1639
Adults		10.4		14.7	0.3587

Chicken changed hands through borrowing of breeding cocks, purchase and sale of live birds. Nearly 42% of the farmers from ECZ III mainly (P=0.0593) acquired their stock from market and 80% marketed chicken and eggs in the neighbouring village, shopping centre or town (P=0.0641) as opposed to 8.3% and 30% in ECZ II respectively. Nearly all the farmers interviewed from the two zones had access to veterinary and extension services from AHAs and chemists. However the frequency of these visits varied significantly (P=0.0002. In ECZ III, 22% of the farmers had access to the services on monthly basis while in ECZ III; all the farmers were visited more than once a month.

The mean percent deaths in the birds of all age groups during the dry season were significantly (P=0.0001) higher (85%) in ECZ II than in ECZ III (59.2%). The percentage mortality rate of chicks was higher in chicks than in growers and adults in the two zones. The mortality in chicks was significantly (P= 0.0677) higher in ECZ II (74.5%) than in ECZ III (62.5%).

Poultry diseases

Figure 1 illustrates the most common diseases described by farmers during the study. Overall, there was no zone specific difference (P=0.8352) in the frequency of occurrence of the described diseases. Newcastle Disease and Salmonellosis were the most common diseases in ECZII (83%) whereas in ECZ III, Salmonellosis was more common (92%). Coccidiosis was the least common in both zones (8%).

Fig 1: The most frequent poultry diseases as described by the 24 farmers from ECZ II and ECZ III

Fig. 2: describes the seasonal pattern of Newcastle disease outbreaks based on the farmers’ experience.

Two separate outbreaks of Newcastle Disease were evident. They were reported from June to September and from November to February with the peaks in July and December respectively.

The ELISA results of the Newcastle disease survey are shown in Table 3. The Percent Positive values of the Newcastle disease antibodies were significantly lower in the dry season compared to the wet season in the two zones (P<0.0001). During the dry season, the Positive Percent values ranged from 3.82% to 7.28% in ECZ II and from 3.64% to 12.13% in ECZ III. The Positive Percent values in the wet season ranged from 31.73% to 64.59% in ECZ II and from 33.77% to 86.77% in ECZ III.

Table 3: Analysis of Percent Positivity to Newcastle Disease in 24 farms selected for study during the wet and dry season.

ECZ	Village	Dry season		Wet season		P-values
		Total tested samples	Percent Positivity	Total tested samples	Percent Positivity
II	Karai	25	5.62 (5.01-6.23)	13	39.79 (31.73-47.85)	2.4228x10^-6
	Kabete	13	5.55 (3.82-7.28)	29	53.44 (42.29-64.59)	3.2766x10^-9
	Nyathuna	22	5.47 (4.74-6.00)	23	57.28 (49.94-64.62)	2.0055x10^-12
III	Mbilini	24	4.84 (4.34-5.34)	0	0	0
	Ngiini	23	7.37 (3.64-11.1)	6	43.09 (33.77-52.41)	2.67X10^-4
	Isinga	25	8.98 (5.83-12.13)	9	61.95 (37.13-86.77)	2.568x10^-3

During the study, 83% of samples from ECZ II and 92% from ECZ III tested positive for Salmonella pullorum antibodies in the wet season. In two farms in ECZIII, all the chicken bled had pullorum antibodies. However the result of the chi-square statistic was not significant (P=0.5371) indicating that no differences existed between the two zones with regard to occurrence of Salmonellosis.

The results of the analysis of the distribution of external and internal parasites from 24 village chicken farms are summarised in figure 3. More than 50% of the chicken from both zones was infested with fleas during dry and wet season. In ECZ III, mites and ticks were found only in 8.3% of the farms during the dry season. The highest worm egg counts (683) were encountered in ECZII in the dry season whereas the lowest (50) were encountered in the same zone in the wet season. Statistically, ECZ II was significantly (P< 0.0565) more infested with parasites than ECZ III.

Fig. 3: Frequency distribution of parasites in village chickens from the study area

Poultry disease control

Farmers interviewed reacted differently to disease problems. Table 4 Illustrates the most commonly used remedies used by the poultry farmers. Overall there was no significant statistical difference between the two zones (P=0.875). For control of poultry diseases 88% of the farmers used Aloe vera and only 0.1% used vaccination. More than 80% of the farmers used kerosene to control fleas.

Table 4: Commonly used methods applied by village chicken farmers in the control of poultry disease and pest.

Methods	Frequency	Percentage
Disease control
Vaccination	3/24	0.12
Poultry antibiotics	15/24	62.5
Aloe vera	21/24	87.5
Red pepper	18/24	75
Piriton	2/24	0.08
Cow's milk	1/24	0.04
Pest control
DDT / malathion	5/24	20.8
Kerosene	20/24	83.3

Discussion

The most common diseases reported were Salmonellosis, Newcastle Disease and helminthiasis.

Salmonellosis was found in 83% of the farms in ECZ II and 92% of farms in ECZ III, although most farmers did not have an idea that the chicken had the disease. There was no history of vaccination against Salmonellosis, which is indicative of active infection of flocks resulting in carrier status. The percentage distribution of Newcastle Disease (ND) in both zones was 83%. It was evident in this study that there was seasonal occurrence of Newcastle disease (Fig 2). There were two peaks; November to February and June to September which were described by the farmers and which were corresponding to seasonal changes, either from wet to dry season or vice versa. The December peak was attributed to Christmas festivities during which many of the chicken are sold (chicken is a delicacy for most communities). The high percentage positivity of Newcastle Disease in the wet season further confirms the occurrence of the disease in November-February period. It is also an indication that the farmers were able to positively identify Newcastle disease. The positivity was due to an infection by a virulent strain since only three farmers had vaccinated their flocks at the time. Though helminthiasis has been attributed to the scavenging diets, it did not seem to be a very big problem in this study considering that 70% of the farms were free of helminth eggs in the two seasons. Coccidiosis was not significant in this study. This is a problem of intensive system whereby the chickens are confined leading to build up of oocysts in the litter and subsequent ingestion of feed contaminated with such litter.

In this study, management factors played a major role on the epidemiology of diseases (Table 2). Only 10% of the farmers from ECZ II cleaned chicken houses and this may explain why external parasites were more rampant in farms in ECZ II (P<0.0565) than ECZ III. The external parasites have high predilection for dirty unkempt chicken houses. The chicken exchange pattern varied. Farmers from ECZ III purchased and sold their chicken from the market more (P<0.0641) than those from ECZ II, yet there was no significant difference in the disease pattern in the two zones. Thus markets, though important in the spread of most viral diseases such as Newcastle (Musiime, 1991) are not the only means of spread. Other factors such as contacts between flocks of different households, exchange of birds as gifts and lack of proper information by the farmer on disease control may have aggravated the disease situation. Despite the farmer’ s claim that they had access to veterinary and extension services, all the farmers interviewed in ECZ II used those services more then once per month. These services were mainly in form of provision of drugs, which they personally sought for, whenever there were disease problems. It was widely established that most farmers used veterinary and human antibiotics, traditional cures such as Aloe vera, cow’s milk and red pepper to treat disease conditions. This is because farmers regard the village chicken production as a low input-low output system and are unwilling to put money into the health of a bird whose economic returns are not forthcoming. Most admitted that some of their traditional cures have been a failure.

Percent deaths in the dry season were significantly (P=0.0001) higher in ECZ III (85%) than in ECZ II (59%). This could be attributed to the different farming systems practiced in the two zones. In ECZ III, families own larger pieces of land, as farming is less intensive. As a result, all farmers free range their birds during the dry season which culminates to birds moving long distances in search for feed and mixing freely with other birds in the neighbourhood thereby getting predisposed to diseases. Chicks, being more vulnerable, were more predisposed and this may explain why their percentage mortality (75%) in ECZ III and (63%) in ECZ II during the dry season was much higher (P=0.0677). Therefore, management factors that would have a positive impact on chick survival can be used to increase output from village chicken flocks.

Conclusion and recommendations

Village chicken production in Kenya has a great potential for provision of poultry meat, eggs and cash to the rural communities. However, the occurrence of diseases to which they are highly susceptible has been a major hindrance to the full exploitation of this potential. Rural poultry rearers were ill equipped with the knowledge on advantages of vaccination. In order to control these diseases effectively there is need to put a vaccination programme with an effective delivery system in place. The country has a Veterinary Vaccine Production Institute, which produces most poultry vaccines such as Newcastle and Fowl typhoid. Though vaccines are available, the village chicken farmer does not utilise them partly due to lack of awareness, unavailability of the vaccines in the rural areas, large quantities per vial, which are not commensurate with the small flock size, and lack of cold chain. The high cost of veterinary drugs prohibits most village chicken rearers from treating their birds when they contract diseases. If successful disease and parasite control in village poultry production is to be realised, there is need to strengthen institutional and organisation support in the supply and distribution of veterinary drugs and vaccines as well as in the provision of extension services. There is also need to train farmers on good management practices and incorporate a participatory health management system in place whereby the local communities would be encouraged to use locally available resources such as; feed resource base, genetic material and indigenous technical knowledge for effective poultry disease control. Designing housing for village birds will go a long way into controlling parasitic diseases and losses associated with predation while proper management would reduce the prevalence of management-related diseases such as coccidiosis. Long-term measures should include provision of rural finance, seromonitoring, and serosurveillance with the ultimate aim of controlling and eventually eradicating diseases such as Newcastle Disease and Salmonellosis. Since poultry are an important source of nutrition and income in ECZ II and ECZ III, This study needs to be extended to other districts where village chickens are found.

Acknowledgement

The authors would like to thank the owners of village chickens and veterinary staff in Kangundo and Kikuyu divisions for their cooperation, which made this work successful. We are also indebted to the staff of Central Veterinary Laboratories Kabete for their assistance in testing the samples. Our gratitude goes the Director of Veterinary Services; the Chief Veterinary Investigation Officer; the Chief Veterinary Field officer; the officer in charge, Central Veterinary Laboratories and the officer in charge Veterinary Epidemiology and Economics Unit, for their tremendous support and goodwill. Our deep appreciation goes to the former IAEA project Technical Officer Dr. Ron Dwinger for his support during the work. We are equally indebted to IAEA Technical officer, Dr. Martyn Jeggo, for his tremendous support and invaluable guidance. This work was conducted under FAO/IAEA Joint Division, Research Contract No. KEN10184/FAO.

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