3 resultados para Zann, Greg

em Digital Repository at Iowa State University


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Forty-four Hampshire (H) and 41 Suffolk (S) ewes were allotted within breed to one of four treatment groups (VitA, VitE, VitAE, and Control) to evaluate the effect of supplemental vitamin E and A on reproductive performance of ewes mated on pasture or in drylot. Beginning two weeks before the mating period, ewes received 0 or 300 IU of vitamin E every 14 days and 0 or 250,000 IU of vitamin A every 28 days. Hampshire ewes remained on pasture during the mating period, whereas S ewes were moved to drylot. Treatment did not affect ovulation rate (OR), embryonic loss (EL), fetal loss (FL) or litter size (LS) of H ewes. Embryonic loss was higher (P<.05) in the H yearlings and two-year olds than in older ewes. Litter size was lower (P<.01) for H yearlings compared with other age groups. Suffolk ewes in the VitE group exhibited a lower (P<.01) OR than S ewes in other treatment groups, but no effect of treatment was observed for EL, FL, or LS. Although S yearling ewes did not differ from ewes of other age groups for OR and EL, they did produce fewer (P<.05) lambs. Analysis of serum samples revealed that H yearling ewes exhibited lower (P<.05) serum a-tocopherol levels than older H ewes. In addition, H ewes had a higher (P<.05) serum a-tocopherol level than S ewes at the beginning of study when they were managed as one group. Even though age and breed influenced certain reproductive parameters, results of this study indicate little effect of supplemental vitamin E and A on the overall reproductive efficiency of ewes mated on pasture or in drylot.

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Forty Hampshire and 40 Suffolk ewes were allotted to one of four groups (VitA, VitE, VitA&E, Control) in a 2 x 2 factorial treatment arrangement to evaluate the effect of supplemental vitamin E (0 or 300 IU) and vitamin A (0 or 250,000 IU) on reproductive performance. Laparoscopy and ultrasonography were used to measure ovulation rate, embryonic loss, and fetal loss. Serum profiles of a-tocopherol (vitamin E) and retinol (vitamin A) also were monitored. There were no differences (P>.05) among treatment groups in any reproductive trait. Suffolk ewes exhibited a higher (P<.02) ovulation rate than Hampshire ewes, and yearling ewes incurred higher (P<.001) embryonic loss than other age groups, resulting in a lower (P<.001) litter size. Serum levels of a-tocopherol were higher (P<.05) for Hampshire than for Suffolk ewes and were lower (P<.001) in yearling ewes versus ewes two years of age and older. Serum levels of a-tocopherol declined (P<.01) throughout the study in VitA and Control ewes but remained unchanged in VitE and VitA&E ewes. Serum level of retinol remained unchanged in VitA ewes, whereas the level increased (P<.01) initially in VitE, VitA&E, and Control ewes before declining toward initial levels. Correlations were detected between ovulation rate and the change of pre-mating a-tocopherol serum level (r=-.29; P<.02), the change in pre-mating retinol serum level (r=-.50; P<.02) and the interval from vitamin A injection (r=-.60; P<.05). These data indicate significant influences of breed, age, and treatment on a-tocopherol and retinol serum levels in ewes and suggest that the timing of vitamin A administration may influence ovulation rate; however, vitamin supplementation, administered at random stages of the estrous cycle, was unable to alter flock reproductive performance.

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This volume represents the proceedings of the Sixteenth Annual Biochemical Engineering Symposium held at Kansas State University on April 26, 1986. Some of the papers describe the progress of ongoing projects, and others contain the results of completed projects. Only brief summaries are given of many of the papers that will be published in full elsewhere. ContentsEnd-Product Inhibition of the Acetone-Butanol Fermentation—Bob Kuhn, Colorado State University Effect of Multiple Substrates in Ethanal Fermentations from Cheese Whey—C.J. Wang, University of Missouri Extraction and Fermentation of Ensiled Sweet Sorghum—Karl Noah, Colorado State University Removal of Nucleic Acids from Bakers' Yeast—Richard M. Cordes, Iowa State University Modeling the Effects of Plasmid Replication and Product Repression on the Growth Rate of Recombinant Bacteria—William E. Bentley, University of Colorado Indirect Estimates of Cell Concentrations in Mass Cultivation of Bacterial Cells—Andrew Fisher, University of Missouri A Mathematical Model for Liquid Recirculation in Airlift Columns—C.H.Lee, Kansas State University Characterization of Imperfect Mixing of Batch Reactors by Two Compartment Model—Peter Sohn, University of Missouri First Order Breakage Model for the Degradation of Pullalan in the Batch Fermentor—Stephen A. Milligan, Kansas State University Synthesis and Nuclear Magnetic Resonance of 13C-Labeled Amylopectin and Maltooligosaccharides—Bernard Y. Tao, Iowa State University Preparation of Fungal Starter Culture in Gas Fluidized Bed Reactor—Pal Mihaltz, Colorado State University Yeast Flocculation and Sedimentation—David Szlag, University of Colorado Protein Enrichment of Extrusion Cooked Corn by Solid Substrate Fermentation—Lucas Alvarez-Martinez, Colorado State University Optimum Design of a Hollow Fiber Mammalian Cell Reactor—Thomas Chresand, Colorado State University Gas Chromatography and Nuclear Magnetic Resonance of Trifluoroacetylated Carbohydrates—Steven T. Summerfelt, Iowa State University Kinetic and Bioenergetic Considerations for Modeling Photosynthetic Microbial P~ocesses in Producing Biomass and Treating Wastewater—H. Y. Lee, Kansas State University Mathematical Modeling and Simulation of Bicarbonate-Limited Photsynthetic Growth in Continuous Culture—Craig Curless, Kansas State University Data Acquisition and Control of a Rotary Drum Solid State Fermentor—Mnasria A. Habib, Colorado State University Biodegradation of 2,4-Dichlorophenoxyacetic Acid (2,4-D)—Greg Sinton, Kansas State University