Experimental infection of Black Belly and INRA 401 straight and crossbred sheep with trichostrongyle nematode parasites

Compared to INRA 401 lambs reared in France, Black Belly (BB) lambs reared in Guadeloupe (F.W.I.) were highly resistant to both primary and secondary experimental infection with Haemonchus contortus. To investigate this huge inter-breed difference, a nucleus flock of BB was constituted, and experiments were conducted to: (i) confirm this difference in lambs born in France, (ii) check whether it was similar for Trichostrongylus colubriformis and Teladorsagia circumcincta, and (iii) find out whether this difference was age-related. Forty BB lambs, 84 F1 lambs (BB siresxINRA 401 ewes) and 88 INRA 401 lambs born in two cohorts were used in an experimental design involving three host breeds, both genders and two age-groups (3.5- and 7-month-old when first infected). The limited availability of BB lambs made the study incomplete. Infection consisted of the administration of two doses of 10,000 infective larvae of one of the nematode species, separated by an anthelmintic treatment and an interval of 1 week before the second dose was administered. Fecal egg counts (FECs) were done on Days 28 and 35 after each infection; ewe lambs of the INRA 401 and F1 breeds were necropsied, the worm burden was established, the length of the female worms measured and the eggs in utero counted. For H. contortus and T. colubriformis, the FEC was lower in the BB than in the INRA 401 lambs, and the FEC found for the F1 lambs was intermediate. For T. circumcincta, only data for the F1 and INRA 401 lambs were available, and the FECs for these breeds were the same. In all three breeds, the FEC determined after the second dose was significantly lower than that found after the first dose in the ewe lambs, but not in the ram lambs. Infecting the lambs when they were 7- instead of 3.5-month-old significantly lowered egg excretion of both parasites in the F1 (P<0.0001), but not the INRA 401 lambs. Worm numbers in the F1 and in the INRA 401 ewe lambs confirmed the FEC data, many F1 lambs being free of T. colubriformis. The H. contortus female worms were shorter and had fewer eggs in utero in the F1 than in the INRA 401 lambs. A higher proportion of T. circumcincta was at the fourth larval stage in the F1 lambs. In conclusion, the BB breed is much more resistant than INRA 401 to H. contortus, with the F1 lambs being more like the BBs after the second dose. This difference was also found for T. colubriformis and, to a lesser extent, for T. circumcincta.     

Replacing cottonseed meal with ground Prosopis juliflora pods; effect on intake,weight gain and carcass parameters of Afar sheep fed pasture hay basal diet

The experiment was conducted to determine the supplementary feeding value of ground Prosopis juliflora pod (Pjp) and cottonseed meal (CSM) and their mixtures on feed intake, body weight gain and carcass parameters of Afar sheep fed a basal diet of pasture hay. Twenty-five yearling fat-tailed Afar rams with mean initial live weight 17.24?±?1.76 kg (mean ± SD) were used in a randomized complete block design. Animals were blocked on their initial body weight. The experiment was conducted for 12 weeks and carcass evaluation followed. Treatments were hay alone ad libitum (T ₁) or with 300 g CSM (T ₂), 300 g Pjp (T ₅), 2:1 ratio (T ₃) and 1:2 ratio of CSM : Pjp (T ₄). The CP contents of the hay, CSM and Pjp were 10.5, 44.5 and 16.7 %, respectively. Hay DM intake was higher (P?<?0.05) for non-supplemented and total DM intake was lower in non-supplemented. Average daily weight gain (ADG) was lower (P?<?0.05) for T ₁ compared to all supplemented treatments except T ₅. Hot carcass weight and rib-eye muscle area also followed the same trend like that of ADG. Compared with feeding hay alone, supplementing with CSM or a mixture of CSM and Pjp appeared to be a better feeding strategy, biologically, for yearling Afar rams.     

Natural and human selection for purple-grain tetraploid wheats in the Ethiopian highlands

Summary Purple-grain tetraploid wheats (Triticum turgidum L.) are widely cultivated in the Ethiopian highlands despite the claim that they have lower industrial quality properties and market prices than the white or red/brown seed-colour types. In an attempt to find a possible explanation for this, the three seed-colour groups were compared for grain yield, other 11 agronomic traits and protein content. Five traits displayed significant differences between seed colour groups where the purple-seed was superior; earlier maturity, shorter height, and higher fertility, tillering capacity and harvest index. Most of these are important adaptive traits to waterlogging stress on dark-clay soils (pellic vertisols) where the great bulk of the Ethiopian tetraploid wheats have been grown. Furthermore, among the three seed-colour groups, purple-seed wheat has the best malting quality for the preparation of arekie, a locally distilled spirituous liquor. It, therefore, appears that both natural and human selections have been reponsible for their continued cultivation. Hence, the notion that purple-seeded wheat is the “least preferred” should be interpreted carefully not to necessarily address the whole community in Ethiopia. As to their taxonomy, all tetraploid wheat taxa (T. turgidum L. sensu lato, 2n = 4x = 28) that are found in Ethiopia, with the possible exception of T. dicoccon Shrank (locally known as Adja), may possess the purple pericarp-colour, although in varying frequencies; very low inT. polonicum L., and high inT. carthlicum Nevski andT. durum Desf.     

Gasterophilosis: a major cause of rectal prolapse in working donkeys in Ethiopia

A retrospective study was conducted to investigate the cause of rectal prolapse in working donkeys in Ethiopia. Analysis of data on rectal prolapse cases obtained from the Donkey Health and Welfare Project clinic at the School of Veterinary Medicine, Addis Ababa University, from 1995 to 2004 revealed that 83.6% (n = 177) of the cases were associated with Gasterophilus nasalis. The rest 10.7% and 5.7% were associated with work-related (overloading) cause and diarrhoea, respectively. The mean and median numbers of G. nasalis recovered from the rectum of infected donkeys were 66 and 64, respectively, with a range of 2–195. Over 100 G. nasalis larvae were recovered from the rectum of 22% of the donkeys. Circular demarcated ulcer-like and deep circumferential pits or ring-like mucosal lesions were found at the larval attachment sites. G. nasalis infection and the associated rectal prolapse were observed year round. However, the intensity of rectal larval infection and incidence of rectal prolapse were significantly higher during the rainy season (P < 0.01). Age and sex of the donkeys had no significant effect on the intensity of rectal larval infection and incidence of rectal prolapse (P > 0.05).     

Community‐based breeding programmes are a viable solution for Ethiopian small ruminant genetic improvement but require public and private investments

Ethiopia has a large and diverse population of small ruminants, which contribute substantially to the livelihood and income of the rural poor and the country at large. However, the sector faces a number of challenges. Productivity per animal and flock offtake are both very low. Reasons attributed for the apparent low productivity are as follows: absence of appropriate breeding programmes, lack of technical capacity, inadequate and poor‐quality feeds, diseases leading to high lamb mortality, and underdeveloped markets in terms of infrastructure and information. Historically, sheep and goats have received little policy or investment attention. Genetic improvement of small ruminants could contribute to bridging the productivity gap. In the past, the government of Ethiopia has placed much emphasis on importing exotic genetics and cross‐breeding with local stock as a strategy for genetic improvement. However, this has not led to a significant productivity improvement and the programmes have generally been unsustainable. Currently, there is a change in approach and a recognition of the need to focus genetic improvement efforts on the local genetic resources that are well adapted to the diverse agro‐ecologies and production environments in the country. Community‐based breeding programmes (CBBPs), which focus on indigenous stock and consider farmers’ needs, views, decisions and active participation, from inception through to implementation, have been identified as programmes of choice. The Ethiopian government and the private sector need to invest in strategic areas around CBBPs to make the programme work for the poor and be sustainable in low‐input systems.     

An upland farming system under transformation: Proximate causes of land use change in Bela-Welleh catchment (Wag, Northern Ethiopian Highlands)

A possible way out of the ‘low-level equilibrium trap’ in the Ethiopian Highlands is agricultural intensification. To characterise and quantify current transformations in these permanent upland cultivation systems, a detailed study on land use changes and its proximate causes was carried out in the 41 km² Bela-Welleh catchment (2050–3682 m a.s.l.) in the Wag zone of Amhara Region, Northern Ethiopia. Land use maps were obtained through aerial photo interpretation (1965 and 1986) and detailed field mapping (2005–2006). Interpretation of topographic maps and field mapping gave knowledge of the spatial distribution of possible explanatory factors. Major land use changes are (1) a gradual abandonment of mountain agriculture which was replaced by woody vegetation (now covering 70% of the upper catchment) and (2) the widespread introduction of irrigation agriculture, wherever water is available (from 0% in 1982 to 5% of the catchment in 2006). Whereas both changes are favoured by government policies, they have now at least partially been taken up by the farming communities. The study demonstrates these land use changes and their influencing factors. Changes of crop- and rangeland into forest occur on the steeper slopes in higher topographical position. Changes from rain fed cropland into irrigated cropland (two harvests) depend obviously on the availability of water, but also on population density, and inversely on distance to Sekota town. We are here in presence of an almost classical example of the mutation of a “permanent upland cultivation system” into a system with irrigated agriculture.     

Hydatidosis of slaughtered cattle in Wolaita Sodo Abattoir,southern Ethiopia

The study was carried out from July 2007 to June 2008 in Wolaita Sodo Abattoir to assess the status of hydatidosis in cattle. Routine meat inspection, hydatid cyst count and characterization were conducted. Out of 400 cattle slaughtered in Wolaita Sodo Abattoir 64 (16%) animals were found harboring hydatid cysts. Thorough meat inspection in the abattoir revealed that 74 visceral organ were found harboring one or more hydatid cysts. The infection of the lung, liver, spleen and kidney were found to be 45.94% 45.94%, 6.75% and 1.35% respectively. From the total of 283 hydatid cysts counted 153(54.06%), 17(6.00%), 5(1.76%), 108(38.16%) were found to be small, medium, large and calcified cysts respectively and 170(60.28%), 5(1.76%) and 108(38.16%) were sterile, fertile and calcified cysts respectively. The rate of cyst calcification was higher in the liver than in the lung while fertility rate was higher among the cysts of the lung. Hydatid cyst viability rate of 40% was observed.     

热带农业生态系统土壤肥力与植物养分综合管理研究进展

The greatest challenge for tropical agriculture is land degradation and reduction in soil fertility for sustainable crop and livestock production.Associated problems include soil erosion,nutrient mining,competition for biomass for multiple uses,limited application of inorganic fertilizers,and limited capacity of farmers to recognize the decline in soil quality and its consequences on productivity.Integrated soil fertility management(ISFM) is an approach to improve crop yields,while preserving sustainable and long-term soil fertility through the combined judicious use of fertilizers,recycled organic resources,responsive crop varieties,and improved agronomic practices,which minimize nutrient losses and improve the nutrient-use efficiency of crops.Soil fertility and nutrient management studies in Ethiopia under on-station and on-farm conditions showed that the combined application of inorganic and organic fertilizers significantly increased crop yields compared to either alone in tropical agro-ecosystems.Yield benefits were more apparent when fertilizer application was accompanied by crop rotation,green manuring,or crop residue management.The combination of manure and NP fertilizer could increase wheat and faba bean grain yields by 50%–100%,whereas crop rotation with grain legumes could increase cereal grain yields by up to 200%.Although organic residues are key inputs for soil fertility management,about 85% of these residues is used for livestock feed and energy;thus,there is a need for increasing crop biomass.The main incentive for farmers to adopt ISFM practices is economic benefits.The success of ISFM also depends on research and development institutions to provide technical support,technology adoption,information dissemination,and creation of market incentives for farmers in tropical agro-ecosystems.     

Serological and parasitological survey of dourine in the Arsi–Bale highlands of Ethiopia

This study was conducted from August 2005 to January 2007 to determine prevalence and distribution of dourine in horses and to investigate the occurrence of clinical and carrier cases in donkeys and mules in the Arsi–Bale highlands. Study methodology was based on questionnaire, serological, clinical and parasitological survey. The questionnaire indicated that dourine is a major health problem of equines in the Arsi–Bale highlands. Though dourine is commonly observed throughout the year, it has a seasonal character and occurs mostly during the breeding season from June to late September. Serological screening of 646 horses showed a seroprevalence of 184 (28%), 161 (25%) and 125 (19%) for card agglutination test for trypanosomosis, LATEX and enzyme-linked immunosorbent assay, respectively. Risk factors were parity number, previous history of abortion and body condition score. No trypanosomes could be detected by Giemsa staining or by haematocrit centrifugation technique. Ten puppies inoculated with blood samples, genital washes and oedematous fluids remained parasitologically negative. Different characteristic signs of dourine were observed. During the genital stage, mares showed vaginal oedema, discharge and presence of depigmented scars over the external genitalia. In stallions, oedema of the scrotum and prepuce, prepucial and urethral discharge, and ulceration of the genital mucosae mainly of the penile were observed. In both sexes, lameness in one or both legs, partial dragging and stiffness of the hind legs and incoordination were the dominant signs observed as nervous form of the disease.     

Drainage,sowing date and variety effects on chickpea grown on a Vertisol in Ethiopia

A field experiment was conducted for three years at Ginchi in Ethiopia to study the effects of three drainage methods [broad-bed-and-furrow (BBF), ridge-and-furrow (RF) and flat beds (FB)] arranged as main plots. Sub-plots comprised a factorial combination of four sowing dates (18 and 31 August, and 14 and 28 September) and three Desi-type chickpea varieties (Worku, Akaki and a landrace) in a split-plot design with three replications. Improved drainage methods (BBF and RF) increased chickpea seed yield by an average of 45% over the flat seedbed. There was a quadratic relationship between seed yield and sowing date with a peak yield in mid-September. Improved varieties (Worku and Akaki) yielded 15–19% more than the local check. Improved varieties were significantly more yielding than the landrace variety under the improved drainage system but not under the flat bed system. Also, improved varieties yielded significantly more than the landrace variety in the first three sowing dates when waterlogging was a problem but not in the last sowing date after which drought stress normally sets in. Sowing of improved chickpea varieties in mid-September using BBF could markedly increase productivity of chickpea on Vertisols in Ethiopia.