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Articles 1 - 30 of 389
Full-Text Articles in Weed Science
Impact On Energy Budgets In Grassland Production And Conservation Of Possible Production Of Energy From Biomass Crops, R J. Wilkins
Impact On Energy Budgets In Grassland Production And Conservation Of Possible Production Of Energy From Biomass Crops, R J. Wilkins
IGC Proceedings (1977-2023)
There is commonly a conflict between output/unit of area of land and output/unit of support-energy (SE) input. The possibility of using a proportion of the total land area for biomass energy production suggests an approach for calculating grassland output/ha unconfounded with differences in SE input. Output can be calculated for an area of land that is devoted to grassland and biomass energy crops in proportions that result in a net demand for SE of zero. Outputs of utilized metabolizable energy (UME) are related to inputs of SE for (1) grazed grass with high application of nitrogen (N) fertilizer and (2) …
Adoption Of Leucaena For Cattle Grazing In Australia, J H. Wildin
Adoption Of Leucaena For Cattle Grazing In Australia, J H. Wildin
IGC Proceedings (1977-2023)
The tree legume Leucaena leucocephala is a high-quality cattle forage in many tropical countries. For the past 30 years, cattlemen have not planted leucaena despite conclusive evidence from small grazing experiments that it improved beef production and was suited to a large area of northern Australia. Seed of four cultivars was available in the 1960s. In 1968 cv. Peru, an ex cellent forage type, was planted in a 24-ha block specifically for seed production. But little of this seed was used in Australia. There were sev.eral probable reasons for the nonadoption of leucaena. Adverse publicity on the extreme effects of …
Optimizing The Use Of Grazed Dryland Pasture In Western Oregon, T E. Bedell
Optimizing The Use Of Grazed Dryland Pasture In Western Oregon, T E. Bedell
IGC Proceedings (1977-2023)
When they are properly fertilized, western Oregon dryland pastures of subterranean dover with grasses such as perennial rp:g:rass, tall fescue, and resident annuals produce total annual dry-matter yields averaging 6,500 kg/ha. Some sites are capable of over 9,000 kg/ha. Optimum use of this forage is complicated by its highly seasonal availability. Over 50 % of the total growth occurs from late April to mid-June. Only about 10% takes place during autumn-early winter, and virtually none occurs during summer. Research shows livestock weight gains from 300 to over 700 kg/ha can be expected depending upon pasture mixture and kind of grazing …
Value Of Lucerne As A Grazing Supplement For Sheep Grazing Natural Pastures In A Semiarid Area Of Australia, D L. Michalk, G E. Robards, E A. Armstrong, J Lacy
Value Of Lucerne As A Grazing Supplement For Sheep Grazing Natural Pastures In A Semiarid Area Of Australia, D L. Michalk, G E. Robards, E A. Armstrong, J Lacy
IGC Proceedings (1977-2023)
In the central areas of New South Wales, the natural pastures are dominated by annual species that grow during the cooler months, producing good-quality grazing that is particularly abundant during spring. -However, these species mature rapidly in late spring and provide poor-quality summer grazing. The 4-year study reported here was designed to examine the value of sown lucerne, equivalent to one-third of the total area, as a supplement to be grazed mainly during late spring and summer. The availability of lucerne for spring grazing by ewes and lambs was of benefit only in one year when maturing grass seeds were …
Influence Of Grazing With Cattle On Establishment Of Forage In Burned Aspen Brushland, R D. Fitzgerald, A W. Bailey
Influence Of Grazing With Cattle On Establishment Of Forage In Burned Aspen Brushland, R D. Fitzgerald, A W. Bailey
IGC Proceedings (1977-2023)
The effect on establishment of introduced forages in aspen (Populus tremuloides) brushland of removal of suckers, by grazing with cattle early in the growing season or just before leaf fall, was investigated in central Alberta following burning of aspen forest in spring. In a year when moisture conditions were suitable, forage species were established successfully by broadcasting in spring shortly after the forest was burned. Suppression of competition from regenerating shrubs was necessary for forage seedling survival and improved establishment more when carried out early than when carried out late in the growing season. Cattle, when concentrated on the burned …
Influence Of Sward Structure Upon Herbage Intake Of Cattle Grazing A Perennial Ryegrass Sward, M H. Wade, Y.L P. Le Du
Influence Of Sward Structure Upon Herbage Intake Of Cattle Grazing A Perennial Ryegrass Sward, M H. Wade, Y.L P. Le Du
IGC Proceedings (1977-2023)
To examine the influence of structural distribution of herbage within a sward on intake by grazing animals, two swards of contrasting structure were established at two periods in the grazing season by either infrequent mowing (C) or hard sheep grazing (G) of a perennial ryegrass (Lolium perenne) pasture. The plots were then allowed to grow undisturbed for about 5 weeks before being grazed by young cattle for periods of 2 weeks at two levels of herbage allowance, 30 and 60 g dry matter/kg live weight/day, in July (1) and in September (2). Detailed measurements of sward structure were …
Methodology For Determining Pasture And Animal Response Differences In Unbalanced Experiments With Intercorrelations Among Treatments, J C. Burns, R W. Harvey, F G. Giesbrecht
Methodology For Determining Pasture And Animal Response Differences In Unbalanced Experiments With Intercorrelations Among Treatments, J C. Burns, R W. Harvey, F G. Giesbrecht
IGC Proceedings (1977-2023)
Conventional statistical analyses require balanced data sets. Unbalanced data can be analyzed using regression procedures, but excessive adjustments may be needed for some treatment means. The objective of this paper is to evaluate an analysis of grazing-trial data using generalized least squares. The data was obtained from a 6-year study involving 12 treatments with not all treatments being made in all years. The analyses involved estimating variance components due to years, fields, and random error and then using these estimates to obtain adjusted treatment means. Variance-component estimates for the complete data set were similar to estimates from two balanced subsets …
Top Grazing High Protein Forages With Lactating Cows, H R. Conrad, R W. Van Keuren, B A. Dehority
Top Grazing High Protein Forages With Lactating Cows, H R. Conrad, R W. Van Keuren, B A. Dehority
IGC Proceedings (1977-2023)
Two grazing systems, top-grazing of alfalfa (Medicago sativa L.) and high-intensity grazing of orchardgrass (Dactylis glomerata L.), were investigated with three and four levels of concentrate, respectively. The concentrates consisted of corn, oats, and minerals. High dry-matter (DM) alfalfa silage fed in the barn with 40% concentrate by weight was used for a positive control ration. Three- or 4-day grazing periods/paddock were used with 16- and 24-day rotation cycles for orchardgrass and alfalfa, respectively. Using alfalfa without concentrate resulted in mean daily yields of 20.2 kg of milk and 0.65 kg of protein. As amounts of concentrates were increased, daily …
Relation Of Animal Production To Stocking Rate On Cultivated Pastures In Cerrados Areas Of Brazil, C J. Escuder
Relation Of Animal Production To Stocking Rate On Cultivated Pastures In Cerrados Areas Of Brazil, C J. Escuder
IGC Proceedings (1977-2023)
The relationships among stocking rate, gain/animal, and gain/ha were compared on six grazed pastures. The experiment was established on an oxisol acrustox in Brazil. The pasture consisted of (1) jaraguagrass (J); (2) jaraguagrass plus legumes (J + L); (3) molassesgrass (M); (4) molassesgrass plus legumes (M + L); (5) pangolagrass (P); (6) Pangolagrass plus legumes (P + L); (7) mixture of grasses (jaragua, molasses, and pangola) plus legumes (JMP + L). Pasture of pangolagrass alone was discarded because of poor establishment. Four stocking rates were applied on each pasture, from 1.0 to 3.4 animals/ha. For all pastures, gains/animal decreased linearly …
Physiology Of Growth Of A Grazed Sward, E L. Leafe, A J. Parsons
Physiology Of Growth Of A Grazed Sward, E L. Leafe, A J. Parsons
IGC Proceedings (1977-2023)
To improve our understanding of grassland utilization under grazing, the physiology of a grazed sward was investigated. An enclosure method, infrared gas analysis, and radiocarbon were used to measure sward and single-leaf photosynthesis and assimilate utilization. Intake by sheep was also measured. Expanding and recently expanded leaves had high rates of net photosynthesis but leaf sheaths, whose projected area in a "hard" grazed sward equaled that of the lamina, had low efficiency and contributed little to canopy photosynthesis. But because high leaf efficiency did not compensate for the small leaf area, canopy photosynthesis decreased markedly as grazing intensity increased. Twice …
Leucaena - A Permanent Dry Season Forage In Australia, J H. Wildin
Leucaena - A Permanent Dry Season Forage In Australia, J H. Wildin
IGC Proceedings (1977-2023)
Leucaena (Leucaena Jeucocephala) can play an important role in alleviating the general low pasture quality during the dry season. Extensive commercial use of leucaena for cattle grazing commenced in central Queensland in 1980 when the grazing management of this tree legume was modified to suit Australian beef producers. Plantings increased from 30 ha in 1979 to 3000 ha in central Queensland by February 1985. This rapid expansion can be attributed to beef producers being more aware ofleucaena management and benefits based on several commercial successes. Mimosine toxicity has not been a problem when cattle have access to tree …
The Role Of Sward Adaptations In Buffering Herbage Production Responses To Management Manipulation, S A. Grant, J King, G T. Barthram
The Role Of Sward Adaptations In Buffering Herbage Production Responses To Management Manipulation, S A. Grant, J King, G T. Barthram
IGC Proceedings (1977-2023)
The aim of this study is to improve understanding of sward responses to grazing manipulation so that objective guidelines for management may be provided. Rates of growth and senescence per tiller, tiller population densities and the photosynthetic efficiency of the sward canopy were measured at intervals on Lolium perenne dominated swards under contrasting management regimes involving steady-state and controlled fluctuations in sward conditions. The results suggest that the combination of changes in tiller populations, sward structure and photosynthetic efficiency and in the balance between growth and senescence per tiller act as a buffer such that net production varies little within …
Herbage Consumption Control Of Herbage Production, W Harris
Herbage Consumption Control Of Herbage Production, W Harris
IGC Proceedings (1977-2023)
Application of a technique whereby predetermined amounts of herbage are removed according to estimates of seasonal changes of feed requirement of livestock is described with reference to three experiments. Common objectives of these experiments were to elucidate differences of results obtained from cutting and grazing experiments, to minimise land area and resource to evaluate pasture under constraints prevailing in real farm situations, and to examine relationships between herbage consumption, standing herbage mass, herbage accumulation rate, and herbage and botanical composition. The first experiment, using cutting, showed interaction between stocking rate and rotational as compared to continuous defoliation management. The second …
The Effects Of The Different Cultivars Of Orchardgrass, S143 And Aonami, On Botanical Composition In Perennial Ryegrass/ Orchardgrass/ White Clover Pasture, T Suyama, T Mitamura, S Murasato, Y Takimoto, K Nishimura, H Takeda, E Tsuneishi
The Effects Of The Different Cultivars Of Orchardgrass, S143 And Aonami, On Botanical Composition In Perennial Ryegrass/ Orchardgrass/ White Clover Pasture, T Suyama, T Mitamura, S Murasato, Y Takimoto, K Nishimura, H Takeda, E Tsuneishi
IGC Proceedings (1977-2023)
The experiment was conducted to determine the effect of two cul ti vars of orchardgrass, S143 and Aonami, on the botanical composition of pasture under the precursor-follower grazing system. Each cultivar was sown as a main component in the mixture with perennial rye grass and white clover. The herbage mass in the pasture with Sl 43(Sl 43-pasture) was less than that in the pasture with Aon
Comparison Of Energy Conversion During Forage Production And Supplemental Investment Efficiencies In Different Livestock Feed Production Systems, T Akiyama, M Shiyomi, S Takahashi
Comparison Of Energy Conversion During Forage Production And Supplemental Investment Efficiencies In Different Livestock Feed Production Systems, T Akiyama, M Shiyomi, S Takahashi
IGC Proceedings (1977-2023)
Solar and supplemental energy dynamics were compared for several years in three different livestock feed production systems including, a) double cropping with barley and corn for whole-crop-silage, b) perennial cutting meadow of orchardgrass for hay-making, and c) grazing by fattening Holsteins with six cool-season grasses. The results obtained are; (1) In the double cropping system, the plot receiving slurry manure (S2) maintained the highest energy yield (3.86xl05MJ, 92,350 Meal of energy for each hectare of land, or 0.94% of overall efficiency as compared to global solar radiation) throughout the 5-year experimental period. (2) From the orchardgrass meadow, 1. 93x105MJ, 46,130 …
Pasture Improvement In Several South Pacific Islands, B Toutain
Pasture Improvement In Several South Pacific Islands, B Toutain
IGC Proceedings (1977-2023)
Summary of past and present studies by French organizations of agronomic research regarding the establishment and management of tropical pastures. A review of stages for pasture improvement on several islands in the South Pacific and suggested future management needs for various tropical pasture species. Final results would give producers in developing countries a choise of species with its associated management, depending on the amount of inputs contributed by the grower.
Winter And Spring Growth Variability Of Grazed Permanent Meadow: The Case Of The Pyrenees Mountains, M Duru
Winter And Spring Growth Variability Of Grazed Permanent Meadow: The Case Of The Pyrenees Mountains, M Duru
IGC Proceedings (1977-2023)
In the Central Pyrenees, winter and early spring growth of permanent meadows provides available feed for flocks. Therefore, we studied the main factors of variation of this growth (soil fertility level, nitrogen fertilization, climate, ... ) to improve pasture availability. During three winters and springs, we measured the growth on three plots of different fertility level (0.108 % - 0.045 % - 0.018 % P205 Dyer) at an altitude of 1250 m. We set a value on growth by measuring cumulated dry matter every three weeks (or less often it there was snow) from November to April. The harvested dry …
The Effects Of Burning And Grazing On The Population Dynamics Of The Native Savanna Of Colombia, H Hayashi, Luis E. Tergas
The Effects Of Burning And Grazing On The Population Dynamics Of The Native Savanna Of Colombia, H Hayashi, Luis E. Tergas
IGC Proceedings (1977-2023)
A series of studies designed to clarify the characteristics of the native savanna in the Colombian Eastern Plain (Llanos Orientales) was carried out. A detailed study of population dynamics of the savanna with and without burning under different stocking rates is described. Density of vegetation in the burnt plot increased year by year, whereas that of the unburnt plots decreased year by year. After the third dry season the differences of density compared with those before the treatments were 111 % for the burnt plot and -41 % mean for the unburnt plots. The density of Trachypogon vestitus and forbs …
Herbage Dry Matter Yield And Nitrogen Content Of A Reproductive Growth According To Spring Management Case Of Permanent Meadows In The Pyrenees Mountains, M Duru
IGC Proceedings (1977-2023)
In mountains farming systems, the wintering is the principal constraint because hay stock by ewe is low and has poor feed value. The objective of this research is to show the effect of spring management (fertilization, grazing) on the reproductive growth. We measured herbage dry matter on three plots of different fertility levels (0.108 % - 0.045 % - 0.018 % P205 Dyer) at an altitude of 1250 m. We show that the net starting growth is afunction of the soil fertility level (we observed differences of a month between plots). Consequently, the grazing effect on the regrowth does not …
Maintenance Of Lolium Perenne L. In Mixture, K Sato, R Meguro, T Nomoto, M Nashiki
Maintenance Of Lolium Perenne L. In Mixture, K Sato, R Meguro, T Nomoto, M Nashiki
IGC Proceedings (1977-2023)
Lolium perenne L. (PRG) is one of the promising species in the northern Japan. However, this species is utilized less widely due to short persistency. The study was conducted to clarify the proper conditions for maintenance of this species in the context of defoliation treatments. The grasslands mixed with Dactylis glomerata L. (OG), Festuca arundinacea Schreb. (TF), Poa pratensis L. (KBG) and PRG were established and botanical composition of this mixture were measured in terms of Summed Dominance Ratio (SDR) under grazing (3 Japanese Black Cattle per ha) and cutting (3 times a year) conditions. PRG were maintained well …
Seasonal Beef Performance On Au Triumph And Kentucky 31 Tall Fescue At Three Fungal Endophyte Infection Levels, J P. Pedersen, S P. Schmidt, C C. King Jr, C S. Hoveland, J A. Mcguire
Seasonal Beef Performance On Au Triumph And Kentucky 31 Tall Fescue At Three Fungal Endophyte Infection Levels, J P. Pedersen, S P. Schmidt, C C. King Jr, C S. Hoveland, J A. Mcguire
IGC Proceedings (1977-2023)
Greatly improved performance has been reported from cattle grazing tall fescue (Festuca arundinacea Schreb.) free of Acremonium coenophialum Morgan-Jones and Garns compared to those grazing heavily infected tall fescue. However, cultivar effects and the effects of intermediate infection levels have not been adequately explored. Therefore, a 3-year grazing study was conducted in west-central Alabama to compare beef steer performance on non infected 'AU Triumph' and 'Kentucky 31' tall fescue at three levels of A coenophialum infection. A. coenophialum infection levels of 0% on AU Triumph and 1, 34, and 90% on Kentucky 31 resulted in average daily gains (ADG) …
Consommation Par Des Caprins De Quercus Ilex Et Quercus Pubescens Dans Un Taillis Mediterraneen, M C. Leouffre, E Lecrivain, B Leclerc
Consommation Par Des Caprins De Quercus Ilex Et Quercus Pubescens Dans Un Taillis Mediterraneen, M C. Leouffre, E Lecrivain, B Leclerc
IGC Proceedings (1977-2023)
Abandonnes depuis une cinquantaine d'annees, Jes massifs forestiers du sud-est de Ia France s'embroussaillent, Jes risques d'incendie augmentent alors que des eleveurs caprins a la recherche de ressources fourrageres pour !es troupeaux sont prets a utiliser ces milieux, done a participer a leur entretien. Afin de bien gerer l'espace et de controler )'impact des caprins, une etude a ete effectuee sur la consommation des deux principales especes ligneuses des taillis mediterraneens.
Evolution Et Degradation D'Un Ecosysteme Pature En Zone Soudano-Guineenne Au Cameroun, G Rippstein
Evolution Et Degradation D'Un Ecosysteme Pature En Zone Soudano-Guineenne Au Cameroun, G Rippstein
IGC Proceedings (1977-2023)
L'Adamaoua est un vaste plateau situe en Afrique Centrale entre Jes 6° et 8° de latitude nord et Jes 10° et 16° de longitude est a des altitudes comprises entre 900 et I 500 m. Le climat y est soudanien avec une saison des pluies de 7 a 9 mois et I 600 a 1 800 mm de precipitation. Les observations foites en station ont montre des modifications relativement foibles de la contribution des especes et des biomasses avec Jes feux, le paturage, Jes chargements moderes, Jes systemes d'exploitation et Jes repos periodiques frequents (Rippstein, 1985). Nous rapportons ici Jes …
Comportement Alimentaire D'Un Troupeau Ovin Dans Un Systeme , A Ben Boubaker
Comportement Alimentaire D'Un Troupeau Ovin Dans Un Systeme , A Ben Boubaker
IGC Proceedings (1977-2023)
En Tunisie, pour freiner !'erosion et satisfaire Jes besoins pressants des animaux domestiques, des plantations de Acacia cyanophylla (Lindi) destinees a etre paturees ont ete creees. Pour rechercher une gestion rationnelle de ces parcours, nous avons etudie notamment le comportement des ovins dans un systeme « Acacia-herbe » partiellement fertilise. L'etude a ete realisee dans la region de Beja (Nord-Ouest de la Tunisie) sous climat mediterraneen sub-humide a hiver doux, sur sol brun calcaire (facies vegetal a Hedysarum coronarium L. et Phalaris truncata L.)
Une Methode D'Etude Et De Classification Des Paturages De Savane, G Rippstein
Une Methode D'Etude Et De Classification Des Paturages De Savane, G Rippstein
IGC Proceedings (1977-2023)
Pour suivre !'evolution et la degradation des paturages naturels (savanes arbustives) du Plateau de l'Adamaoua, au centre du Cameroun, sous l'effet des feux, des chargements, de leur envahissement par les ligneux et des systemes d'exploitation, nous avons ete amenes a deveiopper une methode d'etude et de classification de ces paturages qui couvrent pres de 10 millions d'hectares. La methode recherchee devait etre precise et utilisee eventuellement par des non-specialistes en agro-pastoralisme et applicable sur toute la region. Elle nous a amene a definir une « valeur pastorale » des formations herbacees.
Improving Animal Performance By Grazing Clovers, C P. Bagley, J I. Feazel, C C. Willis
Improving Animal Performance By Grazing Clovers, C P. Bagley, J I. Feazel, C C. Willis
IGC Proceedings (1977-2023)
Warm-season perennial grasses, such as 'Coastal' bermudagrass (Cynodon dactylon L.), are characterized as being relatively high in yield capabilities but low to moderate in forage quality as compared with cool-season grasses (Wilson, 1984). Legumes can be interseeded into grass sods which can increase both forage yield (Knight, 1970) and animal performance (Blaser et al., 1956; Bagley et al., 1988). Performance of stocker animals has been shown to be much lower during the summer on bermudagrass compared with similar weight steers grazing ryegrass (Bagley, 1987). Legumes may be capable of extending the high performance grazing season of stocker beef past …
Production Intensive De Viande Bovine Sur Des Paturages De Haute Belique, M Gielen, P Limbourg, L Istasse, J M. Bienfait
Production Intensive De Viande Bovine Sur Des Paturages De Haute Belique, M Gielen, P Limbourg, L Istasse, J M. Bienfait
IGC Proceedings (1977-2023)
La prairie permanente occupe une place dominante dans l'economie agricole des regions situees dans le Sud-Est de la Belgique. Cette situation est due a des conditions pedologiques, geographiques et climatiques particulieres, a savoir une altitude elevee pour le pays ( ± 500 m), une pluviosite annuelle reguliere ( ± 1000 m) et une temperature moyenne de !'air faible (7-8°C). Une autre caracteristique de ces regions est la presence d'un important cheptel bovin destine a la production de viande. Ce cheptel de race Blanc Bleu Beige est conduit de plus en plus en systeme de vaches allaitantes avec des periodes de …
Utilization Precoce Du Paturage Par Les Veaux D'Origine Laitiere, R Giovanni
Utilization Precoce Du Paturage Par Les Veaux D'Origine Laitiere, R Giovanni
IGC Proceedings (1977-2023)
La mise a l'herbe precoce des veaux doit favoriser ulterieurement leur aptitude au paturage et !'expression de leur potentiel de production a partir de l'herbe, tant pour les males futurs producteurs de viande que pour les genisses de remplacement. Cette technique d'elevage etait a etudier afin de renforcer le role de la prairie paturee par !es jeunes ruminants et de reduire ainsi le co-Gt de leur croissance. Une serie d'experimentations a ete entreprise pour conna'itre les conditions du paturage des veaux nes en fin d'hiver, sevres precocement et mis a l'herbe peu apres. Le poids vif a la mise a …
Efficiency Of Grazing On Growth And Nutrient Intake Of Dairy Heifers, M Okamoto, I Iketaki, N Hasegawa, N Yoshida
Efficiency Of Grazing On Growth And Nutrient Intake Of Dairy Heifers, M Okamoto, I Iketaki, N Hasegawa, N Yoshida
IGC Proceedings (1977-2023)
Grazing has traditionally been recognized as one of the most important labor-saving means in which herbage can be utilized more economically. However, in Japan, the practice of grazing is declining due to improved farm management - more animals per farm, greater harvest yield per area and higher production performance. Grazing animals tend to be healthier and more productive than animals kept in confinement. In addition, feed cost of raising dairy heifers on high pasture system is reduced by more than 50 % relative to the conventional (dry lot) system and to 65 % when the cost oflabor and facilities are …
Aspects Of Reseeding Old Permanent Pasture, N Culleton
Aspects Of Reseeding Old Permanent Pasture, N Culleton
IGC Proceedings (1977-2023)
Grassland occupies some 89 % of the arable land in Ireland (anon., 1984) and of this approximately only 3 % is reseeded annually. Many permanent pastures have poor botanical composition. Frame and Tiley (1988) pointed out that quantity and quality of secondary grass species are inferior to Lolium perenne. Nonetheless, there is evidence that permanent pastures have high animal production potential and that the large responses to reseeding in the first harvest year are rapidly lost (Wilkins et al., 1987). This paper compares new and old pastures under grazing and silage regimes.