Cattle Diet Selection During the Growing Season on Upland Sandhills Rangelands

The Sandhills is a diverse and complex ecosystem comprised of different topographic positions (i.e. slopes and interdunes) that influence grazing distribution, plant species composition, and cattle diet selection. The first objective of this study was to evaluate how grazing intensity influences species composition on slopes and interdunes on native rangeland within the Hillside pasture (160 ha) at the UNL Gudmundsen Sandhill’s Laboratory (GSL). The second objective of this study was to evaluate forage quality of individual species from three plant functional groups (i.e. warm-season grasses, cool-season grasses, and forbs/shrubs) on native rangeland within the Hillside pasture (160 ha) at GSL. Forage quality samples were taken from 4 warm-season grasses, 5 cool-season grasses grass, 1 forb, and 2 shrubs. Samples were collected every 7-15 days from mid-May to early August in 2020 and 2021. The third objective of the study was to evaluate diet composition of cattle grazing (n = 40) within the pasture during the growing season using fecal DNA barcoding (fDNA). Fecal samples were collected from 7-8 cows every 10-20 days from early June to late-July in 2020 and 2021. Frequency of occurrence of western ragweed was 28 percentage points greater (P =0.03) on high grazing intensity interdunes than low intensity grazing interdunes. Additionally, there was a trend (P =0.07) for greater Kentucky bluegrass on high grazing intensity interdunes compared to low intensity grazing interdune. When averaged across the growing season, CP of forbs/shrubs was 3.3 and 2.9 percentage points greater than cool-season grasses and warm-season grasses (P \u3c 0.05). However, there were no differences (P \u3e 0.1) in CP between warm- and cool-season grasses or functional group x collection date interactions. Diet selection as determined by fDNA indicated that cattle obtained most of their dietary protein from cool-season grasses (43.6% ± 1.5) and forbs (29.1% ± 1.5), while shrubs (13.0% ± 1.5) and warm-season grasses (3.5% ± 1.5) contributed significantly less (P \u3c 0.01) to the cattle diets. This research highlights the influence of grazing intensity on species composition and the influence of time during the growing season on forage quality and cattle diet selection within the Sandhills. Advisor: Mitch Stephenso

Comparing simple and complex native forage mixtures for grazing cattle in southwestern Saskatchewan

Diverse forage mixtures have improved resilience to drought, improved persistence, ability to adapt to changing environmental conditions, reduced fertilizer costs, improved root mass and greater soil carbon sequestration but do they improve forage and animal production. The objective was to determine if complex native forage mixtures provide superior nutritional quality throughout the grazing season as compared to simple native mixtures. Three studies were conducted in 2007 at Swift Current, SK to evaluate forage production potentials, nutritive qualities and in vitro dry matter digestibility of native and tame forage species common to or having potential in Southwestern Saskatchewan. In study one, plots were seeded in 2006 on Chernozemic Orthic Brown Swinton Loam soils and consisted of 11 native and three tame monoculture species common to southwestern Saskatchewan. Clippings at a 5 cm stubble height occurred on June 20 and every 28 days after until October 10. Forage DM production, in vitro OMD, NDF, ADF, ADL, CP, Ca and P concentrations were measured. As species matured, production and OMD declined (P¡Ü0.05) but NDF, ADF and ADL concentrations increased (P¡Ü0.05). There were harvest date by species differences (P¡Ü0.05) in forage production and nutritional qualities of C3 and C4 grass and legume species. Study two examined the in situ CP, NDF and DM disappearance of six selected species harvested in the fall. EDNDF and ADDM values did not differ (P>0.05) among C3 grasses. The C4 grasses had higher (

Influence of burning and grazing management practices on subirrigated Sandhill meadow hay production

Subirrigated meadows are a valuable forage resource to Sandhills ranching operations being used for hay production, grazing, or a combination of both. Practices that sustain meadow productivity should be encouraged to ensure a consistent feed supply for cattle. The potential influence of prescribed burning or pre-freeze and post-freeze grazing on forage production and quality are not well understood on these meadows. In grasslands, including meadows, excess dead plant material can accumulate, causing a potential reduction in forage yield and quality. Results of our three-year field study suggest that burning meadows in the spring is a suitable management option to remove dead plant material without negatively affecting future hay production. Additionally, when burning was followed by either grazing exclusion or grazing from early-May to early-June, grazing had a greater influence on end of season biomass, with no interacting effect of burning and grazing. Quality of warm-season grasses was increased slightly following burning, but most improvements in quality were minimal and were a result of spring grazing. Study two evaluates a common practice of grazing meadows in the fall (pre-freeze) and winter (post-freeze) months. In our study, grazing in the fall when vegetation was still green was detrimental to future graminoid production. Relative to pre-freeze grazing, postponing grazing until plant dormancy (post-freeze) returned higher yields of graminoids and total live plant biomass. Deterring meadows from grazing in the fall and winter (control) produced graminoid and total live biomass that was similar to post-freeze treatments. Relative to pre-freeze treatments, summer biomass of ungrazed controls were generally higher in graminoid biomass, while similar in total live biomass. Quality of subsequent year’s forage in pre-freeze treatments was significantly higher than the control or post-freeze treatments and met the total digestible nutrient requirement of lactating cows. Our studies show that tradeoffs in quantity and quality are common under any practice. Therefore individual management objectives should be considered when deciding if a practice is right for them. Advisors: Mitchell Stephenson and Jerry Volesk

Grazing managment for wildlife benefits: a planning framework using integrated ecological tools for development of wildlife-oriented grazing strategies

Includes bibliographical references (pages 47-53).Many traditional rangeland and domestic livestock management guidelines have focused on uniform livestock distribution, often causing simplification of heterogeneous landscapes, with a goal of improvement/maintenance of rangeland function at "climax" conditions. Often it is assumed that proper rangeland management parallels proper management of the wild animals utilizing rangeland habitat. However, wildlife benefits derived from the ecological conditions created by various grazing strategies are typically limited and largely coincidental. This paper will examine 1) the concept of spatiotemporal heterogeneity and its value to wildlife, 2) how existing tools could be integrated to support wildlife‐oriented rangeland planning, 3) how these concepts and tools could be applied with a planning framework, and 4) recognition of some limitations with possible opportunities for refinement and future research

Center for Grassland Studies, Summer 2010, Volume 16, No. 2

Contents: Grazing Systems Research in the Nebraska Sandhills From the Director Ingalls’ Ode to Blue Grass 2010 CGS Fall Seminar Series August 1 Is Pre-registration Deadline for Nebraska Grazing Conference CGS Associates Resources Dig It! Smithsonian Exhibit Omaha Info Tuft

Effects of Grazing Pressure on Defoliation Patterns of Tallgrass Prairie

Few studies have dealt with measuring individual plant defoliations in the context of intensive grazing management. In May, July, and August of 1987, grazing trials were conducted to quantify the effects of cattle grazing pressure on defoliation patterns of little bluestem (Schizachyrium scoparium (Michx.) Nash), big bluestem (Andropogon gerardii Vitman), and indiangrass (Sorghastrum nutans (L.) Nash). Grazing pressures of 10, 20, 30, and 40 kg Auo-1 were replicated twice per trial. Treatment pastures contained 30 marked tillers of each species. Standing crop was measured before and after grazing. Tiller height, relative leaf area removed, and frequency of defoliation were measured every 2 days over 10 day trials. The frequency and intensity of tiller defoliation was highly dependent on species and grazing pressure. Tiller height decreased more rapidly as grazing pressure increased, and leaf area removed increased as grazing pressure increased. Height and 1 eaf area removed were similar for grazing pressures of 30 and 40 kg Auo-1. Indiangrass was the most preferred species in all trials. Tillers were spread among at least three defoliation frequency classes for all species and grazing pressures. Trial 1 had the greatest proportion of undefoliated tillers regardless of species. Under most grazing pressures, indiangrass and big bluestem had more tillers defoliated 3 times in a trial. Tillers were moderately defoliated the first time and severely defoliated afterwards. Defoliating all tillers once in a rangeland community is virtually impossible to achieve without severe defoliation on some species. Planning livestock movements based on a target defoliation intensity and regulating grazing pressure to reduce the risk of severe defoliation can be useful strategies for intensive grazing management.Agronom

Common Grasses of Nebraska: Rangeland Prairie Pasture (Including Grass-Like Plants)

Introduction 3 • Plant Groups 4 • Parts of a Grass Plant 5 • Inflorescence Characteristics 5 • Vegetative Characteristics 5 • Parts of a Grass-Like • Plant 5 • Fruit and Floral Characteristics 5 • Vegetative Characteristics 5 • Warm-Season • Perennial Grasses • Bermudagrass 14 • Blowoutgrass 15 • bluestems: • Big bluestem 16 • Little bluestem 18 • Sand bluestem 20 • Silver bluestem 21 • Yellow bluestem 22 • Buffalograss 24 • dropseeds: • Alkali sacaton 26 • Prairie dropseed 27 • Sand dropseed 29 • Tall dropseed 30 • Eastern gamagrass 32 • gramas: • Blue grama 33 • Hairy grama 35 • Sideoats grama 36 • Indiangrass 38 • Inland saltgrass 40 • Johnsongrass 41 • lovegrasses: • Purple lovegrass 43 • Sand lovegrass 44 • muhlys: • Marsh muhly 45 • Plains muhly 47 • Sandhill muhly 48 • Scratchgrass 49 • Phragmites 50 • Prairie cordgrass 52 • Prairie sandreed 54 • Purple threeawn 55 • Purpletop 56 • Sand paspalum 58 • Switchgrass 59 • Tumblegrass 61 • Windmillgrass 62 Warm-Season • Annual Grasses • Barnyardgrass 66 • Bearded sprangletop 67 • crabgrasses: • Hairy crabgrass 68 • Smooth crabgrass 69 • Fall panicum 70 • foxtails: • Green foxtail 72 • Hooked foxtail 73 • Yellow foxtail 74 • Goosegrass 76 • Poverty dropseed 77 • Purple sandgrass 78 • Sandbur 79 • Stinkgrass 81 • threeawns: • Forktip threeawn 82 • Prairie threeawn 83 • Witchgrass 84 Cool-Season • Perennial Grasses • bentgrasses: • Redtop bentgrass 88 • Spike bentgrass 89 • Winter bentgrass 90 • bluegrasses: • Bulbous bluegrass 91 • Canada bluegrass 92 • Kentucky bluegrass 94 • Mutton bluegrass 95 • Plains bluegrass 96 • Sandberg bluegrass 98 • Bluejoint reedgrass 99 • bromegrasses: • Meadow brome 101 • Smooth brome 102 • Creeping foxtail 103 • Fowl mannagrass 105 • Foxtail barley 106 • Green needlegrass 108 • Indian ricegrass 109 • Needleandthread 111 • Orchardgrass 112 • Perennial ryegrass 114 • Porcupinegrass 115 • Prairie junegrass 116 • Prairie wedgescale 117 • Quackgrass 119 • Reed canarygrass 120 • rosettegrasses: • Scribner rosettegrass 121 • Wilcox rosettegrass 123 • Squirreltail 124 • Tall fescue 125 • Timothy 127 • Weeping alkaligrass 129 • wheatgrasses: • Crested wheatgrass 130 • Intermediate wheatgrass 132 • Slender wheatgrass 133 • Tall wheatgrass 135 • Western wheatgrass 136 • wildryes: • Canada wildrye 138 • Russian wildrye 139 Cool-Season • Annual Grasses: • American sloughgrass 142 • Annual bluegrass 143 • Cheatgrass 144 • Japanese brome 145 • Little barley 146 • Northern wildrice 148 • Sixweeksgrass 149 • Grass-Like • Plants: • American bulrush 152 • Field horsetail 153 • Schweinitz flatsedge 154 • sedges: • Nebraska sedge 155 • Needleleaf sedge 156 • Sun sedge 157 • Threadleaf sedge 158 • Yellow nutsedge 160 • Glossary 161 • Ecological Sites 170 • Selected References 173 • Index 17

Grazing Strategy Effects on Utilization, Animal Performance, Aboveground Production, Species Composition, and Soil Properties on Nebraska Sandhills Meadow

Ultrahigh stocking density (a.k.a., mob grazing) is proposed as a management tool that results in greater harvest efficiency, animal performance, aboveground plant production, species richness, and soil carbon content. The study objective was to determine grazing treatment, haying, or non-defoliated control effects on forage utilization, aboveground production, animal performance, and soil properties. In 2010, 25 ha of Sandhills meadow were divided into 2 replications of 3 grazing, a hay, and control treatment. Grazing treatments were a 120-pasture rotation with one grazing cycle (mob), a 4-pasture rotation with one cycle (4PR1), and a 4-pasture rotation with two cycles (4PR2) at stocking densities of 225,000, 7,000, and 5,000 kg ha-1, respectively. Pastures were stocked by yearling steers (365 kg) at 7.4 AUM ha-1 from May to August in 2010 to 2017. Hay was harvested annually in July. Control plots were not defoliated. In grazed treatments, aboveground biomass was clipped at ground level to estimate utilization after grazing periods (24 hours, 10 and 15 days,). Aboveground biomass was clipped at ground level annually within experimental units in mid-August. Species composition was determined annually in June. Soil cores were taken in 2010 and 2018 at 0-10 cm and 10-20 cm depths. Utilization in grazed treatments differed by treatment. Mob utilization and trampled vegetation was highest followed by 4PR1 and 4PR2. Harvest efficiency did not differ by treatment. Residual standing live herbage had a treatment by year interaction where mob was usually lowest and 4PR2 was usually highest. Aboveground production did not differ among grazing and hay treatments but was greater for grazed treatments than control. Animal performance differed by treatment and year with steers gaining more in 4PR2 than the other treatments. Cool-season grasses decreased in control but increased in grazed treatments. Warm-season grasses decreased in control and were unchanged in grazed treatments. Prairie cordgrass and white clover were affected by treatment. Soil carbon, nitrogen, and bulk density did not differ among treatments. We concluded that management strategy was a driver of utilization, animal performance, and species composition. After 8 years, mob grazing was not a driver of aboveground production or soil property changes. Advisors: Walter H. Schacht and Jerry D. Volesk