Digital Commons Network^™

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 (1977-2023)

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 …

Bee-Friendly Beef: Developing Biodiverse Pastures To Increase Ecosystem Services, J. Wagner, S. Ghajar, M. O’Rourke, B. Tracy

IGC Proceedings (1977-2023)

The capacity of grasslands to provide ecosystem services, such as pollinator resources, is often limited by lack of plant biodiversity. This is true of grasslands in the eastern US that are dominated by tall fescue (Festuca arundinacea) a non-native, cool-season grass that is typically toxic to cattle. This paper summarizes a research project in Virginia, USA exploring the idea that ecosystem services provided by tall fescue-dominated grasslands can be improved by increasing the plant biodiversity available to beef cattle and bees. Within three 6.5 ha tall fescue grasslands, we established 0.8 ha plots with a 17 species mix …

Rangeland In Marajó Island, Brazilian Amazon, A Long History Of Commons For Small-Breeders, T. Barbosa, M. Opplert, R. Folhes, S. Carvalho, Jean François Tourrand

IGC Proceedings (1977-2023)

Rangelands cover almost one third of the earth's surface and are characterized by a low productivity and high sociocultural value. But the lack of recognition of the environmental, social and economic values of rangelands, along with the expansion of agribusiness, tourism and urban sprawl give rise to a rangeland dilemma. This dilemma is found in various regions of the world, where this set of factors leads to the generally irreversible destruction of the rangeland. The process is recent in the Amazon rangeland, such as the eastern part of Marajó Island and the Low Amazon wetlands. A survey conducted on 90 …

Effects Of Herding On Rangeland Use Efficiency In Kenya, A. Seidel, F. Asch, B. Warth

IGC Proceedings (1977-2023)

Within each foraging itinerary, herders can intervene in the forage selection process, encouraging herds to use highly palatable and less palatable rangeland resources. Such a herding strategy could prevent rangeland degradation and increase livestock productivity. The objectives of this study were to examine forage availability and identify factors influencing stocking rates around night resting places on a ranch in Laikipia County, Kenya.

Forage availability was measured along six regularly spaced transects around night resting places corralling one herd of camels, one mixed herd of goats and sheep, and two herds of cattle, with biomass sampling points at 50-, 150-, 250-, …

Livestock Policy In Special Areas, Alberta, Canada, P. L. Strankman

IGC Proceedings (1977-2023)

Special Areas, Alberta, Canada, is a rural municipality of 2.1 million hectares (about 5 million acres) in south-eastern Alberta. It is home to almost 5000 residents, with a unique governance arrangement in Alberta. Most of the farms and ranches utilize a mix of crop and livestock primarily annual cereal and oil seed cultivation and beef cattle. These production units are usually a mosaic of privately-owned land and Crown land leased from the government.

It provides an interesting case study for the local, and national challenges facing western Canadian agriculture. It also provides an opportunity to contrast with different bioclimatic and …

Collaborative Construction Of A Method That Contributes To Improve The Decision Making In Associative Ranches By Controlling The Grass Allowance In A Context Of Climate Variability, Emilio Duarte Esteves, Rómulo Cesar, Javier Fernández, Marcelo Ghelfi, Valentina Herrera, Virginia Caravia, Rodrigo Iribarne, Federico De Brum, Héctor Rodríguez, Marcelo Pereira Machín

IGC Proceedings (1977-2023)

Pasture management and the particular conditions of each year are responsible for productive results, farm income, and condition of the pasture. A simple and robust method that relates the available grass and the required grass was built in a participatory manner, and contributes to a critical reflection process among the group of decision-making, adapting to their context. In 17 farms from the Basalt region in Uruguay, grass and animals were monitored seasonally. A simple method was developed with farmers, and from de offer needed to meet production targets (KgMS/KgPV) the amount of grass requires was calculated. The grass height was …

Transcriptomics Reveals The Putative Mycoparasitic Strategy Of The Mushroom Entoloma Abortivum On Species Of The Mushroom Genus Armillaria, Rachel A. Koch, Joshua Herr

Department of Plant Pathology: Faculty Publications

During mycoparasitism, a fungus—the host—is parasitized by another fungus—the mycoparasite. The genetic underpinnings of these relationships have been best characterized in ascomycete fungi. However, within basidiomycete fungi, there are rare instances of mushroom-forming species parasitizing the reproductive structures, or sporocarps, of other mushroom-forming species, which have been rarely investigated on a genetic level. One of the most enigmatic of these occurs between Entoloma abortivum and species of Armillaria, where hyphae of E. abortivum are hypothesized to disrupt the development of Armillaria sporocarps, resulting in the formation of carpophoroids. However, it remains unknown whether carpophoroids are the direct result of a …

Algal Biodiversity Survey Of The Middle Chattahoochee River Using Dna Metabarcoding, Amanda Howell

Theses and Dissertations

Aquatic plants play vital roles in water systems by providing ecological services, and one group that is understudied is algae. Algae play a crucial role in water systems as bioindicators and primary producers. They can be challenging to identify with the naked eye, so researchers have been using DNA metabarcoding, where DNA belonging to specific taxa can be isolated and identified from water samples. The objective of this study was to conduct an algal biodiversity survey on the middle Chattahoochee River system in Georgia. Water samples (1L) were filtered and sent to RTL Genomics for sequencing and processing; the data …

Searching For Molecular Markers For Salt Tolerance In Rhodes Grass (Chloris Gayana Kunth), E. Taleisnik, M. Salgado, M. D. Bonafede, L. E. Manghers, H. Pérez, L. García Seffino, A. Castagnaro, D. G. Díaz

IGC Proceedings (1977-2023)

Rhodes grass (Chloris gayana Kunth), a C4 forage grass, is regarded as salttolerant and exhibits intra- and inter-cultivar variability for this trait. Plants of cv Boma were selected for salt tolerance at the seedling and adult stages, cloned and characterized by RAPD and AFLP amplification patterns. Both techniques were equally efficient for fingerprinting these clones. More bands were obtained by AFLP but the ratio of polymorphic bands and the proportion present only in tolerant clones were the same by both methods. These bands, along with those exclusive for sensitive clones could be useful as markers for assisted selection.

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 …

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

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

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

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

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

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

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 …

Effects Of Redwood Bark And Leaf Leachate On Different Lichen Populations Found Within The Redwood Forest Of Arcata, Ca, Courtney Michelle Harris, Phoebe Hughes

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

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

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

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

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

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

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

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

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.

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

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

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

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 …