Life Sciences Commons^™

Temporal Changes In The Nutrient Content Of Cattle Dung In The Nebraska Sandhills Ecosystem, Amanda Shine, Martha Mamo, Gandura O. Abagandura, Walter Schacht, Jerry Volesky

Department of Agronomy and Horticulture: Faculty Publications

Dung excreted by cattle composes a significant portion of the nutrient inputs in a grazed ecosystem and can have wide-ranging effects on soil properties and vegetation. However, little research has been conducted on the nutrient dynamics of excreted dung in situ that has not been disturbed prior to field sampling. In this study, we analyzed 294 dung pats (1–24 days old) collected from a Nebraska Sandhills meadow to determine water-extractable organic carbon (WEOC), water-extractable nitrogen (WEN), water-extractable phosphorus (WEP), and percent dry matter (DM) changes over time. In addition, we investigated if sample handling - frozen storage – and the …

Does Integrating Crops With Livestock Production Impact Soil Properties And Crop Production?, Lindsey Anderson

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Re-integrating crop and livestock production through cover crop (CC) and corn residue grazing could efficiently utilize resources and ensure profitability while improving environmental quality, but how this integration affects soils and crops is not well understood. We conducted two studies to address this. In the first study, we evaluated the impact of cattle (1.3-3.7 head ha^-1) grazing an oat (Avena sativa L.) CC on soil and crop yields in two adjacent irrigated no-till corn (Zea mays L.)-soybean (Glycine max L.) fields on silt loam soils in eastern Nebraska. Field I was grazed twice, while Field …

Spring Meadow Management Practices: What’S A Rancher To Do?, Tara M. Harms, Jerry D. Volesky, Mitchell B. Stephenson

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

• Subirrigated meadows are a valuable forage resource to ranching operations in the Nebraska Sandhills, being used for both hay production and livestock grazing. • The water table of these meadows is within one meter of the soil surface during the growing season. • In some years, wet conditions hinder meadow utilization, resulting in a buildup of standing dead and litter plant material which can lower forage production.

• Investigate if burning and mowing are effective strategies to remove dead plant material from meadows • Determine if burning or mowing interact with grazing to influence end of season forage production …

Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nutrient inputs from cattle dung are crucial drivers of nutrient cycling processes in grazed ecosystems. These inputs are important both spatially and temporally and are affected by variables such as grazing strategy, water location, and the nutritional profile of forage being grazed. Past research has attempted to map dung deposition patterns in order to more accurately estimate nutrient input, but the large spatial extent of a typical pasture and the tedious nature of identifying and mapping individual dung pats has prohibited the development of a time- and cost-effective methodology. The first objective of this research was to develop and validate …

Grazing Strategy Effects On Utilization, Animal Performance, Aboveground Production, Species Composition, And Soil Properties On Nebraska Sandhills Meadow, Aaron Shropshire

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

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 …

Changes In Corn Residue Quality Throughout The Grazing Period And Effect Of Supplementation Of Calves Grazing Corn Residue, Amanda J. Burken

Department of Animal Science: Dissertations, Theses, and Student Research

Corn residue is an abundant feed source in Nebraska that can be utilized as an alternative winter feed. Calves were backgrounded on corn residue in order to determine gain and estimate forage intake when supplemented with distillers grains (DGS). Calves grazing the non-irrigated field gained more (1.03 kg/calf daily) when compared to those grazing the irrigated field (0.90 kg/calf daily; P < 0.01). In year 1, a quadratic effect for intake of DGS was present (P < 0.01) while year 2 observed a linear effect for increasing level of DGS (P < 0.01). The nutritional quality of corn residue was evaluated over time in order to determine changes in blade/sheath, cob, husk/shank and stem. Minimal changes in DM of the forage components occurred was grain reached 15.5% moisture. Digestibility of the blade/sheath declined linearly over time (P < 0.01) while the husk remained constant (P = 0.40). Cob digestibility decreased quadratically (P < 0.01) throughout the sampling period with few changes once grain reached 15.5% moisture. Differences observed in the digestibility of the blade/sheath were attributed to the effects of weathering. A third set of trials was conducted to evaluate the effects of by-product supplementation of calves grazing irrigated corn residue and supplemented with DGS or continuous access to lick tubs. The DGS treatment gained more (0.62 kg/calf daily) than the lick tub treatment (0.38 kg/calf daily; P < 0.01). Calves offered DGS consumed more supplement as a percentage of BW (0.52%) when compared with calves offered lick tubs (0.36%; P < 0.01) on a DM basis. Calves supplemented with DGS had a higher supplement efficiency (46.3% to 42.9%, DM basis) although no differences were present between treatments (P = 0.49). When analyzed on an OM basis, however, calves offered lick tubs had a numerically higher supplement efficiency (50.4%) in comparison to calves …

Spatiotemporal Dynamics Of Black-Tailed Prairie Dog Colonies Affected By Plague, David J. Augustine, Marc R. Matchett, Theodore P. Toombs, Jack F. Cully, Tommy L. Johnson, J. G. Sidle

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Black-tailed prairie dogs (Cynomys ludovicianus) are a key component of the disturbance regime in semi-arid grasslands of central North America. Many studies have compared community and ecosystem characteristics on prairie dog colonies to grasslands without prairie dogs, but little is known about landscape-scale patterns of disturbance that prairie dog colony complexes may impose on grasslands over long time periods. We examined spatiotemporal dynamics in two prairie dog colony complexes in southeastern Colorado (Comanche) and northcentral Montana (Phillips County) that have been strongly influenced by plague, and compared them to a complex unaffected by plague in northwestern Nebraska (Oglala). …

Postweaning Performance Of Hair And Wool Sheep And Reciprocal-Crosses On Pasture And In Feedlot, M. A. Brown, H. S. Mayeux

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Lambs from three diallel-mating plans (Dorset-St. Croix, n=140; Rambouillet-Gulf Coast, n=80; Katahdin-Suffolk, n=78) and a terminal-cross mating plan (Suffolk rams mated to Dorset, St. Croix and reciprocal-cross ewes, n=100) were used to evaluate postweaning grazing performance of traditional meat breeds and tropically adapted breeds of sheep.