Browsing by Author "Fantahun Dereje"

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    Agronomic Performance, Nutritional Value, and Simulation of the Impacts of Climate Change on Growth and Yield of four Brachiaria (Trin.) Griseb. (Syn. Urochloa P. Beauv.) Species Under two Locations in Central and Western Ethiopia
    (Addis Abeba University, 2025) Fantahun Dereje; Ashenafi Mengistu; Diriba Geleti; Diriba Diba; Fekede Feyissa
    Ethiopia has the largest livestock population in Africa, yet productivity is limited by chronic feed shortages, largely due to shrinking pasturelands, poor-quality crop residues, and the increasing impacts of climate change. Improved forages like Brachiaria grass offer a promising solution. However, adaptation must prioritize not only biomass yield but also nutritional quality and climate resilience. This study aimed to evaluate the agronomic performance, feeding value, and simulate the growth and yield of Brachiaria species under future climate scenarios in central and western subhumid agroecology of Ethiopia. Four Brachiaria (syn. Urochloa) species—B. mutica, B. brizantha, B. decumbens, and B. humidicola— was compared with Rhodes and Desho grasses (2020–2022). Results showed significant effects of species, year, and interactions. B. mutica revealed the highest DM yield, followed by B. brizantha and Desho grass. CP yield showed a similar pattern. The highest CP content was in B. humidicola, followed by B. mutica and B. brizantha, while Desho grass had the lowest. No significant differences were observed in NDF and lignin. Rhodes grass had the highest ADF, while B. humidicola had the highest ash content. IVDMD was highest in B. humidicola and B. brizantha, and lowest in Rhodes grass. B. mutica and B. brizantha emerged as the most promising forages for subhumid areas. In the feeding value trial, Arsi-Bale rams were fed B. mutica hay supplemented with 100, 200, 300, or 400 g/day of concentrate (noug seed cake and wheat bran). Higher supplementation significantly improved DM intake, digestibility, and growth rates. Rams fed 300 g and 400 g showed the highest gains, with no significant difference between them. Carcass traits, including carcass weight, dressing percentage, and rib-eye area improved with increased supplementation. Economic analysis showed that 200–300 g/day supplementation offered the best cost–performance balance. Thus, supplementing B. mutica hay with 300 g/day of concentrate optimizes growth and return, while 200– 300 g/day is recommended for cost-effective feeding. Further research is needed to validate these findings under small-holder farmer conditions. The CROPGRO-PFM simulation model predicts that B. brizantha showed increases in shoot (9%), herbage (11%), and stem (25%) biomass, but a 7% reduction in leaf biomass and CP content. B. humidicola followed a similar trend. In contrast, B. mutica showed projected biomass reductions of up to 34% by the end of the century and a 14–20% drop in CP content. Overall, B. brizantha and B. humidicola appear more resilient to climate change, while B. mutica is more vulnerable. Further research is recommended to refine adaptive strategies, improve crop management, and support sustainable livestock production in Ethiopia.
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    The Effect of Variety and Seed Proportions on Yield, Nutritional Quality and Compatibility of Oats and Vetch Mixtures
    (Addis Ababauniversity, 2016-06) Fantahun Dereje; Ashenafi Mengistu
    The present study was conducted to assess the varietal and seed proportion effects on yield, quality and compatibility of oats and vetch mixtures under varying seed proportion (100%, 75%, 50%, 25%) using two varieties for each of the component species. The experiment was conducted in Randomized Complete Block Design (RCBD) with three replications. Seedling count, biomass yield, plant height, vigor and plot cover were collected. Forage quality traits considered for the experiments were DM content, ash, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, cellulose and hemicelluloses. Relative yield, Relative yield total, Relative crowding coefficient and Aggressivity index were indices calculated for biological compatibility and yield advantages of oats and vetch. Significant (P<0.05) differences were observed for all measured agronomic traits except for plot cover. The highest DMY (17.61) was obtained from the mixture of 75% SRCP × 80 Ab 2291 + 25% Vicia dasycarpa lana. Mean values of Ash, CP, NDF, ADF and cellulose had significant (P<0.05) difference whereas mean values of DM content, ADL and hemicelluloses had non-significant (P>0.05) difference. The highest DMY, CPY and NDFY was showed by the mixture of 75% SRCP × 80 Ab 2291 + 25% Vicia dasycarpa Lana. Relative yield (RY) of oats and vetch varieties were less than one indicating that the yield obtained in the pure stands were higher than those from the mixed stands of the component species for both varieties. The relative yield total (RYT) of most mixed stands were greater than one indicating xv mixed stands to have superior yield advantage compared to the pure stand plots. The highest RYT value of 1.48, from the mixture of 50% SRCP × 80 Ab 2291 + 50% Vicia sativa ICARDA 61509, suggested a biological yield advantage of 48% in mixed cropping compared to the pure stand plots. The vetch varieties are the dominant except at the seed proportion of 75% +25% oats-vetch mixtures respectively. Generally, the result indicated that vetch species had higher CP and lower NDF than their respective mixtures and pure oats. The DMY, CPY and NDFY of mixtures of 75% oats + 25% vetch and 50% oats + 50% vetch seed proportions were better than pure stands. The RYT values of these mixtures were also greater than one. Therefore, it is concluded mixtures at seed proportions of 75% oats + 25% vetch and 50% oats + 50% vetch had relatively higher yield, quality and better compatible. Key words: Biological compatibility, Herbage DM yield, Nutritional quality, Oat and Vetch varieties and Seed proportions