Digital Commons Network^™

Foraging Strategies On Rangeland: Effects On Intake And Animal Performance, Peter O’Reagain

IGC Proceedings (1977-2023)

Rangelands exhibit extreme spatial and temporal variability in forage quality and availability. The animals that utilise these rangelands have consequently evolved a range of foraging strategies in an attempt to cope with this variability and maintain nutrient intake. In general, animals respond to and exploit spatial variability at all scales by selecting those items or units which optimise the intake of digestible nutrients and hence animal production. Animals similarly employ a variety of strategies to cope with temporal variability on rangelands. These strategies may include adjusting foraging behaviour and/or exploiting critical resources or resource areas to buffer temporal variability in …

On The Scale Dependence Of Foraging In Terrestrial Herbivores, John M. Fryxell, C. B. D. Fortin, J. Wilmshurst

IGC Proceedings (1977-2023)

Meaningful modeling of the spatial and trophic dynamics of terrestrial herbivores demands understanding of the constraints and fitness objectives that presumably underlie behavior. This is complex in terrestrial herbivores, because of scale-dependent constraints on nutrient or energy gain. Mechanistic processes of forage cropping, forage mastication, movements between feeding stations, and forage digestion each have unique constraints that apply on different time, size, and spatial scales. Moreover, competing activities are rarely taken into account. Experimental testing of foraging objectives is therefore clouded by uncertainty regarding which time scale is most relevant from the animal’s perspective, leading to confusion and misrepresentation in …

Influence Of Sward Height, Concentrate Supplementation And Season On Grazing Activity Of Beef Cows, O. J. Gekara, E. C. Prigge, W. B. Bryan, M. Schettini, E. L. Nestor

IGC Proceedings (1977-2023)

The influence of sward height, concentrate supplementation and season on daily pattern of forage consumption of lactating beef cows grazing cool season pastures was determined. Cows (n=24; BW=535±10.8 kg) were randomly assigned to eight plots maintained at sward heights (SH) of either 4-8 cm or 8-12 cm and fed three levels of concentrate supplement: none = 0 kg/day, low = 3.12 kg/day or high = 6.24 kg/day. Cows on lower SH had greater (P < .08) forage dry matter intake and spent an additional 1.2 hours/day (P < .01) grazing compared to the higher SH. Cows on lower SH consumed 7.7 kg/day of forage dry matter and grazed 9.4 hours/day whereas those on higher SH consumed 7.1 kg/day and grazed 8.2 hours/day. Cows on lower SH grazed 0.7 hours/day (P < .06) and 0.4 hours/day (P < .08) longer at 06:00-10:00 hour and 11:00-13:00 hour, respectively, compared to the higher SH. Grazing efficiency (kg of forage consumed/hour of grazing) decreased (P < .01) as season progressed. Season influenced duration of grazing activity (P < .01). Cows grazed 0.5 hours longer (P < .01) at 06:00-10:00 hour late in summer (August) compared to spring (May) and mid summer (June/July). Cows grazed 0.3 hours longer (P < .08) at 11:00-13:00 hour during spring compared to late summer.

Safflower (Carthamus Tintorius): A Promising Forage Crop For Semi-Arid Regions, Y. Leshem, I. Bruckental, S. Y. Landau, G. Ashbell, Z. Weinberg

IGC Proceedings (1977-2023)

The yield, quality, preservation and intake of safflower hay were determined in two successive years - 1998 and 1999. Field experiments carried out at the Bet Dagan experimental station on the coastal plain of Israel under rain-fed conditions. A spineless variety was tested under three sowing dates. Yield decreased and quality improved as the sowing date receded from November 12 to February 3. Respective yields, IVDMD and CP content were: 22 and 8 ton DM/ha, 48.9% and 65.5% , 10.0% and 14.6%. Safflower at 290, 410 and 770 g/kg DM was ensiled in 1.5-l anaerobic glass jars with or without …

Effects Of Different Levels Of Energy On Growth Of Grazing And Drylot Fed Holstein Heifers, L. P. Novaes, C. E. Polan

IGC Proceedings (1977-2023)

Growth of Holstein heifers were studied to evaluate the combination of a drylot phase followed by feeding energy for pasture supplementation during the grazing season of 1988. Heifers grazed a grass-legume mixture in six paddocks of 1.5 ha each. After drylot, animals were equally allotted to pasture and none or 2.0 kg/d of corn were fed in addition to grazing in a changeover design with repeated measurements. Heifers were fed a high (HE) or low energy (LE) diets in confinement and daily gains were 1190 (HE) and 990 g/day (LE) which were different. On pasture, corn supplementation did not enhance …

Leaf Fragment Identification Of Subtropical Native Grass Species, C. H. E. C. Poli, J. M. Rosito, A. G. Schirmer, P. R. Boggiano, P. C. De F. Carvalho

IGC Proceedings (1977-2023)

The present study was carried out to characterise leaf fragments of important plant species of a subtropical native sward in the southernmost state of Brazil. Thirteen important grass species were collected from April to May 1999. Both sides of the leaves were observed using a stereomicroscope. In addition, two approaches were tested to provide a clearer characterisation of the leaves of each species: the leaves were either dried or frozen. The kind and number of veins, the kind and number of hair, and the arrangements and number of stomates on both sides of each leaf are the most useful characteristics …

Effect Of Soil Ph On Emergence And Survival Of Austrodanthonia Spp., M. A. Islam, P. M. Dowling, B. C. Jacobs, P. J. Milham, D. L. Garden, M. K. Conyers, R. Van De Ven

IGC Proceedings (1977-2023)

We evaluated the effects of soil acidity on seedling emergence and seedling persistence of several ecotypes of Austrodanthonia spp. collected from the Central, Southern and Monaro Tablelands of New South Wales (NSW) in southern temperate Australia. A pot experiment was conducted outdoors to identify the most promising material tolerant to soil acidity for domestication. In the experiment, 183 ecotypes and two commercial cultivars of Austrodanthonia were grown in pots at three levels of pH_Ca (3.9, 4.4 and 5.3). The pH treatments were achieved by adding either aluminium sulphate or lime to an acid earthy sandy loam soil collected from …

Effects Of Fertilizer Rates And Pasture Type On Soil Mineral Nitrogen Concentration Under Dairy Pasture, T. A. Cox, D. F. Chapman, Frank R. Mckenzie

IGC Proceedings (1977-2023)

The effects of three rates of nitrogen (N) fertilizer applied to monocultures of perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.), and mixed ryegrass / clover swards, grazed by dairy cows on soil mineral nitrogen levels in the top 10cm of soil were studied on a dryland pasture in south-western, Victoria, Australia. Ammonium and nitrate were monitored for 14 months. Clover monocultures had significantly greater NO₃^- levels, however a similar trend was not observed for NH₄⁺ . Increasing fertilizer application rate significantly increased both NO₃^- and NH₄^{+ …}

Nitrogen Fertilization In Paspalum Dilatatum, Poir: Herbage Production, Nutritive Value And Structural Characteristics, G. Acosta, V. A. Deregibus

IGC Proceedings (1977-2023)

It was studied the effect of nitrogen application on structural changes and quantity and quality characteristics of a Paspalum dilatatum Poir sward, under field conditions during two growing seasons. The nitrogen (N) rates were 0 and 440 kg ha^-1 applied during the first year in split applications. The nitrogen fertilization increased leaf, stem and cumulative total dry matter yield, plant height, tiller density, cover ground and leaf crude protein yield.

Growth Responses Of Acacia Angustissima To Vesicular-Arbuscular Mycorrhizal Inoculation, N. Lucena Costa, Valdinei T. Paulino, T. S. Paulino

IGC Proceedings (1977-2023)

The response of Acacia angustissima to VAM species (Acaulospora laevis, A. muricata, Entrophosphora colombiana, Glomus mosseae, G. fasciculatum, G. macrocarpum, G. etunicatum, Gigaspora margarita, G. gigantea and Scutellospora heterogama) was evaluated under greenhouse conditions, in a P-deficient clayey Oxisol of pH 5.5. The soil was sterilized at 110^oC for one hour each day for three days and reinoculated with a soil microbial suspension free of mycorrhizal fungi spores. The several VAM fungi were effective in increasing DM yield, nodulation, and N and P uptake of A. angustissima plants. The most efficient species were E. colombiana, A. …

The Fertilization Of Forage Grasses With Phosphorus In The Cerrado Area Of Uberaba-Mg, Brazil, I. F. Andrade, M. A. Oliveira

IGC Proceedings (1977-2023)

Using an area of Cerrado at the EPAMIG Experimental Station in Uberaba - MG, it was studied the response of four forage grasses to phosphorus application. It was used the grasses: Andropogon gayanus, Brachiaria brizantha, Hyparrhenia rufa, and Panicum maximum. The phosphorus fertilizer used was a yoorin termophosphate and the doses were: 0, 50, 100, 150, and 200 kg/ha of P₂O₅. The experimental design was a randomized complete block with three replications. Each experimental unit measured 6x8m and the measured parameters were: dry matter production, protein production, percentage of dry matter, and protein, and …

Alfalfa Response To Phosphorus Sources Associated With The Application Of Liming And Gypsum-Shoot Numbers, P. Sarmento, M. Corsi, F. P. Campos

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) was grown in a Typic Mapluolox soil with triple superphosphate (TS), Gafsa phosphate (GP) and GP with gypsum (GP + G). Three rates of phosphorus application were used 50, 100 and 200 mg P dm^-3, before and after liming. Alfalfa was harvested three times. Basal and axillary shoot numbers in alfalfa increased with increasing phosphorus rates. Shoots were produced in higher number with GP in comparison with TS. GP + G resulted in higher basal shoot number than GP. However, there was no gypsum effect on axillary shoot numbers. Liming before or after …

Soil Nitrate Level Variation Under Intensive Nitrogen Fertilized Coastcross Pasture, O. Primavesi, A. C. Primavesi, L. A. Corrêa, H. Cantarella, A. G. Silva

IGC Proceedings (1977-2023)

Nitrate levels in soil profile after the first N application on coastcross pasture, grown on a dark red latosol (Hapludox), in São Carlos, SP, Brazil, under tropical altitude climate, were measured at 7-day intervals, to monitor possible losses in depth. Soil nitrate rates varied with high rates of N-ammonium nitrate (200 kg ha^-1 per cutting) in surface layers. Danger of environmental impact was low in the studied conditions.

Saturated Field Hydraulic Conductivity Variation In Intensively Managed Tropical Pastures, O. Primavesi, A. C. Primavesi, S. R. Vieira

IGC Proceedings (1977-2023)

Saturated field hydraulic conductivity was measured, using a Guelph permeameter, at the depths of 10, 20 and 60 cm, to verify the effect of intensively managed, compared to extensively managed ones, beef cattle production systems on pastures grown on three soils (Hapludox, Eutrudox, Paleudalf), in São Carlos, SP, Brazil, under tropical altitude climate. Significant differences occurred within depths (P < 0.05). However, differences decreased with years and, therefore, differences among soils and between management systems were also reduced. Highest mean conductivity values occurred at 60-cm depth and at the extensively managed sward on the sandy Hapludox. Intensively managed Paleudalf showed high resistance to reduction of conductivity at 10-cm depth. A general year effect appeared claiming for more studies on this matter.

Wildflower Pollen Quality In Roadside Habitats, With Particular Emphasis On Hedera Helix, Aoife Mcmullin, Paul Hamilton

SURE Journal: Science Undergraduate Research Experience Journal

The quality of air is of more significance today than ever before. Human population growth and pollutants emitted through fossil fuel consumption put pressures on air quality. It is widely acknowledged that atmospheric pollutants negatively impact human health; the same is also true for the health of wildlife and plants exposed to these pollutants (Brunekreef & Holgate, 2002; EEA, 2019; Schiavoni, et al., 2017). Pollen and seed formation of flowering plants have been affected when grown in areas of poor air quality (Azzazy, 2016; Sénéchal, et al., 2015). The purpose of this research was to assess pollen of …

The Effect Of Feed Supplementation And Sward Characteristics On The Ingestive Behaviour Of Grazing Ewes, C. H. E. C. Poli, Marta G. Da Rocha, C. C. Pires, Luis H. E. Farinatti, D. Montagner, G. Bica

IGC Proceedings (1977-2023)

The objective of this study was to assess the effect of protein/energy supplementation and sward physical characteristics on grazing behaviour of lactating ewes grazing Italian ryegrass (Lolium multiflorum Lam.). The experiment was carried out in the spring of 1999 at the Universidade Federal de Santa Maria. The grazing behaviour was assessed in two periods: 2 and 3 September, and 8 and 9 October of 1999, using a group of twelve yearling ewes. Groups of four ewes were either supplemented (with 1% of the animals live weight) with soybean meal (protein source), with corn (energy source) or not supplemented. The …

The Effect Of Sward Surface Height On Sheep Grazing Activities, Paulo C. De F. Carvalho, E. O. Silveira, L. S. Pontes, C. H. E. C. Poli, A. B. Soares, H. M. M. Ribeiro Filho

IGC Proceedings (1977-2023)

The objective of this study was to assess the effect of Italian ryegrass (Lolium multiflorum Lam.) sward height on grazing activities. The experiment was carried out at the Research Station of Universidade Federal do Rio Grande do Sul, Brazil. Yearling no-castrated male lambs behavior was assessed in terms of diurnal grazing, ruminating and idling time in three periods: 27 September 11 and 25 October. Sward surface height was monitored using a sward stick and samples of 0.25 m² were cut to ground level to estimate herbage and leaf lamina mass. The experiment was carried out in a randomised …

Grazing Behavior And Activity Patterns By Free-Grazing Cattle In The Pantanal Region, S. A. Santos, C. Costa, L. V. A. S. Chalita, A. Pott, J. M. Alvarez, A. G. Ortiz

IGC Proceedings (1977-2023)

A study of habitat selection and habitat use by free-grazing cattle was conducted in the Pantanal, from October 1997 to September 1999. Observation periods lasted 13 hours per day during three days in each month. The location and activity duration of each group of animals was recorded by continuous sampling. Rumination, walking and resting times were affected (P < 0,05) by interaction between month and year and grazing time differed (P < 0,05) only between months. On average, cows spent 54.9, 29.6, 10.6 and 4.9% of their diurnal hours grazing, ruminating, walking and resting, respectively. The grazing time spent in each landscape unit was influenced (P < 0,05) by interaction between month and year. The cows exploited more intensively the temporary ponds in 97/98 (26 min ha^-1) and the edge of ponds in 98/99 (23.2 min ha^-1). Therefore, the adequate grazing management practice may not follow fixed rules for the Pantanal.

Impact Of Overseeding Cool-Season Annual Forages On Spring Regrowth Of Tifton 85 Bermudagrass, Ricardo A. Reis, Lynn E. Sollenberger, D. Urbano

IGC Proceedings (1977-2023)

Field observations have shown stand reduction and slow spring regrowth of Tifton 85 bermudagrass (Cynodon spp.) pastures overseeded with temperate forages for grazing during the cool season. This experiment compared the effect of cool-season management programs, including overseeding and use of different grazing treatments, on productivity of Tifton 85 the following warm season. There were seven treatments: four were bermudagrass overseeded with a cool-season annual forage mixture (two grasses and two legumes) and grazed differentially, and three were bermudagrass controls with differences in amount of residual stubble remaining at beginning of autumn. There was only a slight delay in …

Influence Of Grazing Frequency On Biomass Production Using Several Selected Tropical Grasses, P. Mislevy, F. G. Martin, F. M. Pate, N. F. G. Rethman

IGC Proceedings (1977-2023)

To provide commercial growers with forage grasses that produce well throughout the year, there is a constant need for screening and testing new germplasm. Two rhodesgrasses (Chloris gayana cv. Rhods and Callide), four stargrasses (Cynodon nlemfuensis Vanderyst var. nlemfuensis cv. Florona, Zimbabwe, Okeechobee, and Rhodesian No. 2), one bermudagrass (C. dactylon var. dactylon cv. Jiggs), and one creeping signalgrass (Brachiaria humidicola CIAT 6369) were tested under a mob-grazing system. Dry biomass yield increased linearly as grazing frequency (GF) was delayed from 2 to 7 weeks. The cultivars, Florona, Zimbabwe and Okeechobee stargrasses and Jiggs bermudagrass, yielded …

Variation Of Herbage Intake (Hi) From Upland Pasture, As Influenced By The Grazing Initiation Date (Gid), D. Maæešiæ, M. Kneževiæ, Z. Štafa, J. Leto

IGC Proceedings (1977-2023)

Studies were conducted on an experimental pasture belonging to the Arrhenatherethum medioeur. and Lolio-Cynosureth. assoc. with D. glomerata, L. perenne and T. repens as main species, at an altitude of 680 m. Four equally sized paddocks (0.3 ha) were grazed by 10 Charolais heifers. The differences in total herbage dry matter intake (HDMI) between the four paddocks with different grazing initiation dates (GID) were significant (P < 0.05). The results of this experiment show that in order to achieve a higher HDMI and better herbage utilization an earlier initiation of grazing is recommended. That is, grazing should commence when the sward height is about 15 cm.

Nutritive Value Of Double Cropped Corn For Ruminant Production, D. Vaz Martins, A. Fassio

IGC Proceedings (1977-2023)

The viability of double cropping corn (Zea mays L.) in Uruguay, germplasm combination, dry matter yield and nutritive value were evaluated. An early (E) maturing hybrid, an early to medium (E-M) one and an E-M variety were planted as spring crops. One E-M hybrid, one medium to late (M-L) hybrid and a late (L) variety were planted as a second crop. PVC laboratory scale silo of the spring crop and the whole plant of the summer crop were chemically analyzed. The nutritive value of the silages were related to plant maturity stage. No differences were detected in nutritive value among …

Two-Dimensional Monitoring Of Spatial Distribution Of Herbage Mass Under Grazing, S. Ogura, Masahiko Hirata

IGC Proceedings (1977-2023)

Spatial distribution of herbage mass (HM) was monitored two-dimensionally during the grazing season (from May to November) in a bahiagrass pasture rotationally grazed by cattle. An electronic capacitance probe was used to estimate HM in 1464 permanent positions (50 × 50 cm) whose centres formed 1.5 × 1.5 m grids in the central 90 × 34.5 m area of the pasture. The highest mean HM was in September and October, while coefficient of variation in November. The two-dimensional charting of HM showed almost stable spatial patterns throughout the grazing season, with some patches of high HM appearing and disappearing. The …

The Effect Of Herbage Mass Of A Pasture On The Spatially Heterogeneous Grazing By Cattle, S. Ogura, Masahiko Hirata

IGC Proceedings (1977-2023)

To obtain information on spatially heterogeneous grazing by large herbivores at different time scales, spatial distribution of herbage mass and rate of defoliation was investigated on a bahiagrass (Paspalum notatum Flügge) pasture grazed by cattle during 4 to 5-day grazing periods in May, August and October. Pre-grazing herbage mass (M_pre) showed decreasing mean values and increasing spatial heterogeneity with the progress of grazing in all grazing periods, while the rate of defoliation showed inconsistent changes with season. Spatial distribution of the rate of defoliation was always more heterogeneous than that of M_pre. The correlation coefficient …

Relationships Between Spatial Distributions Of Herbage Mass And Utilization In A Pasture Progressively Grazed By Cattle, Masahiko Hirata, S. Ogura

IGC Proceedings (1977-2023)

To obtain some information about the mechanisms behind the spatially heterogeneous grazing of a pasture by large herbivores, the relationships between the spatial distributions of herbage mass, herbage consumption and ingestive behavior were investigated on a bahiagrass (Paspalum notatum Flügge) pasture during a 6-day grazing period with cattle. The animals almost always consumed more herbage from locations with higher pre-grazing herbage masses, which was attributed to greater bite weights. It was suggested that the high spatial heterogeneity in the rate of defoliation was caused mainly by the spatial heterogeneity in both the bite weight and the number of visits …

A Machine Learning Interpretation Of The Contribution Of Foliar Fungicides To Soybean Yield In The North‐Central United States, Denis A. Shah, Thomas R. Butts, Spyridon Mourtzinis, Juan I. Rattalino Edreira, Patricio Grassini, Shawn P. Conley, Paul D. Esker

Department of Agronomy and Horticulture: Faculty Publications

Foliar fungicide usage in soybeans in the north-central United States increased steadily over the past two decades. An agronomically-interpretable machine learning framework was used to understand the importance of foliar fungicides relative to other factors associated with realized soybean yields, as reported by growers surveyed from 2014 to 2016. A database of 2738 spatially referenced fields (of which 30% had been sprayed with foliar fungicides) was fit to a random forest model explaining soybean yield. Latitude (a proxy for unmeasured agronomic factors) and sowing date were the two most important factors associated with yield. Foliar fungicides ranked 7th out of …

The Effects Of Ppal-1 In Arabidopsis Gamete Development, Amanda J White, Susana Perez-Martinez, Mark P. Running

The Cardinal Edge

Prenylation is a type of post-translational modification in which a 15- or 20-carbon lipid is added to the carboxyl (C) terminus of the protein. Arabidopsis thaliana contains the PROTEIN PRENYLTRANSFERASE ALPHA SUBUNIT-LIKE (PPAL) gene, which encodes a protein with homology to the α-subunits of the three known prenylation enzymes, PFT, PGGT, and Rab-GGT. We previously identified two mutations in PPAL, one of which is ppal-1, which contains a T-DNA insertion in the fourth intron. We have previously observed that self-fertilizing heterozygous ppal-1 plants produce progeny in which homozygous ppal-1 is underrepresented. This project attempts to ascertain …

Identification Of The Biological Function Of Rab-Ggt Β-Subunits By Reverse Techniques, Briana L. Seibert, Hyun Jin Jung, Mark P. Running

The Cardinal Edge

Abstract

Protein prenylation is a post-translational process where lipids are added to carboxyl end groups of amino acids, which allows proteins to function properly in the eukaryotic cell. The job of prenylation is to target certain proteins to specific membranes and promote desirable protein-protein interactions. In our study we used reverse genetics techniques to investigate the function of protein prenylation in plant development. To discern the function of protein prenylation, we examined the phenotypic changes caused by specific gene disruptions. In this study the model organism Physcomitrella patens (moss) is utilized due to its simple structure, limited quantities of tissues …

Protein Prenylation In The Moss Physcomitrium Patens, Zayna Qaissi, Anam F. Ahmed, Mark P. Running, Katherine Vo. Brown

The Cardinal Edge

TITLE

Protein Prenylation in the moss Physcomitrium patens

AUTHORS

Zayna H. Qaissi*, Anam F. Ahmed*, Katherine V. Brown, Mark P. Running**

*Co-presenters

**Faculty Mentor

Protein prenylation is the addition of a 15 or 20 carbon lipid to a cysteine near carboxyl terminus of target proteins. Prentlyation increases hydrophobicity, which facilitates membrane associations and protein-protein interaction. Protein prenylation is generally conserved among eukaryotes, and mutations in genes that carry out prenylation are lethal in animals and yeast. In plants prenylation mutations are not always lethal, but they do affect development, disease resistance, biofuel production, and drought response, among other processes of …

Adapting Tropical Forages To Low-Fertility Soils, Idupulapati M. Rao

IGC Proceedings (1977-2023)

Tropical forages growing in low-fertility acid soils usually increase the amount of dry matter partitioned to roots at the expense of shoot growth, but substantially different adaptive attributes to such soils have been found, both between and within species. By possessing the C₄ pathway of photosynthesis, grasses are more efficient than legumes in using N, Ca, and P, whereas legume roots are more efficient in extracting nutrients from low-fertility soils. Phosphorus uptake efficiency (mg of P uptake in shoot biomass per unit root length) of the legume Arachis pintoi is several times higher than that of the grass Brachiaria …