Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 115-127). Also available on the Internet.

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

Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on June 9, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Animal Science, Department of Agricultural, Food and Nutritional Science, University of Alberta. Includes bibliographical references.

Thesis (B.App.Sc. (Hons.)) - University of Queensland, / Includes bibliography.

The impact of rate and timing of spring nitrogen application on yield and composition of barley forage and grain and the fermentation and utilization of barley silage was investigated in a 3-yr study. The use of a growth regulator, ethephon, was also investigated. Nitrogen application at a rate of 135 kg/ha increased forage yields in 1984 and tended to increase yields in 1985 and 1986 though dry conditions existed. Crude protein yield was increased with application of 135 kg N/ha all three years. Major impact of N. fertilization appeared to be associated with an application at Feekes stage 5. Nitrogen treatments had little impact on nitrate, NDF or ADF concentration but higher rates generally lowered forage dry matter. Use of N resulted in increased dry matter intake and increased dry matter, crude protein, NDF, and ADF digestibility of silage when fed to lambs. In 2 of 3 yr grain yield appeared to be lowered as forage yield increased due to N treatment. Grain crude protein and crude protein yields were increased with the use of N. Increases in grain crude protein content were associated with applications of N at Feekes stage 5. Generally, test weight and 1000 kernel weight decreased and the number of tillers increased at rates of N application were increased. Use of Ethephon tended to increase yields in 1984 and increased yields in 1985. / M.S.

In this experiment, we used four male llamas that were three to four years of age from the Khara race. They were divided into two ad libitum feeding groups. The digestible energy (ED) was determined using samples that were sent to the laboratory. These samples were derived from a conventional in vivo assay using the method of total fecal collection in order to determine the difference between energy consumed and energy excreted. Metabolizable energy was calculated by deducting digestible energy, energy loss in the urine and energy loss in the gases (methane). Urinary energy was determined through the measurement of nitrogen in the urine as urea. Other studies have reported the energy values of alfalfa hay and barley as 414.05 Kcal/100g and 405.11 Kcal/100g, respectively. Additionally, alfalfa hay and barley have been recorded as having gross energy values of 6,973.92 Kcal/day and 4,373.65 Kcal/day, respectively. In this study, the energies excreted in the feces were 2,365.42 Kcal/day for alfalfa and 1,643.26 Kcal/day for barley. In order to determine the value of metabolizable energy, it is first necessary to obtain the urinary energy values (EU) by measuring the amount of nitrogen excretion as well as the energy of the gases (methane). Then, by deducting the energy calculated from the digestible energy, metabolizable energy may be estimated. The nitrogen content in urinary excretions from the llamas tested was highly variable from one treatment to another. With barley, the observed content was 0.59 g/day whereas with alfalfa hay it was 7.36 g/day. According to the data obtained for nitrogen content in urinary excretions, the amount of urea excreted each day was also obtained. It was also found to be variable from one food to another. Values of urea excretion for alfalfa and barley were 15.76 and 1.27 grams of urea/day respectively. By multiplying the daily amount of urea excreted by its caloric value (2.528 Kcal/g), the energy lost in the urine was determined to be 38.84 Kcal/day for alfalfa and 3.23 Kcal/day for barley. It was not possible to determine the energy of the gases. Instead, we used data obtained from llamas fed with forage (Engelhardt and Schneider, 1977). The data established that the energy loss as methane gas is approximately 7.1% of the gross energy. With this value as a reference for llamas, the energy losses as methane gas in this study were 495.08 Kcal/Kg/MS for alfalfa hay and 310.53 Kcal/Kg/MS for barley. By definition, the metabolic energy (EM) is the amount of energy from food that is calculated by determining the difference between the digestible energy (ED) and the energy lost in urine (EU) and gases (EG) according to the following equation (NRC, 1981): EM = ED - (EU + EG). Based on the equation, the metabolizable energy of alfalfa hay and barley are as follows: EB = 4140.49 Kcal/Kg/MS and EM = 2408.43 Kcal/Kg/MS for alfalfa compared to EB = 4051.20 Kcal/Kg/MS and EM = 2061.32 Kcal/Kg/MS for barley.

This research was completed in Letanías, Viacha, La Paz, Bolivia, to determine the metabolic profile in blood plasma (total protein, glucose, urea, albumin, total lipids, creatinine, triglycerides, and cholesterol concentrations), live weight gain, and Nitrogen balance in adult llamas fed with 4 rations of barley and quinoa residue. Eight adult (4-5 year old) Q’ara type llamas were used in this study. Study llamas were trained to stay in metabolic cages with feces collection harnesses. Llamas were given one of the following feed rations: ration A (20% quinoa residue, 80% barley), ration B (40% quinoa residue, 60% barley), ration C (60% quinoa residue, 40% barley), and ration D (80% quinoa residue 20% barley). The results were protein concentration 7.44±0.39 g/dl; albumin 4.66±0.80 mg/dl; urea 13.87±3.70 mg/dl; creatinine 1.65±0.19 mg/dl; glucose 127.67±50.32 mg/dl; total lipids 318.2±144.14 mg/dl; triglycerides 39.35±13.49 mg/dl; cholesterol 53.85±13.53 mg/dl. Live weight gain was -0.0094±1.44 kg. Nitrogen balance was 0.610±0.0868 g/kg. According to the results of this research, metabolites in blood plasma are higher when compared to other research. Gain in body weight was negative in rations A and D and positive in rations B and C. This is attributed to a better equilibrium among energy levels and protein in these last rations. The nitrogen balance was positive for all four rations due to an adequate source of protein in the feed.

The Highlands of Bolivia present a great diversity of native botanical species with strong forage characteristics, providing them with a considerable potential for usage as a resource in the feeding of cattle. The following work was performed with the idea of taking advantage of the zone’s native species as a source for the feeding of llama cattle. In order to accomplish it, we took into consideration the following variables: food consumption, water consumption, amount of fecal excretions, urine volume, body weight, and the digestibility of the nutrients found in the food prepared with paja brava and barley (ash, protein, fiber, and total digestibles). The experiments were conducted in metabolic cages for 30 days; with 4 llamas of the K’ara breeds, between the ages of 4 and 5 years old, and an average weight in between 105 and 125 kg of life weight. The statistical analysis was conducted using a completely random cross test. We concluded barley and paja brava in their natural state are forage species which nutrient composition does not allow optimal development in llamas.

The main hypothesis tested in this thesis was that poor animal production from saltbush pastures is due to the negative effects of high sodium chloride (NaCl) and potassium chloride (KCl) on the ruminal environment, and subsequent effects on microbial populations and products of rumen fermentation. This main hypothesis was tested in two experiments. In the first experiment (Chapter Four) the effects of saltbush and a formulated high-salt diet on the ruminal environment and microbial populations were measured over 24-hours following feeding. Feeding both the saltbush and high-salt diet increased the salinity of the rumen fluid, but the formulated high-salt diet caused a decrease in ruminal pH while the saltbush caused an increase. This resulted in differences in the composition of the ruminal microbial populations between the sheep fed different diets. In the second experiment (Chapter Five) the effects of saltbush and a formulated highsalt diet on rumen fermentation were measured. Sheep fed saltbush had inefficient rumen fermentation and this was only partially explained by the high salt content of the diet. Diets containing high levels of NaCl and KCl provided low levels of net energy to sheep, but sheep fed saltbush lost more energy as methane and faecal energy compared to sheep fed the formulated high-salt diet. Inefficient rumen fermentation could help to explain poor animal production from saltbush pastures. Energy supplements such as barley grain can improve the value of saltbush pastures as feed for sheep, but there is no information on how much supplement is required. A third experiment (Chapter Six) was designed to test the hypothesis that there would be an optimal amount of barley required to improve the efficiency of rumen fermentation in sheep fed saltbush. Barley and straw were combined in a pellet and substituted for saltbush at 0, 20, 40, 60, 80 and 100% of the maintenance ration. Feeding barley and straw improved the efficiency of rumen fermentation in sheep fed saltbush, with an optimal level of supplementation at 60% of the maintenance diet. This is likely to be lower (approximately 20% of maintenance) if barley is fed without straw.