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Research has been conducted on pantothenate, a cofactor synthesized in Salmonella enterica serovar Typhimurium. Mutations increasing pantothenate accumulation in the growth medium have been isolated and the results indicate that the causative mutations in these strains are the insertion of a CG base pair upstream of the panBCD operon transcription start site.

Two trials were conducted over four yr. In trial 1, 2-yr of data were collected to determine the effect of winter gain on summer forage intake, summer gain, and finishing performance. The treatment arrangement was a 2 x 2 x 2 factorial with yr, rate of winter gain, and summer location as factors. Steers were wintered at either a faster rate of gain using wet corn gluten feed (WCGF) as an energy source (FAST) or a slower rate of gain (SLOW). Forage intake was determined using an intra-ruminal chromium bolus. No differences were noted for forage intake between FAST and SLOW; however, as a percentage of body weight, steers on the SLOW treatment consumed more (P < 0.05) than FAST. Compensation of weight over the summer was 17 and 48% in yr 1 and 2, respectively. Increased forage intake, as a percentage of body weight, likely accounted for at least some of the compensation. In the feedlot, FAST gained more (P < 0.05), consumed more feed (P < 0.05), but was similar in efficiency compared to SLOW. In trial 2, two yr of data were collected to determine the impact of duration and severity of winter feed restriction on compensatory growth on grass and to evaluate slaughter breakevens of wintering systems. Three additional treatments were added (in addition to FAST and SLOW) in trial 2. Steers were fed corn over the winter to increase gain (CORN), steers were grown at a faster rate of gain for the first half of the winter using WCGF followed by a slower rate of gain for the second half (FAST/SLOW), and vice versa (SLOW/FAST). During the summer, compensation ranged from 24-33% for SLOW, FAST/SLOW, and SLOW/FAST compared to FAST. No differences were noted in feedlot performance. For slaughter breakeven, FAST was lower compared FAST/SLOW and SLOW, but was similar to CORN and SLOW/FAST. To equalize breakeven with FAST, 55-65% compensation would be required by steers on the intermediate and SLOW treatments. Steers should be fed at increased rates over the winter to reduce slaughter breakeven. Key Words: Forage Intake, Slaughter Breakeven, Compensatory Growth

The spatial and temporal distributions of volcaniclastic deposits in arc-related basins refl ect a complex interplay between tectonic, volcanic, and magmatic processes that is typically difficult to unravel. We take advantage of comprehensive geothermal drill hole stratigraphic records within the Taupo- Reporoa Basin (TRB), and integrate them with new 40Ar/39Ar age determinations, existing age data, and new mapping to develop a four-dimensional model of basin evolution in the central Taupo Volcanic Zone (TVZ), New Zealand. Here, exceptional rhyolitic productivity and high rates of extensional tectonism have resulted in the formation of at least eight calderas and two subparallel, northeast-trending rift basins, each of which is currently subsiding at 3 to 4 mm/yr: the Taupo fault belt (TFB) to the northwest and the TRB to the southeast (the main subject of this paper). The basins are separated in the northeast by a high-standing, fault-controlled range termed the Paeroa block, which is the focus of mapping for this study, and in the southwest by an along strike alignment of smaller scale faults and an associated region of lower relief. Stratigraphic age constraints within the Paeroa block indicate that a single basin (~120 km long by 60 km wide) existed within the central TVZ until 339 ± 5 ka (Paeroa Subgroup eruption age), and it is inferred to have drained to the west through a narrow and deep constriction, the presentday Ongaroto Gorge. Stratigraphic evidence and field relationships imply that development of the Paeroa block occurred within 58 ± 26 k.y. of Paeroa Subgroup emplacement, but in two stages. The northern Paeroa block underwent uplift and associated tilting first, followed by the southern Paeroa block. Elevations (>500 m above sea level) of lacustrine sediments within the southern Paeroa block are consistent with elevations of rhyolite lavas in the Ongaroto Gorge, the outlet to the paleolake in which these sediments were deposited, and indicate that the Paeroa block has remained relatively stable since development. East of the Paeroa block, stratigraphic relationships show that movement along the Kaingaroa Fault zone, the eastern boundary of the central TVZ, is associated with volcano- tectonic events. Stratigraphic and age data are consistent with rapid formation of the paired TRB and TFB at 339 ± 5 ka, and indicate that gradual, secular rifting is punctuated by volcano-tectonic episodes from time to time. Both processes influence basin evolution. [ABSTRACT FROM AUTHOR]