401 research outputs found
Estrous Synchronization of Heifers Using MGA and Prostaglandin: Ranch Results
total of 315 yearling heifers were exposed to an estrous synchronization program which consisted of feeding MGA for 14 consecutive days (.5 mg per head per day), followed by a prostaglandin injection 17 days after the last day of MGA feeding. Two hundred forty-seven (78%) of the heifers were detected in heat and artifically inseminated within 5 days after the prostagllandin injection. Response rate ranged from 75 to 84% between ranches and years
The Effect of Varying Dietary Selenium Levels, Selenium Source and Dietary Composition on Growing Swine
During the early 1900\u27s, many stockmen in the western Great Plains suffered huge economic losses due to poisoning of their livestock through consumption of seleniferous plant material. Some were forced to discontinue raising livestock entirely and turned to grain farming. However, grain produced on land high in selenium was discounted on the market. Today, this grain marketing problem does not exist to the extent of that of the early 1900\u27s. Selenium has more recently been recognized as an essential micronutrient for several species including swine. The Food and Drug Administration (FDA) has approved sodium selenite and sodium selenate as supplements to pig starter diets up to a level of .3 ppm of selenium. In view of this, the potential exists for selenium poisoning to occur through accidental contamination, incorrect mixing or incorrect formulation of the diet. Reports of selenosis in swine are limited and not well documented. Selenosis in swine has been experimentally produced, but seldom were the experimental objectives to establish the maximum level of dietary selenium that could be tolerated without affecting pig performance. The level at which selenium becomes toxic to swine is thought to be about 8 ppm. This value was derived from the initial selenium research of the 1930\u27s, with considerable extrapolation from data of other species. Often the number of experimental animals used was not statistically sound. In addition, the improved methods of selenium analysis and purity of inorganic selenium compounds available today provide for more accuracy in experimentation. Diet composition has also become much more complex. Nutrient level of diets has increased and feed additives are commonly used. It is not known what effect these factors or other nutritional interrelationships may have on the level at which selenium becomes toxic. Due to the variability of selenium content in feedstuffs and because selenium is now approved as a feed additive, it is important to better define the level at which the element becomes toxic to swine when feeding modern diets. This research was conducted to determine the effect of varying dietary selenium levels, selenium source and dietary composition using the following parameters: 1. Pig performance as measured by daily gain, daily feed intake and feed conversion, 2. Blood composition, 3. Tissue selenium concentration, 4. Blood enzyme activity, 5. Liver weight as a percentage of body weight
Evaluation of Skylab EREP data for land resource management
There are no author-identified significant results in this report
Comparison of Lutylase and Bovilene For Estrus Synchronization of Heifers
A total of 533 yearling heifers were used to compare the effect of Lutylase vs Bovilene on estrus response within 5 days of injection. There was no difference between products in the percentage of heifers showing estrus within 5 days of injection. The average time from injection until detection of estrus was longer for Bovilene than Lutylase (64.5 hours vs 60.7 hours, P\u3c.05)
Nuclear spin polarization transfer across an organic-semiconductor interface
Motivated by Tycko’s proposal to harness optically pumped nuclear spinpolarization for the enhancement of nuclear magnetic resonance(NMR) signals from biological macromolecules, we investigate the transfer of thermal nuclear spinpolarization between 1H or 19F in an organic overlayer and 31P at the surface of micron-sized InP particles by Hartmann–Hahn cross polarization. Comparison with analytic and numerical models indicates that the total quantity of polarization transferred across the semiconductor-organic interface is limited by the relatively short room-temperature 1H T1ρ (11 ms) and the slow diffusion of nuclear spinpolarization in the semiconductor.Models and spin-counting experiments indicate that we are able to transfer approximately 20% of the total nuclear spinpolarization originating in the organic overlayer to the semiconductor, supporting the feasibility of transferred optically pumped NMR
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Drying dip-coated colloidal films
We present the results from a small-angle X-ray scattering (SAXS) study of lateral drying in thin films. The films, initially 10 μm thick, are cast by dip-coating a mica sheet in an aqueous silica dispersion (particle radius 8 nm, volume fraction ϕs = 0.14). During evaporation, a drying front sweeps across the film. An X-ray beam is focused on a selected spot of the film, and SAXS patterns are recorded at regular time intervals. As the film evaporates, SAXS spectra measure the ordering of particles, their volume fraction, the film thickness, and the water content, and a video camera images the solid regions of the film, recognized through their scattering of light. We find that the colloidal dispersion is first concentrated to ϕs = 0.3, where the silica particles begin to jam under the effect of their repulsive interactions. Then the particles aggregate until they form a cohesive wet solid at ϕs = 0.68 ± 0.02. Further evaporation from the wet solid leads to evacuation of water from pores of the film but leaves a residual water fraction ϕw = 0.16. The whole drying process is completed within 3 min. An important finding is that, in any spot (away from boundaries), the number of particles is conserved throughout this drying process, leading to the formation of a homogeneous deposit. This implies that no flow of particles occurs in our films during drying, a behavior distinct to that encountered in the iconic coffee-stain drying. It is argued that this type of evolution is associated with the formation of a transition region that propagates ahead of the drying front. In this region the gradient of osmotic pressure balances the drag force exerted on the particles by capillary flow toward the liquid–solid front
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Holocene dynamics of the Rhone Glacier, Switzerland, deduced from ice flow models and cosmogenic nuclides
We describe efforts to model the Holocene extent of the Rhone Glacier, Switzerland, using four paleoclimate records as templates for paleo-equilibrium line altitude to identify candidate driving mechanisms of glaciers in the Alps. We evaluate the success of each paleoclimate template by comparing cosmogenic 10Be and 14C concentrations in pro-glacial bedrock derived from modeled glacier configurations to measured values. An adequate fit can be obtained using mean summer insolation for 46.5°N. However, use of the Dongee Cave, China, speleothem record yields the best fit by accounting for both sub-millennial (e.g. Little Ice Age and Medieval Warm Period) and multi-millennial climate variations (summer insolation). Our result indicates that glaciers in the Alps primarily responded to changes in insolation during the Holocene were smaller than today during the early Holocene when insolation was relatively high, and became larger during the mid to late Holocene. Superimposed on the first-order insolation response were shorter, sometimes large amplitude, length changes in response to short-lived climate events such as the Medieval Warm Period and the LIA
Effect on Antibiotics in High Fiber Diets on Performance of Growing-finishing Pigs
The majority of the pigs in the Upper Midwest are fed a corn-soybean meal base diet. However, alternative feed ingredients are widely used in some regions. The lower performance, daily gain and efficiency of gain that is sometimes observed when other ingredients are used is often associated with higher fiber content of the diet. The pig has little ability to utilize fibrous materials in the stomach and small intestine where most digestion of feed and absorption of nutrients take place. Microorganisms present in the cecum and large intestine do break down fiber to usable products, but it is assumed that relatively small amounts of these products are absorbed. The effect that antibiotics have on fiber utilization and microbial digestion in the lower digestive tract is largely unknown. The experiment reported herein was designed to evaluate pig performance as affected by fiber level, source of fiber and presence of antibiotics
The Effect of Selenium on Pigs of Different Hair Color
It has been suggested that levels of certain trace elements in hair may be associated with the dietary intake of the element. High levels of selenium in the diet have been shown to increase hair selenium in swine and also in cattle. The possibility that the degree of selenium toxicity is related to hair color has been proposed for cattle, horses and swine. This study was conducted to determine if storage of selenium in the hair of pigs varied with their color and also to determine if hair color was related to degree of selenium toxicity
Effect of Sodium Selenite Levels on Tissue and Blood Composition and Performance of Growing-Finishing Swine
A second trial was conducted to further study the problem of selenium toxicity. In this experiment, sodium selenite was utilized as the selenium source. The FDA has approved sodium selenite and sodium selenate supplementation of pig starter diets up to a level of .3 parts per million (ppm) of selenium. The study reported herein was conducted to determine the effect of sodium selenite levels on tissue and blood composition and performance of growing-finishing swine
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