The objective of this study was to investigate the effects of alkali-treatment (CaOH2) or water addition to corn stover on in situ DM and NDF digestibility (DMD and NDFD) and growth performance of cattle during a backgrounding phase. Fifty-one lightweight Angus steers (average BW 197 kg), fed individually in a Calan-Broadbent feeding system, were randomly allotted to 1 of 3 corn stover (30% of diet DM) feeding treatments: 1) dry, untreated corn stover (85% DM), 2) corn stover treated with CaOH2 at 6% inclusion (as-fed basis) and water hydrated to 50% DM, or 3) corn stover water hydrated to 50% DM. Legume-grass silage (15%), dry rolled corn (25%), dry distillers grains and solubles (25%), and a vitamin and mineral supplement (5%) constituted the balance of the diet DM. Steers were fed once daily at 0600 h, and orts were weighed and sampled during this time. Body weight was measured on d 1and 49 after withdrawing feed and water for 16 h. In situ DMD and NDFD were measured at 12, 24, 36, and 48 h in 2 ruminally cannulated steers. Averaged over time, DMD and NDFD differed (P < 0.05). Digestibility of DM and NDF of calcium hydroxide-treated corn stover were greater (38.1% and 45.7%), that of untreated corn stover was intermediate (28.1% and 32.8%), and that of water-treated corn stover was lowest (16.9% and 15.5%). Similar results were observed using an in vitro gas production batch culture. Cattle fed water-treated corn stover consumed more (P < 0.05) feed DM and had faster rates of gain (P < 0.05) than those fed untreated corn stover. Cattle fed calcium hydroxide-treated corn stover had intermediate rates of gain that were similar (P > 0.05) to those of cattle fed water-treated or untreated corn stover. Feed conversion was not affected (P > 0.05) by corn stover treatment. An alternative to alkali-treatments, albeit when forage supply is not limiting, may be simple water addition as cattle fed water-treated corn stover gained weight more rapidly while consuming more DM.

ObjectivesSixty-seven purebred Angus steers (initial BW 197 ± 38 kg.) were used to evaluate the effects of calcium hydroxide treated corn stover in backgrounding diets and a common finishing phase. Materials and MethodsSteers were randomly assigned to 1 of 4 treatments: untreated corn stover (CON), corn stover treated with 50% DM water (H2O); 50% DM water and calcium hydroxide treated corn stover (CaOH2); grazing on a turnip cover crop (CC) for 29 d before adapted to ad libitum alfalfa haylage diet fed in feed bunks for remaining 20 d of backgrounding. Steers were fed individually using a Calan system. All diets were formulated on a dry matter (DM) basis to contain 30% corn stover, 15% alfalfa haylage, 25% dried distillers grains with solubles, 25% dry rolled corn, and 5% supplement containing monensin. Steers were harvested at 240 d on feed. Carcass characteristics were recorded 48 h postmortem. Strip loins and shoulder clods (IMPS #180 and #114) from the right side of the carcass were collected. The shoulder clods were frozen immediately on arrival to the meat lab. Strip loins were fabricated into 2.54 cm steaks at 96 h postmortem. Strip loin steaks were used to evaluate vacuum purge, cook loss, and Warner-Bratzler shear force (WBSF). Shoulder clods were processed to ground beef before processing into bologna. Consumer sensory panels comprised of untrained panelists were utilized for both strip steaks (n = 130) and bologna (n = 126) to evaluate overall liking, flavor liking, texture liking, toughness, juiciness, and off-flavor. Data was analyzed using Proc Mixed of SAS 9.4 (SAS Inst. Inc., Cary, NC). ResultsTreatment had no effect on HCW (P = 0.694), REA (P = 0.259), backfat (P = 0.780), USDA Yield Grade (P = 0.890), USDA Quality Grade (P = 0.877), and marbling score (P = 0.845). Although purge loss (P = 0.884) and cook loss (P = 0.149) were not affected by treatment, WBSF values were lower for CC than CON (1.6 vs. 2.23kg respectively; P = 0.001). Objective L* and b* values for bologna were different among treatments (P < 0.001) with CaOH2 being higher than all other treatments. Objective a* values were lower for H2O than CC and CaOH2 (P < 0.001) and higher for CC and CaOH2 than CON on Day 0 (P = 0.002 and P < 0.001 respectively). For steak sensory, no differences were found in flavor liking (P = 0.102), juiciness (P = 0.375), or off-flavor (0.313). Differences were found in overall liking (P = 0.008) with CC being more liked than CON (P = 0.013) and CaOH2 (P = 0.019). Texture liking (P < 0.001) for CC was higher than CON (P < 0.001), H2O (P = 0.021), and CaOH2 (P < 0.001). Toughness scores were lowest for CC (P < 0.001) compared to CON (P < 0.001), H2O (P = 0.015), and CaOH2 (P < 0.001). For bologna sensory, no differences among treatments were found in overall liking (P = 0.610), flavor liking (P = 0.707), texture liking (P = 0.828), juiciness (P = 0.371), and off-flavor (P = 0.716). A difference in toughness was found (P = 0.011) with H2O being more tough than CaOH2 (P = 0.008). ConclusionThe use of calcium hydroxide treatment in backgrounding diets of beef calves does not affect carcass characteristics or moisture loss, but does affect processed meat shelf life, and sensory characteristics for fresh steaks and bologna.

This article discusses the lesson learned from an Extension, state, and federal agency coordinated water quality project that was formally started in 1995. In the project, educational programing was provided, high risk areas were identified, and BMPs were implemented on these areas. The net result of BMP implementation was a 38% improvement in South Dakota Bad River water quality. This improvement was attributed to Extension and others providing leadership on: 1) the development of local learning communities and 2) identification and implementing BMP's in high risk areas. This work demonstrates that Extension can make a difference.

Defoliation aimed at introduced cool-season grasses, which uses similar resources of native grasses, could substantially reduce their competitiveness and improve the quality of the northern tallgrass prairie. The objective was to evaluate the use of early season clipping and fire in conjunction with simulated increased levels of atmospheric nitrogen deposition on foliar canopy cover of tallgrass prairie vegetation. This study was conducted from 2009 to 2012 at two locations in eastern South Dakota. Small plots arranged in a split-plot treatment design were randomized in four complete blocks on a warm-season grass interseeded and a native prairie site in east-central South Dakota. The whole plot consisted of seven treatments: annual clip, biennial clip, triennial clip, annual fire, biennial fire, triennial fire, and undefoliated control. The clip plots consisted of weekly clipping in May to simulate heavy grazing. Fire was applied in late April or early May. The subplot consisted of nitrogen applied at 0 or 15 kg N · ha−1 in early June. All treatments were initially applied in 2009. Biennial and triennial treatments were reapplied in 2011 and 2012, respectively. Canopy cover of species/major plant functional groups was estimated in late August/early September. Annual clipping was just as effective as annual fire in increasing native warm-season grass and decreasing introduced cool-season grass cover. Annual defoliation resulted in greater native warm-season grass cover, less introduced cool-season grass cover, and less native cool-season grass cover than biennial or triennial defoliation applications. Low levels of nitrogen did not affect native warm-season grass or introduced cool-season cover for any of the defoliation treatments, but it increased introduced cool-season grass cover in the undefoliated control at the native prairie site. This study supports the hypothesis that appropriately applied management results in consistent desired outcomes regardless of increased simulated atmospheric nitrogen depositions.

A study was conducted on upland range in the Nebraska Sandhills to determine differences in plant species frequency of occurrence and standing crop at various topographic positions on pastures grazed with short-duration grazing (SDG) and deferred-rotation grazing (DRG). Pastures within each grazing treatment were grazed at comparable stocking rates (SDG=1.84 animal unit months (AUM).ha(-1); DRG=1.94 AUM.ha(-1)) by cow calf pairs from 1999 to 2005 and cow calf pairs and spayed heifers from 2006 to 2008. Plant frequency of occurrence data were collected from permanently marked transects" prior to, midway through, and at the conclusion of the study (1998, 2003, and 2008, respectively) and standing crop data were collected annually from 2001 to 2008 at four topographic positions (dune top, interdune, north slope, and south slope). Livestock performance data were collected during the last 3 yr of the study (2006 to 2008). Positive change in frequency of occurrence of prairie sandreed (Calamovilfa longifolia [Hook.] Scribn.) was 42% greater on DRG pastures than SDG after 10 yr. Total live standing crop did not differ between DRG and SDG except in 2001 when standing crop was 23% greater on DRG pastures. Standing crop of forbs and sedge was variable between grazing methods on interdune topographic positions depending on year. Average daily gain of spayed heifers (0.84 +/- 0.05 kg.d(-1) SE) did not differ between SDG and DRG. Overall, SDG was not superior to a less intensively managed grazing method (i.e., DRG) in terms of vegetation characteristics and livestock performance.

Controlled burns and grazing are being tested to manage invasive grasses in the Prairie Pothole region of the Northern Great Plains. These practices, however, may inadvertently promote saltcedar infestations from seed by opening the vegetative canopy. Saltcedar seedling establishment was investigated in greenhouse experiments using intact soil cores from one summit and three footslope sites in eastern South Dakota. Establishment tests were conducted in soil cores collected from treatment and control plots immediately after spring Are treatment (postburn) and in cores that contained peak cool- or peak warm-season vegetation, with or without clipping (simulated grazing treatment), to simulate vegetation conditions typical of saltcedar seed-shed in northern regions. Cores were seeded with 100 saltcedar seeds and subirrigated to maintain high soil water conditions, characteristic of the environment near potholes during late spring/early summer. Seedlings were counted during the first 3 wk to estimate establishment and the height of five seedlings core(-1) were measured weekly to estimate growth rates. Opening the canopy with fire or clipping increased saltcedar establishment. Cores taken immediately after fire treatment had two times more seedlings establish (38% vs. 19%) and greater average seedling growth rate (1.5 mm d(-1) vs. 0.9 mm d(-1)) when compared with no-fire controls. Fire after seeding reduced seedling establishment to 5%, but did not affect growth rate. Saltcedar establishment in peak cool-season vegetation cores was 6% regardless of earlier fire treatment, whereas in peak warm-season vegetation, establishment ranged from 8% (no spring fire) to 17% (spring fire). If soils remain wet, invasion risk following spring fire may be greatest when warm-season grasses are flowering because this time coincides with northern saltcedar seed production. Areas adjacent to viable saltcedar seed sources should be managed to maximize canopy cover when seeds are released to limit further establishment. Fire after saltcedar seed deposition may control propagules and young seedlings.

Understanding the long-term effect of summer grazing date and fall stocking rate on herbage production is critical to extending the grazing season in the Nebraska Sandhills. A study was conducted from 1997 to 2002 at the Gudmundsen Sandhills Laboratory located near Whitman, Nebraska, to determine the herbage production response to summer grazing date and October stocking rate on two different sites. Site 1 was dominated by warm-season grasses and site 2 was dominated by cool-season graminoids. At each site, three 0.37-ha pastures were constructed in each of four blocks before application of summer grazing treatments. Pastures in each block were grazed at 0.5 animal-unit months (AUM) . ha(-1) in June or July, or were deferred from summer grazing. Following summer grazing treatments, October stocking rate treatments (no grazing or 1.0, 2.0, or 3.0 AUM . ha(-1)) were applied to subunits of each summer grazing date pasture during mid-October. Vegetation was sampled in each pasture in mid-June and mid-August and sorted by functional group to determine the effect of 5 yr of grazing treatments on herbage production and residual herbage. Herbage production was not affected by summer or October grazing treatments on the warm-season grass-dominated site. Increasing October stocking rate, however, reduced cool-season graminoid production and subsequent herbage production 25% by year 5 of the study. Residual herbage at both sites at the end of the October grazing periods explained as much as 16% to 34% of subsequent year's herbage production. Grazing managers in the Nebraska Sandhills can extend the grazing season by lightly stocking pastures in the summer to facilitate additional fall grazing. Heavy stocking in October over several years on cool-season-, but not warm-season-, dominated sites will reduce production of cool-season graminoids on these sites.

Characterizing vegetation composition, carbon/nitrogen (C/N) content of soils, and root-mass distribution is critical to understanding carbon sequestration potential of subirrigated meadows in the Nebraska Sandhills. Five subirrigated meadows dominated by cool-season (C3) graminoids and five meadows dominated by warm-season (C4) grasses were selected throughout the Nebraska Sandhills. Vegetation, soil carbon and ni trogen, and root-mass density distribution were sampled in each meadow. Meadows dominated by C3 vegetation had 12% greater (P < 0.1) yields than meadows dominated by C4 vegetation. Total root-mass density was 30% greater (P < 0.1) in C4-dominated meadows than C3-dominated meadows. Total carbon and nitrogen content was 65% and 53% greater (P < 0.1), respectively, in the A horizon of C3-dominated meadows, but was 43% and 52% greater (P < 0.1), respectively, in the C horizon of C4-dominated meadows. Although meadows dominated by C3 vegetation had more carbon in the soil profile, much of the carbon in C3-dominated meadows appeared to be recalcitrant C4 carbon from historic vegetation.

A required learning outcome of courses involving grazing management and plant-grazing animal interactions is an understanding of the cause—effect relationships between sward characteristics and forage intake of grazing animals. Demonstrating these relationships is difficult to accomplish in a standard laboratory setting. Laboratory exercises were developed for a graduate-level forage evaluation course to help students learn the effect of sward height and density on short-term grazing behavior of sheep (Ovis aries). Artificial swards with two different tiller heights and two different tiller densities were constructed by affixing tillers of smooth bromegrass (Bromus inermis Leyss. subsp. inermis) to 0.25-m2 boards. Each board with an artificial sward was placed on the floor of a pen and a ewe was allowed to graze it for 30 s. Boards were weighed immediately before and after grazing to determine intake rate. Number of prehending bites were counted during the grazing period to calculate biting rate and bite size. Bite size and intake rate were generally greater for the tall, high-density swards, whereas biting rate was higher for the short, low-density swards. Grazing boards can be constructed easily for demonstrating the effect of other sward variables (e.g., herbage mass and density, leaf/stem ratio, and species composition) on the components of forage intake. Inclusion of these exercises in courses emphasizing plant-animal interactions is an efficient and effective means of enhancing student learning.

Topography is an important factor in determining vegetation patterns in grasslands. We collected frequency of occurrence data from transects on dune tops, south-facing slopes, north-facing slopes, and interdunal valleys in the eastern Sandhills of Nebraska to determine the effect of topographical position on plant species composition. We used canonical discriminant analysis to separate the four topographical positions based on frequency of occurrence of the 18 principal planttaxa. Topographic position played an important role in plant distribution on upland prairie with interdunal transects strongly separated from transects on other topographical positions. Bluegrasses (Poa L. spp.), switchgrass (Panicum virgatum L.), and white sage (Artemisia ludoviciana Nutt.) were highly associated with interdunal valleys. Little bluestem [Schizachyrium scoparium (Michx.)] and cool-season grasses, such as needlegrasses (Stipa L. spp.) and Junegrass [Koeleria pyramidata (Lam.) Beauv.], tended to be associated with north-facing slopes and warm-season grasses, such as prairie sandreed [Calamovilfa longifolia (Hook) Scrihn.] and sand bluestem (Andropogon hallii Hack.), tended to be associated with south-facing slopes. Sedges (Carex L. spp.), western ragweed (Ambrosia psilostachya DC.), and Scribner dichanthelium [Dichanthelium oligosanthes (Schult.) Gould var. scribnerianum (Nash)] were the most common taxa occurring over all topographic positions. Aspect proved to be an important factor in influencing vegetation distribution in the eastern Sandhills of Nebraska.