Utilizing annual forages to extend the grazing season can improve late-season forage production and quality, cow performance, and soil health; while providing a cost-effective alternative to drylot feeding. A four-year study tested three annual forage treatments using a single, dual, and dual crop with a herbicide burndown response variable (1 L/ha glyphosate, 250 mL/ha dicamba, 250 mL/ha 2,4-D) system. Treatments were foxtail millet (Setaria italica), turnip (Brassica rapa), a cocktail mix of six complementary species, and native range (control). Results found grazing foxtail millet in the single crop system and the dual crop with spray system, plus grazing turnip and cocktail mix in the dual crop with spray system, all provided on average cost-effective grazing options compared to grazing native range and feeding in a drylot system. The opportunity of increasing land-use efficiency was greatest with the dual crop with spray system, which was the most economical option in 2010.

Range land is an important resource in Utah's economy. Of 52.7 million acres of land in Utah about 78 percent is used for production of range livestock (14).1 In 1958, cash receipts of range livestock amounted to 62.7 million dollars, or 38.8 percent of Utah's total agricultural cash receipts (19). Of total land within its boundary, the state owns 2,723,157 acres. or 5.17 percent (32). The state legislature has designated the Utah State Land Board as the responsible agency for administering this land to provide income for various state institutions. The people of the state of Utah are required to pay for the operation of common schools and other public institutions. Many of these tax supported institutions are partly financed by interest from permanent school funds. As the cost of operating these institutions is growing each year, it is in the interest of the state that the permanent school funds yield as much revenue as possible. It is important that management of state land be such that the greatest possible revenue from the resource be forthcoming.

M. S.

A field study was made to correlate cattle grazing patterns of steep terrain with the rest-rotation grazing system. Line-plot transects were positioned across each of three heavily grazed, steep canyons. The rest-rotation system as practiced on the Gooding Cattle Allotment is resulting in good forage use as the animals are grazing forage on slopes up to 60%. Level contour trails extending across slope faces made it possible for cattle to graze on steep slopes at distances up to 80 chains from water. Contour trails originate at watering loctions; hence better distribution of water could be expected to result in better distribution of cattle on steep ranges. Downed timber blocked some contour trails and its removal could inrease forage utilization. Salt should not be placed along a contour but upslope or downslope to increase cattle distribution.

M.S.

No description available.

Cattle operations in the Southeastern United States are primarily cow-calf and stocker based and rely heavily on forage. As such, research regarding supplementation strategies that are specific to both the forage cultivars and management strategies that are common in the region are necessary for accurate nutritional recommendations. Additionally, further research is necessary to develop solutions to cope with the negative effects of fescue toxicosis that are common in the region. Therefore, the objectives of this dissertation are to examine supplementation strategies specific to growing cattle as well as to investigate methods of reducing ergot alkaloid intake. Corn gluten feed (CGF) is a common corn co-product that is used to supply supplemental energy and protein. Experiment 1 investigated the effect of supplementing CGF or corn to grazing cattle and found that in grazing situations, growing cattle that are supplemented with CGF have greater average daily gain (ADG) and feed efficiency compared to those supplemented with corn (P  0.03). This improvement in ADG was without changes in subcutaneous fat accretion (P = 0.87), as there were no differences among treatments in fat thickness at the 12th rib (P = 0.54). This improvement in growth and efficiency was thought to be due to differences in the digestibility of fiber in the rumen. Therefore, experiment 2 was designed to investigate the effect of corn or CGF supplementation on apparent total tract nutrient digestibility when cattle are fed a forage-based diet. However, the results from this experiment indicated that there were no changes in neutral detergent fiber digestibility (P > 0.19). In fact, heifers supplemented with corn at 0.25% BW had greater acid detergent fiber digestibility compared with those supplemented with corn at the same level (P = 0.05). Ultimately, this resulted in animals being supplemented with corn tending to have greater organic matter digestibility compared to those supplemented with CGF (P = 0.10). Therefore, the improvement in performance that is observed when grazing cattle are supplemented with CGF compared to corn does not seem to be due to improvements in fiber digestibility. Experiment 3 examined if prolonged storage of ensiled tall fescue would result in the degradation of ergot alkaloids to levels similar to that of hay. Surprisingly, there were no differences among hay or haylage samples for individual or total ergot alkaloids regardless of storage time. Ergovaline concentrations, however, declined after 30 d of storage and were similar throughout the remainder of the storage period. Although no differences were observed among treatments, the reduction of ergovaline concentrations after 30 d of storage indicate that short-term storage may help to reduce the negative effects of fescue toxicosis for the animals consuming it. / Doctor of Philosophy / The Southeastern United States is home to approximately 20% of the country's cattle population and is a major source of feeder cattle that enter the feedlots in the Midwest. The primary nutrient source for cattle in this region is grazeable forage, and production systems in the Southeast are primarily cow/calf or stocker based, with few forage or grain-based finishing operations. Much of the grazeable area is in a portion of the country termed the fescue belt since the primary species of grass is tall fescue. While this species has desirable forage characteristics, it is commonly infected with a fungal endophyte that produces ergot alkaloids that are toxic to livestock. These ergot alkaloids are attributed to billions of dollars of lost revenue and reduced animal welfare. While the forage in the Southeast is of relatively good quality, many producers choose to supplement grazing cattle. This is particularly common during winter months when forage is dormant, and when desired levels of growth exceed what can be provided by forage alone. However, the source of supplemental nutrients can induce changes in the efficiency of forage digestion, and the optimal nutrient source differs when compared to grain-based diets. Therefore, it is important for producers and nutritionists in the Southeast to have access to data relevant to their region of the country. The objectives of this dissertation are to evaluate supplementation strategies relevant for the Southeast, and to evaluate a potential method of mitigating the negative effects of fescue toxicosis in harvested forage. Corn gluten feed has previously been shown to improve performance to a greater extent compared to corn when included in a forage-based diet in a dry-lot setting but has not been investigated in grazing situations. Therefore, we investigated if this effect would be present in grazing situations. Using growing cattle and an automated feeding system, we demonstrated that grazing cattle supplemented with corn gluten feed had greater growth performance compared to those supplemented with corn. To investigate if this was due to differences in nutrient digestibility, we then investigated how total tract digestibility was influenced by supplement type and inclusion level in forage-based diets. However, our results indicated that at relatively small levels of inclusion, total tract digestibility is not impacted by supplement type. To investigate methods to control fescue toxicosis in livestock, we conducted an experiment to determine if ergot alkaloid concentrations in forage harvested as hay and haylage can be reduced through prolonged storage. While there were no differences in concentrations among forage types (hay and haylage), there was a beneficial effect of day for ergovaline concentrations, one of the principal toxins that is present in endophyte-infected tall fescue. This suggests that profits for livestock producers as well as animal welfare can be improved through the short-term storage of harvested tall fescue. Collectively, these experiments demonstrate potential methods for beef producers in the Southeastern U.S. to improve growth in grazing cattle. As researchers continue to improve the understanding of the interaction between grazing livestock and supplementation programs, improved recommendations can be made regarding nutrition programs and ultimately result in a more efficient and profitable operation.

For Virginia, the primary forage base is endophyte-infected tall fescue (Schedonorus phoenix (Scop.) Holub). However, the decreased animal performance and disorders caused by the presence of the fungal endophyte Neotyphodium coenophialum reduces its suitability for many forage-livestock producers. The endophyte, which is found in the inter-cellular space of tall fescue tissues, forms a mutalistic relationship with the plant and helps the fescue tolerate drought, insect predation, and grazing pressure. The production of toxic ergot alkaloids by the endophyte is associated with decreased performance of animals that graze endophyte infected tall fescue. The objective of the current experiment was to determine how tall fescue type (endophyte free vs novel endophyte) and orchardgrass-legume (alfalfa vs clover) mixture affect grazing behavior of weaned steers. Forty-eight weaned steers (218 ± 18 kg) were blocked by frame score (medium and large), and randomly assigned within block to four treatments with three replications in a 2x2 factorial design. Each treatment consisted of 2 paddocks with the combination of tall fescue and legume-orchardgrass mixture as follow: alfalfa-orchardgrass mixture (A)/E-, clover-orchardgrass mixture (C)/E- , A/E++ and C/E++. Each group of 4 steers had 24 h access to both tall fescue stand and legume-orchardgrass mixture. Botanical composition of paddocks was determined on d 0, and forage mass, sward height and nutritive value were determined on d 0, 17 and 33. Behavior of steers was scanned every 5 min on d 24 and 25 from 0700 to 1900. The proportion of legumes was higher (P = 0.001) in A paddocks(37 %) compared to C paddocks (6%), while the percent orchardgrass was lower (P = 0.040) in A (33 %) than C (53 %). The proportion of broadleaf and grassy weeds was higher (P = 0.013) in E- paddocks (11 %) as compared with E++ paddocks (3 %). Sward height and herbage mass were similar between treatments during the experiment (P > 0.05). Nutritive value (CP, NDF and ADF) did not differ between fescue paddocks (P > 0.05). However, within mixed swards, CP was higher and NDF was lower in A compared with C (P < 0.05). Acid detergent fiber was (P < 0.05) lower in A than C only on d 0 and 17. Average daily gain did not differ between treatments (P > 0.05). Steers spent higher (P = 0.002) proportion of the daylight time grazing in treatments with C (56 %) as compared with A (50 %), and in treatments (P = 0.023) with E++ (55 %) compared with E- (52 %). Time spent ruminating, idling and lying, as well as steps taken per day, did not differ between treatments (P > 0.05). Regardless of differences in weeds between E- and E++, these results indicate that fescue type affected grazing behavior of calves. Difference between mixed swards in proportion of ground cover with legumes and orchardgrass, as differences in nutritive value between A and C may have affected grazing behavior of calves between mixed swards, instead of a legume species effect within mixtures. / Master of Science

I investigated life history traits and secondary production of populations of Goniobasis proxima in four streams from July 2005 to June 2006. Measurements of canopy cover, conductivity, alkalinity, temperature, and nitrate-nitrogen (NO3-N), as well as snail size, density, and occupied substrate were taken monthly for each stream. Snail growth rates were determined in an aquarium for 10 size classes and secondary production was estimated as the summed product of size class growth rates and field biomass measurements. Size class production estimates tracked biomass with intermediate to larger sized snails dominating production, despite smaller snails growing faster. Production estimates across streams ranged from 1,400 mg m-2 yr-1 to 22,183 mg m-2 yr-1 with noticeable summer highs and winter lows. Annual turnover was slow (0.43-0.49) owing to slow growth and long development time. Snails preferred leaves/wood as a substrate to occupy over rock and sand and showed no appreciable grazing effect on the epilithon community. / Master of Science

The Southeastern United States offers a beneficial environment for stocker and cow-calf production. Abundant tall fescue grass offers a feed source that has been underutilized. These studies evaluated how nitrogen rate and source can affect yield and nutritional quality of fall stockpiled tall fescue, and how grazing methods impact weight gains, forage utilization, and forage nutritive value. The first study evaluated the impact of N rate and source on the yield tall fescue stockpiled for winter grazing. In mid-September, seven N sources (ammonium sulfate (AS), ammonium nitrate (AN), urea + Agrotain @ 2.1 l/Mg (AG2), urea + Agrotain @ 4.2 l/Mg (AG4), urea + Agrotain @ 6.3 l/Mg (AG6), Nutrisphere (NuS), and urea) were applied at 0, 45, 90, and 135 kg N/ha. Ammonium sulfate produced the highest nutritive values of all N sources. Only yield in 2012 was found to be influenced by N volatilization inhibitors; said products had no effect on nutritive value. The second study evaluated how grazing methods impact nutritive value, ADG, and utilization of tall fescue stockpiled for winter grazing. Three treatments (continuous grazing, moved once per week, and moved twice per week) were used. In year one, cattle moved once and twice per week showed significantly higher ADG (P < 0.05) than the continuous treatment. In year two, cattle that continuously grazed had higher ADG (P <0.05), than cattle moved once and twice per week. Cattle moved once and twice per week showed greater forage utilization (P < 0.05) than cattle that continuously grazed. / Master of Science