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In recent decades, there has been a rapid shift in livestock breeds used in developing countries, leading to a loss of local genetic resources. The introduction of high-performing livestock breeds might, however, offer opportunities to improve the income of poor livestock keepers. In southern Mali, where cattle play an important role in farmers’ livelihoods, the endemic trypanotolerant N’Dama cattle breed is increasingly being crossbred with the improved Fulani Zebu breed. Thus, the N’Dama cattle face serious threats of genetic erosion, despite their adaptive attributes. This study aims to evaluate and compare the productive and economic performance of endemic N’Dama, Fulani Zebu and their crossbreds in southern Mali in order to assess the comparative advantages of these breed groups for farmers. Data collection methods comprised of interviews with 34, 31, 34 and 61 households keeping N’Dama, crossbreds, Fulani Zebu and mixed herds respectively, and a cow progeny history and body condition scoring (BCS) (n = 770). Data were analyzed using linear mixed models and a non-parametric test. Results on cow individual performances showed a higher body condition for N’Dama compared to Fulani Zebu and crossbred cattle, while cow milk offtake was higher for Fulani Zebu herds. Calving and offtake rates were higher for the Fulani Zebu and crossbred herds. The gross margin/cattle and the benefit-cost ratio were highest in the Fulani Zebu herds, followed by the crossbred herds, whereas the net benefit/cattle, including non-market benefits, such as traction, manure, insurance and home consumption, was similar between the herd categories. The N’Dama cattle remain a valuable breed for subsistence-oriented crop-livestock farmers for whom non-market benefits from cattle play a considerable role. Fulani Zebu and crossbred cattle were the most favorable options for market-oriented local and settled transhumant farmers, given their higher price and increased profitability.

Many local livestock breeds in developing countries are being replaced by exotic breeds, leading to a loss of genetic resources. In southern Mali, for the past two decades, a trend towards increasing crossbreeding between the trypanotolerant N'Dama cattle and the trypano-susceptible Fulani Zebu cattle has been taking place. A survey with 160 farmers owning a cattle herd was carried out in southern Mali to investigate their production objectives, as well as trait and breed preferences and correlated socio-economic determinants in order to understand farmers' breeding decisions and to identify comparative advantages of three breed groups (N'Dama, Fulani Zebu and crossbreds) raised in the study area. Data were analyzed using an exploded logit model. The reasons for raising cattle, as well as trait and breed preferences reflected the multiple objectives of the farmers. Draught power and savings were the most important production objectives. Productive traits were ranked highest; farmers reported large body size as the most preferred trait, followed by fertility, draught ability and milk yield. Crossbreds were the favored breed group. Breed preferences were mainly explained by 'resistance to disease' for N'Dama cattle and 'high market price' for Fulani Zebu and crossbred cattle. Production objectives, trait and breed preferences were mainly influenced by farmer group (local farmers and settled transhumants). Local farmers put comparatively more emphasis on livestock functions linked to crop production such as draught power. They had a higher preference for traction ability as a selection trait and preferred N'Dama over Fulani Zebu cattle. Settled transhumants emphasized milk yield as a selection trait and preferred Fulani Zebu over N'Dama. The results indicate that the trend towards more crossbreeding will continue putting the N'Dama breed under high risk of genetic dilution in southern Mali. The N'Dama cattle remain a valuable breed due to their adaptive traits such as disease and drought tolerance and their good traction ability, fulfilling the diverse objectives of local farmers. Crossbreeding was found to be a promising breeding strategy, which might contribute to the maintenance of the local breed, provided that breeding schemes are thoroughly planned and organized.

In order to design a sound community-based genetic improvement program, identifying breeding objective traits and their relative importance is a prerequisite. The study aims to identify goat breeding objectives in three production systems of Ethiopia based on revealed and stated preference information. Market transaction surveys as well as choice experiments (CE) were conducted in three production systems of Ethiopia. Relationships between goats’ attributes and prices were estimated by hedonic modeling, while economic values of traits included in the CE were estimated by conditional logit (CL) model. Part worth value of a trait which indicates the relative importance of a trait was calculated based on the implicit prices farmers were willing to pay (WTP) for an improvement of a trait. The hedonic regression results showed that body weight was a consistent determinant of goat price in all observed markets. While, attributes such as body condition, age and season had heterogeneous effect on market prices of goats. The CL analysis indicated that farmers living in harsh environments valued functional traits such as disease resistance more than performance traits. Based on revealed preferences and choice models, alternative breeding options, which are in line with farmers’ trait preferences and market demands, were suggested. The suggested alternative trait combinations and their economic values could be used as an input for optimization of the breeding schemes after considering heritability, genetic and phenotypic correlations.

Complex flow fields arise during the reverse flow phase of compressor mild surge cycles, yielding potentially increased flutter risks. Variable nozzle models enable to simulate entire surge cycles and to evaluate the blade flutter stability at reverse flow conditions. Nevertheless, the accuracy of the simulation results strongly depends on the correct selection of the model parameters. Former studies have shown the influence of the surge volume on the compressor global unsteady behavior. The current study focuses on the impact of the nozzle throttle area on the compressor surge behavior and demonstrates that this parameter has to be considered additionally to achieve accurate results with this modelling approach. A conceptual model consisting of one passage of a single rotor row is used to identify the basic system behavior and to determine the influence of the model parameters.

To determine the potential of aeroelastic tailoring to improve flutter stability of carbon fiber turbomachinery compressor blades the structural dynamic and aeroelastic behavior of ten different laminate layups were compared. At first an operating point at off-design conditions was identified as flutter critical. Afterwards the dependency between Laminate properties and eigenbehavior and between eigenbehavior and aerodynamic stability under these off-design conditions were described. The results show that for every of the first three natural oscillations certain conditions for the eigenmode and eigenfrequency have to be satisfied to evoke aerodynamically stable be- havior. Considering these constraints just one of the investigated laminates is suitable to ensure flutter stability for these certain flow conditions. This very small variety of applicable laminate layups shows the complexity to design aerodynamically stable compressor blades but also the great potential of aeroelastic tailoring to improve the flutter stability of carbon fiber turbomachinery compressor blades.

Goat production is an important agricultural activity in Jordan. The country is one of the poorest countries in the world in terms of water scarcity. Provision of sufficient quantity of good quality drinking water is important for goats to maintain feed intake and production. This study aimed to evaluate the seasonal availability and quality of goats' drinking water sources, accessibility, and utilization in different zones in the Karak Governorate in southern Jordan. Data collection methods comprised interviews with purposively selected farmers and quality assessment of water sources. The provision of drinking water was considered as one of the major constraints for goat production, particularly during the dry season (DS). Long travel distances to the water sources, waiting time at watering points, and high fuel and labor costs were the key reasons associated with the problem. All the values of water quality (WQ) parameters were within acceptable limits of the guidelines for livestock drinking WQ with exception of iron, which showed slightly elevated concentration in one borehole source in the DS. These findings show that water shortage is an important problem leading to consequences for goat keepers. To alleviate the water shortage constraint and in view of the depleted groundwater sources, alternative water sources at reasonable distance have to be tapped and monitored for water quality and more efficient use of rainwater harvesting systems in the study area is recommended.

The contribution of dry season silage feeding on daily milk yield (MY) and dairying profitability in terms of income over feed cost (IOFC) was evaluated in dual-purpose cattle production systems in Honduras. MY records of 34 farms from two milk collection centres were collected over a 2-year period. Farms were surveyed to obtain information on the type, quantity and cost of supplemented feed, breed type and number of lactating cows in each month. Farms were classified in silage farms (SF, with a short silage supplementation period), non-silage farms (NSF) and prototype farms (PF, with an extended silage supplementation period). Data were analysed using descriptive statistics and a linear mixed model approach. PF had significantly higher MY than SF and NSF but, due to higher expenses for both concentrate and silage, similar IOFC compared to NSF. SF had similar MY but lower IOFC compared to NSF, due to higher feed expenses. The effect of silage feeding, particularly maize silage, on MY was significant and superior to that of other forage supplements. Silage supplementation contributed to the highest MY and IOFC on farms with crossbred cows of >62.5 % Bos taurus and to the second highest profitability on farms with >87.5 % Bos indicus share. It is concluded that silage can play an important role in drought-constrained areas of the tropics and can contribute to profitable dairying, irrespective of breed.

SUMMARYLittle bag silage (LBS) is seen as a low-cost alternative suitable for resource-poor smallholders to alleviate dry-season feed constraints. Within a research project carried out by the International Center for Tropical Agriculture and partners in Honduras, LBS was tested and its use encouraged during farmer training and field days. The present study highlights the most relevant technological and socio-economic potential and constraints of LBS. Surveys and experimental results revealed great vulnerability of plastic bags to pests, particularly rodents, accompanied by high spoilage losses. The main constraints to wider adoption include availability of i) suitable and affordable plastic bags, and ii) appropriate chopping equipment and storage facilities on smallholder farms. LBS proved to be useful and could play an important role in participatory research and extension activities, as a demonstration, experimentation and learning tool that can be used to get small-scale silage novices started with a low-risk technology.

Over 20 years after the implementation of irrigation schemes in the surrounding area of the Itaparica Reservoir, in the semi-arid region of Northeast Brazil, insufficient infrastructure and low market power still impact smallholders’ incomes and development of market strategies to support rental increase from the smallholders. Lack of access to credit, high input costs, and low producer prices for major crops have helped to maintain the poverty status of smallholders that equally affects small agricultural producers like cattle breeders. Agricultural cooperatives have contributed to increase their members’ market power in agricultural commerce and facilitate their access to credit and agricultural expansion. To analyze the historical context of this situation, as well as the potentials and constraints of agricultural cooperatives and associations, 24 qualitative expert interviews were conducted among members of cooperatives or associations and consultants involved with technical assistance to smallholders. During the study period, no active agricultural cooperatives could be identified. Financial problems related with lack of financial resources, inadequate government support, absence of leadership and poor organization, and missing solidarity and mistrust were considered the main reasons for the cooperatives’ poor situation. However, the potential of these cooperatives are illustrated by the efficiency of the fishery and apiculture associations.