For almost a century both toxic and beneficial qualities have been ascribed to fluorine. During this time emphasis has been placed on many aspects of fluoride metabolism by different groups of workers. Farm animals are exposed to dietary fluorine from small amounts in most natural feedstuffs, from their water supply, from rock phosphate used as a mineral supplement, and from foliage grown in the vicinity of certain industrial operations. [...]

No description available.

ix, 131 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1974)--University of Adelaide, Dept. of Zoology, 1974

ix, 131 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1974)--University of Adelaide, Dept. of Zoology, 1974

A series of experiments was conducted to evaluate the value of jojoba meals in chick, rabbit and laying hen diets. Treated meals used in these studies had been subjected to solvent, chemical and microbial treatments for the removal of simmondsin toxicants. Feeding 5% untreated jojoba meal diets to either chicks, rabbits or laying hens resulted in a general poor performance as evidenced by reduced feed intake, poor growth and poor feed conversion; in addition, low egg production and egg output were obtained with laying hens. Incorporation of the untreated meal (containing 4.7% simmondsin compounds) at 10% of the diet caused 55.6% mortality in chicks. A pair-feeding study with chicks revealed that reduced feed intake rather than toxic effects was responsible for decreased growth and mortality. A similar study with rabbits showed that both high levels of simmondsin toxicants and palatability were responsible for poor growth. Of the seven meals tested with chicks, only the Lactobacillus acidophilus #1911 treated meal supported adequate growth when added to the diet at a level of 10%. However, feed conversion was poor at this level of suplementation. Lowering the simmondsin toxicants to .34% of the meal allowed adequate growth in weanling rabbits when incorporated in the diet at levels up to 15%. Slightly lower amino acid digestibilities were obtained for diets containing this meal. Studies of amino acid availabilities with the jojoba meals indicated a general low availability for the essential amino acids (33.7% for lysine and 43.4% for methionine). Starch digestibility was also low (22%) and true metabolizable energy varied from 1.71 to 1.90 kcal/g in laying hens. Jojoba meal also contains a trypsin inhibitor (TI) with activities reaching 5.48 TIU/g which was inactivated in 30 min at 15% moisture and 100 C. Tannic acid levels in the jojoba meals varied from 1.50 to 2.57%. Poor amino acid availabilities were still obtained after TI inactivation. The use of jojoba meal in the feeding of poultry or rabbits will require the removal of the simmondsin toxicants, denaturation of the TI as well as consideration of the poor amino acid availability and low energy content.

No description available.

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

Graduation date: 1993

Understanding the effect of food abundance on feeding behavior can benefit conservation efforts in many ways, such as to determine whether impacted environments need food supplementation, whether different locations of threatened species contain different food abundances, or whether reintroduction sites are missing key components of a species’ diet. I studied the relationship between feeding behavior and food abundance in the Lower Keys marsh rabbit (Sylvilagus palustris hefneri), an endangered subspecies endemic to the lower Florida Keys. Specifically, my study set out to measure the relative abundance of the primary plants within the natural habitat of the Lower Keys marsh rabbit and estimate the proportion of each of these plants within the rabbit’s diet. With this information, I tested the following hypotheses: first, the Lower Keys marsh rabbit selectively feeds on specific plants; second, that diet does not differ among sites; and third, that diet is not affected by food abundance. Using stable isotope analysis, I determined that two plants were prominent in the rabbit’s diet: a shrub, Borrichia frutescens, and a grass, Spartina spartinae. These two species were prominent in the rabbit’s diet in most patches, even where they were relatively rare, suggesting the rabbits are indeed selectively feeding on these species. In addition, although diet did differ among patches, selective feeding was apparent in all cases. Overall, this study determined that certain food types are important food sources for the federally endangered Lower Keys marsh rabbit and that these rabbits do not feed on plants based on plant abundance. This knowledge can be directly applied to reintroduction and restoration efforts for the Lower Keys marsh rabbit. More generally, the methods used in this study can be applied to other species of concern in order to address questions associated with diet requirements and foraging behavior.