Volume 70, Issue 4, 2016
Research and Review Articles
This paper investigates spatial, quality and temporal factors impacting the pricing of calves and yearlings in the western United States using data from a satellite video auction and a hedonic regression framework. Results suggest that spatial price discounts received by western ranchers closely match reported shipping costs and, thus, are consistent with free-on-board pricing and competitive procurement. This study also identifies the presence of temporal price premiums, on average, for seller-offered forward contracts at video auctions. With respect to quality attributes, this study provides estimates of the marginal value associated with various quality attributes and management practices, including vaccination protocols, weaning, certified Angus beef candidates, and age and source verification. Finally, we show that the considerable year-to-year variability in estimated valuations for value-added attributes in hedonic regression models of cattle pricing can be linked to the stage of the cattle cycle, with premiums paid by buyers being attenuated when cattle inventories are high.
Efficacy of selenium supplementation methods in California yearling beef cattle and resulting effect on weight gain
Selenium (Se) deficiency occurs commonly in California grazing cattle and has been associated with reduced immune function and, in some studies, reduced weight gain. Multiple methods of supplementing Se are available, but little research has compared the effects of these methods on whole blood Se levels and weight gain. In two trials, we evaluated four methods of Se supplementation — an intrarumenal bolus, two injectable preparations and a loose salt containing 120 ppm Se — over an 85- to 90-day period in Se-deficient yearling cattle in Tehama County. The bolus treatment raised whole blood Se levels to an adequate level (0.08 ppm) for the entire study period. Whole blood Se concentrations in injected cattle initially reached adequate levels but then declined to deficient levels. The loose salt treatment acted slowly, with average whole blood Se concentration reaching adequate levels at the end of the study period. None of the treatments significantly affected weight gain and Se blood concentration was not correlated with weight gain. In growing cattle, it appears that Se supplementation may be viewed not as a direct driver of weight gain, but rather as similar to vaccination, in that it can prevent health problems that might otherwise lead to reduced weight gain.
Restoration practitioners use both native and nonnative plant species for revegetation projects. Typically, when rehabilitating damaged working lands, more practitioners consider nonnative plants; while those working to restore habitat have focused on native plants. But this may be shifting. Novel ecosystems (non-analog communities) are commonly being discussed in academic circles, while practical factors such as affordability and availability of natives and the need for more drought tolerant species to accommodate climate change may be making nonnative species attractive to land managers. To better understand the current use of nonnatives for revegetation, we surveyed 192 California restoration stakeholders who worked in a variety of habitats. A large portion (42%) of them considered nonnatives for their projects, and of survey respondents who did not use nonnatives in vegetation rehabilitation, almost half indicated that they would consider them in the future. Across habitats, the dominant value of nonnatives for vegetation rehabilitation was found to be erosion control, and many respondents noted the high cost and unavailability of natives as important drivers of nonnative use in revegetation projects. Moreover, 37% of respondents noted they had changed their opinion or use of nonnatives in response to climate change.
Chronic groundwater overdraft threatens agricultural sustainability in California's Central Valley. Diverting flood flows onto farmland for groundwater recharge offers an opportunity to help address this challenge. We studied the infiltration rate of floodwater diverted from the Kings River at a turnout upstream of the James Weir onto adjoining cropland; and calculated how much land would be necessary to capture the available floodwater, how much recharge of groundwater might be achieved, and the costs. The 1,000-acre pilot study included fields growing tomatoes, wine grapes, alfalfa and pistachios. Flood flows diverted onto vineyards infiltrated at an average rate of 2.5 inches per day under sustained flooding. At that relatively high infiltration rate, 10 acres are needed to capture one CFS of diverted flood flow. We considered these findings in the context of regional expansion. Based upon a 30-year record of Kings Basin surplus flood flows, we estimate 30,000 acres operated for on-farm flood recharge would have had the capacity to capture 80% of available flood flows and potentially offset overdraft rates in the Kings Basin. Costs of on-farm flood capture for this study were estimated at $36 per acre-foot, less than the cost for surface water storage and dedicated recharge basins.