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Conversion of savanna rangelands to bush dominated landscape in Borana,Southern Ethiopia

Ecological Processes 2016年第1期5卷 60-77页

作者： Teshome Abate Ayana Angassa School of animal and range sciences Hawassa UniversityHawasaEthiopia

Introduction:Analyzing trends of land use systems and the changes occurred overtime is an effective way of assessing the impacts of land use/land cover(LULC)changes on ecosystem *** provides important insights for understanding the spatial patterns of land use *** rangelands of southern Ethiopia are adversely affected by increased human population pressure,encroachment of crop cultivation,and bush ***,it is vital to understand the trends of rangeland vegetation cover ***:This paper evaluates land use/land cover changes and spatial patterns between 1987 and 2003 in Yabelo(5426 km2),Borena rangelands of southern *** used a combination of three Landsat Thematic Mapper(TM)1987,Landsat TM 1995 and Enhanced Thematic Mapper Plus(ETM+)2003,and local perceptions.A pixelbased supervised classification with maximum likelihood classifier was used to classify *** accuracy of classification was assessed for 1987(81.8%),1995(84.6%),and 2003(81.3%).Results:The results showed that the Borana rangelands had undergone substantial changes during the last 16 *** 1987 and 2003,we observed a considerable increase in woodland cover(11.7%),bushland cover(17%),cultivated land(72.5%),and settlements(79.8%).The results showed a rapid decline in grassland cover(7.7%),shrubby grassland cover(86%),and bareland(0.7%).The spatial pattern analysis indicate that the Borana rangeland was fragmented and characterized by the proliferation of large numbers of patches with a decline in patch index,increased patch density,and irregular shape of patches within a *** communities’perceptions indicate that recurrent drought,increased human population size,and expansion of cultivation were largely responsible for the observed LULC changes in the study ***:LULC changes contribute to rangeland degradation and weaken the traditional practices of rangeland *** suggest appropriate management measures to halt the

关键词： Bush encroachment Landscapepattern Remotesensing LULC Boranarangeland

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rangeland water requirement satisfaction index under rainfall variability and predicting future rainfall scenarios: implication for availability of feed resources

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Ecological Processes 2017年第1期6卷 264-272页

作者： Hassen M.Ahmed Zewdu K.Tessema Adugna Tolera Diriba Korecha School of animal and range sciences College of Agriculture and Environmental SciencesPO Box 138Dire DawaEthiopia School of animal and range sciences Hawassa UniversityPO Box 222HawassaEthiopia Famine Early Warning Systems Network PO Box 1090Addis AbabaEthiopia School of animal and range sciences College of Agriculture and Environmental SciencesHaramaya UniversityPO Box 1632Dire DawaEthiopia

Introduction:rangeland ecosystems provide multiple ecosystem services,including feed resources for wild and domestic herbivores in semi-arid ***,under the ever increasing environmental changes,the impact of rainfall variability on the productivity and vegetation dynamics of rangelands are the great challenges that pastoral community are facing *** a result,the potentials of most rangelands in semi-arid ecosystems affect the ***,we studied the interconnections between the long-term rainfall variation and the rangeland Water Requirement and Satisfaction Index(WRSI)in Mieso,Jigjiga,and Shinile districts under pastoral conditions of ***:The base period rainfall data(1984–2015)was obtained from the National Meteorological Agency of Ethiopia,whereas the future rainfall trend was predicted using MarkSim software(Representative Concentration Pathways 4.5 GHG concentration trajectory).Mann-Kendall’s statistical tests,coefficient of variation,LEAP software(version 2.61),and Minitab Software(version 15)were used to assess the relationship between rangeland WRSI and long-term rainfall ***:The result indicated that mean annual rainfall anomaly had strong positive correlation with rangeland WRSI in Mieso(Prangeland WRSI,especially in Jigjiga and Shinile pastoral *** base period rainfall as well as the predicted annual rainfall showed variability in amount and distribution in all studied districts in pastoral areas of ***:The mean annual rainfall anomaly is correlated with the rangeland ***,the future rainfall trend analysis indicated that variability of rainfall would be expected in between the years 2020–2049,2040–2069,and 2070–***,the future rainfall variability would limit future rangeland WRSI under pastoral conditions of Ethiopia.

关键词： LEAP software Pastoralist rangeland water requirement Trend analysis

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Effects of grazing intensity to water source on grassland condition, yield and nutritional content of selected grass species in Northwest Ethiopia

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Ecological Processes 2019年第1期8卷 149-161页

作者： Yaregal Melak Ayana Angassa Aster Abebe Department of animal and range sciences Hawassa UniversityAwasaEthiopia Department of range and Forest Resources Faculty of Natural ResourcesBotswana University of Agriculture and Natural ResourcesPrivate bag 0027GaboroneBotswana

Background:Savanna grasslands are globally important ecosystems consisting of one of the most extensive grazing lands with unique *** objectives of the study were to assess the effect of grazing intensity on grassland ecosystem condition,herbaceous plant biomass production,and nutritional content of selected grass ***:The study was conducted at Chagni Ranch,Northwest *** transects to water source point at regular intervals of 20m between sampling plots along transects were used for data *** distance between the four transects was 200m in *** were collected on grass composition,basal cover,litter cover,number of seedlings,and age distribution of dominant grasses(i.e.,young,medium,or old in terms of stage of maturity),soil condition in terms of soil compaction,and soil erosion linked to the effects of trampling by grazing animals along transects(hereafter referred to as transect)to water source *** total sample size for grass species was 160 *** grassland ecosystem condition,herbaceous biomass,and grass nutritional content were used as response variables linked to transect from water source *** effects of transect on grassland ecosystem condition scores and grass nutritional content were analyzed using the analysis of variance(ANOVA).Results:Grassland condition factors like grass composition,basal cover,litter cover,age distribution of dominant grasses,and soil condition were significantly(P<0.05)higher for the furthest transect to water source point than nearest *** of the 28 identified herbaceous species,grasses accounted for 64.3%of the herbaceous *** grass species,about 55.6%were highly desirable in terms of palatability and grazing value(as most palatable species are susceptible to heavy grazing intensity).The results showed a significantly(P<0.05)higher proportion of perennial grasses at the furthest transect to water source point than nearest *** dry matter yi

关键词： Grassland condition Grass yield Nutritional content Transect

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Genome Array on Differentially Expressed Genes of Skin Tissue in Cashmere Goat at Early Anagen of Cashmere Growth Cycle Using DNA Microarray

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Journal of Integrative Agriculture 2014年第10期13卷 2243-2252页

作者： DI Jiang XU Xin-ming Lazate Ainiwaer ZHANG Yan-hua TIAN Ke-chuan YU Li-juan WU Wei-wei Hanikezi Tulafu FU Xue-feng Marzeya Yasen Xinjiang animal sciences Research Institute Xinjiang Academy of Animal Sciences

In order to study the molecular mechanism involved in cashmere regeneration, this study investigated the gene expression profile of skin tissue at various stages of the cashmere growth cycle and screen differentially expressed genes at proangen in 10 cashmere goats at 2 years of age using agilent sheep oligo microarray. Significance analysis of microarray （SAM） methods was used to identify the differentially expressed genes, Hierarchical clustering was performed to clarify these genes in association with different cashmere growth stages, and GO （Gene ontology） and the pathway analyses were con-ducted by a free web-based Molecular Annotation System3.0 （MAS 3.0）. Approximately 10200 probe sets were detected in skin tissue of 2-yr-old cashmere goat. After SAM analysis of the microarray data, totally 417 genes were shown to be differentially expressed at different cashmere growth stages, and 24 genes are significantly up-regulated （21） or down-regulated （3） at proangen concurrently compared to angen and telogen. Hierarchical clustering analysis clearly distinguished the differentially expressed genes of each stage. GO analysis indicated that these altered genes at proangen were predominantly involved in collagen fibril organization, integrin-mediated signaling pathway, cell-matrix adhesion, cell adhesion, transforming growth factor-β （TGF-β） receptor signaling pathway, regulation of cell growth. Kyoto encyclopedia of genes and genomes （KEGG） analysis showed that the significant pathways involved mainly included focal adhesion and extracellular matrixc （ECM）-receptor interaction. Some important genes involved in these biological processes, such as COL1A1, COL1A2, COL3A1, SPARC, CYR61 and CTGF, were related to tissue remolding and repairing and detected by more than one probe with similar expression trends at different stages of cashmere growth cycle. The different expression of these genes may contribute to understanding the molecular mechanism of cashmere regeneration.

关键词： cashmere growth cycle regeneration gene expression microarray

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Influence of previous plane of nutrition on molecular mechanisms regulating the expression of urea and water metabolism related genes in the rumen and kidney of finishing crossbred Angus steers

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animal Nutrition 2024年第2期17卷 232-243页

作者： Aghata E.Moreira da Silva Arturo Macias Franco Bradley S.Ferguson Mozart A.Fonseca College of Agriculture Biotechnology&Natural Resources University of Nevada Department of animal and range sciences Clayton Livestock Research Center New Mexico State University

This study aimed to understand how molecular mechanisms controlling water and urea metabolism at the finishing phase can be affected by previous plane of nutrition of crossbred Angus beef steers. Twentyfour(n = 24) animals were randomly distributed into either a moderate(MP) or high plane of nutrition during the background phase for 85 d. animals were then blocked by their previous plane and were moved onto a 105-d finishing phase in a 2 × 2 factorial arrangement. The forage-finished group received only high-quality alfalfa hay, whereas the grain-fed group received a high grain diet(80% whole corn and20% alfalfa hay). By the end of the finishing phase, animals were harvested and tissue samples from the rumen and kidney were collected. Changes in gene expression of aquaporins(AQP)-2,-3,-4,-7, ATP1A1,ATP1B1, SGK1, CLIC1(kidney and rumen), UT-A1(kidney only) and UT-B(rumen only), were assayed via real-time q PCR; 18S r RNA was used as an endogenous control. One-way ANOVA followed by Tukey's post hoc analysis was conducted. When animals were from MP, forage-finishing increased the relative abundance of AQP3(P ≤ 0.05), AQP7(P ≤ 0.05), ATP1B1(P ≤ 0.05), and SGK1(P ≤ 0.05) in the kidney when compared to grain-fed animals. In the rumen, for the MP group, AQP7 was differentially expressed in both treatments at the finishing phase(P ≤ 0.01), with forage-finished steers having the highest expression of AQP7. For the MP group, UT-B had a tendency of presenting a higher expression on grainfed animals(P = 0.075). Overall, these results suggest that previous plane can impact expression of genes associated with water and urea metabolism during the finishing phase, namely AQP3, AQP7, ATP1B1, and SGK1 in the kidney, and AQP7 and UT-B in the rumen. The greatest impact observed on gene expression changes of investigated genes at the finishing phase was reflective of animals backgrounded on the moderate previous plane.

关键词： Gene expression Aquaporin Sodium channel Urea transporter

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Transcriptional changes in mesenteric and subcutaneous adipose tissue from Holstein cows in response to plane of dietary energy

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Journal of animal Science and Biotechnology 2018年第1期9卷 233-247页

作者： S.J.Moisá P.Ji J.K.Drackley S.L.Rodriguez-Zas J.J.Loor Department of animal sciences Auburn University Department of animal sciences University of Illinois

Background： Dairy cows can readily overconsume dietary energy during most of the prepartum period, often leading to higher prepartal concentrations of insulin and glucose and excessive body fat deposition. The end result of these physiologic changes is greater adipose tissue lipolysis post-partum coupled with excessive hepatic lipid accumulation and compromised health. Although transcriptional regulation of the adipose response to energy availability is well established in non-ruminants, such regulation in cow adipose tissue depots remains poorly ***： Effects of ad-libitum access to high [HIGH; 1.62 Mcal/kg of dry matter（DM）] or adequate（CON; 1.35 Mcal/kg of DM） dietary energy for 8 wk on mesenteric（MAT） and subcutaneous（SAT） adipose tissue transcript profiles were assessed in non-pregnant non-lactating Holstein dairy cows using a 13,000-sequence annotated bovine oligonucleotide microarray. Statistical analysis revealed 409 and 310 differentially expressed genes（DEG） due to tissue and diet. Bioinformatics analysis was conducted using the Dynamic Impact Approach（DIA） with the KEGG pathway database. Compared with SAT, MAT had more active biological processes related to adipose tissue accumulation（adiponectin secretion） and signs of pro-inflammatory processes due to adipose tissue expansion and macrophage infiltration（generation of ceramides）. Feeding the HIGH diet led to changes in m RNA expression of genes associated with cell hypertrophy（regucalcin）, activation of adipogenesis（phospholipid phosphatase 1）,insulin signaling activation（neuraminidase 1） and angiogenesis（semaphorin 4 G, plexin B1）. Further, inflammation due to HIGH was underscored by m RNA expression changes associated with oxidative stress response（coenzyme Q3, methyltransferase）, ceramide synthesis（N-acylsphingosine amidohydrolase 1）, and insulin signaling（interferon regulatory factor 1, phosphoinositide-3-kinase regulatory subunit 1, retinoic acid receptor alpha）. Activation of ribos

关键词： Adipose tissue Dairy cow Dietary energy Transcriptome

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Mechanisms of bush encroachment and its inter-connection with rangeland degradation in semi-arid African ecosystems:a review

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Journal of Arid Land 2017年第2期9卷 299-312页

作者： Anteneh BELAYNEH Zewdu K TESSEMA Department of Biology College of Natural and Computational Sciences Haramaya University Haramaya 282 Ethiopia rangeland Ecology and Biodiversity Program School of Animal and Range Sciences College of Agriculture and Environmental Sciences Haramaya University Dire Dawa 138 Ethiopia

Many studies show that semi-arid rangelands throughout the world have been rapidly converted from a grassland state to a bush encroachment state during the past 50 years. Bush encroachment includes the spread of local woody species and/or incursion of woody species introduced from other ecosystems into semi-arid savannas and grassland ecosystems. rangeland degradation due to bush encroachment causes several challenges, affecting the production of livestock and pastoral people livelihoods in most parts of Africa. Scientists have long been attempting to develop schematic and mathematical theories to explain the observed phenomenon of bush encroachment, and several theories were proposed and developed. The well-regarded theories include：（1） Waiter＇s two-layer model, （2） Moir＇s one-layer model, （3） state-and-transition theory, （4） equilibrium theory, （5） disequilibrium theory, and （6） non-equilibrium theory. Within those theories, the most frequently-indicated driving factors that explain bush encroachment include over-grazing, availability of soil nutrient and moisture, elevated CO2 levels, frequency and intensity of fire, spread of seeds of woody species by livestock and wild animals. It should be stressed that couplings and interactions among diverse driving factors are more often at work in determining the condition of bush encroachment. To summarize, the effort in managing semi-arid ecosystems needs critical knowledge to understand the cause-effect relationships of underlying factors through integrated approach. Therefore, future research on encroachment of woody plants should be multi-discipline oriented and multi-partnership involved.

关键词： climate change exotic woody species indigenous woody species Moir's one-layer model rangelandtheories Walter's two-layer model

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Chicken gga-miR-1306-5p targets Tollip and plays an important role in host response against Salmonella enteritidis infection

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Journal of animal Science and Biotechnology 2019年第4期10卷 873-883页

作者： Weiwei Sun Ranran Liu Peng Li Qinghe Li Huanxian Cui Maiqing Zheng Jie Wen Guiping Zhao Institute of animal sciences Chinese Academy of Agricultural Sciences State Key Laboratory of Animal Nutrition

Background: Increasing evidence indicates that micro RNAs(mi RNAs) are involved in inflammatory response and immune regulation following pathogen invasion. The purpose of this study was to elucidate the roles played by Gallus gallus micro RNA-1306-5 p(gga-mi R-1306-5 p) in host responses against potential invasion by Salmonella enteritidis(SE) in chickens and the underlying ***: In present study, the expression levels of gga-mi R-1306-5 p were determined in both tissues and HD11 cells. The results showed that gga-mi R-1306-5 p was significantly increased following SE infection or lipopolysaccharide(LPS) stimulation. The dual luciferase reporter assay further validated that gga-mi R-1306-5 p targeted the Toll-interacting protein(Tollip), and thereby participated in the regulation of immune response against SE or LPS stimulation through binding with the 3′-untranslated region(3’UTR) of Tollip. Additionally, the expression of Tollip was significantly blocked by over-expressed gga-mi R-1306-5 p. The underlying mechanisms by which ggami R-1306-5 p modulated the production of pro-inflammatory cytokines were also investigated. Molecular biological assays demonstrated that overexpression of gga-mi R-1306-5 p promoted the production of pro-inflammatory mediators, including NF-κB, TNF-α, IL-6, and IL-1β, which produced effects similar to those of Tollip ***: Taken together, gga-mi R-1306-5 p induced by SE or LPS, regulates the immune response by inhibiting Tollip, which activates the production of inflammatory cytokines. This study has provided the first direct evidence that gga-mi R-1306-5 p targets Tollip, and is involved in the host response against SE.

关键词： gga-miR-1306-5p LPS Pro-inflammatory cytokine Salmonella enteritidis Tollip

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Regulatory effects of dietary L-Arg supplementation on the innate immunity and antioxidant ability in broiler chickens

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Journal of Integrative Agriculture 2016年第11期15卷 2578-2587页

作者： HU Ya-di TAN Jian-zhuang QI Ji ZHANG Hong-fu State Key Laboratory of animal Nutrition Institute of Animal SciencesChinese Academy of Agricultural Sciences

Here, we investigated the effect of dietary arginine（Arg） supplementation on innate immunity and the antioxidant ability of broiler chickens. The experiment was designed as a single-factorial arrangement（n=8 cages/treatment, six birds/cage）, and we used four dietary Arg concentrations（10.0, 15.0, 20.0 or 25.0 g kg–1）. On day 21, the birds were killed to obtain spleen, cecal tonsil and liver samples to determine the gene expression and antioxidant characteristics. Increasing the Arg concentration linearly decreased（P0.05） the m RNA expression of splenic interleukin-18（IL-18） and tumor necrosis factor-α（TNF-α）. Dietary Arg supplementation quadratically decreased（P0.05） the expression of interleukin-1b（IL-1b） and interferon-γ（IFN-γ） m RNA in the spleen. Increasing Arg concentrations linearly and quadratically reduced the expression of IL-18 m RNA in the spleen. Meanwhile, increasing dietary Arg supplementation linearly and quadratically increased the lymphotactin m RNA（P0.05） expression, and linearly increased the macrophage inflammatory protein-1β（MIP-1β） and toll-like receptor 15（TLR15） m RNA expression in the cecal tonsils. Dietary Arg supplementation linearly（P0.05） increased the glutathione peroxidase（GSH-Px）, catalase（CAT）, and lysozyme（LZM） activities in the liver. However, the malondialdehyde（MDA） activity in the liver was not influenced by the dietary Arg concentration（P0.05）. No significant（P0.05） effect was found on the activity of superoxide dismutase（SOD） in the liver. Thus high levels of Arg supplementation（20.0 g kg^（–1）） may potentially suppress the innate immunity of broiler chickens, and dietary Arg supplementation enhances the antioxidant activity in broiler chickens.

关键词： arginine innate immunity antioxidant ability broiler

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Effect of Graded Levels of Fiber from Alfalfa Meal on Nutrient Digestibility and Flow of Fattening Pigs

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Journal of Integrative Agriculture 2014年第8期13卷 1746-1752页

作者： CHEN Liang GAO Li-xiang ZHANG Hong-fu State Key Laboratory of animal Nutrition Institute of Animal Sciences Chinese Academy of Agricultural Sciences

The fiber level and composition have an important effect on nutrient digestibility of swine diets. Little information is known about the effects of fiber level and composition from alfalfa meal on nutrient digestibility of fattening pigs fed a corn-soybean meal-based diet. The objective of this experiment was to determine the effects of alfalfa fiber on the growth performance, intestinal nutrient flow and apparent total tract digestibility（ATTD） of nutrients in fattening pigs. 24 barrows（Duroc×（Large White×Landrace）, body weight=（60.6±0.7） kg） were randomly allotted to 4 treatments with 6 replicates of 1 pig per replicate. The pigs were provided a control diet or a diet containing 5, 10 or 20% of alfalfa meal during a 14-d experiment period. Average daily gain（ADG） and the ATTD of dry matter（DM）, organic matter（OM）, crude protein（CP）, neutral detergent fiber（NDF）, acid detergent fiber（ADF） and gross energy（GE） reduced linearly as the level of alfalfa meal in the diet increased（P〈0.01）. The total tract flow of DM, OM, CP, NDF, ADF, and GE increased with the increase in dietary alfalfa（linear, P〈0.05）. Growth performance and nutrient digestion were not affected by inclusion of 5% alfalfa meal in the diet（P〉0.05）. A multiple linear regression analysis, taking into account both soluble and insoluble fiber intake, explained approximately 70% of the variation in the ATTD of DM, OM, NDF, and GE（P〈0.01）. In conclusion, alfalfa meal should be limited to less than 5% of the diet in fattening pigs to maximize growth performance and nutrient digestion. Soluble and insoluble fiber from alfalfa meal has the differential roles in nutrient digestion, which may help explain the main variation observed in nutrient digestibility. These findings suggest that knowledge of specific fiber components is necessary to accurately predict the effects of dietary fiber on nutrient digestibility.

关键词： alfalfa digestibility fiber flow nutrient pig

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