Master of Science / Department of Grain Science and Industry / Cassandra Jones / In two experiments, conditioning time and temperature of swine feed were altered to determine effects of starch, vitamin retention, and swine growth performance. A third experiment evaluated methodologies for estimating gelatinized starch in swine feed. Across all experiments, diet formulation was constant. In Exp. 1, treatments were arranged in a 2 × 3 factorial design plus a control, including 2 conditioning temperatures (77 vs. 88°C) and 3 conditioner retention times (15, 30, and 60 s). A mash diet was added for a total of 7 treatments. Total starch was affected by conditioning temperature (P = 0.04) but not time (P = 0.50). Similar results were observed for gelatinized starch (P = 0.005 and 0.65, respectively). Sample location also affected total starch (P = 0.0002) and gelatinized starch (P = 0.0001), with the greatest increase in gelatinization occurring between conditioned mash and hot pellets. Conditioning alone did not influence gelatinization as evidenced by similar values between cold and hot mash (P > 0.05). Neither conditioning temperature nor time affected vitamin concentrations (P > 0.50). A portion of these treatments were then fed to 180 nursery pigs (PIC 327 × 1050; initially 12.6kg) in an 18-d study. Treatments included: 1) non-processed mash (negative control); 2) pelleted diet conditioned for 30 s (positive control); 3) pelleted diet conditioned for 15 s and reground; 4) pelleted diet conditioned for 30 s and reground, and 5) pelleted diet conditioned for 60 s and reground. Observed growth performance differences appear to be due to feed form, not conditioning time. Average daily gain and G:F did not differ (P > 0.12) between treatments, but ADFI was decreased (P = 0.03) as expected for pigs fed the positive control pelleted diet compared to all other diets. There were no differences (P > 0.05) in any growth performance variables amongst the three conditioning temperatures. In Exp. 3, it was determined that the method developed by Mason et al. (1982) was the best indicator of gelatinization in livestock feed. In summary, feed form, but not conditioning time affected gelatinized starch and swine growth performance.

No description available.

The successful application of crop processing on pull-type forage harvesters requires engineering analysis and experimentation in areas such as roll design, particle aerodynamic, vibration, power measurement and crop physical characterization. The first step of this research project was to design, build and evaluate two processing rolls integrated in an experimental pull-type forage harvester. With a 12.7 mm theoretical length of cut setting, the processing rolls were used to treat alfalfa at a 1 mm clearance between the rolls. Samples analyzed at an animal research centre showed that processing increased the effective ruminal degradability of corn by 3% but did not improve the degradability of alfalfa. / The presence of processing rolls in the forage harvester increased friction. The air inlet area had to be increased to improve particle flow and obtain maximum air outlet speed. The presence of crop processing rolls required an increase in blower speed of 10 to 20% to maintain the throwing capacity. / Critical speeds were analyzed by the Transfer Matrix Component Mode Syntheses (TMCMS) method and three classical approaches using analytical models to predict deflections in the shaft. Experiments showed that the TMCMS method was very reliable and predicted the critical speed with an error of about 4% compared to 8% or higher for classical methods. Modal analysis also proved to be a simple and practical way to measure critical speed. / A laboratory setup was built to investigate various mechanical adjustments: roll clearances of 4 and 6 mm for corn, and 1 and 3 mm for grass; eight peripheral speed ratios between 1.08 and 1.93; two levels of throughput (9 and 18 t fresh crop/h). Optimal adjustment will ultimately depend on animal response to various levels of crop breakage. / A hydrodynamic model of chopped forage processed between rolls was developed to determine crop properties using an experimental database and subsequently predict the power requirement as a function of the configuration. Forage specific area was estimated using an experimental micro-screening method. A program was developed to calculate mechanical stresses within each roll of the crop processor as a function of working conditions and steel properties. (Abstract shortened by UMI.)

Doctor of Philosophy / Animal Sciences and Industry / Joel M. DeRouchey / Eight experiments using a total of 2,964 finishing pigs and 2,947 feed, phytase, or premix samples were used to determine the effects of: 1) wheat source, particle size and feed form on finishing pig performance; 2) feed form feeding strategies; 3) fine generation from pellets during feed manufacturing and delivery, and 4) thermal stability and shelf life of phytase products. Exp. 1 and 2 evaluated wheat sources, particle size, and diet form for finishing pigs. Fine gound hard red winter wheat fed in meal form improved G:F and nutrient digestibility, whereas wheat ground from ~700 to 250 µ in pelleted diets did not influence growth or carcass traits. Feeding hard red winter wheat improved ADG and ADFI compared with feeding soft white winter wheat. In Exp. 3, pellet feeding regimens were used to evaluate finishing pig performance and stomach morphology. Feeding pelleted diets improved G:F but increased stomach ulceration and pig removals; however, rotating pellets and meal diets provided an intermediate G:F response with fewer stomach ulcers and pig removals. Experiments 4 to 6 investigated fines formation during pelleted feed manufacturing and delivery. Pellet quality worsened as pellets were transported through the feed mill post pelleting and during delivery. Unloading speed or feed line location had little effect on pellet quality. There were significant differences between the fines and pellet nutrient profiles as noted by the increased concentration of ADF, crude fiber, Ca, ether extract, and starch in the fines and decreased CP and P when compared to pellets. In Exp. 7 and 8, the thermal stability and shelf life of 4 commercial phytase products was determined. Increasing conditioning temperatures decreased phytase stability regardless of product. Phytase activity was affected by storage duration, temperature, product form, and phytase source. Pure products stored between 15 and 22˚C were the most stable and premixes were affected by longer storage times and higher temperatures.

No description available.

No description available.

Researchers use metal-thiophene complexes to mimic reactions which occur inside hydrodesulfurization (HDS) reactors. Information obtained from these model studies may often be applied to understanding the mechanisms involved with commercially used catalysts. Certain mechanisms¹ for HDS propose thiophene ring cleavage,forming a metallacycle, prior to hydrogenation of one double bond. There are, however, limited examples of complexes derived from C-S cleavage.^2,3,4 Thermal reactions of the iridium complex, [Ir(COD)(PMe₃₎₃]Cl (COD=1,5- cyclooctadiene), with thiophene, thiazole, 4-methyl thiazole and 5-methyl thiazole yields the C-S addition metallacycles (Me₃P)₃Ir-(CH=CHCH=S)CI (I), \ (Me3P)3Ir-(CH=NCH=CHS)CI (II), (Me3P)3Ir-CCH=NC(CH3)=CHS)CI (III) and (Me3P)3Ir (CH=NCH=C(CH3)S)CI (IV), respectively. These compounds were characterized using the following methods: ¹H NMR, ¹³C NMR, ³¹P NMR, elemental analysis and single crystal x-ray diffraction. Following C-S addition to [Ir(COD)(PMe3)3]CI, nitrogen present in the thiazoles exhibit enhanced nucleophilicity. For exmnple, compounds II-IV react with methylene chloride to form dimers: CH2[NCR=CR'SIr(Cl)(PMe3)3CH]2. The above compounds are soluble in water and react with PF6 salts liberating the chloride atom from the Ir center. pKb measurements were recorded as well. This thesis describes the synthesis and examination of con1pounds I-IV as they may model the HDS process. Compounds II-IV represent the first examples of ring opened thiazole metallacycles with iridium. / Master of Science

No description available.

Doctor of Philosophy / Department of Animal Sciences and Industry / R. Scott Beyer / Broiler chicken feed is processed. Cereal grains are ground to reduce particle size and the feed usually is pelleted. When pelleted, broiler diets are steam conditioned and forced through a die causing varying levels of starch gelatinization. Cereal grain particle size and starch gelatinization can be controlled during feed manufacturing. Earlier research has shown that starch gelatinization negatively affects growth performance of 0 to 21 d of age. An experiment was conducted to determine the effects of corn particle size and starch gelatinization on growth performance, dressing percentage, and gizzard size when fed to 22 to 42 d of age broilers. Increasing particle size from 470 to 1240 μm increased body weight gain, dressing percentage, and relative gizzard size. Starch gelatinization increased relative gizzard size. No interaction effects were detected. To expand on previous experiments, a trial was conducted to investigate the effect of starch gelatinization on broiler chick gastrointestinal pH, glucose absorption, and glucoregulation. Starch gelatinization level affected jejunum pH, with a higher pH reported at 20% starch gelatinization. Increases in starch gelatinization decreased blood glucose and increased glucagon level. Highest measured glucagon level was reported in broiler chicks fed the diet with 20% starch gelatinization level diet after 6 hours of starvation. A third experiment was conducted to determine the effect of starch gelatinization on metabolizable energy and amino acid digestibility. Increasing starch gelatinization from 0 to 100% increased true metabolizable energy and fecal output in roosters. No effect was found on apparent metabolizable energy or amino acid digestibility, with an increase in starch gelatinization from 0 to 20%. Increasing particle size from 470 to 1240 μm had a positive effect on 22 to 42 d growth performance. A starch gelatinization level of 20% or lower had no effect on metabolizable energy or amino acid digestion. Older broilers with larger gastrointestinal tracts are unaffected by 20% gelatinized starch; whereas, 20% gelatinized starch reduced blood glucose and increased glucagon levels of young broilers. Lower blood glucose and increased glucagon are indicative of lower glucose storage, and could cause reduced young broiler growth performance when fed diets with gelatinized starch.

Call number: LD2668 .T4 1986 N445 / Master of Science / Grain Science and Industry