The Bovine HapMap Consortium* The imprints of domestication and breed development on the genomes of livestock likely differ from those of companion animals. A deep draft sequence assembly of shotgun reads from a single Hereford female and comparative sequences sampled from six additional breeds were used to develop probes to interrogate 37,470 single-nucleotide polymorphisms (SNPs) in 497 cattle from 19 geographically and biologically diverse breeds. These data show that cattle have undergone a rapid recent decrease in effective population size from a very large ancestral population, possibly due to bottlenecks associated with domestication, selection, and breed formation. Domestication and artificial selection appear to have left detectable signatures of selection within the cattle genome, yet the current levels of diversity within breeds are at least as great as exists within humans.T he emergence of modern civilization was accompanied by adaptation, assimilation, and interbreeding of captive animals. In cattle (Bos taurus), this resulted in the development of individual breeds differing in, for example, milk yield, meat quality, draft ability, and tolerance or resistance to disease and pests. However, despite mapping and diversity studies (1-5) and the identification of mutations affecting some quantitative phenotypes (6-8), the detailed genetic structure and history of cattle are not known.Cattle occur as two major geographic types, the taurine (humpless-European, African, and Asian) and indicine (humped-South Asian, and East African), which diverged >250 thousand years ago (Kya) (3). We sampled individuals representing 14 taurine (n = 376), three indicine (n = 73) (table S1), and two hybrid breeds (n = 48), as well as two individuals each of Bubalus quarlesi and Bubalus bubalis, which diverged from Bos taurus~1.25 to 2.0 Mya (9, 10). All breeds except Red Angus (n = 12) were represented by at least 24 individuals. We preferred individuals that were unrelated for ≥4 generations; however, each breed had one or two sire, dam, and progeny trios to allow assessment of genotype quality.Single-nucleotide polymorphisms (SNPs) that were polymorphic in many populations were primarily derived by comparing whole-genome sequence reads representing five taurine and one indicine breed to the reference genome assembly obtained from a Hereford cow (10) (table S2). This led to the ascertainment of SNPs with high minor allele frequencies (MAFs) within the discovery breeds (table S5). Thus, as expected, with trio progeny removed, SNPs discovered within the taurine breeds had higher average MAFs

Few studies of land-use/land-cover change provide an integrated assessment of the driving forces and consequences of that change, particularly in Africa. Our objectives were to determine how driving forces at different scales change over time, how these forces affect the dynamics and patterns of land use/land cover, and how land-use/land-cover change affects ecological properties at the landscape scale. To accomplish these objectives, we first developed a way to identify the causes and consequences of change at a landscape scale by integrating tools from ecology and the social sciences and then applied these methods to a case study in Ghibe Valley, southwestern Ethiopia. Maps of land-use/land-cover change were created from aerial photography and Landsat TM imagery for the period, 1957-1993. A method called 'ecological time lines' was developed to elicit landscape-scale explanations for changes from long-term residents. Cropland expanded at twice the speed recently (1987)(1988)(1989)(1990)(1991)(1992)(1993) than two decades ago (1957)(1958)(1959)(1960)(1961)(1962)(1963)(1964)(1965)(1966)(1967)(1968)(1969)(1970)(1971)(1972)(1973), but also contracted rapidly between 1973-1987. Rapid land-use/land cover change was caused by the combined effects of drought and migration, changes in settlement and land tenure policy, and changes in the severity of the livestock disease, trypanosomosis, which is transmitted by the tsetse fly. The scale of the causes and consequences of land-use/land-cover change varied from local to sub-national (regional) to international and the links between causes and consequences crossed scales. At the landscape scale, each cause affected the location and pattern of land use/land cover differently. The contraction of cropland increased grass biomass and cover, woody plant cover, the frequency and extent of savanna burning, and the abundance of wildlife. With recent control of the tsetse fly, these ecological changes are being reversed. These complex patterns are discussed in the context of scaling issues and current conceptual models of land-use/land-cover change.

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This study was conducted to characterize the morphological peculiarities and performance characteristics of Mursi cattle in its production environment managed by Bodi and Mursi pastoral communities in Southern Ethiopia. A structured questionnaire survey, group discussion, cattle morphological measurements and morphological descriptions were used to collect data. One hundred and two household heads were selected to administer the questionnaire and 201 adult cattle were selected for morphological description and body measurements. The Mursi cattle population was found to have variable coat colour type (85.9 percent) and coat colour pattern (51.3 percent). Body length, chest girth, withers height, rump width and rump length of Mursi cattle were 122.1 ± 0.9, 144.5 ± 0.9, 113 ± 0.1.1, 36.9 ± 0.3 and 20.4 ± 0.3 cm, respectively. Morphological measurements of most linear traits show no difference in the two locations but all measurements vary (P < 0.001) between males and females. Estimated age at first calving was 4.6 years and was significantly (P < 0.0001) higher in the Mursi area, while the calving interval (14.5 months) and cow reproductive life (14.2 years) were the same in both locations. Average daily milk yield (2.1 litres) and lactation length (7.8 months) of Mursi cattle in the two locations were similar. Cattle production was constrained by high disease prevalence, seasonal feed availability, and water shortage, with frequent drought. Trypanosomosis, black leg, anthrax and skin diseases are major cattle diseases reported in the two study areas. Because of its peculiar morphological characteristics, including large body frame, higher production performance, and survivability in the harsh environment, the Mursi cattle can be used as an alternative genetic resource for production improvement programs. RésuméCette étude a été menée dans le but de caractériser les particularités morphologiques et les performances productives des bovins Mursi dans son milieu de production, géré par les communautés pastorales Bodi et Mursi dans le Sud de l'Éthiopie. Un questionnaire structuré, un groupe de discussion et des mesures et des descriptions morphologiques des bovins ont été utilisés pour la collecte des données. Cent-deux chefs de famille ont été sélectionnés pour le questionnaire alors que 201 animaux adultes ont été choisis pour la description morphologique et les mesures corporelles. Il a été observé que la population bovine Mursi présente des couleurs (85,9 pour cent) et des motifs de la robe (51,3 pour cent) variés. La longueur du corps, le périmètre thoracique, la hauteur au garrot et la largeur et la longueur de la croupe chez les bovins Mursi ont été de 122,1 ± 0,9, 144,5 ± 0,9, 113 ± 0,1, 36,9 ± 0,3 et 20,4 ± 0,3 cm, respectivement. Aucune différence n'a été décelée entre les deux zones pour ce qui est de la plupart des mesures linéaires mais toutes les mesures ont varié (P < 0.001) entre mâles et femelles. L'âge estimé à la première mise bas a été de 4,6 ans et a été significativement (P < 0.0001) plus élevé da...

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