Browsing by Subject "urea"
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Item Effects of Background Procedures and Probiotic Administration on Weight Gain in Growing HeifersParker, Shaylyn Nell; Runyan, Chase A.; Salisbury, Micheal W.; Scott, Cody B.; Mangrum, Leah B.Angus sired heifers (n=96; initial BW 200 kg) were used to evaluate the effects of background procedures and probiotic administration on weight gain in growing heifers. Heifers were stratified by arrival BW into a 2×2 factorial arrangement where treatments consisted of direct fed microbials (DFM) (yes or no), and High Ruminal Ammonia or Control (HRA or CTR). Heifers were acclimated for 7 d, and treatments were applied for 77 d. Rectal temperatures were taken and any heifer with a temperature >40°C was determined to have pyrexia (fever). Overall, heifers that did not exhibit signs of pyrexia had an ADG of 0.973 kg which translates into a 0.085 kg/d greater ADG (P < 0.05). For the first 21 days (Period A), CTR fed heifers experienced higher ADG than the HRA fed heifers. Heifers fed the HRA diet had a higher ADG than those fed the CTR diet for Period B and C.Item Structure of gas-liquid interface and hydrophobic interface for urea aqueous solution: a computer simulation study(2009-05-15) Yu, MengUrea aqueous solution is ubiquitously used to denature protein. Regardless of its extensive use, the mechanism is still unclear and remains an active field of study. There have been two proposed mechanisms, the direct and indirect. The indirect mechanism, which attributes the ability of urea of changing water structure, is susceptible since many research works show that there is little effect of urea on water structure. The current study provided evidence for the indirect mechanism by demonstrating that the introduction of urea slightly changes the water structure in the hydrophobic interfacial areas. In the current study, the urea aqueous solution systems with either gas-liquid or hydrophobic interface are studied by MD simulations, and the structures of water near the interfacial areas are analyzed in terms of density, orientation and number of hydrogen bonds. For each kind of interface, systems with four different urea concentrations are included, ranging from 0M to 8M. The results show slight change of water structure by the urea solute on the hydrophobic interface in terms of the orientation and number of hydrogen bonds per water molecule.