Agronomy and Crop Sciences Commons^™

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 …

The State Of Sustainable Agriculture And Agroecology Research And Impacts: A Survey Of U.S. Scientists, Marcia Delonge, Tali Robbins, Andrea Basche, Lindsey Haynes-Maslow

Department of Agronomy and Horticulture: Faculty Publications

A growing body of research suggests that although sustainable agriculture, particularly agroecology, can address challenges such as those related to climate change, ecosystem services, food insecurity, and farmer livelihoods, the transition to such systems remains limited. To gain insight into the state of U.S. sustainable agriculture and agroecology, we developed a 28-question mixed-method survey that was administered to scientists in these fields. Respondents (N=168) represented diverse locations, institutions, and career stages. They offered varied definitions of sustainable agriculture, with 40% considering economic and social well-being to be core components. Respondents identified the amount and duration of public research funding as …

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 …

Effect Of Grazing Frequency By Dairy Cows On Herb Based Pastures, Soledad Navarrete, Peter D. Kemp, Penny Back, Sarah J. Pain, Julia M. Lee

IGC Proceedings (1977-2023)

Herbage production and quality of perennial ryegrass pastures is often limited over the summer months (Powell et al. 2007). Chicory (Cichorium intybus L.) and narrow-leaf plantain (Plantago lanceolata L.) are perennial herbs that accumulate high herbage masses during late spring and summer (Powell et al 2007; Li and Kemp 2005). These perennial herbs are being used by farmers to supplement dairy cows over summer. However, there have been many cases of poor plant persistence with current management practices. The aim of this research was to determine the effect of two grazing frequencies (GF; 2 weeks and 4 …

Livestock Selective Behaviour In Natural Grasslands Challenges The Concept Of Plant Preference In The Elaboration Of A Successful Diet, Olivier J. F. Bonnet, Ian M. Cezimbra, Marcelo Ritzel Tischler, Julio C. R. Azambuja, Michel Meuret, Paulo C. De F. Carvalho

IGC Proceedings (1977-2023)

Conciliating livestock production and conservation of grassland biodiversity is now an imperative. We propose that a way to reach that goal is to take advantage of the natural tendency of herbivores to exploit environmental heterogeneity. However, it would go against the well-rooted concept that mammalian herbivores have invariable preference for some plants. Preference was defined as being “what the animal selects when given the minimum of physical constraints” (Parsons et al. 1994). But after decades of studies, the concept of preference remains particularly inefficient in predicting observed patterns of selection by herbivores (e.g. Newman et al. 1992; Parsons …

Handling Time And Bite Mass Mechanisms In Large Herbivores: Contrasts Between Sward Structure And Grazing Methods, Jean C. Mezzalira, Lidiane Fonseca, Carlos C. Mezzalira, Lenilson Da Fonseca Rosa, Luan C. Pagani, Marco A. Ebbing, Teresa C. M. Genro, Paulo C. De F. Carvalho, Carolina Bremm, Ricardo Souza Arruda Filho, Luis H. S. Correia, Carlos A. Cangiano

IGC Proceedings (1977-2023)

Grazing is a time-dependent process where jaw movements of prehension, handling and chewing compete with them (Laca et al. 1994; Ungar et al. 2006). The grazing efficiency is dependent of bite mass and time per bite. Bite mass has been related to sward structure by forage height, structural components (Cangiano et al. 2002). In rotational stocking this effect becomes more pronounced, especially under high grazing down levels. Consequently, there is a progressive reduction in short-term intake rate (Fonseca et al. in press). New management targets should be proposed based on the predominant influence of sward structure …

Management Targets To Maximize Short-Term Herbage Intake Rate, Lidiane Fonseca, Jean C. Mezzalira, Paulo C. Vieira, Lenilson Da Fonseca Rosa, Luan C. Pagani, Paulo C. De F. Carvalho

IGC Proceedings (1977-2023)

Besides grazing, the animals carry a host of other essential activities to their survival, such as rumination, vigilance and idling, and these activities compete with each other in the animal’s daily time (Fonseca et al. 2012). Therefore, any management action that provides an increase in forage intake rate, with a consequent reduction in the time necessary to achieve the daily nutrient requirements, is essential for an animal product-ion success. In this study, four experiments were performed based upon the hypothesis that different sward structures, formed by distinct sward surface heights (SSH) and levels of grazing down influence the short-term …

Dry Matter Intake, Digestibility And Diet Selection By Sheep Grazing On Reseeded And Naturally Regenerating Range Sites At Sheikan Locality, North Kordofan State, Sudan, Sahar Ezzat, Babo Fadlalla

IGC Proceedings (1977-2023)

The aim of this study was to evaluate range quality for sheep from reseeded and naturally regenerating (un-reseeded) range sites at Sheikan Locality, North Kordofan State, Sudan. The study area suffers from over-grazing, excessive tree cutting and frequent cyclic droughts, which have led to a domination of short–lived un-preferred annual plants.

Impacts Of Livestock Preference And Frequency Of Grazing On Production And Nutritive Value Of Pastures In Chile, Oscar A. Balocchi, Ignacio F. López, Juan P. Keim

IGC Proceedings (1977-2023)

Cattle are selective grazers since they only consume some plants or some parts of a plant from the pasture and avoid others. Grazing preference is affected by characteristics of the pasture such as the botanical composition, pasture surface height, herbage mass, phenological stage, digestibility, fibre content, protein and ash content. Three studies were conducted in southern Chile to determine how: 1) grazing preferences of dairy cattle was influenced by pasture mixtures and fertilisation; 2) grazing selectivity was related to tiller features; and 3) grazing leaf-stage influenced pasture quantity and quality. For the first study, fertilised pastures had higher herbage mass, …

Diet Selection By Goats On Rangeland Of North Kordofan State, Sudan, Mohammed F. M. Fatur, Babo Fadlalla, Abdelaziz K. Gaiballa, Abdelrahman E. Babiker

IGC Proceedings (1977-2023)

This study was conducted at El Demokeya forest, North Kordofan State, Sudan. The objective was to evaluate goat diet botanical composition as an indicator for pasture quality. Bite counts were obtained from seven goats in protected and open rangeland sites. Percent plant cover in the two range sites were 81.9% and 87.5% respectively. Density was 260.9 and 181.9 plants / m² respectively (P < 0.05). At flowering, goat diet contained 10.8% ± 1.12 and 11.8% ± 5.94 CP in protected and open sites respectively. At seed set CP% was 8.1 ± 1.32 and 8.2 ± 3.01 respectively (P …

How Do Plants Respond To Grazing At A Molecular Level?, Gongshe Liu, Xin Huang, Shuangyan Chen

IGC Proceedings (1977-2023)

Grazing is a multiple-component process that includes wounding, defoliation, and saliva depositing. The molecular mechanism for how plants respond to grazing in grassland is a new topic. To address this question, we performed gene expression activities within 2 to 24 hours of grazing and proteomics analysis of rice seedling, examining hundreds of genes and proteins. Some key genes in GeneChips analysis specifically researched were β-amylase, LcSUT1, LcDREB3, and FEH gene. BSA (bovine serum albumin), an important and abundant component in saliva was used to study the saliva-plant interaction in grazing. Combined with corresponding gene and grazing research by …

Faecal Near Infrared Spectroscopy To Measure The Diet Selected And Productivity Of Grazing Ruminants, Rob Dixon, Maryline Boval, Vincent Blanfort, Virginie Decruyenaere, David Coates

IGC Proceedings (1977-2023)

In ruminants near infrared spectroscopy of faeces (F.NIRS) can measure the concentrations of faecal constituents such as N and fibre. It can also directly estimate many diet attributes, including total N, fibre, digestibility and the major plant groups (e.g. monocots versus dicots, and some plant species). In some situations F.NIRS can be used to estimate voluntary intake and liveweight change, but it is difficult to encompass animal effects (e.g. lactation, maturity), pasture availability or mineral deficiencies. Application of F.NIRS, especially in conjunction with other measurements (e.g. metabolizable energy intake calculated from liveweight change, ^{13 …}

Can Grazing Behaviour Support Innovations In Grassland Management?, Paulo C. De F. Carvalho

IGC Proceedings (1977-2023)

Grazing is a fundamental process affecting grassland ecosystem dynamics and functioning. Its behavioural components comprise how animals search for feed, and gather and process plant tissues in different spatio-temporal scales of the grazing process. Nowadays, there is an increasing emphasis on grazing management and the role of the grazing animal on ecosystem services, concomitantly with a decreasing emphasis on grazing management generating animal production outputs. Grazing behaviour incorporates both approaches, which are not necessarily dichotomist. It would help in order to support innovation in grazing systems. However, it is unclear how the significant knowledge, developed in this research area since …

Local Consequence Of Global Process: Challenges Of Maintaining Pastoral Production In High Mountain Pastures Of Nepal, Lila Nath Sharma

IGC Proceedings (1977-2023)

Grassland pastures are important livelihood resources for local people in agro-pastoral production in high mountainous areas of Nepal. The character of these pastures, as part of cultural landscape, result from historical interaction of human activities and local ecological processes. Fire and grazing are two important landscape drivers that have a direct impact on the structure, diversity and composition of pastures. Recently, grasslands in many semi-arid regions of world are undergoing rapid transformation as consequence of changes in fire and grazing regimes. One conspicuous change is an abrupt proliferation of native shrub species. Migration of herders away from marginal mountain areas …

Linking Farmer Knowledge And Biophysical Data To Evaluate Actions For Land Degradation Mitigation In Savanna Rangelands Of The Molopo, South Africa, Christiaan J. Harmse, Niels Dreber, Klaus Kellner, Taryn M. Kong

IGC Proceedings (1977-2023)

The over-utilization of semi-arid savanna rangelands in the North-West Province of South Africa has resulted in profound habitat transformations. A common regional indicator of rangeland deterioration is the imbalance in the grass:woody ratio characterized by a loss of grass cover with increased shrub or tree density. This can result in profound reductions of rangeland productivity forcing farmers to apply active or passive actions to improve rangeland condition to mitigate economic losses. This study forms part of the multinational EU-project PRACTICE (Prevention and Restoration Actions to Combat Desertification: An Integrated Assessment) and aims to evaluate locally applied restoration and management actions …

Some Pasture Changes In The Eastern Steppe Of Mongolia, Dorjgotov Ariungerel, Ts Ouyntsetseg

IGC Proceedings (1977-2023)

Significant vegetation changes have been recorded in Mongolian steppe types such as Speargrass-Cleistogenes, Cleistogenes-Forbs and Filifolim sibiricum-Speargrass and these changes have been attributed to climate factors rather than human activity. Species dominance in those pasture types exhibited change that was linearly related to the degradation ratio. For example, Speargrass, which is a dominant species in the steppe and is seen as a preferred species for building sustainable grasslands, is slowly losing dominance in the eastern steppe grassland type due to heavy degradation and is replaced by a range of sedges. During the years of this study …

Role Of Fires, Herbicides And Fertilizer In Manipulating Shrub/Grass Balance In Mediterranean Grasslands, Zalmen Henkin

IGC Proceedings (1977-2023)

The decline of traditional pastoral systems has highlighted the problem of managing shrub encroachment in shrublands of the Mediterranean region, especially in marginal habitats. Ephemeral grasslands appear after fire in Mediterranean shrub communities on phosphorus-deficient soils, but natural successional processes rapidly led to their dominance. In a study, aimed at reducing the rate of successional change and extending the period of grassland dominance, phosphorus was applied after fire to improve herbaceous growth and two years later the regenerating Sarcopoterium spinosum shrubs were controlled with selective herbicide. Subsequently, the vegetation in the treated areas was monitored for more than 20 consecutive …

Role Of Competition In Restoring Resource Poor Arid Systems Dominated By Invasive Grasses, S. Mangla, R. L. Sheley, J. J. James, S. R. Radosevich

IGC Proceedings (1977-2023)

An understanding of competition intensity and importance may be a useful step in helping managers understands how to prioritize restoration efforts in resource poor environments within the semi-arid steppe. The aims of this study were to quantify the intensity of competition among invasive annual grasses and native perennial bunchgrasses, and determine the importance of competition in explaining variation in target plant biomass and survivorship in a Wyoming big sagebrush steppe community type in southeastern Oregon, USA. Addition series experiments were conducted in 2008 and 2009 among four species. Treatments consisted of monoculture densities of each species to assess intraspecific competition, …