Tegene Negesse

Effect of Agro-ecology on Nutrient Content, Yield and Digestibility of Forage oat (Avena sativa L.) Varieties

Effect of agro-ecologyon nutrient content, yield and digestibility of three oat varieties (Lamptone, CI8235 and CI8237) were evaluated. Two agro ecologies, which varied in altitude, were selected for the experiment. Gummer site was 2925 masl while Albazer was 2400masl. Representative soil samples at the depth of 20cm were collected from randomly selected spots (20 cm depth) of both the sites. The samples were then sent to the laboratory. Plots were prepared and assigned for each of the each variety randomly using RCBD design. Seeds were sown at 100 kg/ha rate on 7, July, 2015 with replication. Di-ammonium phosphate and urea were applied in the similar rate. From the two fertilizers, urea was applied in two levels. Plots were regularly weeded and supervised for the disease. At maturity, the whole plant from each plot was cut 2cm above the ground. Seed with its husk (SH) and straw were separated. Values were extrapolated to hectare. Similar to the soil sample, forge representative samples were sent to the laboratory. Soil type at Gummer was silt, acidic, with lower cation exchange capacity (CEC) and higher exchangeable acidity (EA) whereas at Albazer it was clay, alkaline with higher CEC and lower EA. Soil organic carbon (OC), dry matter (DM), organic matter (OM), total nitrogen (TN) and available phosphorus (AP) were more at Gummer than Albazer. Crop maturation period was varying between the two agro ecologies. At Gummer, maturation was 161days on average but at Albazer it was141 days in average. Straw had similar DM but more OM at Gummer than Albazer. The lowest DM and OM content SH was from Lamptone but highest from CI8235 and CI8237 at Albazer. Crude protein (CP) content of oats was more at Albazer than Gummer. Highest straw CP was obtained from Lamptone at Albazer than Gummer. CI8237 at Albazer had highest EE but Lamptone at Gummer had the lowest. SH at Gummer had higher EE than at Albazer. Lamptone’s SH was lowest in NDF at Albazer but highest at Gummer. Higher DM, OM and CP yields were from Gummer than Albazer. Interaction was observed between agro-ecology and the varieties for nutrient content and yield. Albazer had better CP content whereas Gummer was efficient in yield. CI8235 at Albazer hadlowest IVDMD while CI8237 at both sites had the highest. Thus, before introducing oats to a new area, determining soil physiochemical characteristics for suitability is recommended.

Residual Feed Intake as a Tool for Selecting More Efficient Animals: A Review

Feeds alone contributes about 60–70% of total cost of ruminants production. There is deficiency to the tune of 10, 37 and 35% for dry fodder, concentrates and green fodders, respectively in India. Therefore, selection of efficient animals could help in reducing the burden of already scarce feed resources. A significant improvement in profitability could be achieved through a reduction in production costs by implementation of selection strategies to improve feed efficiency. There are several measures of feed efficiency viz., feed conversion ratio, relative growth rate, partial efficiency of growth, gross efficiency and residual feed intake (RFI). RFI is difference between actual feed intake and the feed an animal is expected to consume based on its body size and growth rate. Cattle with low RFI eat less than expected for their weight and growth rate and are, therefore, more efficient than cattle with high RFI. Among the feed efficiency measures, RFI is considered to be the best as it is moderately heritable (h2=0.29–0.46) and phenotypically independent of growth rate and body weight in growing cattle and basically reflects the variation in animals maintenance. This makes RFI as selection tool for efficient animals. About one-third of the biological variation in RFI of these calves could be explained by differences in feed intake (2%), digestion (10%), heat increment (9%), composition of gain (5%) and activity (5%) while the remaining variation in RFI was related to differences in protein turnover, stress and tissue metabolism (37%) and differences in cellular energy expenditures such as ion pumping and mitochondrial proton leakage (27%). The low RFI animals consume less feed and produce less enteric methane. hence, there are economic and environmental benefits by selecting such efficient animals. Phenotypic selection for RFI poses challenges because it requires measurement of each individuals feed intake for a minimum of 70 days which is expensive, time and labour intensive. As a result, there is need to develop alternative approaches like biochemical and physiological markers which could differentiate between high and low RFI animals within short period of time. Recently, genomic selection is being used as an appealing alternative tool for selection of low RFI animals. However, such studies need to be conducted using large number of animals so that more efficient animals could be selected for future breeding programmes for economic and environmental benefits.

Nutrient Composition and Degradability of Morphological Fractions of Two Sweet Potato (Ipomoea Batatas) Varieties and the Supplementary Effect of their Vine Feeding on Growth and Carcass Performances of Grazing Arsi-Bale Lambs

Ethiopia owns 55,027,280 cattle, 27,347,933 sheep, 28,163,332 goat, 1,963,010 horses, 6,953,077 donkeys, 356,087 mules, 1,098,312 camels, 51,350,738 poultry and 5,052,297 beehives/colonies.1 They contribute 15 to 17 percent of GDP and 35 to 49 percent of agricultural GDP, and 37 to 87 percent of the household incomes.2 Among livestock production constraints feed inadequacy in terms of quantity and quality3 is the leading one. The common feeds in Ethiopia such as crop residues and natural pasture are inherently low in CP, digestibility and minerals which lower the production capacity and fertility potential of animals.4 In order to improve animal productivity which relay on these feed sources, supplementation with feeds such as sweet potato which is grown on farmers plot and is better in content of CP and IVDMD is of paramount importance. Sweet potato (Ipomoea batatas L.) is an important traditional crop that is grown customarily by small-scale farmers mainly for household consumption. It is traditionally regarded as a ‘poor man’s’ crop as it is typically grown and consumed by resource poor households. It gives satisfactory yields under adverse climatic and soil conditions with low or no external inputs.5–7 As consequences of high livestock population density and reduced grazing area, intensive animal production (confinement and supplementary feeding) is evolving in some areas of SNNPRS.8 From the report of SWAO,9 the land covered by sweet potato plantation has increased from 10 ha to 195 ha between 2002/03 to 2011/12 cropping seasons. The farming communities living in the District feed sweet potato vine and tuber to livestock throughout the year or during dry season (Personal communication). The objective of this study was thus to assess the nutrient content and supplementation effect of vines of two sweet potato varieties on weight gain and carcass characteristics of grazing sheep.