Physical Sciences and Mathematics Commons^™

Vegetation Changes In Southeast Australian Temperate Grasslands, D. L. Garden, T. P. Bolger

IGC Proceedings (1997-2023)

In temperate areas of southeast Australia, the combined effects of tree clearing, grazing, application of fertilizer and the introduction of exotic species have modified the original grasslands. This paper describes these changes and attempts to explain them in terms of ecological principles derived from North American grasslands. Stability of the original grasslands appears to have been due to the lack of disturbance and the slow rates of nitrogen (N) cycling within them. Increased N cycling after disturbance has allowed invasion of species better adapted to higher N status, particularly exotic annual grasses and weeds. The present composition of grasslands, in …

Influence Of Grassland Management And Grazing By Different Farm Animals On Animal Performance And Flora Alterations, W. Jentsch, H.-D. Matthes, A. Admasu, H. Möhring

IGC Proceedings (1997-2023)

The objectives of this study were to test the possibilities of using different farm animals for landscape care on extensive pasture, taking into account their particular performance, and to analyse alterations of the flora in consequence of grazing by different animals and various pasture management. Salers had the highest (836g/d) and Galloways (584g/d) the lowest live weight gain as compared with the other breeds (771g/d). Lambs had higher live weight when grazing together with cattle and horses (mixed grazing) than under one species grazing. The number of legume increased and that of grass decreased. Following 3 years the grazing animals …

Orchardgrass Pastures For Early-Weaned Beef Calves, J. C. Waller, H. A. Fribourg, C. Dixon, A. E. Fisher, B. V. Conger

IGC Proceedings (1997-2023)

Orchardgrass (Dactylis glomerata) grown alone or with ladino white (Trifolium repens) and red (T. pratense) clovers, provides a high quality March to June pasture. However, many beef producers have their cows calving in January-March, thus producing offspring that are too young to utilize spring forage well. As an alternative, some producers have their cows bred so that calves are born in autumn (September-November). By spring, these calves are old enough to consume pasture forage. The few earlier studies on early weaning of fall-born calves consist of drylot feeding of high quality hay or concentrates. …

Management Of Meadow Fescue Pasture For High-Producing Dairy Cows In Northern Japan, K. Sudo, K. Ochiai, T. Ikeda

IGC Proceedings (1997-2023)

The objective of this study was to establish an intensive grazing system of meadow fescue (Festuca elatior L.) pasture for high-producing dairy cows in some areas of Japan where soil freezes in winter. Plant succession of meadow fescue pastures that had been grazed at different plant heights and milk production from cows grazed on meadow fescue pasture compared to that from cows grazed on perennial ryegrass pasture were surveyed over a five year period. Succession of meadow fescue pasture depended on the management of plant height before grazing use. Milk production from cows grazed on meadow fescue pasture was …

Nitrogen Flow To Duodenum Of Steers Grazing On Orchardgrass And Meadowfescue Pastures, Masaaki Hanada, Y. Aibibula, Meiji Okamoto

IGC Proceedings (1997-2023)

This experiment was conducted to evaluate nitrogen flow to the duodenum of steers grazing on orchardgrass (Dactylis glomerata L., OG) or meadowfescue (Festuca elatior L., MF) pasture. Holstein steers fitted with cannulas in the rumen and duodenum were used. Nitrogen content and in vitro dry matter digestibility of herbage did not differ between OG and MF pastures. Herbage nitrogen intake of steers grazing on OG and MF pastures averaged 229 and 271 g/day, respectively. Nitrogen flows to the duodenum of steers grazing on orchardgrass and meadowfescue pastures averaged 187 and 195g/d, respectively. Microbial nitrogen flow to the duodenum …

Intake Estimation Of Rams Under Grazing Condition In A Deferred Pastures Of Panicum Coloratum By Two Techniques, C. M. Ferri, M. A. Brizuela, N. P. Stritzler, H. J. Petruzzi

IGC Proceedings (1997-2023)

The goal of this study was to quantify the organic matter intake (OMI) of Pampinta rams grazing in a Panicum coloratum cv Verde differed pasture. The OMI was compared by two methods: a) the difference between the forage measured in pre and post-grazing condition, and b) the faecal production:digestibility ratio of the diet, estimated by total faecal gathering, and from the quantity of total faecal N in g per 100 g^-1 of OMI and the concentration of total faecal N, respectively. The OMI estimated by difference between the forage measured in pre and post-grazing was 9 % higher (P …

Effect Of Five Different Rest Periods On Tiller Regrowth Of Ryegrass, R. W. Coelho, W. R. Ocumpaugh

IGC Proceedings (1997-2023)

Five rest periods were imposed from April to May on a mixed pasture of two ryegrass (Lolium multiflorum Lam.) varieties and white clover (Trifolium repens L.). The rest period starting dates were: April 4, April 18, May 2, May 16, and May 30, for rest periods 1, 2, 3, 4, and 5, respectively. The total area allocated to the experiment was 1.1 ha, which was divided into 22 pastures. The experimental design used was a split-plot. Rest period was assigned to the main plot, grass to the subplot and legume to the subsubplot. The pastures were “mob-grazed” by …

Contract Grazing Of Young Beef Cattle On Ryegrass In The Southeastern Usa, David I. Bransby

IGC Proceedings (1997-2023)

The objective of this study was to evaluate contract grazing (in which the landowner grazes cattle owned by someone else for a specified fee) as an alternative to traditional ownership of the cattle, in order to improve profitability of grazing young beef cattle on annual ryegrass under limited availability of operating capital in the southeastern USA. Production data from a two-year grazing experiment were used as a basis for an economic analysis which assumed market prices for the beef industry in the region. Return/ha over animal and pasture costs was $312.20 for contract grazing, and $477.50 for purchased cattle. However, …

Horses Grazing Management To Promote Distribution Of Lotus Tenuis (Waldst. Et Kit) In A Temperate Grassland, O. E. Ansín

IGC Proceedings (1997-2023)

In a temperate grassland of the Argentine Pampa, the birdsfoot trefoil (Lotus tenuis Waldst. et Kit) distribution was analyzed as a consequence of the grazing method used. In a plot of 40 ha occupied by native grassland an area of 16 ha was implanted with reed canary grass (Phalaris aquatica L.) and L. tenuis. This area was divided into two parts that contained the same pasture and native grassland surfaces, being grazed by horses. One, under continuous grazing and another one, under a controlled grazing. In the continuous grazing the whole year the animals had permanently access …

Transgenic Maize Hybrid Crop Residues: Nutritive Value And Their Effects On Performance Of Grazing Beef Cows, S. K. Barnhart, J. R. Russell, M. J. Hersom, D. E. Farnham

IGC Proceedings (1997-2023)

Several maize (Zea mays) hybrids, including three transgenic hybrids containing Bacillus thuringiensis (Bt) enzymes (Bt-maize hybrids), were planted in a field study. Mature, midgestation, beef cows (Bos tarus) strip-grazed post-harvest residues as paddocks over 126 days. Body condition-scores and weights were monitored. Forage yield, weathering losses and forage composition were monitored on grazed and ungrazed areas. Forage selection and intake were estimated. Grain yields, dropped grain, initial crop residue concentrations of dry matter (DM), organic matter (OM) and in vitro digestible organic matter (IVDOM) yields were similar among hybrids. Hybrids varied in infestation of maize borers, …

Effects Of Different Levels Of Energy Supplementation On Growth Of Grazing Holstein Heifers, L. P. Novaes, C. E. Polan

IGC Proceedings (1997-2023)

Growth of Holstein heifers was studied for 1987 grazing season to evaluate pasture-drylot systems for raising dairy replacements. Orchardgrass (Dactylis glomerata L), tall fescue (Festuca arundinacea Schreb), bluegrass (Poa pratensis L) and white (Trifolium repens L) and red clover (Trifolium pratense, L) were the principal components of the grass-legume mixture in six paddocks of 1.5 ha each. Carrying capacity was estimated at six animals/ha (3.1 animal units) and excess forage was harvested as hay to control forage growth and quality. Grazing days were 140 days. None or 2.0 kg/d …

Supplementation Of Dairy Cows Under Alfalfa Grazing Conditions With Ground Corn, A. R. Castillo, L. A. Romero, O. R. Quaino, E. A. Comeron, M. C. Gaggiotti

IGC Proceedings (1997-2023)

Two trials were carried out during the Autumn of 1991 and 1992 to investigate the effects of corn supplementation on lactational performance of dairy cows under alfalfa grazing. Forty two multiparous Holstein cows with 30-60 days in milk were used in a randomized continuous design with covariance analysis. The treatments were 0.0, 3.5 and 7.0 kg.day^-1 of corn grain supplementation (T1, T2 and T3 respectively) in 1991 and 0.0, 3.0, 6.0 and 9.0 kg.day^-1 (T1, T2, T3 and T4 respectively) in 1992. Six cows per treatment were used divided in 3 cows per grazing paddock. Dry matter (DM) …

Determination Of N-Alkanes At Different Stratum Heights In A Pasture Of Panicum Maximum Cv. Mombaça, T. C. M. Genro, L. R. L. De S. Thiago, Ê. R. Prates, M. Herrero, V. Sabatel

IGC Proceedings (1997-2023)

The aim of this experiment was to determine n-alkane levels in the stem + leaf sheath and leaf blade components of a pasture of Panicum maximum cv. Mombaça, harvested in 20 cm stratified layers. This pasture was under rotational grazing for intensive beef production throughout the year. The grazing system was based on the use of 16 paddocks with a 2-day grazing period followed by a 30-day resting period. Profiles of n-alkanes were determined in samples harvested in three separate periods: in the middle of the dry season (August 97; PERIOD 1), at the beginning of the wet season (November …

Duration Of Regrowth Of Ryegrass (Lolium Perenne) Swards: Effects On Rumen Fermentation Of Lactating Dairy Cows, P. Chilibroste, S. Tamminga, H. Boer

IGC Proceedings (1997-2023)

The relative importance of duration of sward regrowth and rumen fill and fermentation on the control of grazing time and intake rate during the first grazing session of the day were studied. Four lactating dairy cows were allowed to graze ryegrass (Lolium perenne) swards, with five different regrowth periods after mowing (6, 9, 16, 22 and 30 d). The cows were allowed to graze until they stopped voluntarily. Samples of rumen liquid were taken at approximately 0, 30, 60, 120 and 240 min after the grazing session was finished. Concentration of volatile fatty acids (VFA) followed a significant …

Prediction Of Dry Matter Intake Based On Ruminal Degradation From Milking Cows Grazing Coast-Cross Grass, T. T. Berchielli, J. P. G. Soares, L. J. M. Aroeira, C. L. Furlan, A. K. D. Salman, R. N. Da Silveira, E. B. Malheiros

IGC Proceedings (1997-2023)

Dry matter intake (DMI) of coast-cross grazing by crossbred Holstein-Zebu and Zebu lactating cows was calculated using in vitro dry matter digestibility from extrusa (four esophageal fistulated cows) and fecal output estimate with mordent chromium. Pasture was rotationally grazed with three days grazing period and 27 days resting period, adopting a stocking rate of 1.6 and 3.2 cows/ha, during the dry and rainy season respectively. Voluntary DMI was estimated from degradation characteristics using different equations. Predicted coast-cross DMI varied with models. The prediction of tropical forages dry matter intake from equations based in ruminal degradation parameters needs further investigation before …

Prescribed Fire And Cattle Grazing To Manage Invasive Grasses For Cattle And Wildlife, C. H. Walther, J. Alfonso Ortega‐S., H. L. Perotto-Baldivieso, S. Rideout-Hanzak, D. B. Wester

IGC Proceedings (1997-2023)

Invasive grasses are in most cases introduced species able to outcompete native species. Buffelgrass (Cenchrus ciliaris), Guineagrass (Urochloa minima), and Old World bluestems (Dichanthium spp.) are typical examples of invasive species in southeastern United States. However, native grasses such as tanglehead (Heteropogon contortus) can become invasive and dominant in absence of cattle grazing just like any invasive species. Tanglehead and Kleberg bluestem (Dichanthium ischaemum) increased (p < 0.05) from 1.4 and 1.8% in 1999 to 2.7 and 3.6% in 2002 and then to 8.1 and 9.4% in 2009, respectively. Monocultures of invasive species have very little value for wildlife, and in the case of mature tanglehead its palatability for cattle is very low. Prescribed fire may be used to improve palatability of tanglehead for cattle, and cattle grazing may be used to improve plant species richness for wildlife. To evaluate the effects of prescribed fire and cattle grazing on cattle preference and the botanical composition of a plant community dominated by tanglehead, we burned 3 patches of approximately 0.5 ha in a pasture of 107 ha in October 2016. Two months before the prescribed burning was executed, 10 mother cows were placed in the pasture to graze continually. We fitted GPS collars on 8 cows and location readings were collected every 10 minutes. GPS recordings indicate that cattle used burned patches 4.5 times more after burning compared to before burning. Percent forage utilization of tanglehead was 52% in the burned patches compared to 6% in the control areas. Plant species richness increased from 2.53 to 8.33 plant species per 0.25 m², before and after burning, respectively, an increase of 330%. Prescribed fire and cattle grazing are valuable tools to increase tanglehead palatability and …

Nutrient Return From Plant Litter And Cattle Excretion Grazing On N-Fertilized Grass Or Grass-Legume Pastures In North Florida, Liza Garcia, D. M. Jaramillo, José C. B. Dubeux Jr., Lynn E. Sollenberger, João M. B. Vendramini, N. Dilorenzo, E. R. S. Santos, M. Ruiz-Moreno, L. M. D. Queiroz

IGC Proceedings (1997-2023)

Nutrient recycling via plant litter and livestock excreta is an important ecosystem service provided by grasslands. This study determined nutrient return via these pathways in three grazing systems. The experiment was conducted from May to October (2016 and 2017) and treatments were: 1) Nitrogen fertilized bahiagrass (Paspalum notatum Flügge) pastures (112 kg N ha^-1) during the warm-season, overseeded with a mixture (56 kg ha^-1 of each) of ‘FL 401’ cereal rye (Secale cereale, L.) and ‘RAM’ oat (Avena sativa, L.) during the cool-season (BGN); 2) Ecoturf Rhizoma peanut (Arachis glabrata Benth.)/bahiagrass …

Legumes As A Strategy For Reducing Greenhouse Gas Emissions Of Forage-Livestock Systems, N. Dilorenzo, José C. B. Dubeux Jr., L. Garcia, R. D. Guevara, S. Lagrange, J. Macadam, J. J. Villalba

IGC Proceedings (1997-2023)

Incorporation of legumes into forage systems has been a widely adopted strategy to increase pasture productivity and forage nutritive value, while reducing N inputs. Considering the population growth, and the diminishing land resources for food production, the need to increase the food supply will have to be balanced with the environmental impact of these systems, particularly their carbon footprint. Enteric methane production represents the largest source of greenhouse gas emissions from livestock. Certain forage legumes have evolved plant secondary compounds, such as tannins and other polyphenols, which have been associated with reductions in enteric methane emissions. Studies were conducted at …

Risk Of Climate-Related Impacts On Global Rangelands – A Review And Modelling Study, C. M. Godde, R. B. Boone, A. Ash, K. Waha, L. Sloat, P. Thornton, D. Mason-D’Croz, D. Mayberry, M. Herrero

IGC Proceedings (1997-2023)

Climate change threatens the ability of global rangelands to provide food, support livelihoods and deliver important ecosystems services. The extent and magnitude of potential impacts are however poorly understood. In this study, we review the risk of climate impacts along the rangeland systems food supply chain. We also present results from biophysical modelling simulations and spatial data analyses to identify where and to what extent rangelands may be at climatic risk. Although a quantification of the net impacts of climate change on rangeland production systems is beyond the reach of our current understanding, there is strong evidence that there will …

Regeneration Of Old Ungrazed Old Man Saltbush (Atriplex Nummularia) Stands In South-West Australia, S. J. Bennett, S. G. Low, D. Collins, V. Crouch

IGC Proceedings (1997-2023)

Many old man saltbush (Atriplex nummularia) stands were sown in the grainbelt of Western Australia for soil regeneration and salinity management up to 25 years ago, but have not been effectively grazed subsequently, such that the main feed available for sheep is above grazing height. The aim of the study was therefore to see if it was possible to return the old man saltbush stands to a productive grazing stand.

Two sites were chosen that had been sown up to 25 years previously in Goomalling and Corrigin, in the south-west of Western Australia. The sites were split into …

Exploring Drivers Of Invasiveness Of The Plant Species Senna Obtusifolia In Rangelands To Secure Forage Production In West Africa, O. Ouédraogo, A. Zaré, C. Bougma, S. Kambou, A. Linstädter

IGC Proceedings (1997-2023)

Rangelands in Sahelian countries are continuously over-grazed decreasing forage resources and causing rapid environmental changes. Senna obtusifolia is a less palatable plant species that becomes increasingly invasive. This research explored drivers of its invasiveness in the perspective to propose solutions to secure forage production in the pastoral reserves. Species composition and herbaceous aboveground biomass were assessed in rangelands with different levels of invasion of Senna obtusifolia along a climatic and land-use pressure gradient. A greenhouse experiment was conducted to test the competitiveness of this species. The development of Senna obtusifolia in rangelands affected significantly forage quantity. Indeed the biomass of …

Counteracting Green Alder Shrub Expansion By Low-Input Grazing, M. K. Schneider, T. Zehnder, J. Berard, C. Pauler, M. Staudinger, Michael Kreuzer, A. Lüscher

IGC Proceedings (1997-2023)

In the past decades, the decline of traditional agriculture has caused an abandonment of marginal pastures in many mountain areas of Europe. In the Swiss Alps, green alder (Alnus viridis) is the most abundant successional shrub. A survey of 24 pasture-shrub gradients showed that the encroachment by green alder, in contrast to other shrubs, is associated with a substantial decline in plant species richness. The understorey of alder is primarily populated by very few, broad-leaved herbaceous species benefitting from the atmospheric nitrogen fixed by actinomycetes in symbiosis with green alder. However, the understory vegetation also provides an underestimated …

Foraging Behaviour And Intake In Temperate Cultivated Grasslands, S. Prache, J. L. Peyraud

IGC Proceedings (1997-2023)

In temperate areas, grazing provides a large part of the nutrient requirements of ruminants and may be an important form of land use. In Europe, grassland occupies some 150 million hectares, and grazing provides about 60 to 75% of the nutrient requirements of cattle (Wilkins and Vidrih 2000). From the end of the 80’s, agricultural surpluses in Europe have led to production quotas and increased interest in more extensive systems. At the beginning of the 90’s, the emergence of the notion of sustainable agriculture combining economic, social (concerns in dereliction of less-favoured rural areas), and environmental issues (pollution, loss of …

Influence Of Sward Height, Concentrate Supplementation And Season On Grazing Activity Of Beef Cows, O. J. Gekara, E. C. Prigge, W. B. Bryan, M. Schettini, E. L. Nestor

IGC Proceedings (1997-2023)

The influence of sward height, concentrate supplementation and season on daily pattern of forage consumption of lactating beef cows grazing cool season pastures was determined. Cows (n=24; BW=535±10.8 kg) were randomly assigned to eight plots maintained at sward heights (SH) of either 4-8 cm or 8-12 cm and fed three levels of concentrate supplement: none = 0 kg/day, low = 3.12 kg/day or high = 6.24 kg/day. Cows on lower SH had greater (P < .08) forage dry matter intake and spent an additional 1.2 hours/day (P < .01) grazing compared to the higher SH. Cows on lower SH consumed 7.7 kg/day of forage dry matter and grazed 9.4 hours/day whereas those on higher SH consumed 7.1 kg/day and grazed 8.2 hours/day. Cows on lower SH grazed 0.7 hours/day (P < .06) and 0.4 hours/day (P < .08) longer at 06:00-10:00 hour and 11:00-13:00 hour, respectively, compared to the higher SH. Grazing efficiency (kg of forage consumed/hour of grazing) decreased (P < .01) as season progressed. Season influenced duration of grazing activity (P < .01). Cows grazed 0.5 hours longer (P < .01) at 06:00-10:00 hour late in summer (August) compared to spring (May) and mid summer (June/July). Cows grazed 0.3 hours longer (P < .08) at 11:00-13:00 hour during spring compared to late summer.

Nitrogen Budgets On A Pasture Under Combined Utilization Of Grazing And Cutting, Y. Kurokawa, S. Yamamoto, Y. Iijima, M. Kitagawa, F. Omata, S. Sakamoto, H. Tanaka, S. Suzuki, T. Shioya

IGC Proceedings (1997-2023)

Nitrogen budgets on a pasture being utilized for both grazing and cutting were investigated. A pasture containing tallfescue, orchard grass and white clover was divided into two areas: initially grazed (IA, 0.41ha) and grazed after cutting for hay (BA, 0.49ha). A herd of 4-5 cattle (heifers or steers of Japanese Black or Holstein) grazed at IA from 22 Apr. to 2 Jul. and grazed at both IA and BA from 3 Jul. to 21 Oct. 1999. The amount of N grazed from IA was 3 times higher than the sum of N of grazed herbage and harvested hay from BA. …

Compatibility Of Kura Clover And Cool Season Grass Mixtures In Michigan, P. Jeranyama, R. H. Leep, T. Dietz

IGC Proceedings (1997-2023)

Kura clover (Trifolium ambiguum Bieb.) is an alternative forage legume for rotational grazing in cool-season grass mixtures. However, compatibility with cool-season grasses is unknown. Seven cool-season perennial grasses were seeded into Kura clover in a rotational grazing experiment. The objectives of this study were to evaluate botanical composition, forage yield and quality of binary mixtures of cool-season grass with Kura clover. Field studies were conducted on a Nester (fine sandy loam) soil at Lake City Experiment Station, Lake City, MI. Botanical compositions in the first year of the study heavily favored grasses (avg. 74%) and Kura clover accounted for …

Master Grazer: Educating Kentucky Livestock Producers, S. Ray Smith, Garry D. Lacefield

IGC Proceedings (1997-2023)

No abstract provided.

Conserving Temperate Grasslands In Australia: Historical Constraints, Future Possibilities, Louise Gilfedder, Ian Lunt, John Morgan, Richard J. Williams

IGC Proceedings (1997-2023)

No abstract provided.

Multiple‐Use Grasslands: Integrating Forage, Biofuel, And Carbon/Phosphorus Sinks, James P. Muir, B. Lambert, G. W. Evers, T. J. Butler, K. F. Bronson, L. Stanley‐Stevens, R. D. Wittie

IGC Proceedings (1997-2023)

No abstract provided.

Recent Initiatives In Biodiversity Conservation In Grazed Temperate Grasslands And Woodlands In Australia, Ian Lunt, John Morgan, Louise Gilfedder, Richard J. Williams, Simon Foster

IGC Proceedings (1997-2023)

No abstract provided.