Effect of inclusion of tossign (Thymus serrulatus) in concentrate mix supplementation on performance and sensory quality of meat of Menz sheep

The experiment was conducted to determine feed intake, digestibility, body weight change, carcass characteristics, and sensory quality of meat of Menz sheep supplemented with a concentrate mix and combinations of different proportions of tossign (Thymus serrulatus). Twenty yearling intact male Menz sheep were divided according to their initial body weight into five blocks of four animals in a randomized block design, and treatments were assigned randomly to each sheep within each block. The treatments were a basal diet of hay alone (T1) and supplemented with 300 g concentrate mix (T2), 200 g concentrate mix?+?100 g tossign (T3), and 100 g concentrate mix?+?200 g tossign (T4) on a dry matter basis. The results indicated that supplementation of tossign together with concentrate mix significantly increased (P?<?0.001) feed intake and improved DM and nutrient digestibility compared to the non-supplemented group. Supplementation of tossign with concentrate significantly improved (P?<?0.001) daily weight gain, feed conversion efficiency, and carcass characteristics of sheep compared to the non-supplemented group. Flavor and aroma scores of meat samples of sheep in T3 and T4 were significantly higher (P?<?0.001) than the corresponding values in T1 and T2. The scores for tenderness, juiciness, and degree of marbling of meat samples of sheep were significantly higher (P?<?0.001) in T3 and T4 compared to meat samples of sheep in T1. Inclusion of small amounts of tossign as additive in concentrate mix supplementation can improve the sensory quality of meat of Menz sheep.     

Botanicals and plant strengtheners for potato and tomato cultivation in Africa

This review provides a summary of botanicals and plant strengtheners that have potential uses for disease and pest management in potato and tomato cultivation in African. We discuss their possible use to prevent major diseases and pests which infest potato and tomato, such as early and late blight, bacterial wilt, potato tuber moth, and tomato leafminer. There are several examples of the successful uses of botanicals for pathogen and pest control relevant for different African climatic conditions; however, most of these studies have been conducted in vitro and often lack field verification. Plant strengtheners(substances that induce and improve crop resistance, yield, and quality) are little studied and used in Africa in comparison to North America and Europe. The possible benefits of using botanicals and plant strengtheners instead of conventional pesticides are discussed here in relation to human health and the environment as well as their modes of action and accessibility to farmers. Lack of knowledge of the composition and active ingredients of extracts, environmental concerns, uncertainties regarding stability and formulation, lack of legislation and limited support from governments, hamper the development of botanicals and plant strengtheners for use in sustainable African agriculture.     

Body weight change of Abergelle breed and Abergelle crossbred goats fed hay supplemented with different level of concentrate mixture

The experiment was conducted at Sekota District using 36 intact yearling males of pure Abergelle breed and Abergelle crossbred goats (50%) with a mean live weight of 18.92?±?0.72 kg (mean?±?SE). The objective of the experiment was to evaluate the effect of different levels of concentrate mixture supplementation on feed intake, live weight gain, and economic gain of the breeds. Goats were blocked based on initial body weight and were randomly assigned to the dietary treatments. The experimental design was a 2?×?3 factorial in RCBD (randomized complete block design). The treatments included ad libitum feeding of local grass hay and supplementation with three levels (184, 368, and 552 g/day) of concentrate mixture. The experiment consisted of 90 days of feeding. Daily, total dry matter and CP (crude protein) intakes were affected by diet and genotype (P?<?0.01). Significant decrease (P?<?0.001) in hay intake was observed as the level of the supplement increased. Besides, substitution rate increased with increasing levels of supplementation. Average daily body weight gains were significantly impacted only by diet. Animals fed on 184 significantly lower weights, while nonsignificant difference was observed in live weight gain between 368 and 552 supplemented group. Supplementation of 368 concentrate mix significantly improved (P?<?0.05) feed intake, daily weight gain, and feed conversion efficiency. Supplementation of 368 g/day had showed significantly higher net return for both goat breeds. However, the Abergelle breed was significantly better in net profit and sensitivity than the crossbreed. Both genotypes performed better with the diet containing 368 g/day than that with 184 and 552 g/day of concentrate supplementation.     

Contour furrows for in situ soil and water conservation, Tigray, Northern Ethiopia

In Tigray (Northern Ethiopia), soil moisture has been identified as the most limiting factor in agricultural production; on the other hand, loss of rain water through runoff as well as the induced soil loss has been determined as a critical problem in the region in the last two to three decades. To alleviate the above paradox, the government has mobilized communities and resources for the construction of physical soil and water conservation structures (stone bunds, terraces) in almost all land uses. However, yield improvement was mainly concentrated within the vicinity of the structures and runoff continued to overtop the structures, as no measures for in situ soil conservation were taken. The terwah system, consisting of traditional ploughing followed by making every 1.5–2 m contour furrows, and permanent raised beds with contour furrows at 60–70 cm interval treatments, were considered and evaluated as practices that could increase the efficiency of in situ water utilization and soil conservation. An experiment was started in Gum Selasa, which is one of the drought prone areas in Tigray, whereby runoff volume and sediment load were measured after every rain event. Permanent raised beds with contour furrows at 60–70 cm interval significantly (P < 0.05) reduced runoff volume, runoff coefficient and soil loss as compared to traditional ploughing: 255, 381 and 653 m³ ha⁻¹ runoff was recorded from permanent bed, terwah and traditional ploughing, respectively during the whole cropping season. The above runoff induced 4.7 t ha⁻¹ soil loss from permanent bed, 7.6 t ha⁻¹ from terwah and 19.5 t ha⁻¹ from traditional ploughing. Overall, contour furrows and permanent raised beds can be part of the ongoing intensification process which includes physical soil and water conservation, slope reforestation, irrigation development and agro forestry in crop lands. Moreover, the use of permanent raised beds if combined with crop mulching and crop diversification is an important component for the development of sustainable conservation agriculture practices in the region.     

Effects of conservation agriculture on runoff,soil loss and crop yield under rainfed conditions in Tigray,Northern Ethiopia

The aim of conservation agriculture (CA) is to improve soil quality and crop yield whilst reducing runoff and topsoil erosion. An experiment was carried out in a rainfed field using a permanent raised bed planting system for 3 yr (2005–2007) in Adigudem, northern Ethiopia in order to evaluate the effect of CA on runoff, soil loss and crop yield. CA practices were introduced in fields with Vertisols in a randomized complete block design on permanent 5 × 19 m plots. Three treatments were evaluated: (1) conventional tillage (CT) with a minimum of three tillage operations and removal of crop residues, (2) terwah (TER) that was similar to CT except that contour furrows were included at 1.5 m intervals, and (3) derdero+ (DER+), which consists of permanent raised beds with a furrow and bed system, retention of 30% of standing crop residues and zero tillage on the top of the bed. All ploughing as well as the maintenance of the furrows of the permanent raised beds was done using a local ard plough called maresha. Results from monitoring over 3 yr showed that soil loss and runoff were significantly higher (P < 0.05) in CT followed by TER and DER+. Average soil losses of 5.2, 20.1 and 24.2 t/ha were recorded from DER+, TER and CT, respectively. Runoff was 46.3, 76.3 and 98.1 mm from DER+, TER and CT, respectively. Grain yield was significantly lower (P < 0.05) in DER+ under teff in 2006, probably due to the high sensitivity of teff to weeds. The yield of wheat in 2007 was significantly higher in DER+ followed by TER. The terwah system is recommended as a first measure for wider adoption to reduce runoff and soil loss and to increase crop yield. The long‐term goal is to achieve a derdero+ system, i.e. a permanent raised bed planting system along with the application of crop residues.     

Column Elution Experiments on Volcanic Ash: Geochemical Implications for the Main Ethiopian Rift Waters

Column laboratory experiments were employed to assess the leaching behaviour of pyroclastic glassy ash deposits collected in the central Main Ethiopian Rift, where surface and groundwater resources are affected by fluoride (F^?) pollution, which is the cause of an endemic disease (fluorosis) in the local community. To elucidate the source of F^? and simulate the water–rock interaction processes, as well as quantify its distribution within different grain sizes, the pyroclastic ash was analysed by XRF, XRD and SEM and separated into coarse and fine fractions. Three columns were filled with raw (unsieved), coarse (63 μm–2 mm) and fine (<63 μm) fraction, respectively, and flushed with synthetic rain water in saturated conditions. Very fast F^? leaching was observed in the fine fraction column at the start of the experiment, while in the other two columns, F^? was slowly released; in addition, a strong accumulation of F^? was found in the fine fraction. The effect was more pronounced in the fine fraction column due to the available effective adsorbing surface area. Subsequent to elution experiments, the columns were characterised via moment analysis of tracer test. Finally, flow and transport modelling (MODFLOW-2000 and MT3DMS) was employed to compute the amount of F^? adsorbed onto the solid phase, comparing the calculated conservative transport of F^? and the observed concentrations. The results of this study suggest that fluoride is a fundamental constituent of the glass phase (about 0.3 wt.%) and that it is released during the incongruent dissolution of glassy particles. Dissolution of coatings on glass particles could provide an additional contribution to the geochemistry of the interacting fluids. These processes are more effective in the fine fraction due to a much higher reactive (specific) surface area.