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Full-Text Articles in Agricultural Science

Photoperiod Response In Pensacola Bahiagrass, Ann R. Blount, T. R. Sinclair, R. N. Gates, Kenneth H. Quesenberry, P. Mislevy, R. C. Littell Oct 2021

Photoperiod Response In Pensacola Bahiagrass, Ann R. Blount, T. R. Sinclair, R. N. Gates, Kenneth H. Quesenberry, P. Mislevy, R. C. Littell

IGC Proceedings (1977-2023)

Photoperiod response has been found to influence the growth and development of >Pensacola' derived bahiagrass (Paspalum notatum Flugge var. saure Parodi). Four selection cycles [>Pensacola= (Cycle 0), Cycle 4, >Tifton 9' (Cycle 9) and Cycle 23] resulting from recurrent restricted phenotypic selection (RRPS) of spaced-plants, were field grown in 1999 and 2000, to study photoperiod sensitivity among genotypes. Two day-length treatments were imposed on the field grown plants. One treatment, used only natural light. The second treatment imposed an extended day-length treatment using Quartz-halogen lamps, installed in the field during the fall and winter, to extend day-length to15 …


Genetic Variability Within Two Adapted Populations Of Tall Wheatgrass (Thynopyrum Ponticum) In Argentina, A. Andrés, R. Guillen Oct 2021

Genetic Variability Within Two Adapted Populations Of Tall Wheatgrass (Thynopyrum Ponticum) In Argentina, A. Andrés, R. Guillen

IGC Proceedings (1977-2023)

The genetic variability within two adapted populations of tall wheatgrass (Thinopyrum ponticum) was evaluated in Argentina, as an introductory part of a breeding programme in progress at our Institute. The final aim of this programme is to provide new cultivars of tall wheatgrass, adapted to different management systems. Two hundred fifty plants per population were grown from seeds, clonally propagated and transplanted as a spaced-plant trial in a randomized design with three replicates. The results indicated large differences between genotypes within the two populations for most attributes measured, though there were no significant differences between populations. Attributes related …


Breeding For Resistance To Strike Leaf Blight (Scolecotrichum Graminis) Of Orchardgras In Argentina, A. Andrés, M. Ruiz Diaz, J. Anonne, B. S. Rosso Oct 2021

Breeding For Resistance To Strike Leaf Blight (Scolecotrichum Graminis) Of Orchardgras In Argentina, A. Andrés, M. Ruiz Diaz, J. Anonne, B. S. Rosso

IGC Proceedings (1977-2023)

A collection of orchardgrass (Dactylis glomerata) was screened under field conditions for resistance to strike leaf blight (SLB) caused by the fungus Scolecotrichum graminis. On the whole, thirty five entries from different countries were studied by sampling ten genotypes from each origin, clonally propagated and transplanted as spaced-plant trial in a randomized design with two replicates. Plants were periodically assessed during 1996 and 1997 by estimating disease severity (percentage of leaf affected). During 1997, disease severity data were used to calculate the area under disease progress curves (AUDPC) as a complementary attribute to screen for resistance to …


High Polymorphism For Forage Production Of Lotus Corniculatus Sn Transformants, Sergio Arcioni, F. Paolocci, V. Turchetti, F. Damiani Oct 2021

High Polymorphism For Forage Production Of Lotus Corniculatus Sn Transformants, Sergio Arcioni, F. Paolocci, V. Turchetti, F. Damiani

IGC Proceedings (1977-2023)

Transgenic plants obtained from transformation of one individual of Lotus corniculatus with the maize gene Sn, a transactivator of anthocyanin pathway, were analysed for the expression of the transgene and for the accumulation of condensed tannins. A great variability was observed for these two traits. Some extreme individuals were clonally propagated and analysed for rooting ability and plant growth. Unexpectedly, a strong correlation between condensed tannin level, rooting ability and plant growth was observed. These results are discussed in order to explore new strategies to increase plant productivity in forage legumes.


Gastrointestinal Nematode Infections In Grazing Domestic Ruminants, M. Eysker Oct 2021

Gastrointestinal Nematode Infections In Grazing Domestic Ruminants, M. Eysker

IGC Proceedings (1977-2023)

World wide gastrointestinal nematode infections impair production of ruminants. Particularly in small ruminants control of these infections is seriously hampered by the development of resistance of the parasites against anthelmintic drugs. This implies that alternative control measures have to be implemented in order to maintain a sustainable ruminant industry. In this paper the various possibilities to achieve this are briefly discussed. The possibilities discussed include grazing management, vaccination, selective breeding, biological control, nutrition and the use of bioactive forages such as for instance plants containing condensed tannins. At the end it is concluded that combinations of these options should preferably …


Plant Secondary Compounds; Their Impact On Forage Nutritive Value And Upon Animal Production, T. N. Barry, D. M. Mcneill, W. C. Mcnabb Oct 2021

Plant Secondary Compounds; Their Impact On Forage Nutritive Value And Upon Animal Production, T. N. Barry, D. M. Mcneill, W. C. Mcnabb

IGC Proceedings (1977-2023)

Both the anti-nutritional and beneficial effects of secondary compounds in a range of temperate and tropical forages have been reviewed. Major secondary compounds in temperate and tropical forage plants occur in the phenolic fraction and include condensed and hydrolysable tannins, phenolic monomers and lignin. Condensed tannins (CT) bind to plant protein by pH-reversible hydrogen bonding. In temperate legume forages this reduces rumen protein degradation and can increase the absorption of essential amino acids (EAA) from the small intestine, with reactivity depending on CT concentration, molecular weight and chemical structure. Low concentrations of CT in Lotus corniculatus (20-40g/kg DM) increased EAA …


A Strategy For Detecting Natural Anthelmintic Constituents Of The Grassland Species Plantago Lanceolata, D. L. Gustine, M. A. Sanderson, J. Getzie, S. Donner, R. Gueldner, N. Jennings Oct 2021

A Strategy For Detecting Natural Anthelmintic Constituents Of The Grassland Species Plantago Lanceolata, D. L. Gustine, M. A. Sanderson, J. Getzie, S. Donner, R. Gueldner, N. Jennings

IGC Proceedings (1977-2023)

A strategy to detect anthelmintic constituents in plantain (Plantago lanceolata) using a bioassay-driven purification approach was tested. Plantain consumed by cattle may control or reduce internal parasite titers, possibly due to the iridoid glucoside aucubin. Lyophilized, ground leaves of wild P. lanceolata were extracted with 95 % ethanol or boiling water containing calcium carbonate. Partially purified extracts (0 to 250 mg ml-1), 5 μg ml-1 of the anthelmintic levamisole, or 5 mg ml-1 of aucubin were tested with sheathed bovine parasites (Ostertagia ostertagi). The percent moving worms was unchanged for water controls …


Tree Competition Reduces Cattle Growth Rates In Eucalypt Woodlands Of Queensland, T. J. Hall, J. R. Douglas Oct 2021

Tree Competition Reduces Cattle Growth Rates In Eucalypt Woodlands Of Queensland, T. J. Hall, J. R. Douglas

IGC Proceedings (1977-2023)

The wiregrass/bluegrass (Aristida/Bothriochloa) native pasture community in Eucalypt woodlands is a major cattle producing resource in Queensland. The effects of poplar box tree (Eucalyptus populnea) competition (at 5 m2/ha tree basal area) and grazing pressure on pastures and on growth of Brahman-cross steers were measured in a grazing experiment. Treatments were 2 tree competition levels (live trees or clearing) by 3 grazing pressures (low - 25%, medium - 50% and high - 75% utilisation of annual pasture growth). Pasture yield and pasture foliage cover increased for 3 years from the reduction in tree competition …


Perloline, The Forgotten Plant Alkaloid, L. P. Bush Oct 2021

Perloline, The Forgotten Plant Alkaloid, L. P. Bush

IGC Proceedings (1977-2023)

Perloline, a biologically active plant alkaloid, accumulated in vegetative tissue of tall fescue during the summer months. Perloline content increased with increased available nitrogen and light. Total perloline accumulation was greatest with NO3-N fertilizer, but greatest perloline content per unit of dry wt was measured with NH4-N. In mature plants greatest perloline accumulation occurred in the leaves and immature inflorescences, but was not detected in the seed. Leaves of meadow fescue contained the greatest amounts of perloline, tall fescue was intermediate and giant fescue, and ryegrasses and yellow foxtail had low amounts of the alkaloid. Tryptophan …


Bloat In Ruminants: The Cell Rupture Hypothesis, B. P. Berg, T. A. Mcallister, K.-J. Cheng Oct 2021

Bloat In Ruminants: The Cell Rupture Hypothesis, B. P. Berg, T. A. Mcallister, K.-J. Cheng

IGC Proceedings (1977-2023)

An alfalfa (Medicago sativa L.) cultivar with a low initial rate of digestion (LIRD), AC Grazeland B, was developed to test the hypothesis that the rate of cell rupture was a cause of frothy bloat in cattle or sheep. The amount of cell wall increases and digestibility declines as plants mature. Thus the cell rupture theory also predicts that the bloat potential of alfalfa is related to maturity. This study compared the digestibility of cell walls (NDF) in LIRD cultivars with that of a standard, Beaver, in relation to maturity and bloat incidence. Fresh alfalfa was fed to wethers …


Effect Of Storage Time And Temperature On Recovery Of Synergistes Jonesii From Rumen Fluid And Feces, W. M. Andrew, M. J. Williams, M. J. Allison, C. C. Chase Jr., C. G. Chambliss, R. S. Kalmbacher, W. E. Kunkle Oct 2021

Effect Of Storage Time And Temperature On Recovery Of Synergistes Jonesii From Rumen Fluid And Feces, W. M. Andrew, M. J. Williams, M. J. Allison, C. C. Chase Jr., C. G. Chambliss, R. S. Kalmbacher, W. E. Kunkle

IGC Proceedings (1977-2023)

Synergistes jonesii is a rumen bacterium that degrades 3,4-dihydroxypyridine (3,4 DHP), the toxic breakdown product of mimosine in leucaena (Leucaena leucocephala). Fecal culture is the most practical way to determine S. jonesii presence in zoological ruminants, particularly if feces can be collected from night penning facilities. Fresh rumen fluid and fecal or fecal slurry (sheep [Ovis spp.] only, 1:4 wt to vol. feces and culture media) from cattle (Bos spp.) and sheep, known to be colonized by S. jonesii, were subjected various storage times (0, 6, 12, and 24 h) and temperatures (5, 23, and …


Extensive Livestock Production And Emerging Social Ethics For Animals, Bernard E. Rollin Oct 2021

Extensive Livestock Production And Emerging Social Ethics For Animals, Bernard E. Rollin

IGC Proceedings (1977-2023)

The last 50 years have witnessed a dazzling array of social ethical revolutions in Western society. Such moral movements as feminism, civil rights, environmentalism, affirmative action, consumer advocacy, homosexual rights, children’s rights, the student movement, antiwar activism, public rejection of biotechnology, have forever changed the way governments and public institutions comport themselves. And this is equally true for private enterprise; to be successful, businesses must be seen as operating solidly in harmony with changing and emerging social ethics. It is arguable that morally based boycotting of South African business was instrumental in bringing about the end of apartheid, and similar …


The Importance Of Animal Comfort For Animal Production In Intensive Grassland Systems, P. H. Hemsworth, J. L. Barnett Oct 2021

The Importance Of Animal Comfort For Animal Production In Intensive Grassland Systems, P. H. Hemsworth, J. L. Barnett

IGC Proceedings (1977-2023)

Animals utilise a wide range of regulatory systems to control the conditions within their bodies or homeostasis. These regulatory systems control for example, body temperature, nutritional state, water balance, social interactions and fear and these systems react to environmental and endogenous stimuli so as to correct or prevent displacements from the optimal range. The behavioural and physiological responses utilised by the animal are usually proportional to the challenge to homeostasis. The stress response commences with the central nervous system perceiving a potential challenge to homeostasis. Once the central nervous system perceives a threat, it develops a biological response or defence …


Effect Of Caloric Stress On Milk Production And Animal Comfort, Mónica B. Sacido, F. Loholaberry, N. Sánchez, J. Intruvini Oct 2021

Effect Of Caloric Stress On Milk Production And Animal Comfort, Mónica B. Sacido, F. Loholaberry, N. Sánchez, J. Intruvini

IGC Proceedings (1977-2023)

The objective of this study was to determine the effect of the environmental factors on the animal behaviour of grazing dairy cows, estimated through the THI (Temperature-Humidity Index) and the relationship with the daily milk production, quality of milk, consumption and the detection of zeal. The study was carried out in Azul , in the province of Buenos Aires, Argentina and was developed from December 1999 to February 2000. The effect of the half shade was quantified based on the production in litres of milk/day, % protein, % fat and detection of zeal. In the period analyzed, the THI usually …


Dags In Sheep Grazing Temperate Pastures: Causes And Consequences Of Faecal Adhesion To Wool, Garry C. Waghorn Oct 2021

Dags In Sheep Grazing Temperate Pastures: Causes And Consequences Of Faecal Adhesion To Wool, Garry C. Waghorn

IGC Proceedings (1977-2023)

Dags are the accumulation of faeces on wool in the perianal (breech) region of sheep and are a common problem in sheep fed good quality ryegrass based pastures in New Zealand. Their removal, or prevention, is costly but the consequences of doing nothing are severe. There is a high correlation between dags and flystrike (development of maggots) on sheep with dags, and dags reduce fleece value, live-weight gain and reproductive performance. Information summarised here suggests a range of factors contribute to the incidence of dags: lush (high quality) feeds, high voluntary feed intakes, presence of parasites in the gastro-intestinal tract, …


Nitrogen Fertiliser Effects On Perennial Ryegrass Nutritive And Nitrate Content During The Cool Season, Joseph L. Jacobs, Frank R. Mckenzie Oct 2021

Nitrogen Fertiliser Effects On Perennial Ryegrass Nutritive And Nitrate Content During The Cool Season, Joseph L. Jacobs, Frank R. Mckenzie

IGC Proceedings (1977-2023)

A study was undertaken to determine the effects of differing levels of nitrogen (N) application (0 (N1), 25 (N2), 50 (N3) and 75 kgN/ha (N4)) during late autumn (T1), early (T2) and late winter (T3) on the nutritive characteristics and nitrate content of perennial ryegrass. Changes in crude protein (CP) for all treatments at each application time were similar irrespective of level of N application. At the commencement of all treatments, the existing CP content was highest in N3, followed by N2, N1 and N0. Nitrate content decreased throughout T1 primarily due to dry conditions, whilst during T2, levels for …


Nitrogen Concentration In Cell Wall Of Warm-Season Perennial Grasses, G. F. C. Lima, Lynn E. Sollenberger, J. E. Moore Oct 2021

Nitrogen Concentration In Cell Wall Of Warm-Season Perennial Grasses, G. F. C. Lima, Lynn E. Sollenberger, J. E. Moore

IGC Proceedings (1977-2023)

The objectives of this experiment were to evaluate the influence of N fertilizer, age of regrowth, and season on concentration of N in cell-wall fractions of three warm-season perennial grasses (limpograss, [Hemarthria altissima (Poir.) Stapf et C.E. Hubb.], bermudagrass [Cynodon spp.], and bahiagrass [Paspalum notatum Flügge]. The herbage neutral detergent insoluble nitrogen (NDIN) fraction composed almost half of total N in these grasses. Though acid detergent insoluble nitrogen (ADIN) concentrations generally were 80 g kg-1 of total N or less, this fraction is indigestible and unavailable and composes a significant portion of a nutrient that may …


Biological Behaviour Of Murrah Water Buffaloes, P. B. Alcântara, D. A. Beisman, V. B. G. Alcântara, A. M. F. Pereira Oct 2021

Biological Behaviour Of Murrah Water Buffaloes, P. B. Alcântara, D. A. Beisman, V. B. G. Alcântara, A. M. F. Pereira

IGC Proceedings (1977-2023)

Modest but constant and progressive is the importance that buffaloes are achieving at the scientific’s, producer’s and consumer’s societies. Feeding behaviour is a continuous act in animals. Motivation is a reversible process of the brain induced by external factors. So, consumption tends to be continuous until another stimulus such as satiation becomes dominant. The majority of large domestic animals is fed “ad libitum”. This originates different situations when they are over or underfed. That is the situation that makes the cyrcadian rithm an important tool to be used in order to achieve maximum gains in rangelands. For half a year, …


Effect Of Burning And Management Alternatives On Forage Litter Composition Of A Native Pasture, I. Heringer, A. V. A. Jacques Oct 2021

Effect Of Burning And Management Alternatives On Forage Litter Composition Of A Native Pasture, I. Heringer, A. V. A. Jacques

IGC Proceedings (1977-2023)

The content and quantities of nutrients in forage and litter was evaluated in native pasture under grazing, submitted to burning and alternatives practices. The experimental design was a completely randomized, with three replications. The biennial burning has no effect in nutrients contents of the forage, but in the case of litter plus senescent material the concentration of Ca and Mg decreased as compared to the systems without burning. The sod-seeding treatment increased the nutrient contents in the alive and dead tissues. Nutrient accumulation on forage tissue and litter plus senescent material, was highest in the systems without burning.


Studies On Feeding Value For Five Psammophyte Shrubs In Ningxia Region, Dongmei X., Weixian C., Sijia G., Xiangyun X. Oct 2021

Studies On Feeding Value For Five Psammophyte Shrubs In Ningxia Region, Dongmei X., Weixian C., Sijia G., Xiangyun X.

IGC Proceedings (1977-2023)

A trial was conducted on five psammophyte shrubs -Caragana intermedia, C. korshinskii, Hedysarum scoparium, H. laeve, Salix psammophylla in the post-fruit period in Ningxia, China. Chemical composition, palatability and in vitro digestibility were studied systematically. The feeding value was evaluated through Fuzzy multifactorial model. According to chemical composition, palatability and in vitro digestibility, C. intermedia, had the highest feeding value and C .korshinskii the lowest.


In Situ Dry Matter Ruminal Degradation Kinetics Of Prairie Grass And Annual Ryegrass Forage, J. R. Carrete, I. Ceconi Oct 2021

In Situ Dry Matter Ruminal Degradation Kinetics Of Prairie Grass And Annual Ryegrass Forage, J. R. Carrete, I. Ceconi

IGC Proceedings (1977-2023)

The objective of this study was to evaluate dry matter ruminal degradation kinetics, of prairie grass (Bromus catharticus Vahl.) and annual ryegrass (Lolium multiflorum), by using in sacco technique, on seven different harvesting dates. The forage was incubated in nylon bags, suspended in the rumen of four Hereford steers with a rumen fistula. The dry matter ruminal degradation was calculated through the exponential model P=a+b(1-exp(-ct)). Potential degradabilities (PD) were high and reduced across a temporal trend, ranging between 92,31 and 81,79g 100g -1 of dry matter (DM) for prairie grass (PG) and 95,06 and 77,44g 100g -1 …


Application Of Near Infrared Reflectance Spectroscopy (Nirs) To Forage Evaluation In Uruguay, D. Cozzolino, Y. Acosta, J. Garcia Oct 2021

Application Of Near Infrared Reflectance Spectroscopy (Nirs) To Forage Evaluation In Uruguay, D. Cozzolino, Y. Acosta, J. Garcia

IGC Proceedings (1977-2023)

Near infrared reflectance spectroscopy (NIRS) were used to assess the chemical composition of a wide range of forages. Nearly five hundred herbage samples covering a wide range of temperate pastures species and mixtures, previously analysed by conventional wet chemistry were scanned in reflectance with a NIRS 6500 (NIRSystems, Silver Spring, USA). The coefficients of determination in calibration (R2 ) and the errors in cross validation (SECV) were 0.98 (5.8), 0.94 (22.2), 0.97 (5.6), 0.94 (6.9) and 0.89 (19.7) for crude protein, in vitro organic matter digestibility, dry matter, ash and acid detergent fiber, in g kg –1 on a …


Seasonal Variation Of Brachiaria Spp. Quality In The Pantanal Of Mato Grosso Do Sul, Brazil, S. M. A. Crispim, E. L. Cardoso, F. Fernandes Oct 2021

Seasonal Variation Of Brachiaria Spp. Quality In The Pantanal Of Mato Grosso Do Sul, Brazil, S. M. A. Crispim, E. L. Cardoso, F. Fernandes

IGC Proceedings (1977-2023)

This study aims to evaluate the dry matter yield and the crude protein (CP) of Brachiaria decumbens and Brachiaria humidicola and soil covering by these species, considering stand lasting age and hydrologic cycle periods in the Pantanal, from November 1996 to November 1997. Dry matter yield presented differences between hydrologic cycle periods and age, and their interactions. B. decumbens and B. humidicola over 10 years comparison yielded the largest amount of dry matter yield, observed in February. B. humidicola growth rate was slower than B. decumbens. Pastures stand ages did not cause differences in crude protein, but differences have …


Continuous Digestibility Assessment Of Tropical Grasses, A. Chudy, T. Schmidt, A. Glatzle Oct 2021

Continuous Digestibility Assessment Of Tropical Grasses, A. Chudy, T. Schmidt, A. Glatzle

IGC Proceedings (1977-2023)

The feed value for cattle of three tropical grasses, Gatton (Panicum maximum cv. Gatton), Estrella (Cynodon plectostachyus) and Tifton-85 (Cynodon sp. cv. Tifton-85) was investigated during the growing period, using the method of “continuous digestibility estimation”. Results indicate that feed value is hardly influenced by the growth stage from the 90th day on. Common European in-vitro feed evaluation procedures are not to be recommended for tropical grasses as they presented consistently lower values than did in-vivo measurements.


Prediction Of Intake Of Hay Differing In Species And Maturity By Goats, S. W. Coleman, S. P. Hart, T. Sahlu Oct 2021

Prediction Of Intake Of Hay Differing In Species And Maturity By Goats, S. W. Coleman, S. P. Hart, T. Sahlu

IGC Proceedings (1977-2023)

Eight species of forage, a cool-season perennial (Festuca arundinacea) and annual grass (Triticum aestivum), four warm-season perennial grasses (Bothriochloa caucasica, B. ischaemum, Cynodon dactylon, and Tripsacum dactyloides), a warm season annual (Digitaria sanguinalis) and a perennial legume (Medicago sativa), were cut at two or three maturities to provide a wide array of quality difference (n=20). Twenty wether goats (Capra hicus) were fed the hays in four different trials using an incomplete block so that each hay was fed to four different goats. Alfalfa produced the highest DM, …


Climatic Factors, Acid Detergent Fiber, Neutral Detergent Fiber And Crude Protein Contents In Digitgrass, C. S. Chen, S. M. Wang, Y. K. Chang Oct 2021

Climatic Factors, Acid Detergent Fiber, Neutral Detergent Fiber And Crude Protein Contents In Digitgrass, C. S. Chen, S. M. Wang, Y. K. Chang

IGC Proceedings (1977-2023)

Digitgrass (Digitaria Xumifolia) was treated according to a set of programmed harvest cycles to study the impact of climatic factors on the quality of the grass. It is found that seasonal changes have greater effect on the quality of the grass than does the length of the harvest cycle. The highest correlation coefficient (0.81) between the ADF content and accumulated temperature is attained when the base temperature is set to 15.5 , while the highest correlation coefficient (0.88) between CP and is attained at a base temperature of 15.0 . The determination coefficient of regression (R2 ) …


Effect Of Level Of Surface Spoilage On The Nutritive Value Of Maize Silage Diets, K. K. Bolsen, L. A. Whitlock, G. L. Huck, M. K. Siefers, T. E. Schmidt, R. V. Pope, M. E. Uriarte Oct 2021

Effect Of Level Of Surface Spoilage On The Nutritive Value Of Maize Silage Diets, K. K. Bolsen, L. A. Whitlock, G. L. Huck, M. K. Siefers, T. E. Schmidt, R. V. Pope, M. E. Uriarte

IGC Proceedings (1977-2023)

This study determined the effect of surface spoilage in the diet on feed intake and nutrient digestibilities using growing steers fed whole-plant maize silage-based diets. A bunker silo, 0.9 m in depth, and a 2.7 m diameter AgBag were filled with alternating loads of chopped forage. After 90 days, the bunker was sealed with a sheet of polyethylene, and this silage was designated “spoiled”. The silage in the AgBag was designated “normal”. The four diets contained 90% silage and 10% supplement (dry matter basis), and the proportions of silage in the diets were A) 100% normal, B) 75% normal: 25% …


Selenium And Sulphur Concentrations In Primary Growths Of Different Plant Communities, W. Opitz Von Boberfeld Oct 2021

Selenium And Sulphur Concentrations In Primary Growths Of Different Plant Communities, W. Opitz Von Boberfeld

IGC Proceedings (1977-2023)

The factorised evaluated data of seven different grassland swards and two harvest dates of primary growths led to following results: Regarding the concentrations of selenium and sulphur, a selenium antagonist, and the N/S ratio, there were no significant plant community x harvest date, plant community x year, and harvest date x year interactions. The selenium concentrations, which never met the requirements of ruminants, were the highest in young herbage of a Bromion racemosi community reaching 49 µg kg-1 DM. The average of all swards and treatments was 33 µg kg-1 DM of selenium. Apparently, repeated application of selenate-bearing …


Canopy Characteristics, Ingestive Behaviour And Herbage Intake In Cultivated Tropical Grasslands, Lynn E. Sollenberger, J. C. Burns Oct 2021

Canopy Characteristics, Ingestive Behaviour And Herbage Intake In Cultivated Tropical Grasslands, Lynn E. Sollenberger, J. C. Burns

IGC Proceedings (1977-2023)

Compared to temperate systems, there have been few detailed assessments of canopy characteristics and associated grazing behavior in planted tropical grasslands. Reasons include the large number of forage species used in warm climates, the diversity of their morphology, research priorities emphasizing germplasm evaluation and management, and limited resources. This review describes canopy attributes of C4 grass pastures, highlights the most important relationships between grazing behavior and these canopy characteristics, and discusses the implications of canopy characteristics and grazing behavior for long-term intake and animal performance. It is suggested that the largest differences in canopy characteristics between tropical and temperate …


Foraging Behaviour And Intake In Temperate Cultivated Grasslands, S. Prache, J. L. Peyraud Oct 2021

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

IGC Proceedings (1977-2023)

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 …