Showing papers in "Tropical Grasslands - Forrajes Tropicales in 2014"

Biological nitrification inhibition (BNI) in Brachiaria pastures: A novel strategy to improve eco-efficiency of crop-livestock systems and to mitigate climate change

Abstract: Up to 70% of the nitrogen (N) fertilizers applied to agricultural systems is lost due to nitrification and denitrification. Nitrification is a microbiological process that generates nitrate (NO3 ) and promotes the loss of N fertilizers by leaching and denitrification. Nitrification and denitrification are the only known biological processes that generate nitrous oxide (N2O), a powerful greenhouse gas contributing to global warming. There is an urgent need to suppress nitrification processes in soil to improve N recovery and N use efficiency (NUE) of agricultural systems and to mitigate climate change (Subbarao et al. 2012). Certain Brachiaria grasses (B. humidicola) can suppress soil nitrification by releasing biological nitrification inhibitors (BNIs) from roots, thereby reducing N2O emissions. This phenomenon, termed biological nitrification inhibition (BNI), has been the subject of recent research to characterize and validate the concept under field conditions (Subbarao et al. 2009). Advances on 3 aspects of BNI research are reported here: (1) gene quantification of soil nitrifying microorganisms to determine BNI activity in B. humidicola; (2) screening of B. humidicola breeding materials to identify hybrids with contrasting levels of BNI; and (3) quantification of the BNI residual effect from B. humidicola on N recovery and agronomic NUE of a subsequent maize crop.

Climate-smart Brachiaria grasses for improving livestock production in East Africa

Abstract: beef production, and as a result improve livelihoods and Climate change is a global phenomenon with severe negative impacts on poor people in developing countries (Morton 2007). Across many parts of Africa, rural poor communities rely for their survival on agriculture and livestock, which are amongst the most climate-sensitive economic sectors. Climate-smart agriculture helps farm-ers to increase food production, become more resilient to climate change and reduce greenhouse gas (GHG) emis-sions. The main anthropogenic GHGs are carbon dioxide (CO

Harvest frequency affects herbage accumulation and nutritive value of brachiaria grass hybrids in Florida

Abstract: Brachiaria ‘Mulato II’ is a hybrid brachiaria grass with superior nutritive value when compared with other warm-season grasses. The performance of 2 new brachiaria grass hybrids was compared with that of Mulato II in terms of herbage accumulation, nutritive value and ground cover in a series of experiments. In Experiment 1, Mulato II and lines BR02/1752 (now cv. Cayman) and BR02/1794 were harvested at 3- and 6-wk regrowth intervals in South Florida. Mulato II had greater herbage accumulation and ground cover than Cayman and BR02/1794, while Mulato II and Cayman had greater in vitro digestible organic matter (IVDOM) concentration than BR02/1794. Regrowth interval did not affect herbage accumulation and ground cover but herbage harvested at 3-wk intervals had greater nutritive value than 6-wk regrowth. In Experiment 2, Mulato II had similar IVDOM and CP concentrations to but greater herbage accumulation, ground cover and plant density than Cayman in North-Central Florida. In Experiment 3, Mulato II and Cayman plots were grazed at 2-, 4- or 6-wk intervals, and herbage accumulation and nutritive value were similar for both cultivars. Herbage nutritive value decreased and ground cover increased linearly as regrowth interval increased from 2 to 6 wk, and Mulato II had greater ground cover than Cayman. The new hybrids displayed no production or nutritive value advantages over Mulato II; regrowth intervals of less than 3 wk should be avoided to maintain Brachiaria hybrid stands in this subtropical environment.

Dry matter yield of promising Panicum maximum genotypes in response to phosphorus and lime on Brazilian savanna

Abstract: The trial was conducted at Planaltina, Federal District, Brazil (15°35' S, 47°42' W; 1,007 m asl) from January 2012 to March 2013. Local annual rainfall averages 1,230 mm, concentrated between October and March. The soil of the area is classified as Oxisol with pH 4.2; P (Mehlich-I) 0.33 mg/dm

Developing methods to evaluate phenotypic variability in biological nitrification inhibition (BNI) capacity of Brachiaria grasses

Abstract: O emissions. The current methodologies for quantifying the BNI trait need enhancement to accelerate the process of identify-ing differences between genotypes. In this paper, we aim to develop new (or improve the existing) phenotyping methods for this trait. Preliminary results were obtained using 3 different methods to quan-tify BNI: (1) a mass spectrometry method to quantify brachialactone; (2) a static chamber method to quantify N

Root development and soil carbon stocks of tropical pastures managed under different grazing intensities

Abstract: Grasslands may act as a carbon (C) sink or C source depending on how they are managed. Soil C stocks, root biomass, root length, root length density and soil organic C concentrations were assessed on pastures of elephant grass ( Pennisetum purpureum ) managed under different post-grazing stubble heights and signal grass ( Brachiaria decumbens ) managed under different stocking rates. Soil samples were collected in 20-cm layers down to 1-m soil depth. Neither stubble height nor stocking rate had any significant effects on root parameters. Both the root system and C stocks declined in both pastures with increasing soil depth. Root biomass in the 0–20 cm layer contained 2.84 and 2.04 t C/ha, declining to 0.39 and 0.64 t C/ha at 80–100 cm for elephant grass and signal grass, respectively. Signal grass had greater root development deeper in the soil than elephant grass pastures, possibly due to its greater tolerance of Al toxicity and acidity. Total soil C stocks were greater for signal grass than for elephant grass (358 vs. 214 t C/ha, respectively). Keywords: Carbon sequestration, nutrient cycling, soil nutrients, stocking rate, tropical grass. DOI: 10.17138/TGFT(2)254-261

Climate-smart crop-livestock systems for smallholders in the tropics: Integration of new forage hybrids to intensify agriculture and to mitigate climate change through regulation of nitrification in soil

Abstract: IDUPULAPATI RAO 1 , MANABU ISHITANI 1 , JOHN MILES 1 , MICHAEL PETERS 1 , JOE TOHME 1 , JACOBO ARANGO 1 , DANILO E. MORETA 1 , HERNAN LOPEZ 1 , ARACELY CASTRO 1 , REIN VAN DER HOEK 1 , SIRIWAN MARTENS 1 , GLENN HYMAN 1 , JEIMAR TAPASCO 1 , JORGE DUITAMA 1 , HAROLD SUAREZ 1 , GONZALO BORRERO 1 , JONATHAN NUNEZ 1 , KATHARINA HARTMANN 1 , MORALBA DOMINGUEZ 1 , MAURICIO SOTELO 1 , DANIEL VERGARA 1 , PATRICK LAVELLE 1 , GUNTUR V. SUBBARAO 2 , ALVARO RINCON 3 , CAMILO PLAZAS 4 , REYNALDO MENDOZA 5 , LENA RATHJEN 6 , HANNES KARWAT 6 AND GEORG CADISCH 6

Agronomic, morphogenic and structural characteristics of tropical forage grasses in northeast Brazil

Abstract: The objective of this study was to assess the agronomic, morphogenic and structural characteristics of tropical forage grasses during the establishment phase and throughout the second year in northeast Brazil. The treatments included 9 grasses: Brachiaria humidicola (koronivia grass), Brachiaria hybrid cv. Mulato, Brachiaria brizantha cvv. Piata, Xaraes and Marandu, Brachiaria ruziziensis (ruzi grass), Brachiaria decumbens (signal grass), Panicum hybrid cv. Massai and Andropogon gayanus (gamba grass). The grasses were planted in a randomized complete block design with 4 replications. The following parameters were measured: total forage production, leaf:stem ratio, tiller population density, number of dead tillers, leaf emergence rate, phyllochron, leaf elongation rate, stem elongation rate, rate of leaf senescence, final length of leaf blade and life-span of leaves. In the establishment year, cv. Mulato produced the highest forage yields, followed by cvv. Xaraes and Massai, with gamba grass and koronivia grass worst. In the second year, cvv. Mulato, Xaraes and Marandu, and gamba grass showed highest forage production, while cvv. Massai and Piata produced the least. All grasses showed a marked drop in production during the dry season. Cultivar Massai consistently had the highest leaf:stem ratio. The morphogenic and structural characteristics differed according to cultivar and season of the year. In general, leaf emergence rate, leaf elongation rate, stem elongation rate, rate of leaf senescence, final length of the leaf blade, number of live leaves per tiller and density of living tillers were higher in the rainy season, while the phyllochron and life-span of leaves were higher in the dry season. The results of this research highlight the potential of the Brachiaria cultivars Mulato and Xaraes, gamba grass and Panicum cv. Massai in subhumid Maranhao, northeast Brazil.

Growth of Bali bulls fattened with Leucaena leucocephala in Sumbawa, Eastern Indonesia

Abstract: The contribution of West Nusa Tenggara Province to domestic beef supply in Indonesia is relatively small; however, beef cattle are very important for the livelihoods of smallholder farmers in the region. Bali cattle (Bos javanicus) are the predominant breed, as they are adapted to harsh nutritional conditions, are highly fertile and have low calf mortality (Toelihere 2003). While these cattle are genetically capable of achieving a growth rate of 0.85 kg/d (Mastika 2003), this is rarely achieved as poor nutrition is a severe limitation to animal growth in traditional village systems (Panjaitan 2012). Improving feed quality and supply is vital to increasing growth rates and product quality. Forage tree legumes such as leucaena (Leucaena leucocephala) offer the best chance of providing high quality feed to fatten Bali bulls in village systems, where leucaena is well-adapted. Leucaena has been fed for about 2 decades in Sumbawa district of West Nusa Tenggara, although the practice is limited to specific villages, mostly Balinese, even though farmers nearby have similar biophysical conditions and livestock nutrition problems. The objective of this work was to document the practices employed by farmers in Sumbawa to maximize growth rates by feeding leucaena, so that their detailed knowledge can be passed onto other villagers in a pilot roll-out program (Kana Hau 2014).

Morphological acclimation and canopy structure characteristics of Arachis pintoi under reduced light and in full sun

Abstract: Canopy structure is a key variable in determining the adap-tive potential of forages and influences the radiation use efficiency (RUE) under different light conditions. The light extinction coefficient calculated from the Beer-Lambert formula (k) shows the canopy architecture and light inter-ception patterns of plants and thus their potential ability to convert light energy (photosynthetically active radiation, PAR) into plant biomass (Hirose 2005). Under shade, for-ages may experience changes in plant morphology and canopy structure. Many authors have reported those changes and related them to modifications in light quantity and quality (Varella et al. 2011). The magnitude of these morphological changes may be a determinant in screening forages for shaded environments such as in silvopastoral systems. The objective of this study was to determine the light interception patterns and extinction coefficients of

Production of Aruana guinea grass subjected to different cutting severities and nitrogen fertilization

Abstract: Aruana guinea grass (Panicum maximum cv. Aruana) is widely used as pasture for sheep, which are extremely susceptible to infestation by larvae of gastrointestinal parasites in tropical pasture-based systems (Zanini et al. 2012). One way to mitigate this problem, and consequently reduce the need for use of anthelmintics, is to manage pastures with post-grazing height low enough to ensure sunlight reaches the base of tussocks. This will aid in killing larvae and controlling their development, without jeopardizing canopy regrowth and persistence. The pre-grazing sward height recommended for Aruana guinea grass is 30 cm, when the canopy intercepts 95% of the incident light, with post-grazing height at 15 cm (Zanini et al. 2012). As cutting severity and nitrogen (N) fertilization cause morphological and physiological adaptations in individual plants − altering the production of forage grasses − the objective of this study was to evaluate the accumulation of morphological components of Aruana guinea grass subjected to different cutting severities and N fertilization.

Impacts of projected climate change on pasture growth and safe carrying capacities for 3 extensive grazing land regions in northern Australia

Abstract: The northern beef industry is a major component of the regional economies of Queensland, Northern Territory and northern Western Australia, and has contributed an estimated $5 billion to Australia’s economy in 2009-10. Projected climate change will have an adverse impact on Australia’s agricultural production (McKeon et al. 2008), with an expected 3.5% decline in beef production in northern Australia by 2030 (Heyhoe et al. 2008). The GRASP pasture production model (McKeon et al. 2000) has been used to evaluate impacts of climate change in Australia’s rangelands (Crimp et al. 2002; McKeon et al. 2008), with the positive effects of higher carbon dioxide (CO2) on pasture growth likely to be offset by reductions in pasture productivity and digestibility due to lower rainfall and higher temperatures (Crimp et al. 2002). The impacts of 3 projected future climates on livestock carrying capacity of grazing lands in the Fitzroy, Maranoa-Balonne and Victoria River District regions were assessed using GRASP.

Developing a savanna burning emissions abatement methodology for tussock grasslands in high rainfall regions of northern Australia

Abstract: Fire-prone tropical savanna and grassland systems are a significant source of atmospheric emissions of greenhouse gases. In recent years, substantial research has been directed towards developing accounting methodologies for savanna burning emissions to be applied in Australia’s National Greenhouse Gas Inventory, as well as for commercial carbon trading purposes. That work has focused on woody savanna systems. Here, we extend the methodological approach to include tussock grasslands and associated Melaleuca-dominated open woodlands ( 1,000 mm/annum) regions of northern Australia. Field assessments under dry season conditions focused on deriving fuel accumulation, fire patchiness and combustion relationships for key fuel types: fine fuels − grass and litter; coarse woody fuels − twigs 6 mm diameter; and shrubs. In contrast with previous savanna burning assessments, fire treatments undertaken under early dry season burning conditions resulted in negligible patchiness and very substantial consumption of fine fuels. In effect, burning in the early dry season provides no benefits in greenhouse gas emissions and emissions reductions in tussock grasslands can be achieved only through reducing the extent of burning. The practical implications of reduced burning in higher rainfall northern Australian grassland systems are discussed, indicating that there are significant constraints, including infrastructural, cultural and woody thickening issues. Similar opportunities and constraints are observed in other international contexts, but especially project implementation challenges associated with legislative, political and governance issues.

Pasture characteristics and animal performance in a silvopastoral system with Brachiaria decumbens , Gliricidia sepium and Mimosa caesalpiniifolia

Abstract: Grasslands are the major source of feed for ruminants (Zanine 2005). Seasonality of production, however, is a constraint in forage-based systems. Silvopastoral systems combine different components (animals, trees and forages) into an integrated system and may improve forage distribution across seasons. Resource use is usually more efficient both spatially and temporally, increasing land use efficiency (Nair 1993). Tree legumes present potential for silvopastoral systems because they can fix N from the atmosphere, improve cattle diets and lead to a faster N cycle. In addition, trees provide shade and may reduce heat stress for grazing animals in tropical and subtropical grasslands. Leguminous trees are commonly found in these climates and present potential for use in silvopastoral systems. This research studied the pasture characteristics and animal performance of signal grass (Brachiaria decumbens) in a pure stand or in silvopastoral systems with Gliricidia sepium or Mimosa caesalpiniifolia.

Characterizing feeds and feed availability in Sud-Kivu province, DR Congo

Abstract: Animal husbandry in the Sud-Kivu province of the Democratic Republic of the Congo is gradually moving towards stall feeding, due to demographic pressure (Battistin et al. 2009) and scarcity of collectable forages (DSRP-RDC 2005). Therefore, lack of available feed is considered one of the main constraints faced by livestock production, especially in the dry season (Katunga et al. 2011; Maass et al. 2012). Unaffordable, fluctuating prices and scarcity of feed concentrates and the lack of improved forages adapted to marginal conditions, making them non-competitive with food crops, further exacerbate the livestock feeding situation. This study aimed to assess specific constraints and opportunities in the current feeding systems, as well as feed availability in this area.

The effect of Leucaena leucocephala on beef production and its toxicity in the Chaco Region of Argentina

Abstract: Hedgerows of the fodder tree legume, Leucaena leucocephala ssp. glabrata (leucaena), planted with a companion grass, provide productive, profitable and sustainable tropical pasture (Shelton and Dalzell 2007). Although leucaena can improve beef production, poor grower adoption has limited development of leucaena in the Chaco Region of Argentina. Factors contributing to poor adoption include: (1) unsuccessful establishment; (2) limited understanding of leucaena management as a forage resource; and (3) concerns about mimosine toxicity. While these 3 limitations have been overcome in other regions of the world (e.g. northern Australia and the Chaco Region of Paraguay), in Argentina little is known about leucaena management and the protection of ruminants against mimosine toxicosis. The objective of this study was to evaluate the effects of leucaena on beef production and its toxicity in the west of the Argentine Chaco Region. We hypothesized that the introduction of leucaena into grass pastures would significantly increase beef productivity, if mimosine toxicosis did not appear.

Canopy height and its relationship with leaf area index and light interception in tropical grasses

Abstract: Photosynthetically active tissues, mainly green leaves, are the major component of forage growth and development. The amount of these tissues in a forage plant is influenced directly by cutting management, i.e. cutting frequency and stubble height. The normal recommendation is to cut (or graze) forage whenever it reaches a given stubble height. Brougham (1956) stated that the critical leaf area index (LAI) is reached when the forage canopy is intercepting 95% of the photosynthetically active radiation, and the forage is near its maximum growth rate without shading itself. Alternatively, the optimum LAI occurs when the forage reaches the maximum point of mass accumulation, indicating the time to start grazing or cutting. Generally, the critical and optimum LAI values are quite similar, but not necessarily the same (Brown and Blaser 1968). This trial evaluated the relationships among canopy height, LAI and light interception in 10 tropical grasses.

Tithonia diversifolia for Ruminant Nutrition

Abstract: According to FAO (2006), Brazil is the highest emitter of methane from cattle, followed by India and the USA (9.6, 8.6 and 5.1 Mt CH4/yr, respectively). In livestock, CH4, formed from enteric fermentation of carbohydrates, is primarily responsible for the emissions by the agricultural sector. Regarding livestock methane emission, Delgado et al. (2012) evaluated 20 tree and shrub species using in vitro techniques and demonstrated lower methane production from Tithonia diversifolia, a member of the Asteraceae family, than from grasses, for example, Cynodon nlemfuensis. T. diversifolia can be very useful, not only in animal nutrition, e.g. in silvopastoral arrangements (Plate 1), by increasing the protein content of animal diets at low cost (Murgueitio et al. 2010), but also in the recovery of degraded soils, for it grows in areas with low levels of fertility. Furthermore, it has a high phosphorus uptake ability, even if P is unavailable to other forage species (Kwabiah et al. 2003). The objective of this study was to assess the nutritional quality, including quantification of enteric methane generated during in vitro ruminal fermentation, of T. diversifolia as a forage for ruminant nutrition in the tropics.

Breeding strategies for Brachiaria spp. to improve productivity – an ongoing project

Abstract: Two strategies have been used in the breeding of Brachiaria (syn. Urochloa) to produce new cultivars. The first involves exploring the natural variability existing in nature, which is the selection of ecotypes, mostly apomicts, from the diversity in germplasm banks. This strategy proved efficient originally and the cultivars in use in Brazil were derived in this way, but progress with this strategy is limited in the medium to long term. The generation of novel variability through crossings is the alternative strategy to continue producing new improved varieties. This has been possible only through artificial chromosomal duplication of diploid and sexual B. ruziziensis and the fact that this species is crosscompatible with B. brizantha and B. decumbens, in Brazil the 2 most important species for tropical pastures. Crossings between species have been carried out at Embrapa Beef Cattle, Campo Grande, MS, Brazil, since 1988 (Valle et al. 1993, 2001; Valle 1997; Resende et al. 2007). The initial success in obtaining interspecific hybrids in Brachiaria is indisputable and helped establish a practical methodology as well as allowed for the identification of apomictic parents with good combining ability. However, a comprehensive genetic improvement strategy to benefit from gains in quantitative characteristics associated with the majority of agronomic traits of economic interest in these species had not been started. Therefore, 3 methodologies are being used for this purpose: reciprocal recurrent selection; intra-population recurrent selection; and directed crosses between sexual

Herbage Intake, Methane Emissions and Animal Performance of Steers Grazing Dwarf Elephant Grass with or without Access to Arachis pintoi Pastures

Abstract: The inclusion of legumes in diets based on grass has nutritional benefits due to ingestive and digestive interactions (Niderkorn and Baumont 2009). Moreover, it is speculated that tropical legumes can contribute to reducing the emission of greenhouse gases (GHG) compared with diets exclusively composed of grasses (Archimede et al. 2011). However, under grazing conditions, these advantages are not always possible to obtain. This occurs when the spatial distribution of sward grasses limits access to legumes by grazing animals (Solomon et al. 2011). This can be the case, for example, when legumes are overlapped by the leaves of a tufted tall grass like dwarf elephant grass (Crestani et al. 2013). Considering that management strategies for increasing legume percentage in the diet of grazing animals should be investigated and data on enteric methane emitted by ruminants eating tropical forages are scarce, the aim of this work was to evaluate the effects on herbage intake, animal performance and enteric methane emissions of providing access to an exclusive area of forage peanut (Arachis pintoi cv. Amarillo) for cattle grazing dwarf elephant grass (Pennisetum purpureum cv. BRS Kurumi).

Morning and Afternoon Sampling and Herbage Chemical Composition of Rotationally Stocked Elephant Grass cv. Napier

Abstract: Nutrient intake by grazing animals depends on the amount of dry matter consumed and its chemical composition. Forage grasses produce assimilates during the day via photosynthesis to sustain live tissues, plant growth and organic reserves (Taiz and Zeiger 2013). In that context, herbage chemical composition may vary according to variations in the photosynthesis-respiration balance throughout the day. From dawn to dusk photosynthesis predominates and herbage dry matter content and concentration of soluble carbohydrates increase; the reverse happens from dusk to dawn. That could influence nutritive value and nutrient intake of grazing animals (Delagarde et al. 2000), since for a given bite volume the amount of herbage and its composition could vary depending on the time of the day. This phenomenon could have implications for rotationally managed pastures, with time of changing animals from one paddock to the other assuming greater importance. Against that background, the objective of this experiment was to evaluate dry matter (DM) content and the concentrations of soluble carbohydrates (SC), crude protein (CP), neutral (NDF) and acid (ADF) detergent fiber in herbage samples harvested during the morning and afternoon periods from rotationally stocked elephant grass (Pennisetum purpureum) cv. Napier.

Challenges to Domesticating "Native" Forage Legumes

Abstract: 1 Texas A&M AgriLife Research and Extension Center, Stephenville, TX, USA. stephenville.tamu.edu 2 Universidade Federal Rural de Pernambuco, Recife, PE, Brazil. www.ufrpe.br 3 Instituto de Investigacao Agraria de Mocambique, Maputo, Mozambique. www.iiam.gov.mz 4 Louisiana State University Agricultural Center, Homer, LA, USA. www.lsuagcenter.com 5 The Samuel Roberts Noble Foundation, Ardmore, OK, USA. www.noble.org

Botanical and agronomic growth of two Panicum maximum cultivars, Mombasa and Tanzania, at varying sowing rates

Abstract: A field trial in northeast Thailand during 2011–2013 compared the establishment and growth of 2 Panicum maximum cultivars, Mombasa and Tanzania, sown at seeding rates of 2, 4, 6, 8, 10 and 12 kg/ha. In the first 3 months of establishment, higher sowing rates produced significantly more DM than sowing at 2 kg/ha, but thereafter there were no significant differences in total DM production between sowing rates of 2–12 kg/ha. Lower sowing rates produced fewer tillers/m 2 than higher sowing rates but these fewer tillers were significantly heavier than the more numerous smaller tillers produced by higher sowing rates. Mombasa produced 23% more DM than Tanzania in successive wet seasons (7,060 vs. 5,712 kg DM/ha from 16 June to 1 November 2011; and 16,433 vs. 13,350 kg DM/ha from 25 April to 24 October 2012). Both cultivars produced similar DM yields in the dry seasons (November–April), averaging 2,000 kg DM/ha in the first dry season and 1,750 kg DM/ha in the second dry season. Mombasa produced taller tillers (104 vs. 82 cm), longer leaves (60 vs. 47 cm), wider leaves (2 vs. 1.8 cm) and heavier tillers (1 vs. 0.7 g) than Tanzania but fewer tillers/m 2 (260 vs. 304). If farmers improve soil preparation and place more emphasis on sowing techniques, there is potential to dramatically reduce seed costs. Keywords: Guinea grass, tillering, forage production, seeding rates, Thailand. DOI: 10.17138/TGFT(2)246-253

Village-based tropical pasture seed production in Thailand and Laos – a success story

Abstract: Seed of 6 forage species, Mulato II hybrid brachiaria ( Brachiaria ruziziensis x B decumbens x B brizantha ), Cayman hybrid brachiaria ( B ruziziensis x B decumbens x B brizantha ), Mombasa guinea ( Panicum maximum ), Tanzania guinea ( P maximum ), Ubon stylo ( Stylosanthes guianensis var vulgaris x var pauciflora ) and Ubon paspalum ( Paspalum atratum ), is currently being produced by more than 1,000 smallholder farmers in villages in northeast Thailand and northern Laos, under contract to Ubon Forage Seeds, Faculty of Agriculture, Ubon Ratchathani University, Thailand The seed is mainly exported (95%), with the remainder sold within Thailand Tropical Seeds LLC, a subsidiary of a Mexican seed company, Grupo Papalotla, employs Ubon Forage Seeds to manage seed production, seed sales and export, and to conduct research on new forage species This paper details how the development of a smallholder-farmer seed-production program in Thailand and Laos produced positive social and economic outcomes for the village seed-growers In addition, the strong emphasis on seed quality, high purity, high vigor and high germination enabled pasture growers in more than 20 tropical countries in Asia, Africa, the Pacific and Central and South America, to establish more than 20,000 ha of pastures over the past 3 years

Alternatives for intensification of beef production under grazing

Abstract: Sustainable technological alternatives, which will maintain a constant uniform beef supply year round, are needed, if Brazil is to maintain its position, as one of the most important players in the world beef market. One approach is to more intensively use the alternatives available for pasture management and feed supplementation. However, the responses obtained could be enhanced by using animals with superior genetic makeup, to make better use of the resources provided. Thus, a grazing experiment was designed to evaluate combinations of pasture grasses (Brachiaria and Panicum), pasture management (feed supplementation and rotational grazing) and animal genetic groups.

Is There Genetic Diversity in the ‘Leucaena Bug’ Synergistes jonesii Which May Reflect Ability to Degrade Leucaena Toxins?

Abstract: Leucaena leucocephala, a nutritionally rich forage tree legume, contains a non-protein amino acid, mimosine, which is degraded by ruminal bacteria to toxic metabolites 3,4-DHP and 2,3-DHP, resulting in goitre-like symptoms in animals, severely restricting weight gain. Raymond Jones, in the early 1980s, discovered the ‘leucaena bug’ in the rumen of goats in Hawaii that degraded these toxic DHP metabolites into non-toxic compounds (Jones and Lowry 1984), which was named Synergistes jonesii (Allison et al. 1992). Subsequently, a rumen inoculum containing S. jonesii was used as an ‘oral drench’ for cattle, kept in continuous culture (Klieve et al. 2002) and supplied to farmers to dose cattle foraging on leucaena. Studies on Queensland herds that received this oral drench showed that up to 50% of 44 herds grazing on leucaena had apparent subclinical toxicity based on high 3,4-DHP and 2,3-DHP excretion in urine (Dalzell et al. 2012). In another study by Graham et al. (2013), a 16S rDNA nested PCR showed that rumen digesta from 6 of 8 farms tested had a variant DNA profile from S. jonesii ATCC 78.1 strain, which suggested a different strain of the bacterium. It was postulated that the continually cultured oral inoculum may have undergone genetic modification and/or animals could harbor other DHP-degrading bacteria or S. jonesii strains with differential DHP-degrading potential (C. McSweeney et al. unpublished). The present study looks at changes in the 16S rDNA gene at the molecular level, that may suggest divergence from the type strain S. jonesii ATCC 78.1 in Queensland cattle as well as in cattle

Soil Organic Carbon Stocks in a Brazilian Oxisol under Different Pasture Systems

Abstract: 2009). How-ever, productive well-managed pastures can improve degraded soils and increase soil organic carbon (SOC) stocks through humification of grass and root residues. In order to enhance pasture yields and SOC sequestra-tion, nutrient availability in soils must also be improved, especially for N and P. This work aimed to assess how SOC stocks are affected by the combination of grasses and legumes, in comparison with pure grass pastures and other land uses in a clayey Oxisol in southeast Brazil.

Prevalence of DHP toxicity and detection of Synergistes jonesii in ruminants consuming Leucaena leucocephala in eastern Indonesia

Abstract: 1 The University of Queensland, St Lucia, Qld, Australia. www.uq.edu.au/agriculture/ 2 Assessment Institute for Agricultural Technology – West Nusa Tenggara, Narmada, Lombok, NTB, Indonesia. 3 Assessment Institute for Agricultural Technology – East Nusa Tenggara, Naibonat, Kupang, NTT, Indonesia. 4 Universitas Mataram, Mataram, Lombok, NTB, Indonesia. www.unram.ac.id/en/ 5 CSIRO Animal, Food & Health Sciences, Queensland Biosciences Precinct, St Lucia, Qld, Australia. www.csiro.au/Organisation-Structure/Divisions/Livestock-Industries

Herbage accumulation and animal performance on Xaraés palisade grass subjected to intensities of continuous stocking management

Abstract: 1 Colegio de Postgraduados, Mexico. www.colpos.mx 2 Empresa Brasileira de Pesquisa Agropecuaria, Embrapa Gado de Corte, Campo Grande, MS, Brazil. www.cnpgc.embrapa.br 3 Universidade de Sao Paulo, Escola Superior de Agricultura “Luiz de Queiroz” (ESALQ), Piracicaba, SP, Brazil. www.esalq.usp.br 4 Universidade Federal da Grande Dourados, Dourados, MS, Brazil. www.ufgd.edu.br 5 Universidade Federal de Vicosa, Vicosa, MG, Brazil. www.ufv.br

Litter decomposition of Xaraés grass pasture subjected to different post-grazing residuals

Abstract: Since fertilizers are used less extensively on Xaraes grass (Brachiaria brizantha cv. Xaraes) pastures in Brazil because of costs, the main route of nitrogen (N) supply to plants is through nutrient recycling via litter decomposition. One of the strategies used to maintain the supply of N to the pasture is to manipulate the grazing pressure so that the amount of recycled nutrients in the residue is sufficient to meet the pasture requirements (Jantalia et al. 2006). Thus, the aim of this study was to evaluate different residual leaf area indices (RLAIs), to determine which one provides the best restoration considering the decomposition and mineralization of organic matter.