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Five experiments were conducted to evaluate tree forage as a feedstuff for small livestock, using the foliage of black locust (Robinia pseudoacacia) and hybrid poplar (Populus spp.). In the first trial, rabbits were fed diets containing 40% alfalfa (control), and 10%, 20% and 40% poplar leaves (PL) from untrimmed or uncoppiced growth, and 10% and 20% PL from trimmed or coppiced growth. At the 20% level, crude protein (CP) was better digested for the coppiced PL than for the uncoppiced (p < .05). No significant difference was evident between treatments in the average daily gain (ADG) or feed efficiency, but dry matter (DM) intake increased for all the PL treatments compared to the control (p < .01). In the second experiment, black locust (BL) leaves were treated by various methods in an attempt to counter the effect of tannins. Rabbits were fed diets containing 50% alfalfa (control), 25% alfalfa and 25% black locust meal (BLM) (BLM control), BLM + 1% polyethylene glycol (PEG), BLM + 1% phytase, and BLM + 0.3% L-methionine and 0.3% choline chloride. In general, nutrient utilization and ADG were better for the control than for the BLM treatments. The addition of PEG increased CP digestibility (p < .01) and ADF (p < .03) compared to the BLM control, partially alleviating the reduced nutrient availability. The addition of L-methionine and choline chloride increased ADF digestibility (p < .02). In the third trial, black locust (BL) bark and other tree products were used to study the possible toxic effects of lectins in BL bark. Rabbits were fed diets containing 25% BL bark, oak sawdust, red alder bark, or red alder sawdust (all diets also included 25% alfalfa). A 50% alfalfa diet served as a control. In general, nutrient digestibilities and ADG were higher for the control than the treatments and, also, higher for the BL bark diet than the alder bark diet. The ADG with the BL bark diet was lower than for the alder bark diet (p < .01), which indicated a possible toxic effect of the BL bark. The fourth trial examined the feeding value of poplar leaves for sheep. Sheep were fed diets containing 50% PL or 50% alfalfa. Nutrient digestibilities were lower for the PL diet (p < .01). In the fifth experiment, BL leaves were fed to sheep and goats in order to determine if goats, being browsers instead of grazers like the sheep, are better equipped to tolerate the anti-nutritive effects from BL forage. Sheep and goats were fed diets composed solely of BL leaves or alfalfa (control). Overall, the nutrient digestibilities were higher for alfalfa than for BL leaves, and there was no difference in terms of digestibility between species. Although the leaves of black locust and poplar contain anti-nutritive factors, it was concluded that the trees have potential as multipurpose trees from which the leaves could be harvested as animal fodder, particularly in temperate areas of the developing world. / Graduation date: 1993

Foraging theory suggests that hungry animals balance a complex set of costs and benefits when determining what and how to eat. Prey distribution, patch size, and the presence of conspecifics are important factors influencing a predator's feeding tactics, including the decision to feed individually or socially. Dusky dolphins (Lagenorhynchus obscurus) in New Zealand employ different feeding tactics in varying habitats and seasons. I used programmed survey routes and opportunistic sightings to examine the habitat use and feeding mechanics of dusky dolphins in Admiralty Bay, New Zealand, a protected shallow-water environment frequented by wintering dolphins. I encountered 253 dolphin groups, of which 58.5% were engaged in food-acquisition activities. Photographic efforts revealed a total of 177 individually-recognizable dolphins, 100 of which were returnees from previous seasons. Thirty-seven feeding groups and 70 bouts of feeding behavior were followed. Two-minute interval sampling as well as active acoustic sonar were used to test the hypothesis that diurnally-feeding dolphins would work in a coordinated manner to bring schooling fish to the surface. Feeding tactics observed in Admiralty Bay were then compared to foraging by some of the same animals in the unprotected, deep-water environment off Kaikoura, where large numbers of dusky dolphins feed during the night on organisms associated with a vertically-migrating scattering layer. Evidence supporting coordinated surface feeding was not statistically significant, but indicative of behavioral flexibility in feeding styles as part of a larger feeding repertoire. A potential shift in prey distribution from previous years may also explain some observed patterns. Feeding groups were positively correlated with seabirds and New Zealand fur seals (Arctocephalus forsteri). Mean group size of 6.1 (± 8.23 S.D., n=253) in Admiralty Bay is dramatically less than groups observed off Kaikoura, a variation likely reflecting differences in prey number and distribution, as well as differences in predation risk by deep-water sharks and killer whales. Behavioral flexibility likely confers an adaptive advantage for species subject to environmental fluctuation, whether due to natural or anthropogenic sources. Further research is necessary to evaluate prey distribution in Admiralty Bay and its possible effects on feeding dusky dolphins.

Thesis (M.A.)--Catholic Theological Union at Chicago, 1996. / Vita. Includes bibliographical references (leaves 80-85).

Thesis (M.S.)--University of Michigan, 1978.

Thesis (M.S.)--University of Michigan, 1978.

Thesis (M.A.)--Catholic Theological Union at Chicago, 1996. / Vita. Includes bibliographical references (leaves 80-85).

Thesis (M.A.)--Catholic Theological Union at Chicago, 1996. / Vita. Includes bibliographical references (leaves 80-85).

Habitat use by mule deer, particularly in relation to use by cattle and by California bighorn sheep on the bighorn winter-spring ranges of Flatiron Mountain was studied from January 1968 through November 1969. Observations were made of (1) food habits, (2) forage production and utilization, (3) the effect of spring and summer utilization on subsequent forage production and (4) spatial and temporal distribution of range use. The results indicate that competition for forage between the native ungulates, deer and sheep, is largely obviated by differential habitat use. This may point to long term evolutionary ecological niche specialization. Some competition for forage occurs for a short period in the early spring when both ungulate species seek succulent new grass, the supply of which is at first limited. Cattle use of the winter-spring ranges was excessive and the diets of cattle and the native ungulates are similar, with the exception that utilization of grass by deer was less. Range use by cattle contributed to intra-specific cattle-deer competition on the grasslands in the spring and cattle-bighorn competition on the grasslands during the winter. The study of spring range utilization indicated that deer use was not detrimental to the 1969 annual forage production in areas used by deer. Spring range utilization by bighorn or bighorn in combination with deer reduced the standing crop of forage produced on the Agropyron spicatum dominated winter-spring ranges. Sheep utilization on South Slope during the summer, when forage growth was declining, further reduced the amount of forage available to the wintering bighorn population. / Land and Food Systems, Faculty of / Graduate

This research reports on the determination of the effects of fish size and feed pellet size on the settling characteristics of Rainbow trout (Salmo gairdneri) culture, tank cleaning wastes. Flocculant particle settling curves (Type II) were developed from settling column analysis of cleaning wastes from 11-311 gram Rainbow trout fed a moist pellet diet (Oregon Moist Pellet ®). Four feed pellet sizes were investigated: 3/32, 1/8, 5/32 and 3/16 inch. Overall non-filterable residue removal curves and individual particle settling velocity distribution curves, derived from the Type II settling curve of each fish size and feed pellet size group, were compared. Slopes and y-intercepts of the linearized overall non-filterable residue removal curves and individual particle settling velocity distribution curves were compared using the Equality of Slope Test (S:SLTEST). Results of the test for a common regression equation indicated there were no significant differences in the proportional distribution of particle sizes within the cleaning wastes. Variations observed in the initial rates of removal within the overall non-filterable residue removal curves were considered insignificant Settling trials were pooled in order to obtain single curves, characterizing the overall solids removal rate and the individual particle settling velocity distribution of the waste solids. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate