National Council for Science and Technology

Nairobi, Kenya

National Council for Science and Technology

Nairobi, Kenya
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Odadi W.O.,Mpala Research Center | Karachi M.K.,Egerton University | Abdulrazak S.A.,National Council for Science and Technology | Young T.P.,Mpala Research Center | Young T.P.,University of California at Davis
Science | Year: 2011

Savannas worldwide are vital for both socioeconomic and biodiversity values. In these ecosystems, management decisions are based on the perception that wildlife and livestock compete for food, yet there are virtually no experimental data to support this assumption. We examined the effects of wild African ungulates on cattle performance, food intake, and diet quality. Wild ungulates depressed cattle food intake and performance during the dry season (competition) but enhanced cattle diet quality and performance during the wet season (facilitation). These results extend our understanding of the context-dependent-competition-facilitation balance, in general, and are critical for better understanding and managing wildlife-livestock coexistence in human-occupied savanna landscapes.


Odadi W.O.,Mpala Research Center | Karachi M.K.,Egerton University | Abdulrazak S.A.,National Council for Science and Technology | Young T.P.,Mpala Research Center | Young T.P.,University of California at Davis
Ecological Applications | Year: 2013

It is believed that wildlife and livestock can coexist in semiarid savanna rangelands. However, this coexistence is threatened by intense competition for scarce, but nutritionally vital, forage resources. Specifically, there is evidence that grazing livestock seasonally compete for protein-rich forbs (non-grasses) with browsing and mixed-feeding wildlife. While this has been attributed to protein needs, there are no experimental tests of whether grazers in such a context alter their diet selection when supplemented with protein. We compared forage selection between cattle supplemented with protein (cotton seedcake) and those not supplemented during dry and wet periods, in a semiarid African savanna rangeland where they have been demonstrated to compete with wildlife for forage. We further evaluated whether such dietary alteration affected the overall biting and movement behavior, nutrition, and performance of cattle, by comparing bite and step rates, diet quality (crude protein and digestible organic matter), forage intake, and live mass change between these treatment groups. During the dry period, relative consumption of forbs was 76% lower in supplemented cattle than in non-supplemented cattle. Notably, supplemented cattle significantly avoided forbs relative to their abundance in the environment, while non-supplemented cattle over-sampled this herbage type. Conversely, selection and relative use of Brachiaria lachnantha, the most abundant grass species, and Bothriochloa insculpta, a grass species otherwise avoided, increased following protein supplementation. These patterns were similar but nonsignificant during the wet period. Bite and step rates, diet quality, forage intake, and performance were not significantly affected by protein supplementation in either period. Our study shows that foraging cattle partially trade off protein-rich forbs for protein-poor grasses when supplemented with protein, without suffering detrimental behavioral, nutritional, or performance consequences. These results broaden our understanding of the role of non-grasses in the diets of "grazers" and suggest protein supplementation as a potential tool in managing coexistence between grazing livestock and browsing (forb-consuming) wildlife. © 2013 by the Ecological Society of America.


Osuga I.M.,Kenyatta University | Abdulrazak S.A.,National Council for Science and Technology | Muleke C.I.,Egerton University | Fujihara T.,Philippine Carabao Center
Journal of Food, Agriculture and Environment | Year: 2012

Various parts of the wild sunflower (Tithonia) were analysed for their chemical composition and degradation characteristics. Pyrethrum marc (pymarc), a common agro-industrial by-product was also analysed to compare the potential nutritive value. Leaves and flowers both young and mature were harvested, dried and ground. The crude protein (CP) content ranged from 143.3 g/kg dry matter (DM) in pymarc to 235.6 g/kg DM in mature Tithonia leaves. The neutral detergent fibre (NDF) content was highest in pymarc (421 g/kg DM) and least in mature leaves (264.8 g/kg DM). Concentration of polyphenolic compounds was highest in young leaves and lowest in young flowers. However, the concentrations were far below levels (50.0 g/kg DM) known to have detrimental effects in ruminants. Flowers were more digestible than leaves but overall pymarc recorded the highest value of 60.5% organic matter digestibility (OMD). The same trend was recorded for metabolizable energy (ME). Addition of polyethylene glycol (PEG), a tannin-binding agent did not yield significant increase in gas production values except for mature flowers, which also recorded significant increases in both OMD and ME. Tithonia forages (leaf and flower) at both young and mature vegetative state have high nutritive value compared to pymarc. However, mature leaves and young flowers are slightly higher in CP and low in concentration of phenolic compounds than young and mature leaves and flowers, respectively. This depicts the high potential of Tithonia shrub in feeding of ruminants.


News Article | December 10, 2015
Site: news.mit.edu

A key concern at the Paris climate negotiations (COP21) is to find a fair, effective, and economically viable way to curb greenhouse gas (GHG) emissions in developing countries, which are expected to vastly outpace those produced in developed countries in the coming decades. One approach, adopted in previous United Nations climate summits in Copenhagen and Cancun and now implemented in Paris, is to encourage each country to craft its own climate mitigation policy based on local conditions and challenges. Another strategy, favored by many economists as the best way to reduce global emissions but politically challenging to implement, is to base each country’s contribution to international climate mitigation efforts on a “one-size-fits-all” policy such as a universal carbon price or emissions reduction target. In a study in the journal Energy Economics, researchers at the MIT Joint Program on the Science and Policy of Global Change explored the implications of establishing uniform emissions reduction policies in Brazil and Mexico, which have the two largest economies in Latin America and are well-positioned to engage the developing world in climate negotiations. Using the MIT Economic Projection and Policy Analysis (EPPA) model to determine the economic impact of several climate policy scenarios on Brazil and Mexico between 2020 and 2050, they showed that imposing the same carbon prices or GHG emissions targets on each country would cost about twice as much in Mexico as in Brazil. In Mexico, the largest contributor to GHG emissions is the energy sector; in Brazil, it’s the agriculture sector. Due to differences in energy and land use emissions sources, the same climate policies cost much higher in Mexico under scenarios ranging from extending existing commitments made in Copenhagen and Cancun to 2050, to a more stringent policy aimed at halving all GHGs by 2050 relative to 2010 levels. In the latter scenario, GDP losses between 2020 and 2050 range from 4 percent to 11 percent for Mexico and 0 percent to 4 percent for Brazil. These findings highlight the need for climate policies that account for individual countries’ natural resources, emissions profiles, and economic structures. Even among countries at similar levels of economic development such as Brazil and Mexico, GHG mitigation efforts come with significantly different costs and benefits that cannot be glossed over in a one-size-fits-all policy. “We expect our research to assist in international climate negotiations and policy design by better explaining the costs and conditions that influence different countries’ positions,” says the study’s lead author, Claudia Octaviano, a recent Joint Program postdoc who now serves as general coordinator for climate change and low-carbon development at the National Institute for Ecology and Climate Change of Mexico. “This type of analysis may also assist developing countries in crafting appropriate mitigation actions by comparing the implications of proposed policies with other countries.” To produce their findings, Octaviano and her co-authors — Joint Program Deputy Director Sergey Paltsev and research associate Angelo Gurgel — updated the EPPA model to incorporate the most recent emissions inventories in Mexico and Brazil, and key national initiatives such as Brazil’s policy to reduce deforestation. Policy scenarios were developed by the Latin America Modeling Project and the Integrated Climate Modeling and Capacity Building Project in Latin America. The EPPA model allowed for a comprehensive analysis of all sectors of the global economy and all GHGs, providing a one-stop-shop for policy design and comparison. “Because we represent the global economy in a single framework, we can capture responses that other models ignore, including the trade implications of climate policy,” Octaviano explains. “We also have the capability to consider changes in land use, allowing us to model Brazil’s deforestation policy within the same framework.” The study was funded by the Mario Molina Center, the National Council for Science and Technology of Mexico, the National Council for Research of Brazil, the European Union and sponsors of the MIT Joint Program.


News Article | December 11, 2015
Site: www.theenergycollective.com

Study shows significant differences in costs associated with curbing greenhouse gas emissions in Brazil and Mexico. Mark Dwortzan | MIT Joint Program on the Science and Policy of Global Change A key concern at the Paris climate negotiations (COP21) is to find a fair, effective, and economically viable way to curb greenhouse gas (GHG) emissions in developing countries, which are expected to vastly outpace those produced in developed countries in the coming decades. One approach, adopted in previous United Nations climate summits in Copenhagen and Cancun and now implemented in Paris, is to encourage each country to craft its own climate mitigation policy based on local conditions and challenges. Another strategy, favored by many economists as the best way to reduce global emissions but politically challenging to implement, is to base each country’s contribution to international climate mitigation efforts on a “one-size-fits-all” policy such as a universal carbon price or emissions reduction target. In a study in the journal Energy Economics, researchers at the MIT Joint Program on the Science and Policy of Global Change explored the implications of establishing uniform emissions reduction policies in Brazil and Mexico, which have the two largest economies in Latin America and are well-positioned to engage the developing world in climate negotiations. Using the MIT Economic Projection and Policy Analysis (EPPA) model to determine the economic impact of several climate policy scenarios on Brazil and Mexico between 2020 and 2050, they showed that imposing the same carbon prices or GHG emissions targets on each country would cost about twice as much in Mexico as in Brazil. In Mexico, the largest contributor to GHG emissions is the energy sector; in Brazil, it’s the agriculture sector. Due to differences in energy and land use emissions sources, the same climate policies cost much higher in Mexico under scenarios ranging from extending existing commitments made in Copenhagen and Cancun to 2050, to a more stringent policy aimed at halving all GHGs by 2050 relative to 2010 levels. In the latter scenario, GDP losses between 2020 and 2050 range from 4 percent to 11 percent for Mexico and 0 percent to 4 percent for Brazil. These findings highlight the need for climate policies that account for individual countries’ natural resources, emissions profiles, and economic structures. Even among countries at similar levels of economic development such as Brazil and Mexico, GHG mitigation efforts come with significantly different costs and benefits that cannot be glossed over in a one-size-fits-all policy. “We expect our research to assist in international climate negotiations and policy design by better explaining the costs and conditions that influence different countries’ positions,” says the study’s lead author, Claudia Octaviano, a recent Joint Program postdoc who now serves as general coordinator for climate change and low-carbon development at the National Institute for Ecology and Climate Change of Mexico. “This type of analysis may also assist developing countries in crafting appropriate mitigation actions by comparing the implications of proposed policies with other countries.” To produce their findings, Octaviano and her co-authors — Joint Program Deputy Director Sergey Paltsev and research associate Angelo Gurgel — updated the EPPA model to incorporate the most recent emissions inventories in Mexico and Brazil, and key national initiatives such as Brazil’s policy to reduce deforestation. Policy scenarios were developed by the Latin America Modeling Project and the Integrated Climate Modeling and Capacity Building Project in Latin America. The EPPA model allowed for a comprehensive analysis of all sectors of the global economy and all GHGs, providing a one-stop-shop for policy design and comparison. “Because we represent the global economy in a single framework, we can capture responses that other models ignore, including the trade implications of climate policy,” Octaviano explains. “We also have the capability to consider changes in land use, allowing us to model Brazil’s deforestation policy within the same framework.” The study was funded by the Mario Molina Center, the National Council for Science and Technology of Mexico, the National Council for Research of Brazil, the European Union and sponsors of the MIT Joint Program.


Katiku P.N.,Kenya Agricultural Research Institute | Kimitei R.K.,Kenya Agricultural Research Institute | Korir B.K.,Kenya Agricultural Research Institute | Muasya T.K.,Kenya Agricultural Research Institute | And 4 more authors.
Livestock Research for Rural Development | Year: 2013

A study to assess the role of markets and marketing integration for enhancing efficiency of Small Ruminant Value Chain (SRVC) and the contribution of sheep and goats to human food security and to the general livelihoods in Semi-Arid Lands (SALs) of Kenya was conducted between May and July in 2008. Several districts were selected and sampled based on their importance in the small ruminant value chain either in production, marketing, processing or consumption. A check list was used to guide interview with major sheep and goat players in the chain in selected districts namely, Baringo, Narok, Kajiado, Garissa, Kitui, Kibwezi, Taita, Taveta, Kilindini, Kinango, Nairobi, Thika and Mombasa. The main players in the SRVC in the districts sampled were represented by input suppliers, supportive institutions, producers, traders, butchers and consumers. The input suppliers and processors were represented by agro veterinary shops and slaughterhouse/slaughter slabs respectively. Nairobi and Mombasa had the highest number of processors. The middlemen, mainly brokers, operated at all levels of the value chain. The districts of Baringo and Garissa had the highest populations of goats, over 571,000 and 563,000 heads respectively. The districts with the largest flocks of sheep were Kajiado and Narok with over 498,000 and 372,000 respectively. The population of sheep as compared to that of goats among the agropastoral communities of Kitui and Mutomo districts was almost negligible at slightly above 13,000 and 1,000 respectively. Narok with over 2,000 and Baringo with over 1,000 heads of sheep and goats offered for sale in respective market days were the busiest small ruminant markets in as far as sales volumes were concerned. The highest mean market price for a head of sheep or goat was observed in the terminal market of Nairobi. The constraints experienced by the players in the SRVC were reported to be health, poor or disorganization in markets and marketing, poor genetics and lack of extension services. The study observed that over the years, more sheep than goats were preferred by consumers and the volumes of either of the two offered for sale on monthly basis was significantly (P<0.5) higher than that of cattle. However, the SRVC actors were fewer in the rural areas than in the urban centers. Shoat products at the rural household levels were not recorded and more shoat products flowed through the informal markets than the formal markets. The up grading strategy of SRVC in Kenyan ASAL, among other interventions, ought to put into consideration the issues of marketing and infrastructural development.


Lopez-Martinez E.,National Autonomous University of Mexico | Vazquez-Gomez O.,National Council for Science and Technology | Vazquez-Gomez O.,Morelia Institute of Technology | Vergara-Hernandez H.J.,Morelia Institute of Technology | Campillo B.,National Autonomous University of Mexico
International Journal of Minerals, Metallurgy and Materials | Year: 2015

Austenite formation kinetics in two high-strength experimental microalloyed steels with different initial microstructures comprising bainite–martensite and ferrite–martensite/austenite microconstituents was studied during continuous heating by dilatometric analysis. Austenite formation occurred in two steps: (1) carbide dissolution and precipitation and (2) transformation of residual ferrite to austenite. Dilatometric analysis was used to determine the critical temperatures of austenite formation and continuous heating transformation diagrams for heating rates ranging from 0.03°C•s−1 to 0.67°C•s−1. The austenite volume fraction was fitted using the Johnson–Mehl–Avrami–Kolmogorov equation to determine the kinetic parameters k and n as functions of the heating rate. Both n and k parameters increased with increasing heating rate, which suggests an increase in the nucleation and growth rates of austenite. The activation energy of austenite formation was determined by the Kissinger method. Two activation energies were associated with each of the two austenite formation steps. In the first step, the austenite growth rate was controlled by carbon diffusion from carbide dissolution and precipitation; in the second step, it was controlled by the dissolution of residual ferrite to austenite. © 2015, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.


Ondiek J.O.,Egerton University | Abdulrazak S.A.,National Council for Science and Technology | Njoka E.N.,P.A. College
Livestock Research for Rural Development | Year: 2010

Proximate and mineral composition, in-sacco degradation and in-vitro gas production was conducted using fifteen indigenous Kenyan multipurpose tree and shrub (MPTS) leaf browse to assess their potential as goat feed. The species selected from a field survey were Maerua angolensis, Acacia brevispica, Acacia mellifera, Acacia tortilis, Acacia hockii, Zizyphus mucronata, Grewia bicolor, Acacia elatior, Acacia nilotica, Balanites aegyptiaca, Acacia senegal, Acacia abyssinica, Bridelia micrantha, Albizia amara and Albizia coriaria, The CP levels ranged from 112gkg-1DM for Bridelia micrantha to 321 gkg-1DM for Maerua angolensis; the NDF ranged from 218 to 601 gkg-1DM for Acacia hockii and Albizia amara, respectively. The TEPH and TET were in the range of 1.52-26.4 and 0.301-24.4gkg-1DM, respectively. The major minerals Ca, P, Mg, Na and S were in the ranges of 6.51-28.1, 0.838-3.18, 0.442-8.51, 0.318-0.711 and 1.12-2.45gkg-1DM, respectively. The microelements varied widely (mgkg-1DM) as follows: Fe (51.3-267), Mn (13.8-38.5), Cu (4.81-74.9), Mo (13.9-43.4), Co (1.76-17.4), Zn (12.2-93.2) and Se (19.5-124). In-sacco DM degradation at 48hrs shows Zizyphus mucronata was highest followed by Maerua angolensis with degradability of 93.3% and 88.6%, respectively. Gas production (volume (ml)/200mgDM) levels (a+b) ranged from 19.2 to 52.2 in Bridelia micrantha and Maerua angolensis, respectively. The overall levels of nutrients and degradation showed variations but most of the forages were moderate to high in the nutrient composition and degradability parameters. The ranking of the forages in order of increasing nutritive value into three categories of five species was as follows: low (Bridelia micrantha< Albizia amara< Acacia hockii < Acacia nilotica< Acacia tortilis); medium (Acacia abyssinica< Grewia bicolor< Albizia coriaria< Acacia elatior) and high (Balanites aegyptiaca< Acacia mellifera< Acacia senegal< Zizyphus mucronata< Maerua angolensis), It is concluded that Maerua angolensis and Zizyphus mucronata are outstanding and they have potential for ruminant feed and more so as protein supplements to low quality tropical basal diets.


Osuga I.M.,Kenyatta University | Abdulrazak S.A.,National Council for Science and Technology | Muleke C.I.,Egerton University | Fujihara T.,Mie University
Journal of Animal Physiology and Animal Nutrition | Year: 2012

Twenty growing Small East African goats were used to determine the effects of feeding sun-dried leaves of the browse forages Berchemia discolor and Zizyphus mucronata as supplements to low-quality basal diet, Rhodes grass (Chloris gayana) hay, on voluntary feed intake (VFI), digestibility and growth performance. The grass hay and maize bran were used as a control. The dried leaves were then included at the rates of 15% and 30% of the dry matter intake (DMI). Berchemia discolor had the highest crude protein (CP) content of 195.5g/kg DM, while Z. mucronata had CP content of 169.5g/kg DM. The grass hay had the lowest CP content of 50.9g/kg DM. The browse forages had low fibre content [Neutral detergent fibre (NDF); 257.9-369.5g/kg DM], while the grass hay had high fibre content (NDF; 713.1g/kg DM). Goats in the groups supplemented with either of the browse forages had higher total DMI, nitrogen (N) intake and retention and live-weight gains than those in the control diet group. The digestibility of DM and organic matter (OM) was not affected by supplementation, but the CP digestibility increased with supplementation. The use of the browse forages as supplements for goats fed on poor-quality basal diets would enhance the performance of the animals. © 2011 Blackwell Verlag GmbH.

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