V/BOTANICAL DIVERSITY OF POTENTIAL FORAGE PLANTS IN RANGE AND FARMING SYSTEMS OF GILGEL GIBE CATCHMENT/JIMMA ZONE: A total of 135 forage plant species comprising of 58 families were identified. Asteraceae, Fabaceae and Poaceae are the major forage plant families of the region comprising 31% the forage plant species (P<0.05). Herbaceous plants consist of 61% of total collections and widely grown in open areas, cultivated lands and water banks. Brachiaria, Cynodon, Sporobolus, Pennisetum and Setaria are abundant genera of grasses in road sides and grazing areas whereas the wetland regions are densely colonized by Cyperaceae species The farmers’ traditional measures against pasture shortage was more to rent grazingland and purchase roughages and concentrates, than reducing stock, which is a more used strategy in medium highlands, and might thus also contribute to the higher incidence of cattle deaths in lower altitude regions.These preliminary results suggest that not only browsing herbivores, but also grazers on tannin-rich vegetation can have adaptive mechanisms to tannins. Chemical analysis of the IFTS is a first step in evaluating their nutritional value, but data on digestibility and conservation strategies have to be added. Yet, the nutrient concentrations already suggest that IFTS have a clear potential for being used as feed resources that can maintain normal ruminal function. Plant species identification is a first step in evaluating potential fodder plants, but data on nutritive value, preference to herbivore and conservation strategies have to be added. Ethiopia is African leader in livestock production, but encounters several problems both on the animal and the environmental side: cattle often have difficulties in obtaining sufficient feed resources, leading to overgrazed areas. These areas are therefore likely more prone to soil erosion, thus leading to a vicious circle. This project will study the interactions between the nutritional status of grazing cattle and botanical composition shifts of grazing areas due to erosion and/or overgrazing. If plant ecosystems are under grazing pressure, plants will emerge that contain antinutritional factors (ANF), in an effort to prevent being grazed. A typical example of these ANF is tannins. Little is known on the capacity of cattle breeds to adapt to high levels of tannins in their diet, which is necessary to estimate the available dietary energy and nutrients in a certain region. The identification of animal parameters based on their response to the dietary tannin intake could make an important tool for the measurement of grazing stress of the vegetation in specified regions. The present study is aimed to investigate the following primary objectives: (a)Perform a questionnaire among cattle farmers in the Gilgel Gibe catchment in order to identify the relationship between soil erosion and nutritional status of grazing cattle; (b)Inventorize potential feed resources and their nutritional value (including tannins) according to regional and seasonal differences within the Gilgel Gibe catchment; (c)Investigate the ability of local zebu cattle versus zebu x Holstein crossbreed cattle to cope with tannin-rich diets through tannin-binding salivary proteins; (d)Evaluate the potential of tannin-binding salivary protein concentration as estimator for the availability of feed resources among grazing areas and seasons; (e)Provide a tool for easy identification of nutritional status of cattle through ruminal fermentation and in vitro gas production with and without of tannin- binding agents to prevent the formation of tannin-protein complexes; (f) Map regional differences in the degree of feed resources availability throughout the Gilgel Gibe catchments for optimizing feed assets, and consequently the plane of welfare in the dam region. IntroductionIntroduction I/IMPACT OF SOIL EROSION ON AVAILABLE FEED RESOURCES OF FREE-RANGING CATTLE Soil erosion was clearly associated with decreased feed resources for ranging cattle, both in quantity and in quality(P<0.001). This coincided with deteriorated cattle performance(P<0.01)..Based on their indigenous knowledge, the farmers pointed out a number of indicators of soil erosion: botanical, soil, and cattle productivity related indicators. Generally, there was a reduction in total vegetation covers and palatable plant species, an increase in undesirable plants, and depletion in soil quality and nutrients due to various forms of soil erosions, with a concomitant deterioration of feed quantity and quality over time.(P<0.05). II/ CATTLE BREED EFFECTS ON THE REACTIVITY OF CATTLE TO A TANNIN- RICH DIET The nutritional importance of the tree fodder, Albizia gummifera, to grazing ruminants have been investigated. It is evident that tree fodders have a distinctive advantage over tropical grasses in terms of their superior nutritional value especially during the dry season. The results suggest that the forage trees have a considerable supplement to low quality grasses and straws. Although many different plant secondary compounds, have anti-nutritional effects (ANF) and indicate that they have the potential to reduce mineral and protein bioavailability, have been isolated from many of the potential useful tree fodders they still provide necessary nutrients to grazing ruminants. Results (studies I,II,III,IV& V) The higher plasma Zn in the zebus can point to better tannin-coping ability, seen that tannins can reduce the bio-availability of Zn (Lönnerdal, 2000). Reduce Fe,Mo and Cu status(Spears,2000).The positive association between plasma Zn and plasma Mg,Ca,Cu,Fe, and K can refer to the common inhibitory action of tannins on bivalent cations. Higher concentrations of saliva proline and other amino acids in Zebu higher response to tannins.. Due to shortage of feed resources in Ethiopia, smallholder farmers are increasingly relying on various indigenous fodder trees and shrubs (IFTS). Fodder trees and shrubs can help to balance a plant-animal-soil-ecosystem and form a sustainable source of fodder. Therefore, the occurrence of tannins in the vegetation can be considered as an indicator of relative overgrazing. Zebu cattle react upon dietary tannins through salivary secretion of proline-rich proteins hence might be an estimator of differences in tannin pressure and hence overgrazing status among regions. The mineral binding capacity of tannins was seen in the reduced Cu status, whereas Fe status was not affected, likely because its ubiquity in the region. The salivary arginine to ornithine ratio, as a measure of urea synthesis and hence ruminal protein breakdown, points to lower protein bio-availability in high tannin regions. Syzygium guineense,Draceana studeri, Ficus ovata, Ficus vasta, Ficus sycomorus, Ficus capensis, Ficus thonningii, Salix purpurea, Arundinaria alpine, Syzygium guineense, Milletia ferruginea, Sapium ellipiticum,and Vernonia amygdalina species were some of the trees and shrubs well known to farmers and highly utilized in livestock feeding as indicated by 85.7%(n=360) of the respondents. Nearly 76% of respondents plants the Ficus species for coffee shades, where as 89% of the farmers manage leguminous fodders also for soil fertility improvement. Analytical results ranged between 90 to 350 g CP/kg, 1.3 to 145 g EE/kg, 243 to 831 g NDF/kg, and 2 to 107 g tannins /kg. DiscussionDiscussion ConclusionsConclusions AcknowledgementsAcknowledgements The authors gratefully acknowledge the VLIR-UOS institutional university cooperation program for funding the research project. We also greatly appreciate Jimma University, local government, development agents and farmers in the study area for their all round participation. Tannins and animal nutrition A PhD work done in the context of the IUC-JU project, Contacts: Supervisor: Tannins and animal nutrition A PhD work done in the context of the IUC-JU project, Contacts: Supervisor: IFTS Nutritious fodder for livestock Fuel wood Medicinal value Source of cash income ConstructionShelterShadeFood Balance ecosysem Erosion control Soil fertility IV//INDIGENOUS FODDER TREES AND SHRUBS: NUTRITIONAL AND ECOLOGICAL ASPECTS Due to shortage of feed resources in the study area, smallholder farmers are increasingly relying on various indigenous fodder trees and shrubs (IFTS). Fodder trees and shrubs can help to balance a plant-animal-soil-ecosystem and form a sustainable source of fodder III/RELATIONSHIP BETWEEN SALIVARY PROLINE-RICH PROTEINS AND MICROMINERAL STATUS IN FREE RANGING ZEBU CATTLE The decrease of available feed resources of free-ranging cattle in eroded areas coincides with the emergence of plant species that use antinutritional factors like tannins as an evolutionary strategy to avoid them being grazed(Yisehak et al.,,2009) Therefore, the occurrence of tannins in the vegetation can be considered as an indicator of relative overgrazing. Zebu cattle react upon dietary tannins through salivary secretion of proline-rich proteins hence might be an estimator of differences in tannin pressure and hence overgrazing status among regions. Average tannin concentrations per regions ranged between 0 and 3.9% tannins. The ratio of proline to the sum of total amino acids in the saliva was significantly higher in tannin-rich regions. High tannin levels were associated with reduced plasma Cu, whereas Fe was not affected. The ratio of salivary arginine to ornithine was higher in tannin-rich regions. ObjectivesObjectives Materials & Methods The objectives stated above will be achieved through cross-sectional questionnaire survey, field measurements, series of animal experimentation using cross-over design procedure and laboratory works by means of standard analytical methods.