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A comprehensive dynamic simulation model was developed to describe a community-based breeding program for the Menz sheep population of Ethiopia. Selection of male and female animals based on their own and maternal performance was simulated. The breeding goal traits were 6-mo weight, preweaning survival, and fertility rate. The model input data were obtained from the flock book, questionnaires, and references. The simulation model used a mix of deterministic and stochastic procedures to model the complex system. In the baseline scenario, the proportion of selected male and female animals varied between 20 and 30% and between 70 and 80%, respectively. A reasonable annual genetic gain was predicted for the breeding goal traits at the village level. For 6-mo weight and preweaning survival rate, the annual genetic gain varied from 0.213 to 0.214 kg and 0.255 to 0.256%, respectively. For fertility rate, an annual genetic gain of 0.063% was obtained. The predicted rate of inbreeding per year was between 0.094 and 0.116%. Furthermore, a scenario analysis was conducted by varying the proportions of selected animals. Annual genetic gains of 0.230 kg, 0.277%, and 0.069% were obtained for 6-mo weight, preweaning survival rate, and fertility rate, respectively, when the proportion of selected male and female animals decreased by 10%. The annual genetic gains decreased to 0.198 kg, 0.236%, and 0.059%, respectively, when the selection proportion of male and female animals increased by 10%. The lowest rate of inbreeding per year, ranging from 0.065 to 0.079%, was achieved when the selection proportion of selected male and female animals increased. The model is relevant for the step-by-step evaluation of more than one round of selection. It is flexible and usage driven. The model is a valuable tool to design different population structures and can be easily expanded to adopt different breeding strategies. Hence, the system dynamics modeling approach is a potential tool to describe complex breeding programs.

This is the first report performing the whole genome SNP scanning of snow sheep (Ovis nivicola). Samples of snow sheep (n = 18) collected in six different regions of the Republic of Sakha (Yakutia) from 64° to 71° N. For SNP genotyping, we applied Ovine 50K SNP BeadChip (Illumina, United States), designed for domestic sheep. The total number of genotyped SNPs (call rate 90%) was 47796 (88.1% of total SNPs), wherein 1006 SNPs were polymorphic (2.1%). Principal component analysis (PCA) showed the clear differentiation within the species O. nivicola: studied individuals were distributed among five distinct arrays corresponding to the geographical locations of sampling points. Our results demonstrate that the DNA chip designed for domestic sheep can be successfully used to study the allele pool and the genetic structure of snow sheep populations.

The genetic trends in fitness (inbreeding, fertility and survival) of a closed nucleus flock of Menz sheep under selection during ten years for increased body weight were investigated to evaluate the consequences of selection for body weight on fitness. A mate selection tool was used to optimize in retrospect the actual selection and matings conducted over the project period to assess if the observed genetic gains in body weight could have been achieved with a reduced level of inbreeding. In the actual selection, the genetic trends for yearling weight, fertility of ewes and survival of lambs were 0.81 kg, -0.00026% and 0.016% per generation. The average inbreeding coefficient remained zero for the first few generations and then tended to increase over generations. The genetic gains achieved with the optimized retrospective selection and matings were highly comparable with the observed values, the correlation between the average breeding values of lambs born from the actual and optimized matings over the years being 0.99. However, the level of inbreeding with the optimized mate selections remained zero until late in the years of selection. Our results suggest that an optimal selection strategy that considers both genetic merits and coancestry of mates should be adopted to sustain the Menz sheep breeding program.

Samples from 717 sheep of 11 Austrian sheep breeds were genotyped for 25 microsatellite loci. Twenty-one loci showing no deviation from Hardy-Weinberg equilibrium were used to calculate pairwise genetic distances (Nei's minimum distance and Reynolds' distance). All breeds could be clearly distinguished through these genetic distances. The shortest genetic distance was found between Alpines Steinschaf (AS) and Waldschaf (WS). Within the so-called 'Steinschaf' group [AS, Montafoner Steinschaf (MS), Krainer Steinschaf (KS) and Tiroler Steinschaf (TS)] the MS adopted an extreme status with the largest distance to the other breeds in the group. This finding resulted in the decision to consider the MS no longer as subpopulation of Alpines Steinschaf but as an independent breed. A correct breed assignment using a Bayesian approach was possible for only 66% of all individuals belonging to Alpines Steinschaf, but for at least 90% of individuals for all other breeds investigated.

Breeding programmes described as community-based ( CBBP) typically relate to low-input systems with farmers having a common interest to improve and share their genetic resources. CBBPs are more frequent with keepers of small ruminants, in particular smallholders of local breeds, than with cattle, pigs or chickens with which farmers may have easier access to alternative programmes. Constraints that limit the adoption of conventional breeding technologies in low-input systems cover a range of organizational and technical aspects. The analysis of 8 CBBPs located in countries of Latin-America, Africa and Asia highlights the importance of bottom-up approaches and involvement of local institutions in the planning and implementation stages. The analysis also reveals a high dependence of these programmes on organizational, technical and financial support. Completely self-sustained CBBPs seem to be difficult to realize. There is a need to implement and document formal socio-economic evaluations of CBBPs to provide governments and other development agencies with the information necessary for creating sustainable CBBPs at larger scales. [ABSTRACT FROM AUTHOR]

Identification of breeding objective traits pertinent to specific production environments with the involvement of target beneficiaries is crucial to the success of a breed improvement program. A choice experiment was conducted in four locations representing different production systems and agro-ecologies that are habitat to four indigenous sheep breeds (Afar, Bonga, Horro and Menz) of Ethiopia with the objective of identifying farmers’/pastoralists’ preferences for sheep breeding traits. Following a synthesis of secondary information and diagnostic surveys, two communities per location consisting of 60 households each having at least four breeding ewes were identified. Producers’ priority attributes used in the choice sets were identified through in-depth production system studies conducted from December 2007 to March 2008. On the basis of prior information, four to seven attributes were used to design choice sets with different profiles in order to capture results that mimic real life of the different communities. The attributes and levels chosen for the sheep profile were as follows: body size (large/small), coat color (brown/white/black), tail type (good/bad) for both rams and ewes; horn (polled/horned) and libido (active/poor) for rams; and lambing interval (three lambings in 2 years/two lambings in 2 years time), mothering ability (good mother/bad mother), twinning rate (twin bearer/single bearer) and milk yield (two cups per milking/one cup per milking) for ewes. A fractional factorial design was implemented to construct the alternatives included in the choice sets. The design resulted in a randomized selection of 48 sheep profiles (24 sets) for both sexes, which were grouped into four blocks with six choice sets each. An individual respondent was presented with one of the four blocks to make his/her choices. Results indicate that producers’ trait preferences were heterogeneous except for body size in rams and mothering ability in ewes where nearly homogeneous preferences were investigated. In the pastoral production system, attention was given to coat color of both breeding rams and ewes, favoring brown and white colors over black. Ram libido influenced producers’ decisions in Bonga, Horro and Menz areas. The influence of milk yield and twinning on respondents’ decision making was high in Afar and Horro, respectively. Breeders in all areas attempt to combine production and reproduction traits as well as they can in order to maximize benefits from their sheep. The elicited measurable objective traits were used to design alternative community-based sheep breeding plans for the four indigenous sheep breeds in their production environments that have been implemented since. [ABSTRACT FROM AUTHOR]

Sheep in the cool highlands of central-northern Ethiopia are of the meat type, have coarse wool, and are often perceived to be low in productivity. To increase their productivity, they have been upgraded with Awassi sheep. The aim of this study was to compare the performance of 37.5% Awassi×indigenous crossbreds with that of indigenous lambs in terms of birth weights, body weights and average daily gains at different stages from birth to 210 days of age. Data were collected between 1997 and 1999, and analysed by GLM procedures of SAS. The effects of farmer, season and birth year, linear regression of lambs’ age, and dam postpartum body weights were significant for all traits studied. Sex variation was important as the lambs grew older. Crossbred lambs were heavier than indigenous lambs at birth and at all ages. However, crossbred lambs were not significantly better than indigenous lambs in average daily gains. The birth weight advantage was also lost with increasing age, indicating that the milk production of ewes of the dam breed was inadequate to rear large size crossbreed lambs. [Copyright &y& Elsevier]

Context: The productivity of Ethiopian smallholder farms is considered to be low owing to different factors such as feed shortage, lack of breeding strategies, disease prevalence and missing marketing strategies. Aim: The main objective of the study was to develop a dynamic, stochastic herd model by adopting system dynamic modelling methodology for evaluation of the effect of increased feed availability (forage production) in combination with different fattening strategies on herd dynamics and profitability of an Ethiopian sheep population. Methods: Forage production utilising part of smallholder farmers' cropland was built into a dynamic simulation model. Two alternative feed-supply systems were evaluated: turning 25% and 50% of the current cropland into area used for forage production. The simulation period was 20 years, the first 10 years representing the baseline fattening scenario (culled rams fattened). For the last 10 years, genetic selection was introduced and two scenarios were evaluated: fattening of culled rams (Scenario I) and fattening of young rams (Scenario II). Key results: Increasing the feed supply resulted in an increase to the herd size when the model balanced dry matter supply and demand of the herd. Fattening of young rams (Scenario II) with genetic selection was significantly more profitable than the baseline and Scenario I in both of the simulated alternative feed-supply systems. This can be used for regular cash generation, which might reduce disposal of animals at lower price in cases of need for emergency cash. Conclusions: Overall, the simulation model demonstrates that production of improved forage crops should be combined with selective breeding and an appropriate finishing strategy. The competition for resources (land and labour) with crop production, forage seed shortage and extended family size are other challenges raised by smallholder farmers for the feasibility of the two alternative feed-supply systems. Feed shortage is a critical problem for the livestock sector in Ethiopia; therefore, development and evaluation of alternative feed-supply systems that enhance feed supply are needed. The alternative feed supply systems should be combined with selective breeding and appropriate finishing strategy. Support of farmers by extension service and development agents is crucial to helping farmers adopt this alternative feed supply system. [ABSTRACT FROM AUTHOR]

• Selection on the Awassi sheep resulted in significant differentiation from the local Awassi. • Breeds under selection showed higher level of genomic inbreeding. • The highest level of genomic inbreeding observed in Awassi sheep breed. • ROH based genomic inbreeding suggested as a tool to control the level of inbreeding. Improved Awassi sheep from Israel has been used for the improvement of the productivity of Ethiopian short-fat tailed Menz and Wollo sheep breeds through crossbreeding. High density (~50,000) single nucleotide polymorphism (SNP) markers distributed along the ovine genome were analyzed for Menz (n = =34), Wollo (n = =18), local Awassi (n = =24) and improved Awassi (n = =23) sheep breeds to assess genetic diversity and population structure. Proportion of polymorphism was highest for local Awassi (96.2%) followed by the Ethiopian breeds (91.7 to 93.0%). Lowest proportion of polymorphic SNP was found in improved Awassi (84.3%). Expected heterozygosity was high (0.37) for local Awassi followed by the local Ethiopian breeds (0.35 and 0.36) and the improved Awassi (0.35). Highest genetic differentiation measured as fixation index (F ST) appeared between local Ethiopian breeds and improved Awassi (F ST ~ 0.14) while the two Ethiopian breeds were closely related (F ST =0.004). Surprisingly, local Awassi sheep differentiated from improved Awassi at a higher level (F ST = 0.09) than it differentiated from Wollo (F ST = 0.058) and Menz (F ST = 0.065). Principal component, model based structure and neighbor net analysis revealed clustering of populations according to their geographic location and breed development history. Strong selection pressure on the Awassi sheep resulted in significant differentiation from local Awassi, less within population variation, excess monomorphic loci and high level of runs of homozygosity (ROH) based genomic inbreeding. The high level of differentiation between local Ethiopian and improved Awassi supported the use of improved Awassi sheep to improve Menz and Wollo sheep breeds. However, importation of Awassi sheep and mating should consider strategies of controlling the level of inbreeding. [ABSTRACT FROM AUTHOR]