Controlled grazing is considered a good management strategy to maintain or increase the live weight of livestock and to reduce vegetation degradation of rangelands. The present study investigated soil characteristics,...Controlled grazing is considered a good management strategy to maintain or increase the live weight of livestock and to reduce vegetation degradation of rangelands. The present study investigated soil characteristics, aboveground vegetation biomass dynamics and controlled grazinginduced changes in the live weight of local ewes in the semi-arid rangeland of Ahmadun, Ziarat, Balochistanprovince of Pakistan. An area of 115 ha was protected from livestock grazing in April 2014. In June 2015, soil characteristics within 0-30 cm depth i.e. soil organic matter(SOM), mineral nitrogen, p H and texture in controlled and uncontrolled grazing sites were assessed. Aboveground vegetation biomass measured in early(June) and late summer(August) in 2015 and 2016. The nutritional value i.e. crude protein, phosphorus(P), neutral detergent fiber(NDF), acid detergent fiber(ADF), calcium(Ca), magnesium(Mg) and potassium(K) of dominantplant species were assessed at the beginning of experiment in 2015. Vegetation cover of controlled and uncontrolled grazing sites was also measured during the two years of the study period using the Veg Measure software. From June to November in2015 and 2016, controlled and uncontrolled livestock grazing sites were grazed on a daily basis by local ewes with a stocking rate of 2 and 1 head ha^(-1) respectively. Results reveal that the organic matter contents of coarse-textured, slightly alkaline soil of the study site were in the range of 9.4-17.6 g kg^(-1) soil and showed a strong positive correlation with aboveground vegetation biomass. The biomass of plants was 56.5% and 33% greater at controlled than uncontrolled grazing site in 2015 and 2016 respectively and plant cover was also higher at controlled than uncontrolled grazing site in both years The nutrient contents were significantly(P<0.05)lower in grasses than shrubs. In both years, the controlled grazing increased the weight gain of ewes about two folds compared to the uncontrolled grazing.The results indicate that controlled grazing improved the vegetation biomass production and small ruminant productivity.展开更多
Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the subSaharan Africa’s (SSA) such as the Ethiopian part of the Blue Nile basin. However, its productivity is severely constrained by po...Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the subSaharan Africa’s (SSA) such as the Ethiopian part of the Blue Nile basin. However, its productivity is severely constrained by poor soil, water and crop management practices. This study simulated the water productivity of the crop under varying soil fertility scenarios (poor, near optimal and none limiting) using hybrid seeds under rainfed conditions using the FAO AquaCrop model. The result indicated that grain yield of maize increased from 2.5 tons.ha–1 under poor to 6.4 and 9.2 tons.ha–1 with near optimal and non-limiting soil fertility conditions. Correspondingly, soil evaporation decreased from 446 mm to 285 and 204 mm, while transpiration increased from 146 to 268 and 355 mm. Consequently, grain water productivity was increased by 48% and 54%, respectively, with the near optimal and non-limiting soil fertility conditions. The water productivity gain mainly comes from reduced evaporation and increased transpiration without significantly affecting water left for downstream ecosystem services. This has a huge implication for a basin scale water management planning for various purposes.展开更多
Indigenous pigs in South China are valuable genetic resources with many specific and unique characters, which have played an important role in the establishment of some western modern pig breeds. However, the origin a...Indigenous pigs in South China are valuable genetic resources with many specific and unique characters, which have played an important role in the establishment of some western modern pig breeds. However, the origin and genetic diversity of indigenous pigs in South China have not been fully understood. In the present study, we sequenced 534 novel mitochondrial DNA (mtDNA) D-loop and assembled 54 complete mitogenome sequences for all 17 indigenous pig breeds from Fujian, Guangdong, Guangxi and Hainan in South China. These data were analyzed together with previously published homologous sequences relevant to this study. We found that all 13 coding genes of the mitogenomes were under purifying selection, but ND1 had the most variable sites and CYTB contained the most non-synonymous SNPs. Phylogenetic analysis showed that all indigenous pigs in South China were clustered into the D haplogroup with D1a1, D1b, D1c and D1e sub-haplogroups found to be dominant. Haplotype and nucleotide diversities of D-loop sequences ranged from 0.427 to 0.899 and from 0.00342 to 0.00695, respectively, among which all pigs in Guangdong had the lowest diversity. The estimates of pairwise FST, gene flow (Nm) and genetic distance (Da) indicated that most of these indigenous pig breeds differentiated from each other significantly (P<0.05). Among the western modern breeds, Berkshire and Yorkshire had significant Asian matrilineal footprints from indigenous pigs in South China, especially the Spotted pigs distributed in Guangdong and Guangxi. The neutrality test (Fu’s FS) indicated that indigenous pigs from Fujian and Guangxi had gone through recent population expansion events (P<0.05). It is concluded that indigenous pigs in South China were most likely derived from the Mekong region and the middle and downstream regions of Yangtze River through Guangxi and Fujian. Our findings provide a complete and in-depth insight on the origin and distribution pattern of maternal genetic diversity of indigenous pigs in South China.展开更多
Background Silage is widely used to formulate dairy cattle rations,and the utilization of antibiotics and methane emissions are 2 major problems for a sustainable and environmentally beneficial ruminant production sys...Background Silage is widely used to formulate dairy cattle rations,and the utilization of antibiotics and methane emissions are 2 major problems for a sustainable and environmentally beneficial ruminant production systems.Bacteriocin has received considerable attention because of its potential as an alternative to antibiotics in animal husbandry.However,the impact of bacteriocin-producing lactic acid bacteria on the microbiological conversion process of whole-plant corn silage and rumen fermentation remains limited.The purpose of this study was to assess the effect of 2 classⅡa bacteriocin-producing strains Lactiplantibacillusplontarum ATCC14917 and CICC24194 on bacterial community composition and ensiling profiles of whole-plant corn silage and its in vitro rumen fermentation,microbiota,and CH_(4) emissions.Results Both bacteriocin-producing strains increased the lactic acid concentration in silage fermented for 7 d,whereas the lowest lactic acid was observed in the ATCC14917 inoculated silage fermented for 90 d(P<0.05).The highest DM content was observed in the CICC24194 treatment(P<0.05),and the silages treated with both strains had the lowest DM loss(P<0.05).Bacteriocin-producing strains promoted the growth of Levilactobacillus brevis on d 60of ensiling.In addition,treatment with bacteriocin-producing strains increased the in vitro DM digestibility(P<0.05)and decreased the CH_(4) production(P<0.05).The results of random forest and clustering analyses at the genus level showed that ATCC14917 increased the relative abundance of the influential variable Bacillus compared to that in the control group,whereas CICC24194 decreased the relative abundance of the influential variable Ruminococcaceae UCG-005.The CICC24194 treatment had the lowest total bacterial,fungal,protozoan,and methanogen populations(P<0.05).Conclusions Both classⅡa bacteriocin-producing L.plantarum strains improved the fermentation quality of wholeplant corn silage by regulating the bacterial community composition during ensiling,with CICC24194 being the most effective.Both bacteriocin-producing strains mitigated CH_(4) production and improved digestibility by modulating the interactions among rumen bacteria,protozoa,methanogens,and the composition of fibrolytic bacteria.展开更多
Clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(CRISPR/Cas9)genome editing technology has dramatically influenced swine research by enabling the production of high-quality...Clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(CRISPR/Cas9)genome editing technology has dramatically influenced swine research by enabling the production of high-quality disease-resistant pig breeds,thus improving yields.In addition,CRISPR/Cas9 has been used extensively in pigs as one of the tools in biomedical research.In this review,we present the advancements of the CRISPR/Cas9 system in swine research,such as animal breeding,vaccine development,xenotransplantation,and disease modeling.We also highlight the current challenges and some potential applications of the CRISPR/Cas9 technologies.展开更多
Measurements of photosynthetically active radiation （PAR）, which are indispensable for simulating plant growth and productivity, are generally very scarce. This study aimed to compare two extrapolation and one inte...Measurements of photosynthetically active radiation （PAR）, which are indispensable for simulating plant growth and productivity, are generally very scarce. This study aimed to compare two extrapolation and one interpolation methods for estimating daily PAR reaching the earth surface within the Poyang Lake national nature reserve, China. The daily global solar radiation records at Nanchang meteorological station and daily sunshine duration measurements at nine meteorological stations around Poyang Lake were obtained to achieve the objective. Two extrapolation methods of PARs using recorded and estimated global solar radiation at Nanchang station and three stations （Yongxiu, Xingzi and Duchang） near the nature reserve were carried out, respectively, and a spatial interpolation method combining triangulated irregular network （TIN） and inverse distance weighting （IDW） was imple- mented to estimate daily PAR. The performance evaluation of the three methods using the PARs measured at Dahuchi Conservation Station （day number of measurement = 105 days） revealed that： （1） the spatial interpolation method achieved the best PAR estima- tion （R2 - 0.89, s.c. = 0.99, F= 830.02, P 〈 0.001 ）; （2） the extrapolation method from Nanchang station obtained an unbiased result （R2 = 0.88, s.c. = 0.99, F = 745.29, P 〈 0.001）; however, （3） the extrapolation methods from Yongxiu, Xingzi and Duchang stations were not suitable for this specific site for their biased estimations. Considering the assumptions and principles supporting the extrapolation and interpolation methods, the authors conclude that the spatial interpolation method produces more reliable results than the extrapolation methods and holds the greatest potential in all tested methods, and more PAR measurements should be recorded to evaluate the seasonal, yearly and spatial stabilities of these models for their application to the whole nature reserve of Poyang Lake.展开更多
Sheep is an important livestock species raised globally to produce meat,milk,wool,and other by-products.During the Neolithic Revolution,sheep were domesticated in the Fertile Crescent of Southwest Asia around 10,000 y...Sheep is an important livestock species raised globally to produce meat,milk,wool,and other by-products.During the Neolithic Revolution,sheep were domesticated in the Fertile Crescent of Southwest Asia around 10,000 years ago(Chessa et al.,2009).展开更多
The Kenya dairy sub-sector has been undergoing developments since the 1980s in the areas of adoption of intensive dairy farming, especially zero grazing. There have been concerted efforts by the government and other d...The Kenya dairy sub-sector has been undergoing developments since the 1980s in the areas of adoption of intensive dairy farming, especially zero grazing. There have been concerted efforts by the government and other development partners to commercialize the sub-sector so as to make it more profitable to farmers, especially smallholder farmers, but the profitability in the sector continues to be variable with some smallholder farmers making losses. The causes of the varying profits have not been empirically established, with the influence of institutional arrangements and financial factors contributing to this inconsistency not fully established. This study dwelt on establishing the critical institutional arrangements and financial factors that constrain the profitability of smallholder dairy farmers in Nakuru County. A multi-stage sampling procedure was used to select respondents. Data were collected by structured interviews at the farm level. Data Envelopment Analysis （DEA） was used to come up with profit efficiency rankings among the farmers, and the Frontier Model was used to establish the factors that constrain profit efficiency. The mean efficiency according to the results was 86%. The farm and farmer characteristics that were significant in explaining profitability efficiency according to the frontier results were： feeding system, breed type, and gender. The financial characteristics included debt amount and debt asset ratio. Additionally, issues of trust were also found to have an effect on profitability, and they included trust in local buyer price, trust in unit of measurement of institutional buyer, and trust in unit of measurement of middlemen.展开更多
The study was conducted to estimate flock dynamics of western lowland Arab goat and to assess their contribution to income of smallholder farmers in Kurmuk and Assosa districts, western Ethiopia. Flocks of 30 househol...The study was conducted to estimate flock dynamics of western lowland Arab goat and to assess their contribution to income of smallholder farmers in Kurmuk and Assosa districts, western Ethiopia. Flocks of 30 households were monitored for a period of 12 months in 2016. Data were analyzed using the general linear model procedure of SAS and two-way interaction effects were fitted in the model and retained when found significant in the preliminary analysis. The study result indicates that total entrances for all flock were significantly (p < 0.05) higher in dry and hot-cool seasons than wet season. Most of the entrance was kids born in hot-cool season (January) (4.0 ± 0.42) and hot-dry season (May) (5.4 ± 1.09) for Assosa and Kumruk study sites, respectively. Kid mortality constituted the greater part of outflow. High kid mortality was occurred during July, February, January, and September. Most of the sell of castrated goats were occurred in September and April for both small and large flocks targeting holidays celebrated during this months. Male goat owners had significantly lower goat production potential (GPP) value than female (0.47 ± 0.02 vs. 0.52 ± 0.02). The GPP was lower in small flock than in large flock (0.48 ± 0.02 vs. 0.51 ± 0.02). Higher GPP was recorded in the months of January, February, and March for both large and small flocks. The off-take was higher (P < 0.05) in Assosa (0.06 ± 0.01) than Kumruk (0.02 ± 0.02) district. The average goat production efficiency (GPE) was higher (P < 0.05) in Assosa large (193.23 ± 20.0) and small flocks (93.44 ± 17.3) than Kumruk large (84.71 ± 15.6) and small flocks (33.33 ± 26.3).The production efficiency recorded was not comparable to the potential that the farmers had to sell goats or consume goats’ meat and milk. The lower goat production potential observed for small flocks implies that high mortality rates severely restrict receiving higher benefits from goat. Therefore, in order to optimize the productivity of goats flock dynamics, developing health intervention strategies that target reduction of kids’ mortality is imperative.展开更多
A study was undertaken to characterize production system, breeding practices and production constraints of Begait goat in Kafta humera district, northwestern lowlands of Ethiopia. Personal observations, focus group di...A study was undertaken to characterize production system, breeding practices and production constraints of Begait goat in Kafta humera district, northwestern lowlands of Ethiopia. Personal observations, focus group discussions and a detailed structured questionnaire were used to collect data from 150 respondents (99 small-scale and 51 large-scale farmers). Mixed crop-livestock production system was found to be the dominant farming system in the study district. The farmers kept a variety of livestock species including goats, sheep, cattle, chickens and donkeys. Small ruminants are the most numerous and are of great importance in the area. Goats are herded with sheep in the open fields by the young boys in the family/hired grazers. They have a number of roles though mainly kept as a source of cash income. Breeding was generally uncontrolled. Size, growth rate and libido were the most frequently reported traits in selecting bucks, whereas does were selected based on size, twining ability and milk yield. Effective population size and rate of inbreeding were calculated by considering random mating and flocks were not mixed. The major constraints hampering goat production in the area were water scarcity, feed and grazing land shortages and insufficient veterinary services among the others. Therefore, addressing these constraints is important to design a successful genetic improvement scheme in the area for goat.展开更多
Sorghum (Sorghum bicolour (L.) Moench), the second most important staple crop in Sub-Saharan Africa (SSA) after maize, is well adapted to marginal environments of drought stress and high temperatures. But besides drou...Sorghum (Sorghum bicolour (L.) Moench), the second most important staple crop in Sub-Saharan Africa (SSA) after maize, is well adapted to marginal environments of drought stress and high temperatures. But besides drought stress, the obligate root-parasitic flowering plant Striga hermonthica is an equally economically important biotic stress in agro-ecological zones where soils are marginal. Notwithstanding widespread and intense Striga infestation, genetic variations in defence mechanisms against the parasite have been reported. Sorghum variants, producing low levels of chemical stimulants such as sorgolactones that deter the advance of Striga seed germination and are therefore deemed resistant to the parasite, have been also reported in a few studies. But the existence of sorghum genetic variation for this resistance especially among farmers’ landraces is yet to be demonstrated. The objective of this study was therefore to determine the levels of Striga germination stimulants in response to each of the 111 collected sorghum landraces and their progenies from Eritrea. The ability of a sorghum genotype to cause germination of a Striga seed as a measure of the amount of the germination stimulant produced was used to assess the resistance of these accessions. The data were recorded as Striga germination percentage by counting the number of germinated Striga seeds. Landraces EG47, EG1261, EG830, EG1076, EG54 and EG746 with 14.68%, 15.32%, 11.85%, 13.05%, 15.74% and 16.5% germination percentages respectively were found to stimulate low levels of Striga germination percentage compared to commercial checks, IS9830, SRN39, Framida, with 22.46%, 22.67%, 23.27% germination respectively. While these variants did not show complete resistance against Striga seed germination, the low level production of stimulant indicated their high level of resistance to Striga . These results implied that these accessions are likely potential sources of resistance against Striga infestation in SSA sorghum breeding programs.展开更多
Four released durum wheat varieties, two medium tall (Arsi-Robe and Kilinto) and two recently released semidwarfs (Ude and Yerer) were evaluated under five different N rates (0, 60, 120, 180 and 240 kg·ha-1) in 2...Four released durum wheat varieties, two medium tall (Arsi-Robe and Kilinto) and two recently released semidwarfs (Ude and Yerer) were evaluated under five different N rates (0, 60, 120, 180 and 240 kg·ha-1) in 2005/06 growing season at Akaki and Debre Zeit, central Ethiopia. The quality responses of durum wheat varieties to different N-fertilizer rates and the N responses between tall and short durum wheat varieties were assessed. Protein and gluten content, vitreous kernel count, thousand kernel weight, test weight and lodging were considered. Vitreous kernel count, protein and gluten content were higher at Debre Zeit than at Akaki. Unlike Debre Zeit, there were significant relationships between response variables and fertilizer levels at Akaki. Lodging slightly affected the medium tall varieties at Debre Zeit whereas it was not a problem at Akaki. At Akaki, varieties response to each additional N rate was entirely below the quality standard set by ICC, 2000 except for thousandkernel weight. Therefore, it is unwise to promote durum wheat scaling up/out program for quality production at Akaki.展开更多
Tomato is one of the most widely produced and consumed vegetable crops in Ethiopia. It is not produced during the rainy season, mainly due to high disease pressure and low soil temperature. Therefore, an experiment wa...Tomato is one of the most widely produced and consumed vegetable crops in Ethiopia. It is not produced during the rainy season, mainly due to high disease pressure and low soil temperature. Therefore, an experiment was conducted to study the effect of different types of mulch （black and white plastic mulch as well as grass mulch） on early yield of tomato varieties （Miya ＆ Cochoro） under polyhouse growing condition at Bahir Dar during the rainy season in 2012. Treatments were arranged in 4 - 2 factorial combinations in randomized complete block design with three replications. One month old seedlings were transplanted on 8.4 m2 gross plots size （3 m x 2.8 m） at a spacing of 70 cm x 40 cm between rows and plants, respectively. Data recorded from plants found in the two middle rows of each plot. Di-ammonium phosphate （DAP） and Urea fertilizers were applied at the rate of 200 kg and 100 kg/ha, respectively. Sixteen plants were considered for data collection in each plot. White plastic mulch resulted in significantly （P 〈 0.05） earlier flowering, fruit setting and fruit maturity compared to other mulching materials. Varieties were also significantly different in days required to flowering, fruit setting and fruit maturity. Miya took significantly short period to flower, fruit set and fruit maturity compared to Cochoro variety. The effect of different mulch types on early fruit yield was found statistically significant. The highest early marketable fruit yield of 10.99 ton/ha and 10.54 ton/ha were recorded when Miya variety was grown with white and black plastic mulch, respectively. Therefore, use of white and black plastic mulches recommended for early tomato fruit yield.展开更多
Poor land use management and practice inhibit the growth and establishment of tree seedlings in dryland areas.We assessed arbuscular mycorrhizal fungi(AM)status of Faidherbia albida(Del.)A.Chev.trees grown on differen...Poor land use management and practice inhibit the growth and establishment of tree seedlings in dryland areas.We assessed arbuscular mycorrhizal fungi(AM)status of Faidherbia albida(Del.)A.Chev.trees grown on different land uses.We quantified the growth and nutrient uptake of F.albida seedlings inoculated with AM from different sources.These efforts were based on soil and fine root samples from the rhizosphere soils of F.albida trees.AM root colonization was determined using the gridline intersect method.Spores were extracted by the wet sieving and decanting method and identified to genus level.The seedling experiment had a completely randomized onefactorial design with four treatments and five replications.Faidherbida albida seedlings were grown in a greenhouse.All in situ F.albida trees were colonized by AM fungi.AM root colonization of F.albida trees was significantly higher(P<0.0086)in area exclosures than on lands used for grazing or cultivation.Spore abundance was significantly higher(P<0.0014)in area exclosures followed by cultivated land and grazing land.Glomus was the dominant genus in all land-uses.AM-inoculated F.albida seedlings grew better(P<0.05)than non-inoculated controls.Seedlings inoculated with AM from area exclosure had significantly(P<0.05)higher growth and nutrient uptake than those inoculated with AM from grazing and cultivated land.This emphasizes the importance of the native soil AM potential for better establishment of seedlings to achieve optimum plant growth improvement and assist in rehabilitation of degraded arid lands.展开更多
Goats are one of the oldest domesticated animal species widely distributed in the world playing an important role in the food production system in Sub-Saharan African Region (SSAR). Due to their multiple uses (milk pr...Goats are one of the oldest domesticated animal species widely distributed in the world playing an important role in the food production system in Sub-Saharan African Region (SSAR). Due to their multiple uses (milk production, meat, fiber and hides) and adaptation aptitudes to ecological conditions, goats produce and contribute positively to farmers’ socio-economy status in various production systems. This review aimed at giving a summary overview on the goat’s production systems characteristics, the genetic diversity and the candidate genes affecting reproductive and milk production performances in goat breeds in SSAR. It has been observed that traditional livestock production system with communal grazing system is the most used in goat keeping in SSAR. The geographical locations play an important role in the relationships between goat’s distributions in the region. At the same time, goats might have been differentiated and isolated one to others due to the wide geographic range, the diversify climate and the topography in the region. Among the six worldwide known haplogroups of goat (A, B, C, D, G and F), haplogroup A is the most representative in SSAR. However, haplogroup G and B can be found in some goat populations in some countries in east (Kenya and Ethiopia) and south parts of Africa. This review reveals that little is known on the candidate genes associated with prolificacy and milk production traits in indigenous goat breeds in the region. That observation suggests the importance of assessing candidate genes associated with economic traits in the populations of goat in SSAR.展开更多
Metagenomics has opened new avenues for exploring the genetic potential of uncultured microorganisms,which may serve as promising sources of enzymes and natural products for industrial applications.Identifying enzymes...Metagenomics has opened new avenues for exploring the genetic potential of uncultured microorganisms,which may serve as promising sources of enzymes and natural products for industrial applications.Identifying enzymes with improved catalytic properties from the vast amount of available metagenomic data poses a significant challenge that demands the development of novel computational and functional screening tools.The catalytic properties of all enzymes are primarily dictated by their structures,which are predominantly determined by their amino acid sequences.However,this aspect has not been fully considered in the enzyme bioprospecting processes.With the accumulating number of available enzyme sequences and the increasing demand for discovering novel biocatalysts,structural and functional modeling can be employed to identify potential enzymes with novel catalytic properties.Recent efforts to discover new polysaccharide-degrading enzymes from rumen metagenome data using homology-based searches and machine learning-based models have shown significant promise.Here,we will explore various computational approaches that can be employed to screen and shortlist metagenome-derived enzymes as potential biocatalyst candidates,in conjunction with the wet lab analytical methods traditionally used for enzyme characterization.展开更多
Climate change has increased extreme events over globe and the most robust occurrences of concurrent drought and floods have become more common in Africa. This study focuses on the observed and projected analysis of r...Climate change has increased extreme events over globe and the most robust occurrences of concurrent drought and floods have become more common in Africa. This study focuses on the observed and projected analysis of rainfall extremes of consecutive dry day (CDD) and maximum monthly five day precipitation (RX5day) from Expert Team on Climate Change Detection and Indices (ETCCDI) in June-August season over Africa. The daily CORDEX Africa, reanalysis and CRU datasets were analyzed for extreme trends under RCP4.5 and RCP8.5 scenarios for the periods of 1980 to 2100. The spatiotemporal variability, trend, and magnitude of JJA seasonal rainfall performance exhibits a significant decreasing tendency over Eastern Africa compared to West Africa. The observed results of consecutive dry day (CDD) reveal that increasing trend and moreover RX5day shows that promising positive trend. Both rainfall extremes are influenced by the combined effect of large scale indexes and appear to be correlated negatively and positively with ENSO, NAO and AO. The CORDEX ensemble mean projections of JJA seasonal rainfall performance show a widespread significant change and the first mode of EOF depicts that 13.8% and 24.9% under the RCP4.5 and the highest variability is under RCP8.5 scenario. The projected CDD extreme exhibit an increasing trend in the coming periods and the percentage change revealed that increasing from 25.11%, 28.02% over West and 26.49%, 31.66% East Africa under RCP4.5 and RCP8.5 scenarios respectively. This situation will exacerbate increasing of frequent and intensified drought extremes over Africa. Additionally, the future RX5day indicated that mixed trend and revealed that increasing 3.72%, 2.54% over West and decreases -16.12%, -22.47% over East Africa under RCP4.5 and RCP8.5 respectively. Generally, rainfall extremes of CDD are projected to increase and RX5day shows a mixed trend in the coming periods over Africa and calls for further verification by using high resolution datasets.展开更多
基金supported by the USAID under Agriculture Innovation Program (AIP) Pakistansupported by the ICARDA and the CGIAR Research Program on Livestock (CRP Livestock)
文摘Controlled grazing is considered a good management strategy to maintain or increase the live weight of livestock and to reduce vegetation degradation of rangelands. The present study investigated soil characteristics, aboveground vegetation biomass dynamics and controlled grazinginduced changes in the live weight of local ewes in the semi-arid rangeland of Ahmadun, Ziarat, Balochistanprovince of Pakistan. An area of 115 ha was protected from livestock grazing in April 2014. In June 2015, soil characteristics within 0-30 cm depth i.e. soil organic matter(SOM), mineral nitrogen, p H and texture in controlled and uncontrolled grazing sites were assessed. Aboveground vegetation biomass measured in early(June) and late summer(August) in 2015 and 2016. The nutritional value i.e. crude protein, phosphorus(P), neutral detergent fiber(NDF), acid detergent fiber(ADF), calcium(Ca), magnesium(Mg) and potassium(K) of dominantplant species were assessed at the beginning of experiment in 2015. Vegetation cover of controlled and uncontrolled grazing sites was also measured during the two years of the study period using the Veg Measure software. From June to November in2015 and 2016, controlled and uncontrolled livestock grazing sites were grazed on a daily basis by local ewes with a stocking rate of 2 and 1 head ha^(-1) respectively. Results reveal that the organic matter contents of coarse-textured, slightly alkaline soil of the study site were in the range of 9.4-17.6 g kg^(-1) soil and showed a strong positive correlation with aboveground vegetation biomass. The biomass of plants was 56.5% and 33% greater at controlled than uncontrolled grazing site in 2015 and 2016 respectively and plant cover was also higher at controlled than uncontrolled grazing site in both years The nutrient contents were significantly(P<0.05)lower in grasses than shrubs. In both years, the controlled grazing increased the weight gain of ewes about two folds compared to the uncontrolled grazing.The results indicate that controlled grazing improved the vegetation biomass production and small ruminant productivity.
文摘Maize (Zea mays) is among the major cereals grown in the high rainfall areas of the subSaharan Africa’s (SSA) such as the Ethiopian part of the Blue Nile basin. However, its productivity is severely constrained by poor soil, water and crop management practices. This study simulated the water productivity of the crop under varying soil fertility scenarios (poor, near optimal and none limiting) using hybrid seeds under rainfed conditions using the FAO AquaCrop model. The result indicated that grain yield of maize increased from 2.5 tons.ha–1 under poor to 6.4 and 9.2 tons.ha–1 with near optimal and non-limiting soil fertility conditions. Correspondingly, soil evaporation decreased from 446 mm to 285 and 204 mm, while transpiration increased from 146 to 268 and 355 mm. Consequently, grain water productivity was increased by 48% and 54%, respectively, with the near optimal and non-limiting soil fertility conditions. The water productivity gain mainly comes from reduced evaporation and increased transpiration without significantly affecting water left for downstream ecosystem services. This has a huge implication for a basin scale water management planning for various purposes.
基金supported by the Basic Work of Science and Technology Project, China (2014FY120800)the Science and Technology Project of Guangdong Province, China (2014YT02H042, 2014B020202001)
文摘Indigenous pigs in South China are valuable genetic resources with many specific and unique characters, which have played an important role in the establishment of some western modern pig breeds. However, the origin and genetic diversity of indigenous pigs in South China have not been fully understood. In the present study, we sequenced 534 novel mitochondrial DNA (mtDNA) D-loop and assembled 54 complete mitogenome sequences for all 17 indigenous pig breeds from Fujian, Guangdong, Guangxi and Hainan in South China. These data were analyzed together with previously published homologous sequences relevant to this study. We found that all 13 coding genes of the mitogenomes were under purifying selection, but ND1 had the most variable sites and CYTB contained the most non-synonymous SNPs. Phylogenetic analysis showed that all indigenous pigs in South China were clustered into the D haplogroup with D1a1, D1b, D1c and D1e sub-haplogroups found to be dominant. Haplotype and nucleotide diversities of D-loop sequences ranged from 0.427 to 0.899 and from 0.00342 to 0.00695, respectively, among which all pigs in Guangdong had the lowest diversity. The estimates of pairwise FST, gene flow (Nm) and genetic distance (Da) indicated that most of these indigenous pig breeds differentiated from each other significantly (P<0.05). Among the western modern breeds, Berkshire and Yorkshire had significant Asian matrilineal footprints from indigenous pigs in South China, especially the Spotted pigs distributed in Guangdong and Guangxi. The neutrality test (Fu’s FS) indicated that indigenous pigs from Fujian and Guangxi had gone through recent population expansion events (P<0.05). It is concluded that indigenous pigs in South China were most likely derived from the Mekong region and the middle and downstream regions of Yangtze River through Guangxi and Fujian. Our findings provide a complete and in-depth insight on the origin and distribution pattern of maternal genetic diversity of indigenous pigs in South China.
基金supported by the National Key R&D Program of China(grant number 2022YFD1301002)。
文摘Background Silage is widely used to formulate dairy cattle rations,and the utilization of antibiotics and methane emissions are 2 major problems for a sustainable and environmentally beneficial ruminant production systems.Bacteriocin has received considerable attention because of its potential as an alternative to antibiotics in animal husbandry.However,the impact of bacteriocin-producing lactic acid bacteria on the microbiological conversion process of whole-plant corn silage and rumen fermentation remains limited.The purpose of this study was to assess the effect of 2 classⅡa bacteriocin-producing strains Lactiplantibacillusplontarum ATCC14917 and CICC24194 on bacterial community composition and ensiling profiles of whole-plant corn silage and its in vitro rumen fermentation,microbiota,and CH_(4) emissions.Results Both bacteriocin-producing strains increased the lactic acid concentration in silage fermented for 7 d,whereas the lowest lactic acid was observed in the ATCC14917 inoculated silage fermented for 90 d(P<0.05).The highest DM content was observed in the CICC24194 treatment(P<0.05),and the silages treated with both strains had the lowest DM loss(P<0.05).Bacteriocin-producing strains promoted the growth of Levilactobacillus brevis on d 60of ensiling.In addition,treatment with bacteriocin-producing strains increased the in vitro DM digestibility(P<0.05)and decreased the CH_(4) production(P<0.05).The results of random forest and clustering analyses at the genus level showed that ATCC14917 increased the relative abundance of the influential variable Bacillus compared to that in the control group,whereas CICC24194 decreased the relative abundance of the influential variable Ruminococcaceae UCG-005.The CICC24194 treatment had the lowest total bacterial,fungal,protozoan,and methanogen populations(P<0.05).Conclusions Both classⅡa bacteriocin-producing L.plantarum strains improved the fermentation quality of wholeplant corn silage by regulating the bacterial community composition during ensiling,with CICC24194 being the most effective.Both bacteriocin-producing strains mitigated CH_(4) production and improved digestibility by modulating the interactions among rumen bacteria,protozoa,methanogens,and the composition of fibrolytic bacteria.
基金supported by the National Transgenic Project of China(2016ZX08006003-004 and 2018ZX08009-26B)the NSFC Major Research Plan-Major Scientific Problems of African Swine Fever virus(31941008)+3 种基金the Fundamental Research Funds for the Central Universities(2662018JC002)the IDRC Livestock Vaccine Innovation Fund(109212-001)the CGIAR Research Program on LivestockNatural Science Foundation of Anhui Province(2008085QC138)。
文摘Clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated protein 9(CRISPR/Cas9)genome editing technology has dramatically influenced swine research by enabling the production of high-quality disease-resistant pig breeds,thus improving yields.In addition,CRISPR/Cas9 has been used extensively in pigs as one of the tools in biomedical research.In this review,we present the advancements of the CRISPR/Cas9 system in swine research,such as animal breeding,vaccine development,xenotransplantation,and disease modeling.We also highlight the current challenges and some potential applications of the CRISPR/Cas9 technologies.
基金Supported by the National Natural Science Foundation of China (No. 40971191)the Scientific Research Starting Foundation of Ministry of Education of China for Returned Overseas Chinese Scholars+1 种基金the Special Foundation of Ministry of Finance of China for Nonprofit Research of Forestry Industry (No.200904001)the International Institute for Geo-information Science and Earth Observation (ITC),the Netherlands
文摘Measurements of photosynthetically active radiation （PAR）, which are indispensable for simulating plant growth and productivity, are generally very scarce. This study aimed to compare two extrapolation and one interpolation methods for estimating daily PAR reaching the earth surface within the Poyang Lake national nature reserve, China. The daily global solar radiation records at Nanchang meteorological station and daily sunshine duration measurements at nine meteorological stations around Poyang Lake were obtained to achieve the objective. Two extrapolation methods of PARs using recorded and estimated global solar radiation at Nanchang station and three stations （Yongxiu, Xingzi and Duchang） near the nature reserve were carried out, respectively, and a spatial interpolation method combining triangulated irregular network （TIN） and inverse distance weighting （IDW） was imple- mented to estimate daily PAR. The performance evaluation of the three methods using the PARs measured at Dahuchi Conservation Station （day number of measurement = 105 days） revealed that： （1） the spatial interpolation method achieved the best PAR estima- tion （R2 - 0.89, s.c. = 0.99, F= 830.02, P 〈 0.001 ）; （2） the extrapolation method from Nanchang station obtained an unbiased result （R2 = 0.88, s.c. = 0.99, F = 745.29, P 〈 0.001）; however, （3） the extrapolation methods from Yongxiu, Xingzi and Duchang stations were not suitable for this specific site for their biased estimations. Considering the assumptions and principles supporting the extrapolation and interpolation methods, the authors conclude that the spatial interpolation method produces more reliable results than the extrapolation methods and holds the greatest potential in all tested methods, and more PAR measurements should be recorded to evaluate the seasonal, yearly and spatial stabilities of these models for their application to the whole nature reserve of Poyang Lake.
文摘Sheep is an important livestock species raised globally to produce meat,milk,wool,and other by-products.During the Neolithic Revolution,sheep were domesticated in the Fertile Crescent of Southwest Asia around 10,000 years ago(Chessa et al.,2009).
文摘The Kenya dairy sub-sector has been undergoing developments since the 1980s in the areas of adoption of intensive dairy farming, especially zero grazing. There have been concerted efforts by the government and other development partners to commercialize the sub-sector so as to make it more profitable to farmers, especially smallholder farmers, but the profitability in the sector continues to be variable with some smallholder farmers making losses. The causes of the varying profits have not been empirically established, with the influence of institutional arrangements and financial factors contributing to this inconsistency not fully established. This study dwelt on establishing the critical institutional arrangements and financial factors that constrain the profitability of smallholder dairy farmers in Nakuru County. A multi-stage sampling procedure was used to select respondents. Data were collected by structured interviews at the farm level. Data Envelopment Analysis （DEA） was used to come up with profit efficiency rankings among the farmers, and the Frontier Model was used to establish the factors that constrain profit efficiency. The mean efficiency according to the results was 86%. The farm and farmer characteristics that were significant in explaining profitability efficiency according to the frontier results were： feeding system, breed type, and gender. The financial characteristics included debt amount and debt asset ratio. Additionally, issues of trust were also found to have an effect on profitability, and they included trust in local buyer price, trust in unit of measurement of institutional buyer, and trust in unit of measurement of middlemen.
文摘The study was conducted to estimate flock dynamics of western lowland Arab goat and to assess their contribution to income of smallholder farmers in Kurmuk and Assosa districts, western Ethiopia. Flocks of 30 households were monitored for a period of 12 months in 2016. Data were analyzed using the general linear model procedure of SAS and two-way interaction effects were fitted in the model and retained when found significant in the preliminary analysis. The study result indicates that total entrances for all flock were significantly (p < 0.05) higher in dry and hot-cool seasons than wet season. Most of the entrance was kids born in hot-cool season (January) (4.0 ± 0.42) and hot-dry season (May) (5.4 ± 1.09) for Assosa and Kumruk study sites, respectively. Kid mortality constituted the greater part of outflow. High kid mortality was occurred during July, February, January, and September. Most of the sell of castrated goats were occurred in September and April for both small and large flocks targeting holidays celebrated during this months. Male goat owners had significantly lower goat production potential (GPP) value than female (0.47 ± 0.02 vs. 0.52 ± 0.02). The GPP was lower in small flock than in large flock (0.48 ± 0.02 vs. 0.51 ± 0.02). Higher GPP was recorded in the months of January, February, and March for both large and small flocks. The off-take was higher (P < 0.05) in Assosa (0.06 ± 0.01) than Kumruk (0.02 ± 0.02) district. The average goat production efficiency (GPE) was higher (P < 0.05) in Assosa large (193.23 ± 20.0) and small flocks (93.44 ± 17.3) than Kumruk large (84.71 ± 15.6) and small flocks (33.33 ± 26.3).The production efficiency recorded was not comparable to the potential that the farmers had to sell goats or consume goats’ meat and milk. The lower goat production potential observed for small flocks implies that high mortality rates severely restrict receiving higher benefits from goat. Therefore, in order to optimize the productivity of goats flock dynamics, developing health intervention strategies that target reduction of kids’ mortality is imperative.
文摘A study was undertaken to characterize production system, breeding practices and production constraints of Begait goat in Kafta humera district, northwestern lowlands of Ethiopia. Personal observations, focus group discussions and a detailed structured questionnaire were used to collect data from 150 respondents (99 small-scale and 51 large-scale farmers). Mixed crop-livestock production system was found to be the dominant farming system in the study district. The farmers kept a variety of livestock species including goats, sheep, cattle, chickens and donkeys. Small ruminants are the most numerous and are of great importance in the area. Goats are herded with sheep in the open fields by the young boys in the family/hired grazers. They have a number of roles though mainly kept as a source of cash income. Breeding was generally uncontrolled. Size, growth rate and libido were the most frequently reported traits in selecting bucks, whereas does were selected based on size, twining ability and milk yield. Effective population size and rate of inbreeding were calculated by considering random mating and flocks were not mixed. The major constraints hampering goat production in the area were water scarcity, feed and grazing land shortages and insufficient veterinary services among the others. Therefore, addressing these constraints is important to design a successful genetic improvement scheme in the area for goat.
文摘Sorghum (Sorghum bicolour (L.) Moench), the second most important staple crop in Sub-Saharan Africa (SSA) after maize, is well adapted to marginal environments of drought stress and high temperatures. But besides drought stress, the obligate root-parasitic flowering plant Striga hermonthica is an equally economically important biotic stress in agro-ecological zones where soils are marginal. Notwithstanding widespread and intense Striga infestation, genetic variations in defence mechanisms against the parasite have been reported. Sorghum variants, producing low levels of chemical stimulants such as sorgolactones that deter the advance of Striga seed germination and are therefore deemed resistant to the parasite, have been also reported in a few studies. But the existence of sorghum genetic variation for this resistance especially among farmers’ landraces is yet to be demonstrated. The objective of this study was therefore to determine the levels of Striga germination stimulants in response to each of the 111 collected sorghum landraces and their progenies from Eritrea. The ability of a sorghum genotype to cause germination of a Striga seed as a measure of the amount of the germination stimulant produced was used to assess the resistance of these accessions. The data were recorded as Striga germination percentage by counting the number of germinated Striga seeds. Landraces EG47, EG1261, EG830, EG1076, EG54 and EG746 with 14.68%, 15.32%, 11.85%, 13.05%, 15.74% and 16.5% germination percentages respectively were found to stimulate low levels of Striga germination percentage compared to commercial checks, IS9830, SRN39, Framida, with 22.46%, 22.67%, 23.27% germination respectively. While these variants did not show complete resistance against Striga seed germination, the low level production of stimulant indicated their high level of resistance to Striga . These results implied that these accessions are likely potential sources of resistance against Striga infestation in SSA sorghum breeding programs.
文摘Four released durum wheat varieties, two medium tall (Arsi-Robe and Kilinto) and two recently released semidwarfs (Ude and Yerer) were evaluated under five different N rates (0, 60, 120, 180 and 240 kg·ha-1) in 2005/06 growing season at Akaki and Debre Zeit, central Ethiopia. The quality responses of durum wheat varieties to different N-fertilizer rates and the N responses between tall and short durum wheat varieties were assessed. Protein and gluten content, vitreous kernel count, thousand kernel weight, test weight and lodging were considered. Vitreous kernel count, protein and gluten content were higher at Debre Zeit than at Akaki. Unlike Debre Zeit, there were significant relationships between response variables and fertilizer levels at Akaki. Lodging slightly affected the medium tall varieties at Debre Zeit whereas it was not a problem at Akaki. At Akaki, varieties response to each additional N rate was entirely below the quality standard set by ICC, 2000 except for thousandkernel weight. Therefore, it is unwise to promote durum wheat scaling up/out program for quality production at Akaki.
文摘Tomato is one of the most widely produced and consumed vegetable crops in Ethiopia. It is not produced during the rainy season, mainly due to high disease pressure and low soil temperature. Therefore, an experiment was conducted to study the effect of different types of mulch （black and white plastic mulch as well as grass mulch） on early yield of tomato varieties （Miya ＆ Cochoro） under polyhouse growing condition at Bahir Dar during the rainy season in 2012. Treatments were arranged in 4 - 2 factorial combinations in randomized complete block design with three replications. One month old seedlings were transplanted on 8.4 m2 gross plots size （3 m x 2.8 m） at a spacing of 70 cm x 40 cm between rows and plants, respectively. Data recorded from plants found in the two middle rows of each plot. Di-ammonium phosphate （DAP） and Urea fertilizers were applied at the rate of 200 kg and 100 kg/ha, respectively. Sixteen plants were considered for data collection in each plot. White plastic mulch resulted in significantly （P 〈 0.05） earlier flowering, fruit setting and fruit maturity compared to other mulching materials. Varieties were also significantly different in days required to flowering, fruit setting and fruit maturity. Miya took significantly short period to flower, fruit set and fruit maturity compared to Cochoro variety. The effect of different mulch types on early fruit yield was found statistically significant. The highest early marketable fruit yield of 10.99 ton/ha and 10.54 ton/ha were recorded when Miya variety was grown with white and black plastic mulch, respectively. Therefore, use of white and black plastic mulches recommended for early tomato fruit yield.
基金supported by the Steps towards sustainable forest management with the local communities in Tigraynorthern Ethiopia at Mekelle University funded by NORAD/NORHED(ETH 13/0018)program+1 种基金Mekelle UniversityNORADⅢproject
文摘Poor land use management and practice inhibit the growth and establishment of tree seedlings in dryland areas.We assessed arbuscular mycorrhizal fungi(AM)status of Faidherbia albida(Del.)A.Chev.trees grown on different land uses.We quantified the growth and nutrient uptake of F.albida seedlings inoculated with AM from different sources.These efforts were based on soil and fine root samples from the rhizosphere soils of F.albida trees.AM root colonization was determined using the gridline intersect method.Spores were extracted by the wet sieving and decanting method and identified to genus level.The seedling experiment had a completely randomized onefactorial design with four treatments and five replications.Faidherbida albida seedlings were grown in a greenhouse.All in situ F.albida trees were colonized by AM fungi.AM root colonization of F.albida trees was significantly higher(P<0.0086)in area exclosures than on lands used for grazing or cultivation.Spore abundance was significantly higher(P<0.0014)in area exclosures followed by cultivated land and grazing land.Glomus was the dominant genus in all land-uses.AM-inoculated F.albida seedlings grew better(P<0.05)than non-inoculated controls.Seedlings inoculated with AM from area exclosure had significantly(P<0.05)higher growth and nutrient uptake than those inoculated with AM from grazing and cultivated land.This emphasizes the importance of the native soil AM potential for better establishment of seedlings to achieve optimum plant growth improvement and assist in rehabilitation of degraded arid lands.
文摘Goats are one of the oldest domesticated animal species widely distributed in the world playing an important role in the food production system in Sub-Saharan African Region (SSAR). Due to their multiple uses (milk production, meat, fiber and hides) and adaptation aptitudes to ecological conditions, goats produce and contribute positively to farmers’ socio-economy status in various production systems. This review aimed at giving a summary overview on the goat’s production systems characteristics, the genetic diversity and the candidate genes affecting reproductive and milk production performances in goat breeds in SSAR. It has been observed that traditional livestock production system with communal grazing system is the most used in goat keeping in SSAR. The geographical locations play an important role in the relationships between goat’s distributions in the region. At the same time, goats might have been differentiated and isolated one to others due to the wide geographic range, the diversify climate and the topography in the region. Among the six worldwide known haplogroups of goat (A, B, C, D, G and F), haplogroup A is the most representative in SSAR. However, haplogroup G and B can be found in some goat populations in some countries in east (Kenya and Ethiopia) and south parts of Africa. This review reveals that little is known on the candidate genes associated with prolificacy and milk production traits in indigenous goat breeds in the region. That observation suggests the importance of assessing candidate genes associated with economic traits in the populations of goat in SSAR.
基金Funding was provided by the Agricultural Biotechnology Research Institute of Iran(ABRII),Swedish Research Council(Vetenskapsrådet grant no.:2017-05019)the BBSRC Institute Strategic Programme Gut Microbes and Health(BB/r012490/1,its constituent project BBS/e/F/000Pr10355).
文摘Metagenomics has opened new avenues for exploring the genetic potential of uncultured microorganisms,which may serve as promising sources of enzymes and natural products for industrial applications.Identifying enzymes with improved catalytic properties from the vast amount of available metagenomic data poses a significant challenge that demands the development of novel computational and functional screening tools.The catalytic properties of all enzymes are primarily dictated by their structures,which are predominantly determined by their amino acid sequences.However,this aspect has not been fully considered in the enzyme bioprospecting processes.With the accumulating number of available enzyme sequences and the increasing demand for discovering novel biocatalysts,structural and functional modeling can be employed to identify potential enzymes with novel catalytic properties.Recent efforts to discover new polysaccharide-degrading enzymes from rumen metagenome data using homology-based searches and machine learning-based models have shown significant promise.Here,we will explore various computational approaches that can be employed to screen and shortlist metagenome-derived enzymes as potential biocatalyst candidates,in conjunction with the wet lab analytical methods traditionally used for enzyme characterization.
文摘Climate change has increased extreme events over globe and the most robust occurrences of concurrent drought and floods have become more common in Africa. This study focuses on the observed and projected analysis of rainfall extremes of consecutive dry day (CDD) and maximum monthly five day precipitation (RX5day) from Expert Team on Climate Change Detection and Indices (ETCCDI) in June-August season over Africa. The daily CORDEX Africa, reanalysis and CRU datasets were analyzed for extreme trends under RCP4.5 and RCP8.5 scenarios for the periods of 1980 to 2100. The spatiotemporal variability, trend, and magnitude of JJA seasonal rainfall performance exhibits a significant decreasing tendency over Eastern Africa compared to West Africa. The observed results of consecutive dry day (CDD) reveal that increasing trend and moreover RX5day shows that promising positive trend. Both rainfall extremes are influenced by the combined effect of large scale indexes and appear to be correlated negatively and positively with ENSO, NAO and AO. The CORDEX ensemble mean projections of JJA seasonal rainfall performance show a widespread significant change and the first mode of EOF depicts that 13.8% and 24.9% under the RCP4.5 and the highest variability is under RCP8.5 scenario. The projected CDD extreme exhibit an increasing trend in the coming periods and the percentage change revealed that increasing from 25.11%, 28.02% over West and 26.49%, 31.66% East Africa under RCP4.5 and RCP8.5 scenarios respectively. This situation will exacerbate increasing of frequent and intensified drought extremes over Africa. Additionally, the future RX5day indicated that mixed trend and revealed that increasing 3.72%, 2.54% over West and decreases -16.12%, -22.47% over East Africa under RCP4.5 and RCP8.5 respectively. Generally, rainfall extremes of CDD are projected to increase and RX5day shows a mixed trend in the coming periods over Africa and calls for further verification by using high resolution datasets.
