The objective of the study was to evaluate the dry matter production, intake and the nutritive value of Indigofera species. The dry matter yield, leaf:stem ratio, chemical composition, voluntary intake and digestibility of Indigofera species were determined. The leaves as well as the leaves and stems (<3mm) of five different Indigofera species (I. amorphoides, I. cryptantha, I. costata, I. viciodes and I. arrecta) were harvested. There was a greater total dry matter yield during autumn 2004 from I. amorphoides. However, no significant differences were obtained between all the species over the seasons. There were significant differences between all the species in autumn with a lower proportion of leaves than in spring, except for I. arrecta, which had the same leaf: stem ratio in both seasons. During spring, I. amorphoides and I. cryptantha generally had a higher proportion of leaf material than other species. There were significant differences between all the species for the leaves as well as leaves and stems (<3mm) as a result of advancing maturity and decrease in leaf: stem ratio with respect to ash, crude protein (CP), neutral detergent fibre (NDF) concentration and in vitro digestibility of organic matter (IVDOM). Despite a decrease in leaf: stem ratio, all the species had an adequate CP concentration for optimal animal production. All the minerals (macro and micro elements) found in this study, in both years, will satisfy the nutrient requirements of sheep. However, all mineral elements in this study appeared to decrease with ageing of the plants and decline in leaf: stem ratio, except for Mn concentration, which increased with ageing of the plants. Lucerne, which was used during the intake study as a control, had a significantly higher organic matter intake (OMI) and digestible organic matter intake (DOMI) than Indigofera species and Leucaena leucocephala. However, there were no significant differences between Indigofera species and L. leucocephala. Intake levels in this study for L. leucocephala and Indigofera species would be insufficient for maintenance requirements of grazing sheep. The relatively lower IVDOM for Indigofera species and L. leucocephala compared to that of lucerne was because of a higher NDF concentration. Despite the relatively high NDF concentration, Indigofera species appeared to be a good fodder because of its high CP and Ca, P, Mg, Cu, Zn and Mn concentrations. / Dissertation (M Inst Agrar ( Animal Production))--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted

In aerial seeding of clearcut-logged sites above 1000 m elevation near Kamloops, British Columbia, mixtures of 5 forage species have been applied; orchardgrass (Dactylis glomerata L.), timothy (Phleum pratense L.), smooth brome (Bromus inermis Leyss.), alsike clover (Trifolium hybridum L.), and white clover (T. repens. L.). Seeding has been done by the B.C. Ministry of Forests during winter when such sites are snow-covered. A survey of stand establishment on operational winter seedings resulted in survival estimates for orchardgrass (2.3%), timothy(1.2%) and bromegrass(1.3%),in contrast to the 0.1% survival observed for clover species. On operational spring seedings, grass survival was 1.3%, 0.5% and 1.9% respectively for the above three species, while clover survival was 2.6%. In high elevation date-of-seeding trials established on a new clearcut winter mortality of clover seeds occurred after all seeding dates. First and second year clover plant establishment averaged 1.5% and 0.2% respectively for winter seedings (Nov. 11 to Mar. 22) compared to 20.5% and 13.2% for the May 2 seeding. Orchardgrass seeds were not damaged during the winter and first and second year survival of winter seedings was 43.8% and 21.9% compared to 37% and 12% for the spring (May) seeding. When broadcast from an aircraft, seed of the five species became lodged in the upper snowpack and soon after deposition were able to imbibe melt water. A model snowpack was developed in the laboratory to show that when the snow melted, pack shrinkage was localized at the top and that grass and clover seeds did not sink into the pack. In the field a similar pattern was observed; shrinkage was localized in the top of the pack so that seed was eventually exposed on the surface of the remaining pack. Therefore, seeds broadcast on any date in winter would eventually be located on the pack surface, regardless of the occurrence of post-seedng snowfalls. Field measurements showed that rapid freezing and thawing could occur in the upper layers of the pack. Laboratory simulation of such freeze-thaw cycling caused significant reductions (r₂=0.71;P<0.05) in alsike clover viability while not apparently affecting that of orchardgrass (r₂=0.10;NS). The effects on viability could not be explained by changes in seed moisture content of the two species. It is concluded that no date during winter is suitable for snow seeding of alsike and white clover on high elevation clearcut sites at Kamloops. / Land and Food Systems, Faculty of / Graduate

A review of the literature on black-tailed deer (Odocoileus hemionus columbianus Richardson) feeding habits reveals considerable variation among animals, locations, and seasons. Processes affecting food selection, however, are poorly understood. Optimal foraging theory was explored as a means of predicting deer foraging behaviour and diet breadth. Because of complex constraints and objectives involved in predicting diet selection, food preference was determined under ad libitum conditions. Feeding behaviour of two deer was studied in a 0.5-ha enclosure to examine the effects of density and distribution of their preferred foods on diet selection. When deer had to search for food, diet selection remained the same as that under ad libitum conditions as long as preferred food was abundant. Deer nearly exhausted their highly preferred food before switching to lower ranked foods. This switch was gradual, as deer continued to search for preferred food. The amount of preferred food already eaten during a trial was positively correlated with the time that animals would continue searching before switching to lower-ranked foods. Switching was related to the amount and type of food encountered and not to the amount of food in the pen. Dispersion of the preferred food (clumped versus unclumped) had no significant effect on the amount of food eaten, but did significantly influence the types of food encountered by one of the two animals. Both animals became more efficient (intake per distance travelled) at finding preferred foods with increasing experience with a specific distribution of food. Animals increased their efficiency of finding apples by repeating searching patterns which had been effective during previous trials. Performance was poor, however, when distributions were changed. When preferred food was abundant, platforms containing preferred food were not always completely cleared of food the first time a platform was visited. Intake rates of non-preferred foods tended to increase with declining abundance of preferred food. This increase was not caused by changes in the amount of non-preferred food eaten at feeding stations, but rather by the rate at which non-preferred feeding stations were visited. The influence of intraspecific plant variation on food habit studies and the utility of preference indices are discussed. I conclude that foraging bouts are highly dynamic and that some foraging questions may not be adequately answered if this internal variation is ignored. / Forestry, Faculty of / Graduate

Phosphorus loads in waterways are a focus of environmental concern. Animal agriculture\'s contribution to this problem has been documented and efforts are focused on mitigating the issue. The effect of increasing amounts of mineral P supplementation on fecal P characteristics was studied in forage fed beef steers. Eight Hereford steers were fitted with total fecal collection bags and fed four diets with a low P grass hay and supplemented with increasing amounts of a mineral source of P, dicalcium phosphate. Dietary DM P concentrations were 0.10 (no P supplementation), 0.23, 0.34, and 0.45% P. Manure was sampled and dried, followed by analysis for total P and inorganic P (Pi). Blood was collected via jugular venipuncture following each collection period and plasma Pi was quantified. Total fecal P increased linearly with increasing dietary P concentration: 6.44, 10.6, 16.1, and 18.8 g/d (P < 0.0001). Fecal Pi increased linearly with increasing dietary P concentration: 1.58, 2.43, 2.74, and 3.84 g/d (P = 0.0119) Manure P solubility, however, did not increase with increasing dietary P concentration: 23.6, 22.3, 17.3, and 20.2% (P = 0.3646). Plasma Pi increased linearly with increasing dietary P (P = 0.0047). ADG and G:F were not affected by increasing dietary P content. Reducing or eliminating mineral P supplementation to forage fed beef animals is possible, if forage base proves to be adequate in P. Reducing dietary P reduces fecal P excretion and the pollution potential in ecologically sensitive areas like the Chesapeake Bay watershed. / Master of Science

As one of the major forage crops of the United States management programs to optimize stockpiled tall fescue (Festuca arundinacea Schreb.) can potentially increase livestock profitability.  This study consists of two experiments designed to assess different aspects of summer stockpiling.  Experiment 1 evaluated the effects of summer stockpiling endophyte infected Kentucky 31 tall fescue on biomass and nutritive value of tall fescue forage.  Treatments included four whole plot treatments (two nitrogen (N) application timing, legume inclusion, and control) each divided into sub-plot cut and no cut treatments.  The cut treatment consisted of a single cutting taken in May.  Nitrogen in the form of urea was applied at a rate of 56 kg/ha for the March N treatment and for the June N treatment.  Yield and quality of summer stockpiled fescue was adequate to support dry beef cows.  Experiment 2 evaluated the effects of summer stockpiling on the biomass yield and nutritive value of three types of tall fescue with N fertilization (endophyte infected (E+), endophyte-free (E-), and novel endophyte (MaxQ)) and four species of native warm-season grasses without N fertilization (switchgrass (Panicum virgatum L.), big bluestem (Andropogon gerardii Vitman), indiangrass (Sorghastrum nutans (L.) Nash), and little bluestem (Schizachyrium scoparium (Michx.) Nash)).  Native warm-season grasses produced much higher yields than all tall fescue types but the nutritive value was not adequate to support the nutrient requirements of livestock.  Summer stockpiled tall fescue is a viable resource to provide low requirement animals with quality forage during late summer and early fall. / Master of Science

In the southeastern United States, there is a need for a native, cool-season grass component for restoring and reclaiming grasslands and providing quality forage for livestock. Experiments were conducted on southeastern wildrye [Elymus glabriflorus (Vasey) Scribn. & C.R. Ball] to assess agronomic parameters, and establish a base of information for use in future research and breeding programs. Optimal germination requirements (temperature, light, pH, and physical dormancy) were evaluated. Our data suggests that for southeastern wildrye, the optimal temperature required for germination is between 15 and 20oC. Light treatments (constant dark, constant light, short day, and long day) did not influence germination as much as temperature, but can be a limiting factor to stand establishment. Acid source and pH treatments (HCl, H2SO4, and H3PO4 at four pHs 3, 4, 5, and 7) revealed that southeastern wildrye tends to germinate the greatest in soils with a pH greater than 5.0 (HCl at 66.7%), even though germination was observed in lower pHs. Physical dormancy treatments [bearded/glume intact (control), bearded/glumeless, debearded/glume intact, and bearded/glumeless removed] revealed the debearded/glume intact treatment had significantly less mean percentage germination (43.3%) than all other treatments. Planting depth was evaluated under five treatments ranging from surface planting to a depth of 2.54 cm. For the two years this study was conducted, the 0.64 cm treatment had greater percentage of seedlings to emerge than most other treatments. Forage quantity and quality were measured in three experiments. Orchardgrasses and tall fescue entries outperformed native entries in height, yield, and ground cover ratings. Forage quality analysis revealed statistical similarities between southeastern wildrye and improved, non-native cultivars. Harvest management evaluating cutting intervals (20, 30, 40, 60, and 80-d) and subsequent regrowth for two years was conducted. Quantity and quality analysis indicated that harvests should be conducted every 20 to 30-d in order to maintain nutritional requirements for livestock consumption. Future research should include: identification, selection, and development of southeastern wildrye plants with enhanced forage traits (persistence, palatability, lodging resistance) and establishment characteristics (higher germination, awnless), grazing trials, and fertility response trials.

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