Thesis (Ph. D.)--University of Wisconsin, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 337-353).

6 pp. / Originally published 09/2000. / The objectives of this article are to provide an overview of the major grazing systems that have been used on rangelands in the western U. S. and Canada, to summarize the conditions under which they may be applicable, and to highlight examples from the southwestern U. S. when relevant. Revised 12/2014. Originally published 09/2000.

The study was conducted in the Eastern Kalahari sandveld of Botswana on a shrub savanna vegetation type dominated by Terminalia sericea / Boscia albitrunca / Grewia flava and Dichrostachys cinerea woodland. It was initiated in an attempt to determine the impact of livestock grazing within piospheres on soil nutrients, range condition and the influence of season on forage quality and diet composition of livestock. The study was centered around the water points and conducted on both free range grazing and controlled conditions. Measurements on soil and vegetation attributes were recorded at particular points along the transects from the water point. Vegetation and livestock diets were measured seasonally over a period of two years. Chemical analyses of soil revealed the low background fertility of the Kalahari sandveld. The impact of dung and urine on soil chemistry was localized in the area immediate to the vicinity of the water point. Phosphorus, pH and cation exchange capacity were the most responsive attributes to variation along the transect from the water point. High livestock units carried at any particular borehole had an influence on the level of soil nutrient status. Management plans should aim at a more even spread of nutrients by improving the distribution of water points. The zonation of vegetation along the transect from water point reflected the type of management, indicating different class of range condition which can be used in range evaluation and planning. Heavy grazing pressure and trampling in the vicinity of the water point kills sensitive perennial grasses resulting in a zone dominated by annual plants. High amount of available biomass were recorded during summer and autumn and low biomass occurred in spring. The 3 - paddock system produced less biomass compared to other systems, while biomass of palatable species was favored by the 9 - paddock system. Forage utilization was higher following drought years, when grazing pressure was concentrated on reduced forage availability. Utilization of forage was greatest in spring and lowest in summer. Utilization along the transect from water did not taper off until after 4000m from the water point in the free range grazing situation suggesting that forage availability was limiting factor, while in the controlled conditions the influence of grazing tapered off at 1200m. Piosphere size as determined by the distance livestock can travel was greater in the free range grazing management area than in the controlled management conditions. Canopy volumes and leaf dry mass values reflect quantitative variations in the contribution of relatively small number of woody species. In general, both leaf volume and leaf mass decrease with the increase in distance from water due to the reduced plant density. Grewia flava and D. cinerea contributed substantially to the total leaf dry mass within the height below 2m. Leaf dry mass above 2m was largely contributed by Acacia gerrardii, T. sericea and B. albitrunca. Woody species diversity increased with the increase in distance from the water point. High density of G. flava was concentrated to the immediate vicinity of the water points, while species such as Bauhinia petersiana and Croton gratissimus occurred only at further distances from water. There was no clear pattern in the density distribution of D. cinerea along the transect from the water point. Plants exhibit variations in the concentration of nutrients between species and season. High levels of crude protein, phosphorus and low crude fibre content occurred in summer for most species and the opposite was observed during winter or spring. Crude protein and phosphorus during dry periods were believed to be the limiting nutrients in maintaining nutritional quality in grazing animals. Mature forage generally is deficient, and may require supplementation of crude protein or phosphorus. Crude protein, phosphorus and crude fibre were not influenced by the grazing systems. The nutrient enrichment through cattle dung and urine in the vicinity of the water point was reflected in the forage nutrient content. The micro - histological technique proved to be a useful tool for estimating the botanical composition of livestock diets. The technique, however, under-estimates the forbs in the diet of livestock. Diets of cattle were dominated by grasses all year round with a high proportion of woody plants occurred during the spring when available herbaceous biomass was low. Diet of goats was 72% and 82% browse in summer and spring, respectively. Competition for herbaceous plants was high between cattle and sheep. Seasonal species diversity was high in summer and lowest in spring. Goats are more diverse in their diets compared to cattle or sheep which have a strong similarity in their diets. / Dissertation (PhD(Plant Production and Soil Science: Pasture Science))--University of Pretoria, 2002. / Plant Production and Soil Science / unrestricted

Simulium chutteri is considered a major pest in South Africa and it has been estimated that it can potentially cause stock losses amounting to more than R88 million per annum. Although a larval control programme has been launched to control the pest, major outbreaks still occur, since major fitness traits such as longevity are ignored in the planning of control actions. To improve the control programme, the aim of this study was to study the longevity of S. chutteri females under various conditions, and also to relate longevity to factors such as size, mass and metabolic reserves as these traits show variation that can be linked to changes in developmental temperature. It was conclusively demonstrated in this study that the body size and mass of S. chutteri increases with a decrease in temperature and therefore both seasonal and geographical variations occur. A consequence of larger body size is that these individuals carry proportionally more lipid reserves than smaller ones, although these relationships were not found for glycogen. It was shown that major seasonal variation occurred in the survival of S. chutteri, although these could not be attributed solely to variations in size, mass and metabolic reserves. For example, despite the large body size and mass and metabolic reserves of the winter population, it showed comparatively lower survival than all the other populations. It is argued that this is due to the interaction between fecundity and other fitness traits such as desiccation and starvation resistance. Adaptive explanations are, however, also proposed. These results are used to explain the seasonal variation found in the annoyance levels of S. chutteri along the lower Orange River. Moreover, recommendations are given for the improvement of the current blackfly control programme. These include the need to control the summer population (when certain criteria are met) and showing the importance of effectively controlling the winter population. / Dissertation (MSc (Entomology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

This research was undertaken to determine the profitability of investing research funds into the Three Strata Forage System (TSFS) project, a cattle production project funded by the International Development Research Centre (IDRC) and carried out in the village of Pecatu, Bali. The purpose of the project was to increase the production of cattle and productivity of the traitional farming system by introducing different grass, ground ground legumes, fodder shrubs and trees, and changing the pattern of land allocated to these forages. A TSFS plot foregoes 0.09 hectares of crop production to produce 0.09 hectares of grass and ground legumes (strata 1), 2000 shrubs (strata 2) and 42 fodder trees (strata 3) on the perimeter of a 0.25 hectare crop field. Cattle are fed exclusively with forages obtained from the plot, in contrast to the traditional system where cattle are tethered on marginal land and fed with feed obtained from other locations on the farm. The TSFS researchers have claimed that the TSFS will "not only increase the quantity and quality of the forages, but it could also increase the stocking rate [of cattle] and carrying capacity of the land, increase the soil fertility, reduce the soil erosion, increase the firewood supply, increase the farm income, induce other on-farm activities, and induce better ecological balance of the environment" (Nitis et al, 1989). In this study, the claims made by TSFS project researchers have been evaluated using financial analyses. Using data collected from farms in Pecatu, Bali, the values of TSFS production inputs are estimated from local market prices and regressions estimating farm production relationships. The results of the financial analyses were then used to infer the social welfare effects of the TSFS. The results of the analyses show that the TSFS plot incurs negative returns, relative to a traditional crop field. Elements of the TSFS system, such as improvements to the local ecosystem, are believed to have a minimal effect on the final estimates of the profitability of the plot and are excluded from the analysis. The large negative returns of the plot indicate that there are resource allocation costs associated with the transfer of high value crop land to the low value forage production advocated by the TSFS. The grasses and ground legumes introduced by the TSFS project were not familiar to farmers in Pecatu. However, the farmers were willing to experiment with the new varieties, with varying degrees of risk averseness and success in adoption (in accordance to the findings of Antle and Crissman (1990)). The tree and shrub forages of the TSFS were already known to farmers in Pecatu; the introduction of the TSFS did not appear to affect the use of tree fodder resources but may have increased the use of forage shrubs. The results of financial analysis of individual project forages indicate farmers have preferences for specific forage species. While farmers agreed to participate in the TSFS project due to financial incentives, they found they could reduce the costs of the TSFS by adopting profitable aspects of the TSFS, using a more flexible approach to land allocations and choice of forage species. As the shrubs, grasses and ground legumes are well-known throughout Asia, it appears that the only new management techniques introduced by the TSFS are the planting arrangement and feeding system - and these aspects have resulted in negative returns. Therefore, any positive welfare effects associated with the project are due to an increase in the rate of adoption of the forages included in the TSFS - although these effects are not large enough to offset the losses imposed by an inefficient allocation of land and labour resources to forage production. Reviewing all resource allocation effects of the TSFS, and given the size of the payments needed to obtain farmer participation it is clear that the net welfare effects are negative. Notwithstanding the optimistic claims of the project literature, the forages produced by the TSFS regime are not valuable enough to match the profitable crop activities they are supplanting. There is evidence to suggest that TSFS researchers have been prone to misjudge the true costs and benefits associated with the TSFS plot. This arises not only as a result of overly optimistic claims of project benefits and understated project costs, but a pervasive disregard for the rationality of traditional farmers. For future research projects, it is recommended that the funding agency, IDRC, require ex ante economic analyses, to determine the true social costs and benefits of a proposed technology. In this way, projects of net negative social value can be identified and improved before research resources have been allocated to the generate an inefficient technology. / Land and Food Systems, Faculty of / Graduate

MPM-2, a monoclonal antibody specific for phosphorylated epitopes of mitotic proteins, has been used to identify unique 75-85 kD proteins of the mammalian sperm tail, named MPM-2 reactive sperm tail phosphoproteins (MSP). Due to the loss of MPM-2 reactivity following fertilization in bovine and rabbit zygotes, additional antibodies were produced to non-phosphorylated epitopes of MSP. One rabbit polyclonal sera (rMSPab) and three mouse monoclonal antibodies were produced. These antibodies were used to immunolabel rabbit and bull whole sperm cells and resulted in nearly identical patterns and labelled the sperm tail similar to MPM-2. Immunoelectron microscopy of whole rabbit sperm and rabbit testicular sections, showed MPM-2 reactivity primarily over the outer dense fibers and the capitulum of the sperm tail. Immunolabel with rMSPab revealed labelling of the outer dense fibers, fibrous sheath and the material surrounding the centrioles of the connecting piece. Immunoblots labelled with rMSPab indicated that reactivity is predominate at a 70-85 kD region of whole rabbit, bull, boar and mouse sperm proteins, with accessory labelled bands at 62, 64 and 55 kD. Immunoblots of extracted boar sperm proteins with MSP monoclonal antibodies displayed reactive bands at 70-85 kD as well as an additional cross reactive band at 55 kD, suggesting that the 55 kD protein is immunologically related. Zygote labelling with MSP antibodies revealed that MSP remains associated with the sperm tail throughout the first cell cycle and is centered in the sperm aster. Labelling of rabbit tissue proteins (spleen, liver, heart, lung, intestine, uterus, ovary and brain) on immunoblot with rMSPab and MPM-2 revealed that MSP is unique to mammalian sperm and all tissues contain immunologically related proteins, strongly reactive at 51-53 kD region. Injection of MSP antibodies into mature bovine oocytes, followed by sperm penetration, inhibited sperm derived microtubule aster formation. Taxol treatment of injected oocytes and zygotes suggested that MSP antibody blocked aster formation, but not by preventing microtubule nucleation. These data suggest that MSP is a structural component of the sperm tail outer dense fibers, specifically dephosphorylated following fertilization and blocking MSP with specific antibodies results in the failure of the sperm aster to develop but not by interfering with microtubule nucleation. We hypothesize that MSP is a possible intermediate filament type protein, forms a structural component of the sperm tail and MSP disassembly is a prerequisite for microtubule aster formation around the paternal centrosome.

The structure and function of headwater streams was evaluated in response to livestock exclusion implemented through Virginia's Conservation Reserve Enhancement Program (CREP). We measured riparian plant characteristics along with stream organic matter dynamics, benthic macroinvertebrates, algal biomass, and leaf breakdown in non-fenced, fenced, and forested streams. Increased growth of non-woody vegetation and the pre-existence of woody plants had a significant influence on stream organic matter dynamics. Tree basal area in a 20 m wide riparian corridor was predictive of stream coarse benthic organic matter standing stocks. Higher benthic organic matter standing stocks and differences in algal biomass in fenced and forested sites indicate different food resources may be structuring macroinvertebrate communities in these systems. We found a significant relationship between coarse benthic organic matter and percent shredder density, and scraper density generally followed patterns of algal biomass among treatments. Leaf breakdown rates among treatments were not indicative of differences in shredder density with two of the three fenced sites having the fastest overall breakdown rates observed. We attributed faster breakdown rates in these streams to available food resources and shredder community structure existing prior to the implementation of livestock exclusion. Our results suggest that a certain amount of ecological recovery may be possible through livestock exclusion. Macroinvertebrate structure in our study streams was primarily influenced by the presence or absence of riparian trees. Maturation and successional changes in woody riparian vegetation after livestock exclusion may allow certain characteristics of pastoral streams to return to those found in forested reaches. / Master of Science

No description available.

Among the vast diversity of plants in the mid-South to which grazing livestock are exposed, there is a need to address certain species that are potentially harmful to livestock health and production. Field and greenhouse experiments were conducted on endophyte-infected tall fescue [Schedonorus arundinaceus (Schreb.) Dumort = Lolium arundinaceum (Schreb.) Darbysh.], a cool-season perennial forage, and perilla mint, (Perilla frutescens (L.) Britton) an herbaceous annual, to determine management techniques and control measures for healthier pasture and livestock systems. When seedheads reached maturity, spring and autumn glyphosate applications at 1.68 kg ae ha-1, coupled with autumn tillage and summer and winter cover crops effectively reduced tall fescue coverage to < 27% by 10 months after initial treatment (MAT) following a single year of management. If seedhead maturity is inhibited prior to first glyphosate application, tall fescue was reduced to <1% coverage 10 MAT. Despite seedhead suppression, at least 78% increase in coverage occurred in 24 months from remnant populations suggesting two years of renovation is required. Forage soybeans proved to be a valuable cover crop that maintained nutritive quality and mean dry matter yields of 5487 kg ha-1 across two years. Tall fescue seedheads were suppressed below 14% coverage (> 68% visual control) by nicosulfuron + metsulfuron (20 + 5 and 40 +11 g ai ha-1), imazapic (26 and 53 g ai ha-1), and sulfosulfuron (53 g ai ha-1) at 90 DAT. Reduction in forage heights may be expected, but was not consistently reduced when compared to untreated plots across locations. To control perilla mint, postemergence applications of aminocyclopyrachlor blends, glyphosate, picloram + 2,4-D, aminopyralid + 2,4-D, and 2,4-D alone provided superior control when applied prior to the plant’s reproductive growth stage. Picloram + 2,4-D also provided inield soil residual activity and the most effective preemergence control, followed by aminocyclopyrachlor + chlorsulfuron, pendimethalin, and aminopyralid + 2,4-D for at least 141 DAT. Seed from weedy populations in north Mississippi tend to germinate in a range of night/day soil temperatures from 10/15 C to 25/30 C. Therefore, effective preemergence treatments should be applied by mid- to late- February in this region.