This study links participatory research methods, geographic information systems (GIS) techniques, village and householdlevel surveys, and a tobit analysis to examine the adoption and impact issues related to a new technology, improved varieties of dual-purpose cowpea (IDPC), developed by International Institute of Tropical Agriculture (IITA) and International Livestock Research Institute (ILRI) and recently released in Nigeria. The article analyzes factors affecting the adoption and impact of the technology across different socioeconomic domains as defined by degree of market access and population density. The results show multiple benefits from this flexible leguminous crop, many of which relate to the fodder and soil fertility-enhancing aspects of IDPC rather than higher grain yields per se. The intensity of adoption was affected by different village-and household-level factors in each socioeconomic domain, allowing more sharply defined recommendation domain-targeting strategies. The multiple research approaches taken also provided useful lessons at different system levels regarding the benefits of, and perceived problems with, this technology for researchers, development practitioners, and policy makers. The collaborative research approaches taken in this study are helping to close the "feedback loop" from farmers back to researchers and others attempting to disseminate the technology, and by doing so, should contribute to faster and more widespread uptake of this technology.

Cowpea is an important legume crop in Africa, valued highly for its grain and also haulms, which are a tradable commodity in fodder markets. Fodder market surveys in Northern Nigeria showed that groundnut haulms were priced higher than cowpea haulms, probably because of their superior nutritive value. The economic value of haulms has prompted cowpea breeders and livestock nutritionists to explore haulm fodder traits as additional selection and breeding criteria. Fifty cowpea genotypes cultivated across five locations in Nigeria in 2013 and 2014 were evaluated for food fodder traits. Significant (P < 0.05) genotypic dependent variations were observed in yields (kg/ha) of grains (537-1082) and haulms (1173-3368), though significant (P < 0.05) effects of location and year were observed. Grain and fodder yield had a tendency to be positively correlated (r = 0.26, P = 0.07). Haulms were analyzed for nitrogen (N), fiber fractions, in vitro digestibility, and metabolizable energy content. Highly significant variations were observed in all genotypic and livestock nutrition traits, although location and year had significant effects. Trade-offs between grain yield and haulm fodder quality traits were largely absent and haulm acid detergent lignin and grain yield were even inversely correlated (r = −0.28, P = 0.05), that is high grain yielders had decreased haulm lignin. However, haulm N and grain yield also tended to be negatively associated (r = −0.26, P = 0.07). Haulm fodder quality traits and haulm yield were mostly positively correlated (P < 0.05). Broad sense heritabilities for grain and fodder yield were 0.50 and 0.29, respectively, while heritability for haulm fodder quality traits ranged from 0.61 to 0.67, providing opportunities for concomitant increase in grain yield and haulm fodder quality traits. Selection of the 10 highest ranking genotypes for grain yield, haulm yield, haulm N, and haulm in vitro organic matter digestibility showed selection groups overlapping, suggesting that multi-trait selection is feasible. Economical evaluation showed that choice of primary traits is context specific, highlighting the need for identifying and targeting appropriate genotypes to fit different production systems. Considering haulm quantity and quality as traits of economic value can increase overall plant value in mixed crop-livestock systems.

Highly pathogenic avian influenza HPAI H5N1 was first reported in Africa in 2006, in Nigeria. The country experienced severe outbreaks in 2006 and 2007, strongly affecting the poultry population. Current knowledge on potential risk factors for HPAI H5N1 occurrence in poultry farms in Nigeria is limited. Therefore, we conducted a case-control study to identify potential farm-level risk factors for HPAI H5N1 occurrence in two areas of the country that were affected by the disease in 2006 and 2007, namely the States of Lagos and Kano. A case-control study was conducted at the farm level. A convenience sample of 110 farms was surveyed. Data on farm characteristics, farm management and trade practices were collected. Logistic regression was used to identify factors associated with farms that confirmed positive for HPAI. Having a neighbouring poultry farm was identified as a potential risk factor for disease occurrence [OR, 5.23; 95% CI, (0.88-30.97); P-value = 0.048]. Farm staff washing their hands before handling birds was a protective factor [OR, 0.14; 95% CI, (0.05-0.37); P-value <0.001], as well as not allowing traders to enter the farm [OR, 0.23; 95% CI, (0.08-0.70); P-value = 0.008]. Our study highlighted the importance of trade and proximity between poultry farms in the epidemiology of HPAI H5N1 and the role of biosecurity in disease prevention in Kano and Lagos States. Despite the limitations owing to the sampling strategy, these results are consistent with other risk factor studies previously conducted on HPAI H5N1 in both Africa and other regions, suggesting similar risk factor patterns for HPAI H5N1 virus spread and substantiating current knowledge regarding the epidemiology of the disease. Finally, this study generated information from areas where data are difficult to obtain.

Agricultural intensification involving greater crop-livestock interactions and integration is emerging as the most promising strategy for improving agricultural production and productivity in much of Sub-Sahara Africa. In West Africa, where this process is at various stages of evolution, 559 farm households from the Sudan Savanna (SS) and Northern Guinea Savanna (NGS) zones were studied to examine the factors affecting production efficiency. The farms in each zone were divided into four socioeconomic domains using a combination of population density and market access as criteria. Estimation of stochastic frontier production function indicated the need to include ecological and socioeconomic variables in both the production function and the accompanying inefficiency equation, failing which such models may suffer from omitted variables bias. The results showed that inefficiency effects of a stochastic nature existed among the sample farms and average efficiency was 76%: 68% in the SS and 86% in the NGS zones. Further, increased resource use associated with agricultural intensification was not always accompanied by an increase in production efficiency; and while agricultural intensification based on high external input strategies yields higher marginal returns in the NGS, a similar strategy is not critical to success in the SS given

We quantified the between-village transmission rate, β (the rate of transmission of H5N1 HPAI virus per effective contact), and the reproductive number, Re (the average number of outbreaks caused by one infectious village during its entire infectious period), of H5N1 highly pathogenic avian influenza (HPAI) virus in Nigeria using outbreak data collected between December 2005 and July 2008. We classified the outbreaks into two phases to assess the effectiveness of the control measures implemented. Phase 1 (December 2005-October 2006) represents the period when the Federal Government of Nigeria managed the HPAI surveillance and response measures, while Phase 2 (November 2006-July 2008) represents the time during which the Nigeria Avian Influenza Control and Human Pandemic Preparedness project (NAICP), funded by a World Bank credit of US$ 50 million, had taken over the management of most of the interventions. We used a total of 204 outbreaks from 176 villages that occurred in 78 local government areas of 25 states. The compartmental susceptible-infectious model was used as the analytical tool. Means and 95% percentile confidence intervals were obtained using bootstrapping techniques. The overall mean β (assuming a duration of infectiousness, T, of 12 days) was 0.07/day (95% percentile confidence interval: 0.06-0.09). The first and second phases of the epidemic had comparable β estimates of 0.06/day (0.04-0.09) and 0.08/day (0.06-0.10), respectively. The Re of the virus associated with these β and T estimates was 0.9 (0.7-1.1); the first and second phases of the epidemic had Re of 0.84 (0.5-1.2) and 0.9 (0.6-1.2), respectively. We conclude that the intervention measures implemented in the second phase of the epidemic had comparable effects to those implemented during the first phase and that the Re of the epidemic was low, indicating that the Nigeria H5N1 HPAI epidemic was unstable.

Outbreaks of highly pathogenic avian influenza (HPAI) H5N1 occurred in Nigeria between December 2005 and July 2008. We describe temporal and spatial characteristics of these outbreaks at State and Local Government Area (LGA) levels. A total of 25 of 37 States (67.6%; Exact 95% CI: 50.2-82.0%) and 81 of 774 LGAs (10.5%; Exact 95% CI: 8.4-12.8%) were affected by HPAI outbreaks over the period from 2005 to 2008. The incidence risk of HPAI outbreak occurrence at the State level was 5.6% (0.7-18.7%) for 2005, 50.0% (30.7-69.4%) for 2006, 54.5% (29.9-80.3%) for 2007 and 0% for 2008. Only very few LGAs experienced HPAI outbreaks within the affected States. The incidence risk of HPAI outbreak occurrence on a LGA level was 0.3% (0.0-0.9%) for 2005, 6.6% (4.9-8.6%) for 2006, 4.2% (2.9-6.0%) for 2007 and 0% for 2008. The mean period between farmers noticing HPAI outbreaks and reporting them to veterinary authorities, and between reporting HPAI outbreaks and the depopulation of infected premises, was for both 4.5 days; both periods also had medians of 1 day. We have estimated the spatially smoothed incidence risk for the whole outbreak period and identified the existence of a large corridor in the western part of Nigeria and a smaller corridor in south-eastern part, where the risk of HPAI occurrence was lower than in the rest of the country. The effect of HPAI control policies on the outbreaks patterns are discussed, as well as possible reasons why HPAI did not become endemic in Nigeria.

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Highly Pathogenic Avian Influenza (HPAI) is classified by the World Organization for Animal Health as one of the notifiable diseases. Its occurrence is associated with severe socio-economic impacts and is also zoonotic. Bangladesh HPAI epidemic data for the period between 2007 and 2013 were obtained and split into epidemic waves based on the time lag between outbreaks. By assuming the number of newly infected farms to be binomially distributed, we fit a Generalized Linear Model to the data to estimate between-farm transmission rates (β). These parameters are then used together with the calculated infectious periods to estimate the respective basic reproduction numbers (R ). The change in β and R with time during the course of each epidemic wave was explored. Finally, sensitivity analyses of the effects of reducing the delay in detecting infection on a farm as well as extended infectiousness of a farm beyond the day of culling were assessed. The point estimates obtained for β ranged from 0.08 (95% CI: 0.06-0.10) to 0.11 (95% CI: 0.08-0.20) per infectious farm per day while R ranged from 0.85 (95% CI: 0.77-1.02) to 0.96 (95% CI: 0.72-1.20). Sensitivity analyses reveal that the estimates are quite robust to changes in the assumptions about the day in reporting infection and extended infectiousness. In the analysis allowing for time-varying transmission parameters, the rising and declining phases observed in the epidemic data were synchronized with the moments when R was greater and less than one, respectively. From an epidemiological perspective, the consistency of these estimates and their magnitude (R ≈ 1) indicate that the effectiveness of the deployed control measures was largely invariant between epidemic waves and the trend of the time-varying R supports the hypothesis of sustained farm-to-farm transmission that is possibly initiated by a few unique introductions.