| Livestock Research for Rural Development 18 (11) 2006 | Guidelines to authors | LRRD News | Citation of this paper |
Vaccination has continuously been reported world wide to be the main method of controlling poultry against Newcastle disease. A study was therefore carried out to assess the cost effectiveness of vaccinating Free-range poultry against Newcastle disease in Busede sub-county, Jinja district. Using a multistage cluster sampling procedure, a flock within each of the 30 households per the two selected parishes (vaccinated and non-vaccinated areas) was used for the study.
Questionnaires were administered in both the cross-sectional and longitudinal surveys to monitor for the changes in flocks' size, egg production and flock dynamics. Data collected were subjected to a repeated measure analysis, which compared the two treatment groups in order to assess the costs and benefits (farmer's income) from vaccination using partial budget analysis at household level. Haemaglutination inhibition (HI) tests were carried out on serum samples collected pre and post vaccination to detect the immunity status of the flock.
Results show a flock size increase of mean number of 26 birds in vaccinated compared to a mean number of 17 birds in control area (p = <0.001). The dynamics of this increased flock size resulted into a marked high net benefit value of 6,422,000/= (Ug shillings) for the vaccinated area compared to 1,629,700/= value in the control area (p = <0.001). The HI tests analyzed using chi-square test value of 9.8, 2df and p<0.07, produced 66% pre and 75% post vaccination titres for protective antibody.
Keywords: Cost effectiveness, free-range chickens, Newcastle didease, vaccination
Poultry is now by far the largest livestock group in the world with a population estimated to be approximately 14,000 million (FAO 2000). An estimated 80% of the poultry population in Africa is found in traditional scavenging systems where the indigenous domestic fowl (Gallus domesticus) is the predominant species in the rural poultry sector (Gueye 1998). Similarly, in Uganda, free-range poultry is reported to be the most widely practiced among the many livestock production systems (Mukiibi-Muka 1992). The population of chicken in Uganda is estimated at 22.2 million (MAAIF Report 2000) and indigenous type constitutes approximately 90 percent of the total population (Bamusonighe 1998, personal communication).
A diagnostic survey conducted in Busede sub-county, one of the seven sub-counties in Jinja District, identified free-range poultry as the major livestock enterprise in this area. Busede sub-county, is influenced by activities of the Kakira Sugar Works in the vicinity. The surrounding undulating hills and valleys are cultivated with sugar cane plantations therefore leaving little or no land available for other livestock keeping and crop cultivation activities other than poultry production that requires minimum land availability. This is probably the reason why it was ranked as the major livestock enterprise (LSRP / NARO report 1999).
Newcastle disease was identified as the major constraint to enhanced productivity in free-range poultry (LSRP/NARO Report 1999). In order to control the devastating effects of this disease a participatory health chicken management including vaccination against Newcastle disease was introduced in the area, under LSRP/NARO/DANIDA free-range poultry project.
There was, therefore, need to assess the cost-effectiveness of a rural farmer vaccinating free-range poultry against Newcastle disease in Busedde- Jinja.
The study was carried out in two parishes of Nabitambala (vaccinated area) and Nalinaibi (non-vaccinated area) in Busedde sub-county, Jinja district.
Initially, a cross-sectional study was conducted using a structured questionnaire to access baseline information on health status, husbandry, productivity (egg, hatchability) and the role played by free-range poultry in the community.
A six months longitudinal participatory study then followed on a portion of sampled groups of chicken-households to monitor for:
Using the formula for calculating the sample sizes in observational studies or field trials involving two treatments (Martin et al 1987):
n = [Zα (2 PQ)1/2 - Zβ (Pe Qe + Pc Qc)½]2 / (Pe - Pc)2
Where:
n= sample size of households
Zα=1.96 if α, the type I error is 0.05
Zβ= -0.84 if the type II error is 0.2
Pe= estimate of mortality of birds due to NCD (50%) in non-vaccinated parish (Wambura et al 2000)
Pc=estimate of mortality of birds due to NCD (10%) in vaccinated parish (Spradbrow 1999)
Qe= 1- Pe.
Qc= 1- Pc
P=(Pc+ Pe)/2
Q= (1- P)
The sample size was calculated to be 30 households per parish for the two parishes. The whole flock of each of the sampled household was included in the longitudinal study.
A multistage cluster sampling procedure was used for this study particularly in identifying the villages and the households. The villages within the selected parishes were randomly sampled as the primary units from which different households (with flocks of birds) were then randomly sampled as the secondary units. A list of all the households in each village was collected from the local council chiefs to provide a sampling frame from which 30 households per parish were chosen. Entire flocks of selected households including all age groups were then monitored using a structured questionnaire on the structure and dynamics changes of their flock.
Data were entered using EPIINFO and analysis was done using Microsoft Excel and SAS version 8 statistical packages for the cross - sectional and longitudinal survey findings. Data analysis entailed both descriptive and analytical statistics. Repeated measures and 2 by 2 table analysis was carried out using SAS software package in order to cater for time aspect of repeated observation of the same farmers and to determine the immune status of the birds using haemagglutination inhibition (HI) tests respectively.
The cost-effectiveness of vaccinating village birds against Newcastle disease was determined using partial budget analysis formula as out-lined below: -
Partial budget's formula consists of four basic items namely:
|
Costs |
Benefits |
|
a) New costs |
c) Costs saved |
|
b) Revenue foregone |
d) New revenue |
Net benefit = Total benefits - Total costs
Where:
Total costs consist of:
Total benefits consist of:
Flock ownership was distributed as follows; Women (44%) men (41%), the family (13%) and care taking (2%) of the flock.
Women folk mainly managed the birds (cleaning of the chicken house (98%), care of chicks (85%), nursing of sick birds (84%), nest making (87%), provision of supplementary feeds and water (92%)).
Decisions and access to products of the birds were mainly done by men (home consumption of the chicken (74%), decision to vaccinate (71%), purchase of drugs (65%), donation/gifts of birds (67%).
Regarding awareness about Newcastle disease (NCD), 98% of the farmers had heard of the disease, mostly (66%) from neighboring places.
Majority of the farmers (89%) had experienced NCD in their own flock, where (35%) had had their whole flock wiped out; (53%) had had more than half of the flock destroyed, while 13% had had less than half the flock destroyed.
Vaccination was ranked by 66% of the households as the best control strategy.
Repeated measure analysis was carried out on the changes in the flock size structures and dynamics. Results (Table 1) showed a highly significant (p = 0.01) difference in the flock size mean number between the vaccinated area, mean number 26 compared to that of control area mean number 17 birds.
|
Table 1. Flock characteristics by treatment groups in the longitudinal study |
|||||
|
Variable |
Non-vaccinated |
Vaccinated |
P* |
||
|
Mean |
SD |
Mean |
SD |
|
|
|
Total flock size |
17 |
9 |
26 |
13 |
<0.01 |
|
No. of chicks |
9 |
6 |
14 |
7 |
0.00* |
|
No. of growers |
6 |
3 |
7 |
5 |
0.00* |
|
No. of hens |
3 |
1 |
5 |
4 |
0.00* |
|
No. of cocks |
1 |
2 |
2 |
1 |
0.14 |
|
Flock sold |
3 |
2 |
5 |
7 |
0.95 |
|
Flock gifted |
2 |
2 |
3 |
3 |
0.86 |
|
Flock consumed |
1 |
1 |
2 |
2 |
0.11 |
|
Flock dead |
15 |
12 |
7 |
5 |
0.980 |
|
Flock lost |
16 |
29 |
7 |
6 |
0.81 |
|
Flock exchanged |
7 |
1 |
10 |
8 |
0.80 |
|
Value of flock @ h/h |
26,589 |
14,739 |
34,720 |
21,445 |
0.05 |
|
Value of flock sold |
9,383 |
6,194 |
14,031 |
18,167 |
0.15 |
|
Value of flock gifted |
6,073 |
4,652 |
9,486 |
13,894 |
0.29 |
|
Value of flock consumed |
5,574 |
3,130 |
7,314 |
5,698 |
0.05 |
|
Value of flock dead |
18,762 |
25,185 |
5,744 |
6,545 |
0.52 |
|
Value of flock sick |
34,368 |
46,097 |
9,485 |
9,159 |
0.03 |
|
Value of flock lost |
27,852 |
61,091 |
6,689 |
7,198 |
0.01 |
|
Value of flock exchanged |
20,667 |
4,677 |
22,556 |
18,068 |
0.87 |
Similarly, significant (p = 0.01) differences were also observed in the sizes for chicks, growers, and hens between the vaccinated area (mean numbers 14, 7 and 5 respectively) compared to that of the control area (mean numbers, 9, 6 and 3 respectively). Non significant (p = 0.139) difference were however observed in the cocks size between the vaccinated area (mean number 2.0) compared to that of control group mean (number 1.0).
Non significant (p>0.05) differences were, however, observed (Table1) in the flock dynamics changes between the vaccinated area as compared to the non vaccinated area. Significant differences were however observed (Table1) in the values of flock per household (p = 0.05), flock consumed (p = 0.05), flock sick (p = 0.26) and flock lost (p = 0.01) between the vaccinated area as compared to the non vaccinated area.
Non significant differences were however observed in the values of flock sold (p = 0.15), flock gifted (p = 0.29), flock dead (p = 0.52) and flock exchanged (p = 0.87) between the vaccinated area as compared to that of the non-vaccinated area.
A partial budget analysis was carried out from the changes in the flock dynamics and results (Table 2) indicated highly significant (p = 0.01) differences in the total costs and benefit calculations leading to a net benefit at 70% flock saved (mean value = 50,567) higher in the vaccinated area than in non-vaccinated area (mean value = 14,511).
|
Table 2. Cost benefit analysis |
|||||
|
Variable |
Non-vaccinated |
Vaccinates |
P* |
||
|
Mean |
SD |
Mean |
SD |
|
|
|
Cost saved at 70% |
18,613 |
10,318 |
24,304 |
15,011 |
0.05 |
|
Cost saved at 100% |
26,589 |
14,739 |
34,720 |
21,445 |
0.05 |
|
Positive output |
38,688 |
21,610 |
52,479 |
39,867 |
0.08 |
|
Negative output |
29,445 |
64,829 |
7,567 |
9,279 |
0.00 |
|
Revenue foregone |
13,295 |
7,370 |
17,360 |
10,722 |
0.05 |
|
Total costs |
13,295 |
7,370 |
18,649 |
11,301 |
0.01 |
|
Total benefits at 70% |
27,846 |
67,922 |
69,216 |
51,404 |
0.00* |
|
Total benefits at 100% |
35,822 |
70,011 |
79,632 |
57,391 |
0.00* |
|
Net-benefits at 70% |
14,511 |
64,962 |
50,567 |
41,208 |
0.00* |
|
Net-benefits at 100% |
22,528 |
66,656 |
60,983 |
46,947 |
0.00* |
Results from the partial budget analysis (Tables 3, 4 and 5), indicate higher total costs incurred for vaccinated area however, the total benefits and overall net-benefits (Table.2) out weigh the costs.
|
Table 3. Comparison of costs incurred between the two treatment groups |
|||
|
Variable |
New cost |
Revenue foregone |
Total costs |
|
Researcher intervention |
16,3700 |
2,204,750 |
2,368,450 |
|
Control |
0.0 |
1,489,000 |
1,489,000 |
|
New cost = expenses spent on vaccination (total costs of flock) per bird Revenue foregone = 50% of the total flock per household Total costs = New costs + Revenue foregone |
|||
|
Table 4. Total benefits for the study period |
|||||
|
Variable |
Costs saved at 70% |
Costs saved at 100% |
New revenue |
Total benefit at 70% |
Total benefit at 100% |
|
Researcher intervention |
3,086,650 |
4,409,500 |
5,703,800 |
87,90,450 |
10,113,300 |
|
Control group |
2,084,600 |
2,978,000 |
1,034,100 |
31,18,700 |
4,012,100 |
|
Total Benefit = costs saved + new revenue [(+output) – (-output)] |
|||||
|
Table 5. Net-benefit (total benefit –total costs) |
||
|
Variable |
Net benefit at 70% flock saved |
Net benefit at 100% flock saved |
|
Researcher intervention |
6,422,000 |
10,113,300 |
|
Control group |
1,629,700 |
4,012,100 |
A 2 by 2 table analysis was carried out on the haemagglutination inhibition (HI) tests using SAS software package to determine the immune status of the birds. Results (Table 6) indicated high antibody titres (66 and 74.5) above the protective concentration of 1/8 for pre and post vaccination though a similarly high antibody titre was also observed in the control group. This implied some exposure of the birds to infection in the control area
|
Table 6. Proportion of chickens with haemagglutination antibody titres above the protective concentration of 1/8 in the control and the Vaccination intervention parishes in Busedde sub-county |
|||
|
Variable |
Non-vaccinated, % * |
Vaccinates, % |
|
|
N=93 |
Pre-vaccination N = 95 |
Post-vaccination N = 47 |
|
|
1Negative |
4.3 |
34 |
17 |
|
2Titre >0<1/8 |
0 |
0 |
8.5 |
|
3Titre ≥1/8 |
96 |
66 |
74.5 |
|
1Percentage not exposed to infection or vaccination. 2Percentage exposed to infection or vaccination but not protected. 3Percentage exposed to infection or vaccination and protected |
|||
Serum samples from control birds were collected at the time when post-vaccination samples were taken. In a comparison of control with post-vaccination titres the chi-square value was 9.8, 2 df and p<0.07.
The baseline results showed that women owned 44% of the chickens, men 41%, and the family 13%. Most of the management of the birds was done by female (98%) house cleaning, care of chicks (85%), nursing sick birds (84%), nesting (87%) and provision of supplementary feeds and water (92%). The high involvement of women in free-range poultry keeping has been reported many countries developing world (Alders et al 2001), Botswana (Moreki and Masupu 2001), Morocco (Benabdeljelil et al 2001). It has also been reported that women have considerable knowledge about poultry and poultry production more than their men counterparts (Tadelle et al 2003). This therefore calls for a purposeful targeting of the women when introducing technologies in free-range management as this is likely to be the appropriate entry point to poverty alleviation in the rural communities.
Flock characteristics were used in the longitudinal study to compare the area that had Newcastle disease vaccination against that which did not have (Table 1). There was substantial increases in the flocks of farmers who participated in the Newcastle disease vaccination control which is shown by a mean of 26 birds per household compared to the mean number of 17 birds in the control area (p value 0.01). This compares with the value reported (21.6+/-11.6) for Oodi village, Kgatleng district, Botswana by Mushi et al (2000). However there was n o outbreak of Newcastle disease during the six month period of the longitudinal study. This absence of the disease may suggest that the period was rather short and might not have captured seasonal outbreaks in the remaining part of the year.
To estimate the costs and benefits free-range poultry vaccination against Newcastle disease, a partial - budget analysis was performed. Results indicated a significantly (p =0.00) high net benefits in vaccinated than control area which supports the usefulnes of vaccinating free-range poultry against Newcastle disease. Similarly, a cost benefit evaluation for the Tigray region, in northern Ethiopia showed that Newcastle disease vaccination was cost effective (Udoet al 2001). It is also thought that control of Newcastle disease as an individual activity gives confidence to farmers on the survivability of their stock.
In free-range poultry a Haemagglutination inhibition (HI) titre of 1 in 8 or ≥ 23 or higher could be an indication of protection of chickens against potentially lethal challenge with virulent virus (Rehmani 1996, Spradbrow 1999, Wambura et al 2000). Thus this estimate was used to determine the percentage of free-range chicken which were protected either as a result of vaccination or field virus. 66% of the free-range were protected were protected at pre-vaccination while 74.5% were protected after vaccination. The control area revealed a 96% protection contrary to the expected results. There is likely to have been a field Newcastle disease virus in the control area as well as elsewhere. This underscores the difficulties of doing experiments under field conditions and more so with free-range poultry.
We are grateful for the financial support from the Livestock Systems Research Project (LSRP) supported by the Danish International Development Agency (DANIDA). We acknowledge the cooperation of the free-range farmers in Busedde sub-county, Jinja district for offering their time and birds for the study. The authors are grateful to Dr Cyprian Ebong, the LSRP coordinator and Mrs. Suzan Olet for their logistical and biostatistical support respectively.
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Received 3 August 2006; Accepted 4 September 2006; Published 1 November 2006