This paper reports an evaluation of eleven oat genotypes in four environments for two consecutive years to identify high-biomass-yielding, stable, and broadly adapted genotypes in selected parts of Ethiopia. Genotypes were planted and evaluated with a randomized complete block design, which was repeated three times. The additive main effect and multiplicative interaction analysis of variances revealed that the environment, genotype, and genotype–environment interaction had a significant (p ≤ 0.001) influence on the biomass yield in the dry matter base (t ha⁻¹). The interaction of the first and second principal component analysis accounted for 73.43% and 14.97% of the genotype according to the environment interaction sum of squares, respectively. G6 and G5 were the most stable and widely adapted genotypes and were selected as superior genotypes. The genotype-by-environment interaction showed a 49.46% contribution to the total treatment of sum-of-squares variation, while genotype and environment effects explained 34.94% and 15.60%, respectively. The highest mean yield was obtained from G6 (12.52 kg/ha), and the lowest mean yield was obtained from G7 (8.65 kg/ha). According to the additive main effect and multiplicative interaction biplot, G6 and G5 were high-yielding genotypes, whereas G7 was a low-yielding genotype. Furthermore, according to the genotype and genotype–environment interaction biplot, G6 was the winning genotype in all environments. However, G7 was a low-yielding genotype in all environments. Finally, G6 was an ideal genotype with a higher mean yield and relatively good stability. However, G7 was a poor-yielding and unstable genotype. The genotype, environment, and genotype x environment interaction had extremely important effects on the biomass yield of oats. The findings of the graphic stability methods (additive main effect and multiplicative interaction and the genotype and genotype–environment interaction) for identifying high-yielding and stable oat genotypes were very similar.

Barley straw serves as livestock feed and mulch for soil and water conservation in the mixed barley-livestock systems of the Ethiopian highlands. High demand for barley straw biomass in the system creates competition between the two uses. This study aimed to identify the determinants of the utilization of barley straw for mulch and feed. Data on the production and use of barley straw were collected from 236 households using a structured questionnaire. Use of the straw for the purposes of soil mulch at three levels, 0–15% (marginal mulching), 15–35% (optimal mulching), 35–100% (over-mulching), was analyzed using a multinomial logit model. The optimal proportion of barley straw used as soil mulch was positively affected by the educational level of the household head, family size, distance between cropping land and homestead, number of equines in the household and amount of straw production. Female-headed households were more likely to mulch less than the optimal amount of barley straw. In general, the more the farmer’s exposure to formal extension, the less the proportion of barley straw used for soil mulching. This study provides guidance for the proportional utilization of barley straw. This will contribute to the design of appropriate biomass utilization strategies in barley-livestock farming systems.

The objective of this study was to investigate the fermentation characteristics and nutritional value of A. sativa genotypes ensiled either solely or in combination with P. purpureum 16791. Three different A. sativa genotypes (SRCPX80AB2806, ILRI_5527A, and ILRI_5526A) were harvested at the dough stage and ensiled solely or in combination with equal parts of P. purpureum 16791 with the addition of 3% molasses for all treatments in a completely randomized design with three replications over a period of 45 days. P. purpureum harvested at 60 days was ensiled and used as a control treatment. All treatments were evaluated for fermentation characteristics (pH, temperature, physical properties, and flieg point) and subjected to chemical analysis. The results showed that ensiling A. sativa ILRI_5527A, in combination with equal parts of P. purpureum 16791, produced the best silage with a significantly lower pH of 3.52. Optimal temperature (25 °C), nutrient losses based on the total dry matter (2.17%), gas (3.74%), and effluent (4.28%) were significantly (p < 0.0001) lower for T6 compared to the others. The dry matter recovery rate of T6 was significantly (p < 0.0001) higher than that of the others. T6 ranked first in the quality of physical properties (smell, color, mold, and texture). The highest dry matter (24%), organic matter (96.80%), crude fat (3.32%), and metabolizable energy (10.05 MJ/kg DM) were recorded for T6. The flieg score for T6 silage (96.6%) was also better than the others. In conclusion, ensiling A. sativa ILRI_5527 with equal parts of P. purpureum 16791 and the addition of 3% molasses improved fermentation characteristics and silage quality.

Twenty lambs (18 ± 0.22 kg initial weight) were blocked by weight and individually assigned into pens to evaluate the effects of barley straw variety on digestibility, growth performance and carcass characteristics. The following four treatments were tested: (1) a local barley straw (as control), (2) HB1963 (high grain and straw yields), (3) Traveller (high straw yielder), and (4) IBON174/03 (high grain yielder). A concentrate (50:50 wheat bran and noug seed cake) was offered constantly (300 DM g), whereas the straw was offered ad libitum. The digestibility trial lasted 22 days (15 days to adapt to dietary treatments and 7 days for sampling). The growth performance trial lasted 90 days. At the end, all of the lambs were slaughtered, and their carcasses were evaluated. The IBON174/03 variety had a higher (p < 0.05) intake of organic matter and crude protein, a higher dry matter and organic matter digestibility than the control, and a faster growth than the control. The feed-to-gain ratio was similar among treatments. The slaughter and empty body weights of lambs in the IBON174/03 group were higher than the control variety (p < 0.05). The present study showed that the feeding value of barley straw can differ substantially between varieties and therefore must be considered in the choice of a barley variety.

With a growing export and local market, sheep farming is critical to the economy of smallholder farmers; however, indigenous sheep breeds usually exhibit low carcass output and live weight due to nutritional constraints. The study aimed to investigate the impact of supplementing local sheep with dawri‐damaa leaf meal (DDLM) on their performance, carcass characteristics, and profitability when fed native grass hay. The research used a randomized complete block design (RCBD) to administer four feeding treatments (T1, T2, T3, and T4 at 0%, 30%, 50%, and 70% DDLM, respectively) to 20 local uncastrated male lambs having an average 23.72 ± 0.73 kg body weight and average age of 11.72 ± 0.74 months. Greater doses of DDLM in the diet resulted in greater average daily gain (ADG) of 51.4–83.8 g/day and feed conversion efficiency (FCE) of 0.066–0.089 in lambs, compared to 15.0 g/day ADG and 0.025 FCE in lambs under control diet (T1). Additionally, the lambs had increased slaughter body weight (SBW), empty body weight (EBW), and hot carcass weight (HCW) in T4 and T3 compared to other treatments (p < .05). There were no significant differences in dressing percentages (DPs) across any treatment group. The study also discussed the economic viability of supplementing with DDLM, suggesting that feeding 70% daily dry matter of DDLM at 2.5% live weight might be beneficial depending on availability, access, and cost factors. In conclusion, feeding DDLM up to 70% has improved the performance of sheep and is economically feasible. Further research might be required to discover whether such levels of inclusion are harmful and apply different processing methods for feeding animals.