The problem of reduced appetite in ruminants fed silages persists but the factors responsible for reduced intake of silage have not been elucidated. This study was conducted with the objective of testing the hypothesis that ammonia loading in ruminants could suppress appetite. In a 5 x 5 latin square design, sheep were fed alfalfa silage (S), fresh alfalfa (FA), and FA with added equimolar amounts (450 mmol. kg$ sp{-1}$ feed DM) of NH$ sb4$Cl, NH$ sb4$HCO$ sb3$ and urea; the latter was infused directly into the rumen. The silage had a DM content of 33.1%, pH 4.4, and a lactic acid content of 4.3% of DM. Unfermented herbage had a pH of 5.5 and lactic acid content of 0.2% of DM. Digestibility of organic matter (OMD) exceeded 70% for both S and FA. Organic matter intake (OMI), digestible organic matter intake (DOMI), concentration of rumen NH$ sb3$, rumen pH, osmolality and volatile fatty acids (VFAs) did not differ (P $>$ 0.05) among treatment groups. The lack of differences among treatments may have been as a result of a failure to accentuate qualitative and quantitative differences between the FA and S and to raise ammonia in the rumen and peripheral blood to levels that could alter appetite.

The objectives of the study were to determine whether intercropped alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.) or rye grass (Lolium multiflorum Lmk.) could simultaneously contribute to the nitrogen regime of grain-corn (ie: increased yield), improve edaphic quality, and decrease the level of inorganic nitrogen present in the soil after corn harvest. To achieve these objectives the seeding of the intercrops was delayed, the corn population was increased, and the red clover was spring-ploughed. / Fall-ploughed red clover maintained the mean weight diameter (MWD) of aggregates on the Ste-Rosalie clay. Spring-ploughed red clover on the other hand caused a decrease in bulk density in the top 10 cm of the Chicot loam. / The nitrogen-response of corn indicated that the intercrops did not contribute to the nitrogen regime of grain-corn. There were also indications that intercrops competed with corn for available inorganic nitrogen and water. The intercrops, however, did reduce the levels of soil inorganic nitrogen in the fall allowing for a possible decrease in the nitrogen load of soil percolates. / Despite the beneficial effect of nitrogen fertilisation on the organic nitrogen content of the soil, the presence of leguminous intercrops did not prevent the increase of the soil CN ratio.

Forage growth in the subarctic is sub-optimal due to low soil nutrient levels. Forage crops in the Yukon Territory consistently require nitrogen (N) and phosphorus fertilization to meet plant requirements. Fertilization is expensive due to transportation costs and potentially harmful to the environment so alternative, more sustainable, sources of nutrients are being sought. Alfalfa is an alternative, but there is limited knowledge in the Yukon of the benefits and management of this crop as a replacement for fertilizer N. Experiments were carried out in south central Yukon during the 2005 and 2006 field seasons to examine the potential of co-inoculation of alfalfa with N-fixing Ensifer meliloti and phosphate-solubilizing Penicillium bilaii to increase the dry matter yield and N fixation of monoculture alfalfa (Medicago sativa) cv Peace and binary mixed alfalfa with smooth bromegrass (Bromus inermis) cv Carlton or timothy (Phleum pratense) cv Climax forage swards. Interactions between alfalfa inoculation and N fertilization and late season harvest treatments were assessed. The TagTeam® inoculant from Philom Bios was used as the rhizobium source which contains both Ensifer meliloti isolate NRG-34 and Penicillium bilaii isolate PB-50. Nitrogen fixation was determined using the total plant N difference method. Alfalfa growth and nodulation was successful in the trials. Inoculation had a positive impact on N fixation, whereas urea fertilizer at 25 kg N/ha had a negative impact in most cases. In the mixed alfalfa and smooth bromegrass stand there was a positive contribution from the alfalfa in both the establishment and second year with N fixation rates of up to 14 kg/ha. In the mixed timothy and alfalfa stand the N fixation reached 35 kg/ha in the establishment year and 102 kg/ha in the second year. In the establishment year the dry matter yield and N fixation of the TagTeam® inoculated, monoculture alfalfa plots were 3.1 t/ha and 77 kg N/ha. In the second year, the unharvested inoculated alfalfa treatment yielded 3.4 t/ha with N fixation of 66 kg/ha compared to the late harvest treatment which yielded only 1.5 t/ha and an N fixation rate of 20 kg/ha. The effects of the late season harvest are startling and reflect the importance of removing grazing animals during the fall to allow plant energy reserves to accumulate in the roots. Fertilizer N replacement is possible with the seeding of alfalfa into existing hay stands or in monoculture.

Includes Appendix listing other publications by the author. / Includes bibliographical references (leaves 134-181). / vi, 182 leaves : ill., photos ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Alfalfa mosaic virus was isolated from lucerne (Medicago sativa) plants with a variety of disease symptoms. Experiments showed that each isolate was biologically distinct and that the host range and symptomatology of each isolate was affected by the environmental condition. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Pathology, 1990

Thesis (Ph.D.)--Department of Crop Protection, University of Adelaide,1992. / Includes bibliographical references (leaves 147-171).

Thesis (M.Sc.). / Written for the Dept. of Plant Science. Title from title page of PDF (viewed 2008/12/09). 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 152-155).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--Brigham Young University. Dept. of Integrative Biology, 2005. / Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xviii, 141 p.; also includes graphics (some col.) Includes bibliographical references (p. 116-130). Available online via OhioLINK's ETD Center