The objective of this research was to determine the effect of stage of maturity at the time of harvest for barley and oat whole-crop forage on feed intake, ruminal fermentation and digestibility, and the impact forage allocation has on intake and ruminal fermentation. In the first 2 studies, whole-crop barley (Study 1; c.v. CDC Cowboy) and oat (Study 2; c.v. CDC Weaver) forage were harvested at the late milk (LM), hard dough (HD) and ripe (RP) stages and offered ad libitum to ruminally cannulated heifers. Diets were supplemented in an attempt to balance crude protein (CP) among treatments. Heifer performance, dry matter intake (DMI), ruminal fermentation parameters, ruminal digestibility, and total tract digestibility were evaluated. In Study 3, whole-crop oat (c.v. CDC Weaver) forage harvested at HD and RP was offered ad libitum to ruminally cannulated heifers in either daily (1-D) or 3 d (3-D) allocations. Dry matter intake and ruminal fermentation parameters were measured. In Study 1, harvest maturity of barley did not affect DMI (P = 0.70; average 5.4 kg/d) or average daily gain (ADG; P = 0.64). Total tract digestibility was decreased for barley harvested at HD (P = 0.003), but harvest maturity did not affect daily digestible energy (DE) intake (P = 0.52). Minimum ruminal pH for heifers fed the barley forage was lowest for LM (6.09), intermediate for RP (6.13), and greatest for HD (6.25; P = 0.016). Total short chain fatty acid (SCFA) concentrations were not affected by harvest maturity (P = 0.36). In Study 2, harvest maturity of whole-crop oat did not affect DMI (P = 0.26; average 8.1 kg/d) or ADG (P = 0.52). There were no effects of harvest maturity of oat forage on total tract digestibility (P = 0.78) or daily DE intake (P = 0.68). The minimum ruminal pH from heifers fed oat forage was lowest for HD (5.84; P = 0.012), intermediate for RP (5.94) and greatest for LM (5.99). There was no effect of harvest maturity of oat forage on total SCFA concentrations (P = 0.21). The quantity of forage allocation (Study 3) had no effect on total or forage DMI over a 3-d duration (P ≥ 0.47). Throughout the 3-d feeding period, 3-D allocated heifers had a reduction in the area pH was under 5.8 (214.4, 79.5 and 10.9 pH × min/d, for d 1, 2 and 3, respectively; P = 0.003). Total SCFA concentrations were not affected by forage allocation or harvest maturity (P ≥ 0.14), however there was an interaction of forage allocation and day in the feeding cycle (P = 0.046). Heifers allocated 1-D had no change iii in total SCFA concentration over the 3-d feeding period (averaged 122 mM), but 3-D allocation had elevated concentrations on d 1 (138 mM) intermediate on d 2 (135 mM) and decreased on d 3 (117 mM). These data suggest that harvesting barley and oat at the HD stage improves DM yield without negatively affecting cattle DMI and ADG. These data also suggest that providing 3-d allocations of forage does not affect DMI, but can increase daily fluctuations of ruminal pH and ruminal SCFA concentrations.

The magpie goose (Anseranas semipalmata) is a spectacular and unique waterbird from tropical north Australia and southern New Guinea. Due to recent human persecution, the species has been eliminated from most of its former strongholds in southern and south-eastern Australia – reduced to small conservation-dependent populations through habitat loss, exploitation and drought. Yet, genuine conservation opportunity still exists in northern Australia, in the country's Northern Territory in particular, to maintain viable populations through evidence-based management of wetlands that support the waterbirds and mitigation of the threats posed by global change. Much has been achieved over the last 50 years to understand the ecology and life history of magpie geese, but little has been done to understand important population-level interactions with wetland habitat and the likely outcomes under climate warming, wetland loss to sea level rise, altered competitive interactions among wetland plants, increased frequency and severity of epizootics, and synergies with over-hunting. My review of pathogens and parasites likely to cause morbidity and mass mortality in magpie geese shows that bacterial diseases such as avian cholera and botulism, as well as pathogenic avian influenza viruses, pose the most serious threats. Bacterial diseases in particular are more likely to occur under warmer and wetter conditions, and geese are susceptible to these given large aggregations at favoured nesting and feeding sites. I use a metapopulation model to demonstrate that increased frequency and severity of epizootics will likely force extirpation of geese under current harvest rates across the Northern Territory. Magpie geese are also vulnerable to climate change through dependency on a favoured food plant – the water chestnut (Eleocharis dulcis). As a result of a two-year field programme, I was able to show how birds seasonally migrate and aggregate in response to the availability of this resource and gain body condition following predation on the root tubers of the plants. My geospatial modelling of ocean level inundation of wetlands that support E. dulcis show marginal habitat loss under 1.4 m of sea level rise, and large-scale losses under multi-metre sea level rise, but the current resolution of GIS data do not account for fine-scale saline water intrusion through channel or eroded levees. The population models constructed predict that magpie geese are broadly resilient to change where harvest is tightly regulated, but current harvest rates are unlikely to be sustainable. Given the importance of maintaining viable, connected subpopulations large enough to maintain genetic diversity, and because of the value of magpie geese to Aboriginal Australians as a food source, ongoing monitoring of geese population trends will be essential. Wetland management options include erecting buffers to stop or slow down saltwater intrusion resulting from sea level rise, and implementing a system to monitor annual indigenous harvest. Temporary restrictions on harvest may be necessary following mass mortality events such as epizootics or droughts. Only the careful management of wetlands that support current geese populations, and close monitoring of populations will ensure continued sustainable harvest of geese under global change. Given the cultural and biological significance of this species and the north Australian wetlands that support it, this is a conservation resource we cannot afford to squander. / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Science, 2009

No description available.

No description available.

This study examined the demography of giant kelp Macrocystis pyrifera (Linnaeus) and its interactions with understorey algae and invertebrates in southern New Zealand over two and a half years. Most of the study was done at two sites within Akaroa Harbour (Banks Peninsula) but ancillary sites at Tory Channel (Marlborough Sounds) were used for parts of the study. The kelp forests within Akaroa Harbour were generally highly productive, with a high annual turnover of giant kelp. Macrocystis plants were mostly annual and rarely reached ages greater than 12 months. Peak recruitment occurred in spring (November) during 1995-97, but lesser recruitment episodes occurred throughout the year. The maximum growth rates of Macrocystis fronds were comparable to rates reported elsewhere in southern hemisphere populations (22 mm - 24.5 mmlday), but considerably lower than those in northern hemisphere populations. The major experiment incorporated in the study tested the effects of the Macrocystis canopy and the understorey canopy of the stipitate laminarian Ecklonia radiata on macroalgae and invertebrates. The experiment was structured so that the effects of clearances at different times could be determined. One impetus for this experiment was the need to address issues relating to the commercial harvesting of giant kelp, its sustainability and its effects on other species. The effects of canopy removals on understorey algae, mostly juvenile Macrocystis, Ecklonia and Carpophyllum spp, were highly dependent on the timing of canopy removals and the combinations of canopies removed. For example, winter harvests of the Macrocystis canopy alone enhanced the survival of post-settlement Macrocystis recruits, but had little effect on Ecklonia recruitment. However, when both Macrocystis and Ecklonia canopies were removed in spring, there was heavy recruitment of Ecklonia that grew to dominate the understorey. Strong inter and intraspecific interactions from the Macrocystis surface canopy appeared to have been reduced by physical factors including water turbidity, sedimentation and the deterioration of the surface canopy during summer. These physical factors were not as limiting in Tory Channel. Fine scale extrinsic factor effects including nutrients, light and grazing on the early life history of Macrocystis were investigated in small experiments. Results suggest that recruitment may be nutrient limited even at moderately low temperatures, and that small herbivorous gastropods are an important source of mortality in the early life stages of Macrocystis. Culturing and transplantation cultivation techniques were also examined as a means of supplementing algal supplies. Macrocystis was cultured successfully through its life cycle onto culture ropes, but generally failed to produce visible sporophytes when placed in the field. Cultured plants did grow in Tory Channel, however. Juvenile plants transplanted to ropes for on-farm cultivation showed little growth during summer, but the addition of nutrients significantly enhanced growth rates of these plants during warmer months when natural nutrient levels were low. Increased growth rates at the onset of winter and with the addition of nutrients during summer confirmed that low nutrient levels during summer are growth limiting. Akaroa Harbour kelp forests exhibited considerable variation in Macrocystis canopy biomass through time. For example, the 32,000 m2 kelp forest at Wainui had a biomass of 144 t in October 1995, which then decreased to 21 t in October 1996. Canopies tended to deteriorate during summer. Thus, at Ohinepaka Bay kelp forest had a biomass of 31 t during winter 1997, which decreased to 0.06 t the following summer. The greatest reduction in biomass, however, coincided with a period of hugely increased sediment, which smothered blades in the sea-surface canopy, covered the substratum, and prevented successful recruitment of kelp for over a year. Nutrient depletion was one of several factors thought to cause the summer deterioration of the Macrocystis sea-surface canopy, which has important ramifications for the commercial harvesting of Macrocystis pyrifera in summer. Management considerations and options are discussed in relation the commercial harvesting of Macrocystis in New Zealand. The major conclusion of this study is that although Macrocystis was able to form dense surface canopies during winter its ability to dominate kelp forests was constrained by physical factors, especially sedimentation, high turbidity, nutrients, and storms. The lack of strong interactions between Macrocystis and Ecklonia are also largely a result of their different life history characteristics. Overall, there appear to be no significant negative flow-on effects resulting from kelp harvesting and it appears that Macrocystis can be harvested sustainably.

Thesis (D. Min.)--Trinity International University, 2005. / Abstract. Includes bibliographical references (leaves 193-197).

Thesis (Ph.D.)--Bowling Green State University, 2009. / Document formatted into pages; contains xiv, 226 p. : col. ill. Includes bibliographical references.

Thesis (D. Min.)--Trinity Evangelical Divinity School, Deerfield, Ill., 1999. / Abstract. Includes bibliographical references (leaves 185-188).

Thesis (D. Min.)--Trinity International University, 2005. / Abstract. Includes bibliographical references (leaves 193-197).

This diploma thesis deals with the evaluation of CLAAS TUCANO 440 and CLAAS TUCANO 450 combine harvesters for the harvest of cereals and winter rape. It evaluates problems in terms of losses, depending on grain humidity, quality of crushing and spreading plant residues. The thesis sets basic performance and is supplemented by a simple analysis of investment and operating costs. The methodology of the solution was based on own measurements, information obtained from the owner, literature and agricultural standards.