Helminth parasites of sheep and goats in Eastern Ethiopia

A two-year epidemiology study of helminths of small ruminants involved the collection of viscera from 655 sheep and 632 goats from 4 abattoirs in eastern Ethiopia. A further more detailed epidemiology study of gastro-intestinal nematode infections used the Haramaya University (HU) flock of 60 Black Head Ogaden sheep. The parasitological data included numbers of nematode eggs per gram of faeces (EPG), faecal culture L3 larvae, packed red cell volume (PCV), adult worm and early L4 counts, and FAMACHA eye-colour score estimates, along with animal performance (body weight change). There were 13 species of nematodes and 4 species of flukes present in the sheep and goats, with Haemonchus contortus being the most prevalent (65–80%), followed by Trichostrongylus spp. The nematode infection levels of both sheep and goats followed the bi-modal annual rainfall pattern, with the highest worm burdens occurring during the two rain seasons (peaks in May and September). There were significant differences in worm burdens between the 4 geographic locations for both sheep and goats. Similar seasonal but not geographical variations occurred in the prevalence of flukes. There were significant correlations between EPG and PCV, EPG and FAMACHA scores, and PCV and FAMACHA scores. Moreover, H. contortus showed an increased propensity for arrested development during the dry seasons. Faecal egg count reduction tests (FECRT) conducted on the HU flocks, and flocks in surrounding small-holder communities, evaluated the efficacy of commonly used anthelmintics, including albendazole (ABZ), tetramisole (TET), a combination (ABZ + TET) and ivermectin (IVM). Initially, high levels of resistance to all of the anthelmintics were found in the HU goat flock but not in the sheep. In an attempt to restore the anthelmintic efficacy a new management system was applied to the HU goat flock, including: eliminating the existing parasite infections in the goats, exclusion from the traditional goat pastures, and initiation of communal grazing of the goats with the HU sheep and animals of the local small-holder farmers. Subsequent FECRTs revealed high levels of efficacy of all three drugs in the goat and sheep flocks, demonstrating that anthelmintic efficacy can be restored by exploiting refugia. Individual FECRTs were also conducted on 8 sheep and goat flocks owned by neighbouring small-holder farmers, who received breeding stock from the HU. In each FECRT, 50 local breed sheep and goats, 6–9 months old, were divided into 5 treatment groups: ABZ, TET, ABZ + TET, IVM and untreated control. There was no evidence of anthelmintic resistance in the nematodes, indicating that dilution of resistant parasites, which are likely to be imported with introduced breeding goats, and the low selection pressure imposed by the small-holder farmers, had prevented anthelmintic resistance from emerging

An integrated molecular and conventional breeding scheme for enhancing genetic gain in maize in Africa

Open Access Journal; Published online: 06 Nov 2019Maize production in West and Central Africa (WCA) is constrained by a wide range of interacting stresses that keep productivity below potential yields. Among the many problems afflicting maize production in WCA, drought, foliar diseases, and parasitic weeds are the most critical. Several decades of efforts devoted to the genetic improvement of maize have resulted in remarkable genetic gain, leading to increased yields of maize on farmers’ fields. The revolution unfolding in the areas of genomics, bioinformatics, and phenomics is generating innovative tools, resources, and technologies for transforming crop breeding programs. It is envisaged that such tools will be integrated within maize breeding programs, thereby advancing these programs and addressing current and future challenges. Accordingly, the maize improvement program within International Institute of Tropical Agriculture (IITA) is undergoing a process of modernization through the introduction of innovative tools and new schemes that are expected to enhance genetic gains and impact on smallholder farmers in the region. Genomic tools enable genetic dissections of complex traits and promote an understanding of the physiological basis of key agronomic and nutritional quality traits. Marker-aided selection and genome-wide selection schemes are being implemented to accelerate genetic gain relating to yield, resilience, and nutritional quality. Therefore, strategies that effectively combine genotypic information with data from field phenotyping and laboratory-based analysis are currently being optimized. Molecular breeding, guided by methodically defined product profiles tailored to different agroecological zones and conditions of climate change, supported by state-of-the-art decision-making tools, is pivotal for the advancement of modern, genomics-aided maize improvement programs. Accelerated genetic gain, in turn, catalyzes a faster variety replacement rate. It is critical to forge and strengthen partnerships for enhancing the impacts of breeding products on farmers’ livelihood. IITA has well-established channels for delivering its research products/technologies to partner organizations for further testing, multiplication, and dissemination across various countries within the subregion. Capacity building of national agricultural research system (NARS) will facilitate the smooth transfer of technologies and best practices from IITA and its partners

Quantitative trait loci mapping for resistance to maize streak virus in F2: 3 population of tropical maize

Open Access Article; Published online: 01 Feb 2020Maize streak virus (MSV) continues to be a major biotic constraint for maize production throughout Africa. Concerning the quantitative nature of inheritance of resistance to MSV disease (MSVD), we sought to identify new loci for MSV resistance in maize using F2:3 population. The mapping population was artificially inoculated with viruliferous leafhoppers under screenhouse and evaluated for MSVD resistance. Using 948 DArT markers, we identified 18 quantitative trait loci (QTLs) associated with different components of MSVD resistance accounting for 3.1–21.4% of the phenotypic variance, suggesting that a total of eleven genomic regions covering chromosomes 1, 2, 3, 4, 5 and 7 are probably required for MSVD resistance. Two new genomic regions on chromosome 4 revealed the occurrence of co-localized QTLs for different parameters associated with MSVD resistance. Moreover, the consistent appearance of QTL on chromosome 7 for MSVD resistance is illustrating the need for fine-mapping of this locus. In conclusion, these QTLs could provide additional source for breeders to develop MSV resistance

Agronomic performance of elite drought tolerant maize (Zea mays L.) hybrids under natural disease inoculation in the rainforest of Nigeria.

The tropical rainforest agroecology is highly vulnerable to a myriad of plant disease infections and the likelihood that farmers would adopt a new maize cultivar largely depends on its resistance to the common diseases. In the present study, a set of newly developed single cross drought tolerant maize hybrids were evaluated under natural disease inoculation and their performance for grain yield, breeder’s traits, and response to infections by four cosmopolitan foliar diseases were assessed. A trial comprising 96 experimental hybrids and 4 hybrid checks were planted over two rainy seasons at Ikenne using a 10 x 10 triple-­‐lattice design. Hybrids differed significantly (p < 0.0001) for grain yield and other measured traits. Significant hybrid x year interaction was also observed for all traits except plant aspect. Ranking of mean grain yields of hybrids between the two years revealed moderate but highly significant correlation (r = 0.50, p < 0.0001). All measured traits except curvularia were negatively and significantly correlated (r = -­‐0.16 to -­‐0.58, p < 0.0001) with grain yield. Mean grain yields ranged between 2,282 and 6,132 kg ha-­‐1 with a trial mean of 4,509 kg ha-­­‐1. The top five yielders exceeded the best drought tolerant check (M1026-­‐7; 5,485 kg ha-­­‐1) by a least 2 standard errors whereas the top 20 hybrids produced significantly higher yields than the best commercial check (Oba 98; 4,150 kg ha-­­‐1) and had mostly favorable scores for the breeder’s traits and response to foliar disease infections. Promising high yielding and drought tolerant hybrids that have appreciable resistance to common foliar diseases can be selected among the tested genotypes

Assessing the Bacteriological Quality of Drinking Water from Sources to Household Water Samples of the Rural Communities of Dire Dawa Administrative Council, Eastern Ethiopia

In Ethiopia, access to improved water supply and sanitation was estimated at 38% and 12% respectively. Three- forth of the health problems of children in Ethiopia are communicable diseases due to polluted water and improper water handling practices. Thus, this study was conducted to assess the bacteriological quality of drinking water sources in Dire Dawa Surrounding area. The study was conducted from February 2011 to May 2011. A total of 90 water samples from different water sources (-protected and unprotected well; protected and unprotected spring; and tap water) and bacteriological water quality parameters were analyzed using the membrane filtration method. Water analysis demonstrated that all water sources in the study areas were contaminated with total coliforms, fecal coliform and parasites. The average counts of TC were in the range of 1.5-133.05CFU/100ml whereas the average counts of FC were found to be 0.34- 54CFU/100ml. In all samples, the TC, FC was above the  recommended limit of WHOM for drinking water quality (1-10CFU/100ml for TC, 0CFU/100ml for FC. The fact that, about 83.34% of the water  sample was positive for indicator bacteria shown that the three selected PA had risk of contamination in the three selected PAs had high risk of microbiological water quality parameters. High concentration of  microbiological indicators in all water sources of this study area may  demonstrated the presence of pathogenic organisms which constitute a threat to anyone consuming or in contact with these waters. This is due to lack of good water treatment, improper water handling practices and lackof the protection of the water sources. Consequently, protection of water sources accompanied by sanitation and hygiene promotion programs can improve the water quality of rural water sources, where disinfection is not feasible

Maize genetic improvement for enhanced productivity gains in West and Central Africa

During the past 45 years, the genetic improvement programs of IITA and its partners have made spectacular progress in developing high-yielding crop varieties that offered best-bet solutions to major production constraints, such as, cassava mosaic, maize streak, Striga, soybean rust, insect pests, and even drought. These have led to dramatic increases in the production of cassava, maize, soybean, cowpea, and yam in sub-Saharan Africa that have directly contributed to increases in food availability and indirectly to improvements in national economies. This section presents the status, progress, and achievements, and also outlines future work on crop improvement by genetic enhancement in IITA's six crops

Untersuchung des Gesichtsfelds der HEGRA-Kamera auf unbekannte TeV-Gamma-Quellen

Eine Suche nach unbekannten TeV-Gammaquellen, die möglicherweise innerhalb des Gesichtsfeldes der HEGRA-Kamera anwesend sein könnten, wurde durchgeführt. Es wurde angenommen, dass jeder Himmelsbereich, dem die Kamera aufnehmen kann, eine potenzielle Quelle ist. Bei dieser Suche wurde des Weiteren davon ausgegangen, dass der Prozess der Gammastrahlen-Erzeugung stetig ist. Eine separate Monte Carlo-Simulation wurde durchgeführt, die ein Kriterium dafür liefert, ab wann ein Signal als unbekannte Quelle akzeptiert wird. Keine unbekannte TeV-Quelle mit hoher Signifikanz, bezogen auf die Simulation, wurde identifiziert. Jedoch sind neun Himmelspositionen lokalisiert, die möglicherweise TeV-Gammaquellen sind. Weil fünf dieser Himmelspositionen durch HESS beobachtbar sind, werden sie für künftige Beobachtungen sehr empfohlen

Retention of Pro-vitamin A Carotenoids in Ogi Powder as Affected by Packaging Materials and Storage Conditions

The effect of different packages and storage conditions on the retention of pro-vitamin A carotenoids (pVAC) in ogi powder produced from yellow-seeded maize was investigated to study its storage stability on micronutrient retention. The ogi powder produced was packaged in a high-density polyethylene bag (HDPE), a polypropylene woven sack (PP), and a polyvinyl chloride container (PVC), and stored in different conditions for 12 weeks with sampling done at three-week intervals for pVACanalysis. At the end of the storage period, ogi powder packaged in HDPE stored outside the storage box had the highest percentage retention (31.32%) of trans-β-carotene and that packaged in PVC container stored in the lighted compartment had the least (21.57%). Therefore, HDPE could be a good package for the retention of trans-β-carotene (which is the most bioactive) in ogi powder when stored at a temperature of 27°C and relative humidity of 73%

Impact of Moisture Deficit on Physiological Quality of Maize Seeds

There is limited empirical information on the physiological basis of the development of seed quality despite the awareness that vigorous seeds provide a basis for solving cropestablishment problems. To address this problem, seeds of 16 maize (Zea mays L.) genotypes were planted in the dry season and the crop was grown entirely under irrigation. In one of the blocks, irrigation was suspended from five weeks after planting to harvest, whereas the control plot received irrigation from planting to physiological maturity. The seeds produced under the irrigated and moisture deficit conditions were harvested and subjected to seed viability and vigor tests as well as to seedling-evaluation tests. High-yielding genotypes did not necessarily produce seeds with high vigor. Moisture deficit resulted in 34% loss in germination potential, whereas vigor loss was between 40% and 220%, depending on the type of vigor test used. The seeds produced under moisture deficit had slow and non-uniform germination and seedling growth, with poor storage potential. Water availability to the crop affected seed vigor more than the genotypic effect, suggesting an inelastic limit to the extent that genotype can compensate for inadequacy of moisture of a maize plant

Evaluating testcross performance and genetic divergence of lines derived from reciprocal tropical maize composites

The development of hybrids with enhanced expression of heterosis depends on the genetic background of the source population and the effectiveness of a breeding scheme used to identify and use divergent inbred lines with good combining ability. The present study was conducted to examine the potential of improved tropical reciprocal composites as sources of inbred lines for developing productive hybrids. Thirty-six S lines derived from the third RRS cycle of each composite were crossed in pairs to form 36 testcrosses, which were evaluated along with com- monly grown commercial hybrids in Nigeria across nine test environments. Results showed consistent ranking of testcrosses for grain yield and other traits across the diverse test environments. The best 22 testcrosses produced 21% to 51% more grain yields than the highest yielding commercial hybrid. Several testcrosses combined high grain yields with other desirable agronomic traits. The SSR and SNP markers used in the present study detected a broad range of genetic diversity among the 72 S lines, which was structured along the two composites. The two markers portrayed similar trends in determining genetic distance estimates and detecting composite-specific al- leles in the S lines. These results highlight the potential of improved reciprocal composites as sources of new and divergent parents for developing productive hybrids and as sources of novel alleles for broadening and diversifying the genetic base of adapted germplasm to sustain genetic gain in productivity of hybrids in WCA