Physical Sciences and Mathematics Commons^™

Resilience And Degradation In A Tropical Wetland Overgrazed By Cattle, Sandra A. Santos, Humberto L. Perotto-Baldivieso, Dylan Young

IGC Proceedings (1993-2023)

The Pantanal, one of the largest wetlands in the world, is highly valued for its diversity of flora and fauna, and the dynamic hydrological regime, combined with heterogeneous topography, has resulted in a mosaic of diverse habitats types in terms of species and physical structure. However, the Pantanal floodplains are also important for beef cattle production due to the abundance of forage resources. Cattle prefer grazing near water bodies because these areas have high quality forage as a result of flooding regimes (Santos et al. 2002). Many wetlands go through a wet/dry cycle that is essential to maintain their …

Estimating Pasture Land Cover In The New England Region Of Northern New South Wales, Graham E. Donald, Mark Trotter, Elizabeth L. Hulm

IGC Proceedings (1993-2023)

Land cover across the southern Australian temperate agricultural region comprises primarily of native pasture, introduced improved pastures and crops for livestock production and also perennial remnant vegetation. A feed-base pasture audit was carried out throughout southern Australia commencing mid-year 2011 (Donald and Burge 2012; Donald et al. 2012). The purpose of the audit was to map and analyse information obtained about the pasture feed-base for livestock production by surveying Statistical Local Areas (SLAs) across the southern states. The purpose of this Feed-Base audit was to survey pastures within agricultural NSW, Victoria, Tasmania, South Australia and South-Western Australia, collate these …

An Efficient Sampling Protocol For Sagebrush/Grassland Monitoring, Larry L. Larson, Mounir Louhaichi, Patrick E. Clark, Douglas E. Johnson

IGC Proceedings (1993-2023)

Rangeland scientists and quantitative ecologists have developed numerous methods and monitoring techniques that can be used for vegetation sampling (Barbour et al. 1987). The methods used to position samples (transects, quadrats, lines, and points) vary and can be classed as selective, capricious, systematic, or random. One of the prerequisites for valid statistical inference is that samples are taken randomly. A random sampling procedure implies that all elements or units of the population being studied have an equal chance of being represented in the sample. It also implies that selection of an element or unit does not influence the chance …

Landscape Change In Arid And Semi-Arid Rangeland Of Borana, Southern Ethiopia: Implication For Management, Teshome Abate, A. Angassa

IGC Proceedings (1993-2023)

The Borana rangelands in southern Ethiopia (between 4°3’N to 5°0’N and 37°4’E to 38°2’E) comprise important cultural landscapes with a unique feature of the tula-well landscapes. Until a few decades ago, the Borana rangelands were considered one of the most productive and resilient ecosystems in East Africa. In recent years, however, the Borana rangelands have undergone a large reduction in grassland cover probably as a result of anthropogenic and natural-induced factors (Coppock 1994), with consequences on the livelihood of the local communities. Therefore, the objective of the study was to investigate the dynamics of landscape change in the Borana …

Calibration Of The Rising Plate Meter For Pasture Yield Determination In Kikuyu (Pennisetum Clandestinum) Over-Sown With Ryegrass (Lolium Spp.), Janke Van Der Colf, Philip R. Botha, Robin Meeske, Wayne F. Truter

IGC Proceedings (1993-2023)

Accurate feed budgeting and management of forage in grazing systems requires frequent assessment of forage mass and growth of pastures (Gabriёls and Van den Berg 1993; Sanderson et al. 2001). The rising plate meter (RPM) developed by Earle and McGowan (1979) has been used widely by researchers and farmers to estimate pasture dry matter (DM) production. The advantages associated with using the RPM for the estimation of pasture DM yield include its low sensitivity to environmental conditions, stability of calibration equations across years and seasons (if pasture composition remains similar), and the fact that its robustness and ease of …

Spatial Gis Database For Adaptive Grassland Management In Dudhwa National Park, India, Neha Midha, Pradeep K. Mathur

IGC Proceedings (1993-2023)

Ecologically important tall grasslands of Dudhwa National Park (DNP) in Northern India are being threatened by various natural and biotic factors including varying grassland burning regimes viz. cut and burn, harrowed and burn, or only burn adopted by management for their maintenance (De 2001). Uncertainty regarding resultant grassland composition and disturbance to grassland obligate species prompted the management and scientific communities concerned to develop an adaptive management strategy for long term conservation goals (Chadden et al. 2004). In view of this, the present study attempted to develop comprehensive GIS (Geographic Information System) spatial database and associated hard copy …

Describing Ecological Potential And Ecological States Of Rangeland To Support Livestock Management In Mongolia, D. Bulgamaa, Brandon T. Bestelmeyer, U. Budbaatar, S. Sumjidmaa, T. S. Enkh-Amgalan, J. W. Van Zee, B. Bolormaa, L. Otgontuya

IGC Proceedings (1993-2023)

Perception of rangeland degradation in Mongolia and its causes are well known but herders and policy makers lack clear messages on how much rangeland is degraded, whether is it reversible, and what management changes should be implemented. This paper illustrates a portion of our ongoing efforts to develop ESDs that can be used at the grass roots level as management tools. At the Undurshireet soum study site, which is split mainly into Gravelly, Loamy, Sandy, and Deep sandy ecological sites, rangeland community shifts in Gravelly and Loamy ecological sites are interpreted as reversible shifts in species composition or species proportion …

Identifying Grazing-Driven Plant Indicators Of Rangeland Degradation In Semi Arid Zones Of Uzbekistan, Toshpulot F. Rajabov, Bakhtiyor K. Mardonov, Mahmud A. Muminov

IGC Proceedings (1993-2023)

The development of practical indicators of vegetation degradation is an important element in predicting and assessing rangeland health due to disturbances such as livestock grazing. Once established, phytoindicators provide a simple and visual operative way to diagnose active and possibly undesirable vegetation changes. This paper aimed to identify rapid, yet realistic and easily communicated plant indicators of rangeland degradation caused by intense grazing. The grazing gradient approach is applied to study plant traits affected by increased levels of grazing pressure. Qualitative and quantitative changes in key species of the plant community alongside successive changes of vegetation attributes along an apparent …

The Influence Of Geo-Morphological Landscape Patterns On Vegetation Characteristics In Tajikistan Grasslands, Mounir Louhaichi, Aziz Nubekov, Abdulla Madaminov, Barbara Rischkowsky

IGC Proceedings (1993-2023)

Grassland ecosystems are affected by a combination of physical and environmental factors, as well as by grazing and human induced activities. The primary objective of this study was to examine the influence of geo-morphological landscape patterns on vegetation characteristics in Tajikistan where two sites were selected. The vegetation sampling took place in spring and fall. Vegetation characteristics were assessed using the line intercept method for vegetation cover and species composition and quadrat sampling for biomass production. An ANOVA using replicated trials in complete block design was used to determine the relationship between aspect and vegetation characteristics. Treatments included location (site), …

Spatial Variability Of Soil Phosphorus In Grazing Systems, Mark Trotter, Warwick B. Badgery, Joshua Barron, Chris Guppy, Rebecca Haling, David Mitchell, Geoff Millar

IGC Proceedings (1993-2023)

Phosphorus (P) use efficiency has been identified as a key issue for Australian grazing systems. This project examined the spatial variability in soil P concentration from two separate surveys of grazed pasture fields. A field on the central tablelands of NSW had a range in Bray P of 1.2 to 140 mg/kg and a COV of 107%. The other field on the northern tablelands of NSW reported a range in Colwell P from 13.0 to 121.1 mg/kg and a COV of 59%. Maps of the spatial variability of soil P demonstrated that there is a relationship with field elevation. Application …

Monitoring Landscape Changes Using Remote Sensing Technology In Southern Africa, Anthony R. Palmer

IGC Proceedings (1993-2023)

Rangelands are a major global resource, and there is an urgency to improve the assessment of landscape performance to capture carbon, produce biomass, and improve water use. Effective monitoring necessitates the collection of high quality rangeland condition data using repeatable techniques. Despite much effort, there are few comprehensive data sets that allow confident detection of landscape change. Data are lacking for several reasons, including high cost of data collection, conflicting methodologies, and loss of archival data. Satellite imagery provides the basis for trend and pattern analysis of rangeland in different conditions classes and this paper presents some examples of the …

Alternative For Intensification Of Beef Production Under Grazing, Valéria P. B. Euclides, Kepler Euclides Filho, Denise B. Montagner, Geraldo Ramos Figueiredo, Flávia Da Conceição Lopes

IGC Proceedings (1993-2023)

One of the challenges to overcome in order to assure the position occupied by Brazil as one of the most important players in the world beef market is to design sustainable technological alternatives, which will maintain a constant uniform beef supply all year round. This crucial problem could be solved by using more intensively, the alternatives available for pastures management and feed supplement-ation. However, the potential results created by these strategies might be better explored by using the right choice of animals as far as genetic group and weaning weight is concerned. Thus, in order to fulfill this goal it …

Pasture Improvement Needs And Options For New Zealand Sheep And Beef Farms, Andy R. Bray, Tom J. Fraser, Warren Mcg. King, Alec D. Mackay, Derrick Moot, David R. Stevens

IGC Proceedings (1993-2023)

In recent years in New Zealand, sheep and beef farming has been outcompeted for prime land. This means that the government and industry targets to increase sheep and beef production have to be achieved on farms with significant constraints on pasture production. They are increasingly restricted to hilly and other locations with variable climates and soils, and landscape constraints on farming practices. Thus there are limits on the ability to improve pasture production – whether by pasture renewal or through means like grazing management, fertiliser use, or weed and pest control.

Improving Summer/Autumn Feed Quality In New Zealand Hill Country, Grant M. Rennie, Warren Mcg. King, Coby J. Hoogendoorn, Brian Devantier, Trevor L. Knight, Catherine Cameron

IGC Proceedings (1993-2023)

Pasture management in spring has a strong influence on pasture quality in summer and autumn in New Zealand hill country pastures. Manipulation of defoliation frequency and intensity during mid-late spring can impact summer and autumn pasture quality and quantity (Orr et al. 1988). Summer/autumn management is mainly concerned with maintaining herbage quality in summer wet areas and controlling animal pressure in summer dry areas for drought management and winter feed stocks (Clark 1994). Deferred grazing to transfer pasture growth from late spring into summer and autumn deficits is difficult due to detrimental effects on pasture quality, plant density and …

Effects Of Continuous Grazing And Exclusion On The Structure Of Modified Flooding Pampa Grassland In Argentina, Estrella M. Oyhamburu, María L. Agnelli, Roberto O. Refi, Mario C. Ursino

IGC Proceedings (1993-2023)

The breeding of beef cattle is the predominant activity in the Flooding Pampa wet grasslands. The stocking rate of this region is increasing because of livestock displaced by agriculture in other regions. This increased load has been achieved through the alteration of grassland with the use of herbicides and fertilizers or replacement thereof by pasture (Cahuepé and Hidalgo 2005). The large herbivores grazing cause changes in species composition and diversity (Hall et al. 1986) in both the original and the modified grassland. The aim of this study was to evaluate the effects of different stocking rates under continuous grazing …

Beef Heifers Performance Under Continuous Grazing On Modified Grassland In Argentina Flooding Pampa, María L. Agnelli, Roberto O. Refi, Estrella M. Oyhamburu, Mario C. Ursino

IGC Proceedings (1993-2023)

The Salado river basin is the main beef cattle breeding region of Argentina. It is a flat flooding area with poor slopes (< 3%). Their soils are Natracuoles, Natraqualfes and Argiacuoles. The grasslands are predominately continuously grazed and with a set stocking rate cow – calf system. Stocking rate and grazing pressure are two core variables that directly affect animal production. Reduced animal performance is believed to be due to poor grazing management. During 2010, 2011 and 2012 an experiment on the effect of stocking rate on animal growth and body condition with Angus heifers continuously grazing annual winter grasses, was carried out. Previous studies have demonstrated the practicability of producing replacement females with this management (Carrillo 2001; Eirin et al. 2011; Agnelli et al. 2011) that involves mesothermic grasslands modification into self sown winter grasses by using glyphosate and other herbicides (Oyhamburu et al. 2000, Rodriguez and Jacobo 2010).

The aim of this study was to establish the stocking rate that optimizes beef rearing heifer’s performance for early mating.

The Nutritional Status Of Japanese Black Breeding Cows Grazed In A Larger Abandoned Paddy Field, Motohiko Ishida, Naoki Matsumoto, Yojiro Maki, Jyunichi Tanimoto, Kohei Takahashi, Keigo Asano, Mizuho Ogino

IGC Proceedings (1993-2023)

Because rice consumption has decreased in Japan, the number of abandoned paddy fields has increased. Some of the abandoned paddy fields are being used for livestock grazing, effectively using the abandoned fields and reducing the production costs on livestock farms. Such grazing may use an integrated grazing system of scattered small pastures where each of the small abandoned paddy fields scattered in a given agriculture area is defined as one grazing yard, and a herd consisting of two or three head of cattle is moved from one grazing yard to another. However, because the number of abandoned paddy fields has …

Pasture Grass Conversion In Digestive Tract Of Red Deer Over Different Grazing Periods, Imants Jansons, Ira I. Vitina, Vera Krastina, Aleksandrs Jemeljanovs, Sallija Cerina, Biruta Lujane, Baiba Osmane, Liga Proskina

IGC Proceedings (1993-2023)

Deer farming is an alternative to traditional animal farming which also promotes a more economic use of pasture grass resources in Latvia. 61 holdings of farmed red deer and fallow deer have been registered in this country (Paeglits et al. 2006). Over the summer season, pasture grass is the main feed source for red deer (Cervus elaphus) (Miller 2004). No matter how much feed animals get, it is of no use unless it can be digested. This is the process that happens in the stomach and gut, when the feed is broken down (Tuckwell 2003).

The goal …

Effect Of Plant Spacing On The Growth And Yield Of Forage Plant, Maize, Intercropped With Cowpea (Vigna Unguiculata Sub Spp. Sesquipedalis), Kelechi A. Ike, Leonard C. Nwaigbo, Ugochukwu H. Ukpabi, Sunday N. Ukachukwu, Olufemi S. Onifade, Uchenna Y. Anele, Princewill N. Njoku

IGC Proceedings (1993-2023)

Feed constraint is the most important impediment to improved livestock production in the Sub-Saharan African (SSA) countries (Agyemang 2003), as a result of seasonal shortages in the quantity and quality of forage from natural pastures that supply most of the feed for animals due to the prolonged annual dry season. Appropriate technologies to improve the performance of the local animal breeds and feed resources under the traditional system are generally lacking. Maize forms a major part of the cereal crops consumed by man and the residues serve as a source of fodder for livestock (Asawalam and Adesiyan 2001). Demand for …

Pasture Yield And Sward Intake By Suckler Cows In The Extended Grazing Season, Piotr Goliński, Barbara Golińska, Józef Biniaś

IGC Proceedings (1993-2023)

Recent advancements in grazing management have shown opportunities to extend the grazing season in late autumn (Hennessy et al. 2006). The increase in the grazing season length will have profound effect on the overall system through reducing the quantity of slurry to be stored, reduction in the quantities of silage and hay required for winter feeding and reductions in the energy associated with sward harvesting and conservation. Also, in Central Europe the extending of grazing season has become highly desirable in the recent years (Opitz v. Boberfeld et al. 2006; Skladanka et al. 2010), because it can …

Short-Term Herbage Intake Rate In Temperate Pastures Grasses Grown In Pure Or In Intercropping Stands, Gabriela C. Guzatti, Paulo G. Duchini, Henrique M. N. Ribeiro Filho, João G. R. Almeida, André F. Sbrissia

IGC Proceedings (1993-2023)

Oat and ryegrass pastures grown in intercropping systems are the most common forages used during the fall and winter in subtropical and in some temperate climate regions. Nevertheless, it must be taken into account that the way in which the different species of plants are presented to the animals may lead to consequences for the efficiency of the grazing process (Prache and Damasceno 2006). Moreover, in hetero-geneous environments, animals may reduce intake rate due to a partial preference for a specific species (Gonçalves et al. 2009).

Regarding the pasture development stage, it is known that the decrease of the …

Grazing Termination Dates Of Summer-Dormant Flecha Tall Fescue, Sindy M. Interrante, Twain J. Butler

IGC Proceedings (1993-2023)

Summer-dormant, Mediterranean-type tall fescue (Festuca arundiancea Schreb.) has potential to replace summer-active, Continental-type tall fescue and trad-itional, annual small grain graze-out systems in the Southern Great Plains region of the USA. This region is characterized by severe water deficits accompanied by extreme heat in summer, and by relatively mild, rainy winters (Malinowski et al. 2009). Although the climate of the southern Great Plains is different from the Mediterranean climate, the temperature and precipitation patterns during summer are historically similar. However, in the past decade, the bimodal precipitation pattern with peaks in May and September has become highly unpredictable, …

Forage Biomass And Bovine Live Weight Changes Within Monospecific And Mixed Prairies Over The Dry Season In Tropical México, Régulo Jiménez-Guillén, Adrián R. Quero-Carrillo, P. A. Martínez-Hernández, D. H. Noriega-Cantú

IGC Proceedings (1993-2023)

In the tropical systems of cattle grazing, the limited period of forage production and low forage protein content and digestibility of the same, are the main constraints to increasing live weight gain. Grass-legume pasture improves forage quantity and quality and sowing mixed swards in both the wet and dry tropics is now common practice. However, much less is known if inclusion of a fodder tree as a third component could further improve forage parameters. The aim of this study was to evaluate three types of grasslands, grazed by cattle in the dry season of the dry tropics. Swards were established …

Economic Values For Perennial Ryegrass Traits In New Zealand Dairy Farm Systems, David F. Chapman, Jeremy R. Bryant, Graham A. Kerr, Glenn Judson, Tim Cookson, Grant R. Edwards, William H. Mcmillan

IGC Proceedings (1993-2023)

Perennial ryegrass (Lolium perenne L.) is the main species used in dairy pastures throughout New Zealand. There are approximately 30 perennial ryegrass cultivars sold commercially in New Zealand, but currently there is no evaluation system which allows farmers to compare the potential impact of different cultivars on the profitability of their farm business. Such an economic evaluation system requires information on performance values (PV) for cultivars which quantifies their performance with respect to the major productivity traits (herbage accumulation (HA, kg DM/ha), nutritive value and persistence) relative to a genetic base, and economic values (EV, Doyle and Elliott 1983) …

The Variation In Morphological Fractions Of Perennial Ryegrass Cultivars Throughout The Grazing Season And Subsequent Impacts On Organic Matter Digestibility, Marion Beecher, Deirdre Hennessy, Tommy M. Boland, Norann Galvin, Christina Fleming, Mary Mcevoy, Michael O’Donovan, Eva Lewis

IGC Proceedings (1993-2023)

The grass plant is comprised of leaf blades, leaf sheath (pseudostem), true stem and dead material each differing in digestibility and their relative proportions can impact significantly on sward quality. The objective of this study was to determine the change in the proportion and organic matter digestibility (OMD) of leaf, pseudostem, true stem and dead fractions of four perennial ryegrass cultivars throughout a grazing season.

Effect Of Enclosure On Botanical Composition, Forage Biomass And Other Range Productivity Parameters In A Semi-Arid Area Of El-Khuwei Locality, North Kordofan State, Sudan, Mohammed Abdelkreim, Babo Fadlalla

IGC Proceedings (1993-2023)

Animal production in North Kordofan State is mainly traditional depending on natural rangeland (Cook and Fadlalla 1987), (DHP, 1998). The State has an area of about 25 million ha of which 14.5 million ha is rangeland (Africover 2004). It is among the leading Sudanese States in animal and range resources. It contains more than 13 million heads of sheep, goats, camels and cattle (IFAD 2011). This paper deals with the effect of enclosure and stage of maturity on botanical composition, forage biomass production and other range productivity parameters in this semi-arid area.

Immediate And Carryover Effects Of Post-Grazing Sward Height Imposed In Early Spring On Sward And Milk Production, Elodie Ganche, Luc Delaby, Michael O’Donovan, Tommy M. Boland, Emer Kennedy

IGC Proceedings (1993-2023)

A grazing experiment was undertaken to investigate the immediate and carryover effect of post-grazing sward height (PGH) in early spring on sward and dairy cow production. Ninety Holstein-Friesian spring calving dairy cows were randomly assigned across 3 PGH treatments: 2.7, 3.5 and 4.2 cm from February 14 to April 24, 2011. Following the experimental period animals were managed similarly until the end of the lactation. Grazing to 2.7 cm during the experimental period reduced milk (-159 kg/cow; P < 0.01) and milk solids (-16 kg/cow; P < 0.01) yields and increased BW loss (+13 kg loss; P < 0.05) when compared to the 3.5 and 4.2 cm treatments which performed similarly. Grass utilisation (>2.7 cm) increased (P < 0.001) by decreasing PGH from 4.2 cm (0.74) to 3.5 cm (0.82) and further to 2.7 cm (0.94). During the carryover period (April 24 to November 13), cumulative milk (3542 kg/cow) and milk solids (281 kg/cow) yields did not differ between the experimental treatments. End BW was similar across treatments (503 kg). Total lactation performance of cows grazing to 2.7 cm in spring was -24 kg milk solids (P < 0.05) than the total lactation production of the 3.5 and 4.2 cm treatments (405 kg milk solids) indicating that cows offered a restricted pasture allowance in early lactation do not recover lost production. This study recommends a PGH of 3.5 cm in the first 2 grazing rotations to achieve a compromise between sward utilisation and animal performance in early spring while also ensuring high subsequent lactation milk production.

Dry Season Forages For Improving Dairy Cattle Production In Smallholder Dairy Systems, Jolly Kabirizi, Emma Zziwa, Swidiq Mugerwa, Agnes Namagembe

IGC Proceedings (1993-2023)

Economically feasible strategies for year-round feed supply to dairy cattle are needed to improve feed resource availability, milk yield and household income for the smallholder dairy farming systems that dominate in the rural Eastern and Central African region. Currently, napier grass (Pennisetum purpureum) is the major forage in zero-grazing production systems, but production is often constrained. While forage legumes, including Centrosema pubescens and Clitoria ternatea are used to complement napier grass, Brachiaria spp, a new drought tolerant grass, is being introduced. Our results showed that the introduction of drought tolerant forage technologies improved milk yield and household income. …

Systematic Management Of Stocking Rates Improves Performance Of Northern Australian Cattle Properties In A Variable Climate, Lester I. Pahl, Joe C. Scanlan, Giselle L. Whish, Robyn A. Cowley, Neil D. Macleod

IGC Proceedings (1993-2023)

The risks for extensive cattle properties in the rangelands of northern Australia arising from high inter-annual rainfall variability are predominantly managed through adjustments in stocking rates (SR). This modelling study compared the performance of SR strategies that varied considerably in the extent that they adjusted SR annually at three locations in northern Australia. At all locations, land types and pasture condition states, the SR strategies that achieved the best pasture condition were those that least increased and most decreased SR annually in response to changes in forage availability. At Donors Hill (Qld), these conservative strategies also achieved the highest cattle …

Effects Of Grazing Management On Grassland Production And Animal Performance, Yingjun Zhang, W. Q. Chen, D. Huang, Z. Q. Li, Y. P. Rong

IGC Proceedings (1993-2023)

Five grazing treatments with a set of design for evaluation of seasonal grazing influencing grassland conditions and animal performance have been conducted across northern and western China, in order to identify the key solutions for degradation of grazing grasslands. Here, the effects of seasonal grazing within two systems-one based on current ‘survival’ practices and the other taking more of a ‘production’ focus in Bashang grasslands were reported. The experiment involved a factorial combination of alternative practices (survival vs. production systems) in spring, summer and autumn with a layout of 15 plots and 1.5 ha per plot. Results of consecutive two …