Plant Pathology Commons^™

Contrasting Impacts Of Grazing On Soil Properties And Plant Communities Between Semiarid And Temperate Rangeland Ecosystems, Eduardo Medina-Roldán, Jorge Paz-Ferreiro, J. Tulio Arredondo, Elisabeth Huber-Sannwald, Richard D. Bardgett

IGC Proceedings (1977-2023)

We discuss how grazing by large herbivores as a land use option does not necessarily involve a trade-off in terms of soil carbon (C) storage, by presenting results from field grazing gradient experiments from rangeland ecosystems under different climatic conditions in semiarid grasslands from Central Mexico and temperate ecosystems from Northern England. In general, moderate grazing pressure did not reduce soil C in both ecosystems after comparisons with long-term grazing exclusions, and moderate grazing even showed higher soil C in the semiarid area. In the semiarid area, our results are likely explained by grazing tolerance of plant species in moderate …

Palatability Of Psolarea Spp. Accessions Offered As Micro-Swards To Dairy Sheep, Mauro Decandia, Marco Acciaro, Maria Sitzia, Andrea Cabiddu, Carla Manca, Valeria Giovanetti, Giovanni Molle

IGC Proceedings (1977-2023)

Psoralea bituminosa C.H. Stirton (syn. Bituminaria bituminosa L.) is a perennial legume usually considered of low palatability because of the strong smell that can be emitted by oil glands located on its foliage. However the nutritive value of P. bituminosa in terms of forage composition and digestibility was proven similar to or even better than that of other legumes. The aerial part of this species may contain a high concentration of furano-coumarins, out of which psoralen and angelicin are the most abundant (Pecetti et al. 2007). These substances could be harmful to animals, being responsible for contact photodermatitis, in …

Is There Genetic Diversity In The ‘Leucaena Bug’ Synergistes Jonesii Which May Reflect Ability To Degrade Leucaena Toxins?, Jagadish Padmanabha, Michael J. Halliday, Stuart E. Denman, Carl K. Davis, H. Max Shelton, Chris S. Mcsweeney

IGC Proceedings (1977-2023)

Leucaena leucocephala, a nutritionally rich forage tree legume, contains a non-protein amino acid, mimosine, which is degraded by ruminal bacteria to toxic metabolites 3,4-DHP and 2,3-DHP resulting in goitre-like symptoms in animals, severely restricting weight gain. Raymond Jones, in the early 1980s, discovered the ‘leucaena bug’ in the rumen of goats in Hawaii that degraded these toxic DHP metabolites into non-toxic compounds (Jones and Lowry 1984) which was named Synergistes jonesii (Allison et al. 1992) Subsequently, a rumen inoculum containing S. jonesii was used as an ‘oral drench’ for cattle, kept in continuous culture (Klieve et al. …

Rates Of Urinary Toxin Excretion In Unprotected Steers Fed Leucaena Leucocephala, Joseph H. O’Reagain, Sam R. Graham, Scott A. Dalzell, H. Max Shelton

IGC Proceedings (1977-2023)

Leucaena (Leucaena leucocephala) is a productive, nutritious, leguminous forage tree with high capacity for ruminant live weight gain. The plant does however contain the non-protein amino acid mimosine which is degraded within the rumen to 3-hydroxy-4(1H)-pyridone (3,4-DHP) with potential to cause adverse effects on animal health and production. Stock can be protected via rumen inoculation with the bacterium Synergistes jonesii, which is capable of degrading the toxin. However surveys have demonstrated sub-clinical toxicity is persisting in Queensland herds (Dalzell et al. 2012).

Currently, testing for toxicity involves analysis of urine samples using high performance liquid chromatography …

Prevalence Of Dhp Toxicity And Detection Of S. Jonesii In Ruminants Consuming Leucaena Leucocephala In Eastern Indonesia, Michael J. Halliday, Tanda Panjaitan, Jacob Nulik, H. Dahlanuddin, Jagadish Padmanabha, Chris S. Mcsweeney, Sulaiman Depamede, Debora Kana Hau, Kurniawan, Muhammad Fauzan, Sutartha, Baiq Tutik Yuliana, Charles Pakereng, Putri Ara, Dessy Liubana, Resti G. Edison, H. Max Shelton

IGC Proceedings (1977-2023)

Leucaena leucocephala (leucaena) is a productive forage tree legume widely used in eastern Indonesia. While highly nutritious, it possesses the toxin mimosine which adversely affects animal production. In ruminants, mimosine is readily converted to the two isomers of dihydroxypyridine (3,4-DHP and 2,3-DHP) known to cause goitre, suppress appetite, and cause severe mineral deficiencies. These adverse symptoms may be partially responsible for the reluctance of some farmers to feed leucaena.

A bacterium capable of complete degradation of DHP, Synergistes jonesii, originally discovered in Hawaii in goats consuming leucaena (Jones and Megarrity 1986), was later found in Indonesia which led to …

The Efficacy Of In Vitro Synergistes Jonesii Inoculum In Preventing Dhp Toxicity In Steers Fed Leucaena-Grass Diets, Michael J. Halliday, Hayley E. Giles, Scott A. Dalzell, Chris S. Mcsweeney, H. Max Shelton

IGC Proceedings (1977-2023)

Leucaena leucocephala (leucaena) is a valuable forage tree legume for tropical animal production that contains the toxin mimosine. The breakdown products of mimosine in ruminants (3,4-DHP and 2,3-DHP) can adversely affect their health and limit weight gains (Jones and Hegarty 1984). The rumen bacterium Synergistes jonesii, introduced into Australia in 1983 was shown to completely and rapidly degrade these toxins to safe levels (Jones and Megarrity 1986). Since 1996, an in vitro produced inoculum has been made commercially available to Australian graziers (Klieve et al. 2002). Accordingly, the issue of leucaena toxicity in Australia was thought to be …

Detection Of Toxicity In Ruminants Consuming Leucaena (Leucaena Leucocephala) Using A Urine Colorimetric Test, Sam R. Graham, Scott A. Dalzell, Graham L. Kerven, H. Max Shelton

IGC Proceedings (1977-2023)

Leucaena (Leucaena leucocephala), a productive leguminous shrub for feeding ruminant livestock, contains the toxic amino acid, mimosine which post- ingestion is converted to 3,4-DHP and 2,3-DHP, isomers of dihydroxy-pyridone. While DHP generally does not exhibit acute toxic symptoms, it has been suggested that it is an appetite suppressant that reduces animal live weight gain (Jones 1994). With no observable symptoms, subclinical toxicity is difficult to detect (Phaikaew et al. 2012). In 1982 the DHP-degrading rumen bacterium named Synergistes jonesii was introduced into Australia as a potential solution to DHP toxicity as it spreads easily throughout cattle herds …

Diurnal Urinary Excretion Of Dhp In Steers Fed Leucaena Leucocephala, Hayley E. Giles, Michael J. Halliday, Scott A. Dalzell, H. Max Shelton

IGC Proceedings (1977-2023)

Leucaena (Leucaena leucocephala) contains the toxin mimosine which is quickly degraded by rumen microorganisms to isomers of dihydroxypyridine (DHP). DHP is detrimental to animal production, causing reduced thyroid hormones, reduced weight gain, goiter and severe deficiencies in essential minerals (Tsai and Ling 1971; Hammond 1995). There are several methods of testing for exposure to DHP toxicity but the simplest is the colorimetric urine spot test (Graham et al. 2013). Several researchers have noted high variability in the excretion of DHP among animals on similar leucaena diets (Dalzell et al. 2012; Phaikaew et al. 2012) and …

Relationships Between Goat Foraging Behaviour And Pastoral Value In High Bassin Zone Of Mandrare Rangeland In Southern Of Madagascar, A. J. M. Randrianariveloseheno, J. N. Rakotozandriny, R. Daccord

IGC Proceedings (1977-2023)

Goats have particular anatomical behaviour for browsing leaves to satisfy their energy requirements. In rangelands, available shrubs, leaves and biomass resources influence ruminant’s activities and rhythms such as foraging, walking, resting, ruminating and drinking. At semi-arid areas, this study aimed to determine how shrubs interact with pasture value to effect goat foraging behaviour.

Relative Preference, Palatability And Intake Of Stylosanthes Scabra Accessions Adapted In Pretoria, Thamsanqa D. E. Mpanza, Abubeker Hassen, Ned E. F. Donkin

IGC Proceedings (1977-2023)

Inadequate supply of forage particularly during dry season is the major constraint in livestock production in sub-Saharan Africa (Anele et al. 2011). Poor management of the available feeds, seasonal variability in weather and climate changes may contribute to the high fluctuation of forage quality and quantity between season and years (Sultan et al. 2008). To improve livestock production in sub-Sahara Africa there is a need to improve feed deficiencies both in quantity and quality. Stylosanthes scabra cv. Seca was evaluated for dry season feed supplementation, and was found to be adaptive and productive under subtropical climate of Gauteng …

Modelling The Effect Of Maize Silage And Winter Oat Forage Crop On Cow-Calf Systems In Argentina, Horacio Berger, Claudio F. Machado, Carolina Zabala, Catalina Fernandez Rosso, Julio C. Burges

IGC Proceedings (1977-2023)

Cow-calf systems in the flooding Pampa - Argentina, are facing increasing competition with cropping systems for resources and land. In this context, to be more competitive livestock systems require system intensification, which demands an improvement on the feedbase. Forage crops and feeding silage have been used widely on dairy and beef cattle finishing systems. The purpose of the study was to assess with a model the level of intensification that can be achieved in cow calf systems and its economic effects by incorporating maize silage and winter grazing oat crops.

Plant Traits Relevant For Multi-Functionality Of Grassland Swards For Free-Range Chicken Husbandry, Laura Breitsameter, Matthias Gauly, Nicole Wrage-Mönnig, Johannes Isselstein

IGC Proceedings (1977-2023)

The sward of the outdoor run serves multiple important functions in free-range chicken husbandry systems. Vegetation ground cover is crucial for soil conservation. Moreover, by providing a foraging enrichment it is relevant for animal welfare (Shimmura et al. 2008). Scientific knowledge of the plant-animal interactions of swards in outdoor chicken runs is only just emerging. An understanding of these will help to improve swards both in view of the conservation of an intact vegetation cover, and for fostering animal welfare.

In the present field study, we investigated: (1) the growth of a number of grassland plant species under conditions …

Relationship Between Grazing Jaw Movements And Time Per Bite In Cattle: Effect Of Sward Structure And Grazing Methods, Jean C. Mezzalira, Lidiane Fonseca, Olivier J. F. Bonnet, Carlos C. Mezzalira, Lenilson Da Fonseca Rosa, Luan C. Pagani, Teresa C. M. Genro, Paulo C. De F. Carvalho

IGC Proceedings (1977-2023)

The time per bite is the result of the interaction between mouth morphology, animal behaviour and sward structure (Laca et al. 1994). The time per bite increases with bite mass (Laca et al. 1994), but it has a constant component that is the time required to open and close the jaws, namely, the time required for one jaw movement (Hirata et al. 2010, Newman et al. 1994). In this experiment we tested the hypothesis that the time per jaw movement will remain constant independently of sward structure and grazing method.

The Proportion Of The Ungrazed Area Of The Pasture (Pup) Determines When Forage Intake And Diet Quality Decline In Grazing Systems, Marcelo A. Benvenutti, Daniel R. Pavetti, Carlos A. Cangiano, Dennis P. Poppi, Iain J. Gordon, Jérôme Bindelle, Lucas Zakidalsky, Deli Chen

IGC Proceedings (1977-2023)

Grazing management has to deal with the spatial and temporal heterogeneity of pastures. In this context it is desirable to have a grazing management strategy that can be applied in a wide range of pasture conditions to control daily forage intake, diet quality and thus, animal performance. Sward height has been extensively studied and has been found not to be universally applicable to control the animal response as its relationship with intake changes with sward structure (Prache and Peyraud, 2001; Sollenberger and Burns, 2001) . Selective grazing is a universal phenomenon where, independently of pasture condition, cattle prefer the more …

Intake Rate And Nutritive Value Of Elephant Grass Cv. Napier Subjected To Strategies Of Rotational Stocking Management, Eliana V. Geremia, Lilian E. T. Pereira, Adenilson J. Paiva, Thiago M. Santos, Laiz P. Oliveira, Laiz P. De Oliveira

IGC Proceedings (1977-2023)

Several research papers on forage tropical grass species have demonstrated that grazing management interferes with sward structure that, in turn, alters patterns of ingestive and foraging behaviour of the grazing animals. For that reason it has been used as explicative variable for adjustments in intake characteristics like bite mass, bite rate, intake rate and nutritive value of the consumed herbage (Fonseca et al. 2012). Tall tufted growing plants like elephant grass (Pennisetum purpureum Schum.) cv. Napier show a continuous pattern of growth characterised by stem elongation during their vegetative state (Da Silva and Carvalho 2005), causing swards to …

Nutritive Value And Cattle Preferences In An Old Boer Lovegrass Stand Treated With Biosolids In Cananea, Sonora, México, Salomón M. Moreno, Martha R. Martin, Fernando Ibarra, Roque Martínez, Agustín Cabral Martell, Francisco B. Denogean, Rafael Retes

IGC Proceedings (1977-2023)

Boer lovegrass (Eragrostis curvula var. conferta) is an introduced species planted to increase productivity on deteriorated rangelands in northern Mexico. Forage production with Boer lovegrass achieves an increase of two to three fold when compared to native grasses, however, as stands became old, pasture productivity and forage quality declines due to a reduction in available nutrients causing a reduction in grazing capacity and beef production. Previous studies have shown that biosolids enhance seedling establishment, plant growth and increases forage production in the species, but no data is available to measure changes in forage quality and animal performance. This …

Volatile Plant Secondary Metabolites In Eremophila Glabra And Their Influence On Animal Foraging Preference, Stewart M. Jones, Jason Emms, Charles Price

IGC Proceedings (1977-2023)

One response to global climate change effects on Australia is to investigate the use in sustainable farming systems of native plants, which have evolved to cope in their harsh environment (Monjardino 2009). The Enrich^TM project has screened many Australian native plants for their potential use as methane reducers in ruminants, as anthelmintics, and as nutrition sources systems (Revell 2010). Eremophila glabra is one plant that shows promise in this regard, but first the foraging animal must want to eat it. This decision is assisted by the animal's assessment of the emitted volatile plant secondary metabolites (PSM) (Provenza 2007).

In …

Grazing Behaviour Of Dorper Sheep And Farmed Goats And Their Implications For Natural Resource Management In Western Nsw, Yohannes Alemseged, Ronald B. Hacker, Ian D. Toole, Warren J. Smith, Cathy M. Waters, Gavin J. Melville

IGC Proceedings (1977-2023)

The introduction of exotic herbivores into the semi-arid and arid zones of Australia resulted in dramatic change in the native vegetation (e.g. Noble and Tongway 1986; Friedel et al. 1990). Overgrazing and trampling reduced ground cover and changed species composition from dominance by perennial grasses and shrubs to dominance by annual species over extensive areas (e.g. Gunn 1986), or assisted the encroachment of woody species (Wilcox and Cunningham 1994).

It is particularly in this context that the recent introduction of new sheep breeds, reputedly hardier than traditional Merinos, and the increasing trend to farming or …

Change Of Behavior Of Bos Grunniens In The Alpine Rangeland In The Eastern Tibetan Plateau, Nobumi Hasegawa, Rende Song, Guomei Li, Xumin Cao, Masahiro Tasumi, Sachiko Idota, Akira Fukuda

IGC Proceedings (1977-2023)

Over 6 million yaks (Bos grunniens) are grazed in the alpine rangelands of the eastern Tibetan Plateau in Qinghai Province, China. Degradation of rangelands has been caused by increased numbers of domestic animals following the rise of the human population. In our previous study in northern and southern sites of Tibetan Plateau in Qinghai Province from 2003 to 2006, behavior of yaks and chemical composition of the faeces (Hasegawa et al. 2006; Hasegawa et al. 2008) and vegetation (Li et al. 2006; Song et al. 2006) were investigated and compared between the two sites, …

Microhistological Analysis Of Cows' Diet During A Severe Drought In The Semi Arid Region Of North Patagonia (Argentina), E. Schmale, L. I. Lindström, M. G. Klich

IGC Proceedings (1977-2023)

The continuous use of the livestock fields of the Middle Valley of Río Negro, North Patagonia, Argentina, combined with adverse weather conditions that occur periodically, have contributed to the degradation of rangelands. The historical annual average rainfall regime in the Valle Medio of Río Negro is 303 mm but between 2002 and 2011, the average deficit was 33%. According to the Rural Society of Choele Choel, due to the decreased forage on offer, the existence of cattle in 2011 dropped to 85,000 animals, representing 50% of the normal amount for the area. During these critical times of drought, when grasslands …