Plant Biology Commons^™

Biomass Vertical Distribution In A Grazed Grassland Under Monoespecific And Mixed Grazing, C. Saroff, S. González, A. Ohanian, H. Pagliaricci, Y. R. Chiaramello

IGC Proceedings (1977-2023)

Mixed grazing is defined as the use of the same forage resource for more than one herbivore species. It has been shown that different herbivore species have specific grazing modalities (Black and Kenney, 1984), which may differentially modify the structure of the pasture. The aim of this study was to evaluate the biomass vertical distribution in a sward with mixed grazing.

Cattle And Sheep Mixed Grazing: 2. Competition, S. J. C. González-Montagna, Pedro A. Martínez-Hernández, R. D. Améndola-Massiotti

IGC Proceedings (1977-2023)

The outcome of mixed grazing depends on the degrees of complementarity and competition between animal species. Complementarity increases the utilisation of herbage resource but competition may be desirable when one grazing species has a higher priority ranking in the farming system. A species wins in the competition by harvesting a higher proportion of the available herbage than the other (Nicol, 1997). De Wit (1960) used the replacement series based on degrees of substitution of species, for the quantification of the outcome of mixtures experiments. The use of species equivalence is required in order to apply this approach to the analysis …

Cattle And Sheep Mixed Grazing: 1. Species Equivalence, R. D. Améndola-Massiotti, S. J. C. González-Montagna, Pedro A. Martínez-Hernández

IGC Proceedings (1977-2023)

The effects of mixed grazing of cattle and sheep depend on stocking rate (SR) and species ratio (Nicol, 1997). Calculations of SR and species ratio require the use of species equivalence. Equivalents are often estimated in terms of intake requirements related to live weight (LW), while maintenance energy requirements are calculated on the basis of LW^0.75. Freer (1981) stated that LW^0..9 would be more appropriate for comparisons of intake requirements for maintenance of sheep and cattle. Nonetheless, Nolan & Connolly (1977) stated that the equivalent is system-specific and depends on the species being considered. The objective of …

Diversity Of Diet Composition Decreases With Conjoint Grazing Of Cattle With Sheep And Goats, A. M. Nicol, M. B. Soper, A. V. Stewart

IGC Proceedings (1977-2023)

Conjoint or mixed grazing can affect the diet selected by each species (Nicol & Collins, 1990). Diet similarity coefficients are often used to compare pairs of diets (Krebs, 1999). However this approach is awkward when a number of contrasts are required in a multifactorial comparison. Species diversity is a descriptor of a particular environment. Many models provide an estimate of species diversity, the most common of these being a log-normal distribution (Tokeshi, 1996). We tested whether this model could be applied to dietary components selected from a pasture, and thus provide a coefficient of dietary diversity for the individual diets …

Elasticity Of Ingestive Behaviour And Intake In Sheep Associated With Food Diversity On Plurispecific Swards, C. Cortes, J. C. Damasceno, G. Bechet, J. Jamot, S. Prache

IGC Proceedings (1977-2023)

Animals on heterogeneous swards generally opt for a varied diet. This may stimulate their intake, unless searching constraints limit intake rate (Champion et al., 1998). However the management of plurispecific swards presents a risk of overgrazing the preferred species and undergrazing the less-preferred species. This study aimed to test the effect of type of diversity and type of management on the elasticity of ingestive behaviour and intake in sheep.

Theoretical Considerations On A One-Parameter Approach To Compare Actual And Estimated Compositions Of Multi-Component Diets, C. Elwert, M. Rodehutscord

IGC Proceedings (1977-2023)

The composition of ingested herbage mixtures can be estimated using the alkane technique (Dove & Moore, 1995), with the accuracy of the estimate assessed by linear regression of estimated and actual proportions of the dietary components (Dove, 1992). However, although the linear regression might not differ from the line of equality, large discrepancies may occur within individual components (Hoebee et al., 1998). This paper presents an approach to compare actual and estimated diet compositions using only one parameter.

Estimating Pasture Intake By Dairy Cows, Dennis R. Cosgrove, D. P. Cooper

IGC Proceedings (1977-2023)

Proper nutrient management planning minimizes the environmental impact of manure from dairy farms. Manure output from dairy cows can be predicted from feed intake (Wilkerson et al., 1997). Weighing feed and refusals each day can determine accurately the feed intake of dairy cows in confinement. Intake determination is more difficult for dairy cows on pasture (Vasquez & Smith, 2000). As part of a larger study aimed at estimating manure production of dairy cows on pasture, this study compares 3 methods for estimating pasture yield and feed intake.

An Evaluation Of The N-Alkane Technique For Determining Diet Composition In Animals Grazing Complex Swards, M. D. Fraser, J. M. Moorby, V. J. Theobald, R. Jones

IGC Proceedings (1977-2023)

The n-alkane profiles of epicuticular waxes derived from different plant species are sufficiently distinct to allow assessment of the proportions of different herbages in two-component mixtures including perennial ryegrass/white clover, heather/hill grass and rush/perennial ryegrass (Dove & Mayes, 1996). Evidence suggests the reliability of such estimates declines as the number of different dietary components increases. However, recent studies have shown analysis of additional compounds, including long-chain fatty alcohols, may improve discrimination between different dietary components. The aim of this experiment was to quantify the accuracy of such methods for determining the diet composition of animals grazing complex swards.

Estimating Pasture Intake By Cattle Using Alkanes And A Known Amount Of Supplement, E. Charmley, J. L. Duynisveld, H. Dove

IGC Proceedings (1977-2023)

The alkane ratio method for estimating pasture intake involves calculating the fecal ratio of plant (endogenous) and exogenous alkanes. This method is effective for sheep, although the delivery mechanism for the exogenous alkanes has presented challenges in cattle (Charmley et al. 2003). Dove et al. (2003) have shown that the relative concentration of components in a mixed diet can be estimated from fecal alkane concentrations using least squares methods. Further, if the amount of one dietary component is known, then the amount of all components, and hence intake, can be determined. In this trial beeswax was added to …

Using The N-Alkane Technique To Estimate The Herbage Intake And Diet Composition Of Cattle Grazing A Miscanthus Sinensis Grassland, Y. J. Zhang, Y. Togamura, K. Otsuki

IGC Proceedings (1977-2023)

Plant wax alkanes are now widely used as marker substances (Dove & Mayes 1991) for the estimation of forage intake and diet composition of grazing herbivores. The objective of this study was to evaluate this method with cattle grazing a M. sinensis grassland in Japan.

Rich Information In The Acoustic Signals From Feeding And Grazing In Ruminants, Montague W. Demment, J. R. Galli, Carlos A. Cangiano, Emilio A. Laca

IGC Proceedings (1977-2023)

Because of their impact on productivity and the environment, feeding behaviour, ingestion and rumination are critical to understand intake in grazing ruminants. Many systems, mainly mechanical, have been developed to measure ingestive behaviour. However, these systems have problems, including mechanical failure and the inability to distinguish between the complex jaw movements of prehension and ingestion (Laca et al., 1994). The sounds generated by these behaviours are rich in information that holds potential not only to distinguish and count behaviours, but also identify aspects of the nature of the foods ingested.

The Sound Of Chewing, J. R. Galli, Carlos A. Cangiano, Emilio A. Laca, M. W. Demment

IGC Proceedings (1977-2023)

Acoustic biotelemetry has been proposed as a way to count ingestive bites and chews of grazing animals. Recent work has indicated the possibility that detailed analysis of 'sounds of chewing' contains information about other characteristics of the ingestive process that can be used to study grazing behaviour of free ranging animals (Laca & Wallis DeVries, 2000), or to monitor stall-fed animals in more detail.

Development Of A 2-Dimensional Video-Acoustic Tool For Monitoring Bite Placement, Wendy Griffiths, V. Alchanatis, R. Nitzan, V. Ostrovsky, E. Ben-Moshe, R. Yonatan, S. Brenner, H. Baram, E. D. Ungar

IGC Proceedings (1977-2023)

Studies of grazing behaviour conducted at the spatial scale of a feeding station demonstrate that intake rate declines with increasing depletion, a response attributed to an increase in bite overlap (Ginnett et al., 1999; Ungar et al., 2001). In order to understand the rules that govern bite placement, a methodology is required that can map the sequential placement of bites on the sward surface. We developed a video-acoustic tool to achieve this and report the findings of using the tool on small uniform patches of herbage.

Spatial Heterogeneity Of Seasonal Grazing Pressure Created By Herd Movement Patterns On Hilly Rangelands Using Gps And Gis, A. I. Arnon, E. D. Ungar, T. Svoray, A. Perevolotsky, M. Shachak, H. Baram, R. Yonatan, E. Ben-Moshe, S. Brenner, D. Barkai

IGC Proceedings (1977-2023)

The spatial heterogeneity of grazing pressure on extensive rangelands has management implications (Adler et al., 2001) but it has traditionally been difficult to quantify. Combination of technologies based on GPS (Global Positioning System) and GIS (Geographic Information Systems) is a quantum leap in our ability to address this issue. These tools were used to estimate the spatial heterogeneity of grazing pressure at a farm scale, and examine the relation between local landscape features and local grazing pressure.

Chew-Bites, Jaw Movement Allocation And Bite Rate In Grazing Cattle As Identified By Acoustic Monitoring, E. D. Ungar, N. Ravid, T. Zada, E. Ben-Moshe, R. Yonatan, S. Brenner, H. Baram, A. Genizi

IGC Proceedings (1977-2023)

Bite rate derives from the time budget of the biting and chewing processes of intake, which are both performed by jaw movements. A new type of jaw movement was revealed by acoustic monitoring in cattle - the "chew-bite" -which chews herbage already in the mouth and harvests fresh herbage with the same jaw movement (Laca et al., 1992). Chew-biting should enable the animal to reduce the total number of jaw movements performed per bite without reducing the number of chews per bite. We examined the variation among individuals in the allocation of jaw movements between the three types, and …

First Things First: Widespread Nutrient Deficiencies Limit Yields In Smallholder Oil Palm Fields, Hendra Sugianto, Juan Pablo Monzon, Iput Pradiko, Fatima A. Tenorio, Ya Li Lim, Christopher R. Donough, Sunawan, Suroso Rahutomo, Fahmuddin Agus, James Cock, Joni Amsar, Rana Farrasati, Ridho Iskandar, Juan I. Rattalino Edreira, Shofia Saleh, Heri Santoso, Antonius P. Tito, Nadib Ulfaria, Maja A. Slingerland, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

CONTEXT: Indonesia is the most important oil palm producing country. Nearly 40% of planted area is managed by smallholders, with yields well below the potential. Efforts to increase productivity have focused on the source of planting material, with little attention paid to plant nutrition.

OBJECTIVE: To assess the degree to which current productivity in smallholder oil palm fields is limited by nutrients in scenarios with distinct sources of planting material.

METHODS: We collected detailed data on leaf nutrient concentration from 30 fields to derive minimum sampling size needed to diagnose nutrient status. Subsequently, we collected data on …

P3 And Nia-Pro Of Turnip Mosaic Virus Are Independent Elicitors Of Superinfection Exclusion, Haritha Nunna, Feng Qu, Satyanarayana Tatineni

Department of Plant Pathology: Faculty Publications

Superinfection exclusion (SIE) is an antagonistic interaction between identical or closely related viruses in host cells. Previous studies by us and others led to the hypothesis that SIE was elicited by one or more proteins encoded in the genomes of primary viruses. Here, we tested this hypothesis using Turnip mosaic virus (TuMV), a member of the genus Potyvirus of the family Potyviridae, with significant economic consequences. To this end, individual TuMV-encoded proteins were transiently expressed in the cells of Nicotiana benthamiana leaves, followed by challenging them with a modified TuMV expressing the green fluorescent protein (TuMV-GFP). Three days after …

P3 And Nia-Pro Of Turnip Mosaic Virus Are Independent Elicitors Of Superinfection Exclusion, Haritha Nunna, Feng Qu, Satyanarayana Tatineni

Department of Plant Pathology: Faculty Publications

Superinfection exclusion (SIE) is an antagonistic interaction between identical or closely related viruses in host cells. Previous studies by us and others led to the hypothesis that SIE was elicited by one or more proteins encoded in the genomes of primary viruses. Here, we tested this hypothesis using Turnip mosaic virus (TuMV), a member of the genus Potyvirus of the family Potyviridae, with significant economic consequences. To this end, individual TuMV-encoded proteins were transiently expressed in the cells of Nicotiana benthamiana leaves, followed by challenging them with a modified TuMV expressing the green fluorescent protein (TuMV-GFP). Three days after …

Cover Crops And Soil Health In Rainfed And Irrigated Corn: What Did We Learn After 8 Years?, Humberto Blanco-Canqui, Sabrina J. Ruis, Katja Koehler-Cole, Roger Elmore, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Duration of cover crop (CC) management, CC biomass production, and other factors could impact how CC affects soil health. We studied the 8-year cumulative impacts of winter rye (Secale cereale L.) CC on soil physical, chemical, and biological properties in rainfed and irrigated no-till corn (Zea mays L.)-based systems in the western US Corn Belt. Average annual CC biomass production was 0.56 ± 0.51 Mg ha⁻¹ at the rainfed site and 0.98 ± 0.95 Mg ha⁻¹ at the irrigated site. After 8 years, CC improved particulate organic matter (POM) and mean weight diameter of waterstable aggregates …

Editorial: New Insights Into Mechanisms Of Epigenetic Modifiers In Plant Growth And Development, Volume Ii, Ming Luo, Tomasz Jacek Sarnowski, Marc Libault, Gabino Ríos, Jean-Benoit Charron, Nitin Mantri, Shoudong Zhang

Department of Agronomy and Horticulture: Faculty Publications

As we have learned, chromatin modifications, including histone modifications and DNA methylation, play a key role in plant development (Ng and Bird, 1999). However, accumulated evidence shows that, besides chromatin biochemical modifications, other epigenetic regulations such as chromatin architecture also function at a pivot point to regulate plant development (Zhang et al., 2021). In this Research Topic, five research papers describe multiple developmental facets mediated by different epigenetic mechanisms besides histone modifications. These manuscripts report experimental evidence or summarize recent advances in epigenetic regulations of some important developmental genes or development-related mechanisms. This Research Topic allows readers to learn of …