Physical Sciences and Mathematics Commons^™

Effects Of Stocking Rates On Water Use Efficiency Of Established Species In Stipa Breviflora Desert Steppe, M. Zhao, G. M. Yin, S. B. Liu, W. J. Meng

IGC Proceedings (1997-2023)

Plant water use efficiency reflects the survival adaptation strategies adopted by plants to obtain maximum carbon harvest. Understanding the water and resource utilization strategies of Stipa breviflora in desert steppe will help people understand its growth mechanism, and it is of great significance to analyze the ecological countermeasures of Stipa breviflora to cope with disturbance. In this study, the water use efficiency (WUE) of the established populations of Stipa breviflora in desert steppe was measured by stable carbon isotope method and photosynthometer method, and the adaptation mechanism of Stipa breviflora under different stocking rates was discussed based on the basic …

Performance Of Finishing Nellore Beef Steers In Intensively Managed Pastures And Silvopastoral Systems In Southeast Of Brazil, P. P. A. Oliveira, Neto R. Pasquini, G. S. Pádua, L. H. C. Junior, R. Vechi, A. J. Furtado, G. V. Silva, A. A. Lobo, A. L. Abdalla-Filho, A. F. Pedroso, P. H. M. Rodrigues

IGC Proceedings (1997-2023)

This study evaluated the average daily weight gain (ADG), stocking rates, and live weight gain per hectare (LWG) in different intensified animal production systems. The experiment was carried out from September 2020 to September 2021 at Embrapa Southeast Livestock, São Carlos, SP, Brazil. Thirty Nellore steers (285±21 kg of live weight and 12±13 months old) were randomly distributed into five treatments, with two replicates: 1) intensively managed and irrigated Megathyrsus maximus cv. Tanzânia pasture overseeded in the dry season with Avena byzantina and Lolium multiflorum (IHS); 2) intensively managed rainfed M. maximus cv. Tanzânia pasture (RHS); 3) intensively managed rainfed …

Livestock Production And Economic Implications From Augmenting Degraded Rangeland With Atriplex Halimus And Salsola Vermiculata In Northwest Syria, A. E. Osman, F. Bahhadi, N. Hassan, F. Ghassali, T. Al Ibrahim

IGC Proceedings (1997-2023)

Three stocking rates (low: one sheep 2.25 ha-1, medium: one sheep 1.5 ha-1 year-1 and high: one sheep 0.75 ha-1 year-1) were studied for 7 seasons (1990/91-1996/97) on native range and on pasture over sown with fodder shrubs at Maragha, northwest Syria. There were 8 Awassi sheep in each stocking rate treatment, and the treatments were replicated 3 times in fenced paddocks. Milk yield, lamb production, live weight and supplementary feeding of the sheep were monitored. The results showed significantly higher forage availability on the range over-sown with fodder shrubs by 82% and 41% in the medium and high rainfall …

Effect Of Tan-Sheep Rotational Grazing On Soil Erosion In Typical Steppe On The Loess Plateau Of China, Shi Li-Yuan, Hou Fu-Jiang, Lou Shan-Ning

IGC Proceedings (1997-2023)

The effect of stocking rate on soil erosion has been at the forefront of water and soil conservation studies in recent years. By observing soil erosion caused by rainfall in typical steppe on the Loess Plateau in China, this research aimed to further explore the effect of stocking rate on soil erosion. The results showed that all the concerned indicators of soil erosion (runoff, runoff coefficient, soil loss, soil organic carbon loss, and soil total nitrogen and total phosphorus loss) had a significant (P < 0.001) positive linear correlation with stocking rate alone, and precipitation alone, while the indicators of runoff and soil loss had a significant (P < 0.01) negative linear correlation with typicalsteppe biomass (aboveground biomass, litter mass, and belowground biomass). Both stocking rate and precipitation had large significant (P < 0.01) effects on soil erosion via changes in aboveground biomass, litter mass, and soil organic carbon.

Legacy Effects Of Herbivory Trampling On Soil Organic Carbon Via Soil Properties, Plant Biomass And Functional Traits, Lan Li, Fujiang Hou

IGC Proceedings (1997-2023)

Herbivores are important for ecosystem biogeochemistry, including soil carbon pools. Non-trophic interactions between herbivores and soil processes have recently gained attention, but remain underexplored. They include both direct and indirect effects of herbivore behaviour and physical soil disturbance by herbivores (e.g., trampling) causing compaction, and therefore probably influence historical contingency; however, little empirical data on the persistent impact or legacy effect of trampling and subsequent drivers of shifts are available. To address the knowledge gaps described above, we investigated whether the soil organic C (SOC) is driven by the legacy effect of sheep trampling intensity (0, 40, 80 and 120 …

The Paired-Paddock Model As An Agent For Change On Grazing Properties Across Southeast Australia, J. Thompf, P. W. G. Sale, Geoffrey Saul

IGC Proceedings (1997-2023)

From the mid 1970s to the mid 1990s the low productivity of wool and beef producing farms in the high rainfall zone (>550 mm annual rainfall) in south east Australia has been a major contributing factor to the difficulties faced by farmers in this region. This was despite research from the Long-term Phosphate Experiment at Hamilton in south west Victoria indicating that there is considerable potential to increase the productivity and profitability of wool production (Saul, 1994). By implementing the productive pasture technology (PPT) that involves increased rates of fertiliser on pastures containing productive species and increased stocking rates …

Farmer Adoption; Ten Years Of Productive Pasture Systems In Southern Australia, Geoffrey Saul, H. L. Quinn, J. T. Trompf

IGC Proceedings (1997-2023)

n Southern Australian sheep and beef farmers have been slow to adopt technology related to grazing management and pasture utilisation despite clear evidence of a strong link between utilisation (stock per ha) and profitability. Between 1971-95, the average stocking rate on farms was 10-12 dry sheep equivalent per hectare (dse/ha) (Anon 2004). Results from the Hamilton Long-term Phosphate Experiment (Cayley et al., 2002) show higher pasture production, herbage digestibility, stocking rates and profitability as phosphorus fertiliser applications increase. In 1993, the Grassland Productivity Program (GPP) started in the winter rainfall areas of southern Australia (Trompf & Sale 2000), initiated …

Systems Simulation Assists Land Capability Estimation In Australia’S Temperate Grasslands, Richard J. Simpson, L. Salmon, P. Graham, A. D. Moore, A. Stefanski, D. J. Marshall, J. R. Donnelly

IGC Proceedings (1997-2023)

Intensification of production in the water-limited grasslands of temperate Australia has increased the need to quantify their sustainable carrying capacity. Empirical rainfall-based rules for estimating stocking rate fail when used in districts with differing weather patterns, or when soil and pasture resources limit the utilisation of rainfall. Grazing systems simulation should help to overcome these problems because local conditions can be taken into account. This study investigated the impact of soil resources on potential stocking rate, profitability and production risk in a local climatic area of the southern tablelands of NSW, Australia.

Methane Production By Cattle Grazed At Two Stocking Rates On A Semi-Natural Grassland, Cesar S. Pinares-Patiño, Y. Rochette, M. Fabre, J.-P. Jouany, C. Martin

IGC Proceedings (1997-2023)

Global warming induced by the human-enhanced concentrations of greenhouse gases (GHG) in the atmosphere is a major environmental concern of our day. Enteric methane (CH₄) is the most important GHG associated with grazing livestock. The emissions of methane may be influenced by environmental conditions and grazing management. Stocking rate (SR), the number of animals per unit of land area, remains the simplest management tool in pastoral farming. However, little is known about the influence of SR on CH₄ emission. The objective of this study was to compare the CH₄ emissions from cattle managed under low and …

The Effect Of Stocking Rate And Lamb Grazing System On Sward Performance Of Trifolium Repens And Lotus Corniculatus In Uruguay, F. Montossi, R. San Julián, M. Nolla, M. Camesasca, F. Preve

IGC Proceedings (1997-2023)

Lambs have a great potential to diversify and stimulate meat and wool production and economical returns within the industry. The main objective of this study was to evaluate different feeding and management alternatives for the production of high quality wool and meat as well as their effects on sward characteristics in the Basaltic region of Uruguay.

Effect Of Forage Legume Species And Stocking Rate Of Lambs On Sward Characteristics In Uruguay, F. Montossi, D. F. Risso, R. San Julián, M. Iglesias, N. Ramos, I. De Barbieri, R. Cuadro, A. Zarza

IGC Proceedings (1997-2023)

The sheep industry is a mayor component of the pastoral industries, given its importance for the Uruguayan economy. In the last decade, sheep farmers have been more interested in low cost technologies to enhance productivity and profit. The objective of this study, conducted in the Basaltic region of Uruguay, was to evaluate the effect of legume species and stocking rate of lambs on sward structure, production, composition and nutritive value.

Effect Of Stocking Rate And Grazing System On Fine And Superfine Merino Wool Production And Quality On Native Swards Of Uruguay, I. De Barbieri, Fabio Montossi, E. J. Berretta, A. Dighiero, A. Mederos

IGC Proceedings (1997-2023)

Modern textile tendencies show that consumers prefer light, soft, resistant, natural, and comfortable clothes, for which fine and superfine wools are in great demand, particularly at the high value markets (Whiteley, 2003). The main objective of the present study was to define sustainable stocking rates and grazing systems on native swards for fine and superfine wool production in the Basaltic region of Uruguay.

Effect Of Stocking Rates On Plant Morphology In The Inner Mongolia Steppe Of China, Shiping Wang, Y. F. Wang, Z. Z. Chen, Bob Patton, Paul Nyren

IGC Proceedings (1997-2023)

During the long period of co-evolution with herbivores, range plants have adapted and developed resistant mechanisms in response to grazing (Briske, 1991). The objective of this experiment was to determine the morphological response of a number of the dominant plant species in the Inner Mongolia steppe of China to stocking rate.

Cattle And Sheep Mixed Grazing: 1. Species Equivalence, R. D. Améndola-Massiotti, S. J. C. González-Montagna, Pedro A. Martínez-Hernández

IGC Proceedings (1997-2023)

The effects of mixed grazing of cattle and sheep depend on stocking rate (SR) and species ratio (Nicol, 1997). Calculations of SR and species ratio require the use of species equivalence. Equivalents are often estimated in terms of intake requirements related to live weight (LW), while maintenance energy requirements are calculated on the basis of LW^0.75. Freer (1981) stated that LW^0..9 would be more appropriate for comparisons of intake requirements for maintenance of sheep and cattle. Nonetheless, Nolan & Connolly (1977) stated that the equivalent is system-specific and depends on the species being considered. The objective of …

Growth Performance Of Crossbred Steers On Unfertilised Mountain Pastures At Low Stocking Rates, A. Chassot, J. Troxler

IGC Proceedings (1997-2023)

As a consequence of increasing economic pressure on Swiss agriculture, marginal areas are threatened by abandonment, especially in the mountainous regions. Using these areas for extensive beef production might preserve an open landscape and favour biodiversity. A grazing experiment was conducted with steers on an unfertilised mountain pasture to study the effects of a reduction of stocking rate on the growth of the animals and on changes in the vegetation.

Grazing Impacts On Rangeland Condition In Semi-Arid South-Western Africa, A. Rothauge, G. N. Smit, A. L. Abate

IGC Proceedings (1997-2023)

The savannah biome, consisting of a dense herbaceous layer and a relatively open woody layer in competitive balance, constitutes 64% of the land surface of Namibia, an arid country in south-western Africa, and is used mainly for extensive cattle and sheep ranching. About half of the savannah area is affected by dense to moderately dense bush-thickening, resulting in a ten-fold decrease in the rangeland’s grass-based carrying capacity and a concomitant loss in meat production of about US$115 million per year (De Klerk, 2004). Bushencroached areas typically have densities > 2 000 bushes/ha with > 90% belonging to a single species. High grazing …

Stocking Rate Theory And Profit Drivers In North Australian Rangeland Grazing Enterprises, Neil D. Macleod, A. J. Ash, John G. Mcivor

IGC Proceedings (1997-2023)

Setting correct stock numbers is a key decision for successful pastoralism. In marginal environments, typified by northern Australia, this involves careful cattle herd management across landscapes and seasons characterised by heterogeneous land condition and extreme climatic uncertainty. Stocking rate theory which links animal production to stocking rates concentrates only on liveweight gain of sale animals and ignores complex herd (e.g. reproduction, mortality) and pasture dynamics (e.g. land condition) and costs of maintaining stock numbers (e.g. supplementary feeding). Related economic models are generally naïve and incomplete, being based on liveweight gain, meat prices and variable husbandry costs (e.g. Workman, 1986). Modelling …

A Comparison Of Perennial Ryegrass Cultivars Differing In Heading Date And Grass Ploidy For Grazing Dairy Cows At Two Different Stocking Rates, M. O'Donovan, G. Hurley, L. Delaby, G. Stakelum

IGC Proceedings (1997-2023)

Animal productivity is the ultimate performance indicator of any new grass cultivar. Direct assessment is complex and expensive. Recent research has identified a number of important sward factors that influence intake and production. The most important factor appears to be green leaf mass. The objective of this two year study was to investigate the effects on milk yield, composition and grass intake of grass cultivars with contrasting heading dates (HD) and grass ploidies (PL) when grazed at different stocking rates.

Effect Of Stocking Rate And Grazing System On Fine And Superfine Merino Wool Production And Quality On Native Swards Of Uruguay, I. De Barbieri, F. Montossi, E. J. Berretta, A. Dighiero, A. Mederos

IGC Proceedings (1997-2023)

Modern textile tendencies show that consumers prefer light, soft, resistant, natural, and comfortable clothes, for which fine and superfine wools are in great demand, particularly at the high value markets (Whiteley, 2003). The main objective of the present study was to define sustainable stocking rates and grazing systems on native swards for fine and superfine wool production in the Basaltic region of Uruguay.

The Effect Of Stocking Rate And Lamb Grazing System On Sward Performance Of Trifolium Repens And Lotus Corniculatus In Uruguay, F. Montossi, R. San Julián, M. Nolla, M. Camesasca, F. Preve

IGC Proceedings (1997-2023)

Lambs have a great potential to diversify and stimulate meat and wool production and economical returns within the industry. The main objective of this study was to evaluate different feeding and management alternatives for the production of high quality wool and meat as well as their effects on sward characteristics in the Basaltic region of Uruguay.

Cattle And Sheep Mixed Grazing 1: Species Equivalence, R. D. Améndola-Massiotti, S. J. C. González-Montagna, P. A. Martínez-Hernández

IGC Proceedings (1997-2023)

The effects of mixed grazing of cattle and sheep depend on stocking rate (SR) and species ratio (Nicol, 1997). Calculations of SR and species ratio require the use of species equivalence. Equivalents are often estimated in terms of intake requirements calculated on the basis of LW^0.75. Freer (1981) stated that LW^0.9 would be more appropriate for comparisons of intake requirements for maintenance of sheep and cattle. Nonetheless, Nolan & Connolly (1977) stated that the equivalence is system-specific and depends on the species being considered. The objective of this experiment was to estimate species equivalence for the evaluation …

The Effect Of Stocking Rate And Initial Grass Height On Herbage Production And Utilization, And Milk Production Per Unit Area Under Set Stocking By Lactating Dairy Cows, H. Nakatsuji, T. Endo, S. Bawm, T. Mitani, M. Takahashi, K. Ueda, S. Kondo

IGC Proceedings (1997-2023)

In our previous study with lactating dairy cows (Nakatsuji et al., 2004), annual herbage production and utilization, and milk production per unit area under set stocking was not always lower than under rotational grazing at the same stocking rate (6 cows/ha). Furthermore, there was a possibility that set stocking could increase pasture utilization and milk production over rotational grazing when cows were grazed at adequate stocking rate and at the appropriate initial date of grazing. The purpose of the present study was to evaluate the effect of stocking rate and initial grass height on herbage production and utilization, and …

The Effect Of Early And Delayed Spring Grazing On The Milk Production, Grazing Management And Grass Intake Of Dairy Cows, E. Kennedy, M. O'Donovan, J. P. Murphy, L. Delaby, F. P. O'Mara

IGC Proceedings (1997-2023)

Earlier access to pasture can increase the overall proportion of grazed grass in the diet of the spring calving dairy cow. Further benefits can also be achieved from early turnout, including improved animal production, increased sward utilisation and enhanced sward quality (O’Donovan et al., 2004). The objective of this study was to compare the effect of initial spring grazing date and stocking rate on the performance of spring calving dairy cows.

Interactions Between Foraging Behaviour Of Herbivores And Grassland Resources In The Eastern Eurasian Steppes, Deli Wang, Guodong Han, Yuguang Bai

IGC Proceedings (1997-2023)

1. In rangeland areas such as the eastern Eurasian steppes (Mongolia and China), foraging behaviour is influenced by plant or vegetation properties with high heterogeneity.
2. Until recently foraging theory has not accounted for the foraging process or ingestive behaviour. Existing theories on foraging behaviour need to evolve and begin to coalesce, and combine with observations or manipulative experiments.
3. Plant and patch properties such as diversity and height influence animal foraging behaviour (related to foraging process or diet selection) in heterogeneous steppes.
4. Stocking rate is the most important management factor for grazing or vegetation management, and determining the optimal stocking rate in …

Characterisation Of Soil Organic Matter From Pensacola Bahiagrass Pastures Grazed For Four Years At Different Management Intensities, J. C. B. Dubeux Jr., Lynn E. Sollenberger, N. B. Comerford, Ana C. Ruggieri, K. M. Portier

IGC Proceedings (1997-2023)

Soil fertility and agricultural system sustainability depend upon soil organic matter (SOM), particularly in the tropics, because of highly weathered soils and low fertiliser inputs. Because of the beneficial effects of SOM on chemical, physical, and biological soil properties, Greenland (1994) suggested that SOM is an indicator of agro-ecosystem sustainability. Pasture management may affect SOM by altering the production/decomposition ratio of residues (Johnson, 1995). The objective of this study was to characterise the SOM of Pensacola bahiagrass pastures grazed for four years at a range of management intensities.

Interactions Between Foraging Behaviour Of Herbivores And Grassland Resources In The Eastern Eurasian Steppes, Deli Wang, Guodong Han, Yuguang Bai

IGC Proceedings (1997-2023)

Key points

1. In rangeland areas such as the eastern Eurasian steppes (Mongolia and China), foraging behaviour is influenced by plant or vegetation properties with high heterogeneity.

2. Until recently foraging theory has not accounted for the foraging process or ingestive behaviour. Existing theories on foraging behaviour need to evolve and begin to coalesce, and combine with observations or manipulative experiments.

3. Plant and patch properties such as diversity and height influence animal foraging behaviour (related to foraging process or diet selection) in heterogeneous steppes.

4. Stocking rate is the most important management factor for grazing or vegetation management, and …

Pasture Utilization At Islands In Northern Norway, V. Lind, Ø. Holand, F.-A. Haugen, G. Steinheim

IGC Proceedings (1997-2023)

The Norwegian sheep industry is based on utilization of “free” rangeland pasture resources. Use of mountain pastures is dominating, with about two million sheep grazing these pastures during summer. Regional challenges related to e.g., loss of sheep to large carnivores make farmers think differently. The Norwegian coastline is among the longest globally and is scattered with islets and islands. Alone along the coast of Nordland county, it is estimated more than 14,000 islands. Use of islands for summer pasture is an alternative but there is a limited knowledge about such a management system. In this study, we examined lambs’ average …

Effects Of Cattle Grazing On A Perennial Legume, Bitumen Trefoil (Bituminaria Bituminosa (L.) Stirton), In A Mediterranean Grassland, M. Gutman, M. Sternberg, A. Perevoltsky

IGC Proceedings (1997-2023)

A six-year study was conducted in a Mediterranean grassland in north-eastern Israel to investigate the effects of cattle grazing management on a perennial legume, Bitumen Trefoil (Bituminaria bituminosa (L.) Stirton). The relationship between grazing pressure and its relative plant cover was studied in the context of inter-annual variation in rainfall. Treatments included manipulations of stocking rates (moderate, heavy and very heavy) and of grazing regimes (continuous vs. seasonal), in a factorial design. The results showed that inter-seasonal rainfall variation was a dominant factor in the expression of plant cover changes of this species. Grazing showed no significant effect on …

Productivity And Composition Of Two Improved Native Pastures Under Different Grazing Managements In Uruguay, D. F. Risso, E. J. Berretta, G. Carracelas

IGC Proceedings (1997-2023)

Two improved native pastures were established by phosphoric (P) fertilisation and oversowing of: white clover (Trifolium repens) mixed with birdsfoot trefoil (Lotus corniculatus) (TbL) and annual lotus (Lotus subbiflorus) (Rin). Such pastures were evaluated during 5 years with steers at two stocking rates (High and Low) and two grazing managements (Rotational and Alternate). Presence of legumes was high and botanical changes were favourable in both pastures that evidenced good persistence. Daily liveweight gains of steers and total animal production were high in both pastures, but significantly (P≤ 0.05) higher in TbL. No significant differences …

Analysis Of Some Farm Driving Variables And Its Relation With Milk Production In A Pastoral Dairy Farm Of Buenos Aires, Argentina, J. L. Rossi, A. Ayala Torales, G. Acosta, V. A. Deregibus

IGC Proceedings (1997-2023)

The quantity of milk solids produced determines a dairy farm income and contributes to its profit. Total pasture production, forage quality and herd consumption are factors to be managed in this production system. The outcomes of two years were analyzed. Primary production showed its dependence on climatic conditions and use of technological inputs. Forage quality was promoted through interseeding legumes, applying fertilizer and maintaining the pasture young and leafy. Total forage removed by the herd was similar in both years although pasture production decreased. It was possible to cope with seasonal variations in forage production, by varying the grazing pressure …