Valuing Farmland Protection with Choice Experiments That Incorporate Preference Heterogeneity: Does Policy Guidance Depend On the Econometric Fine Print?

Although mixed logit models are common in stated preference applications, resulting welfare estimates can be sensitive to minor changes in specification. This can be of critical relevance for policy and welfare analysis, particularly if policymakers are unaware of practical implications. Drawing from an application to agricultural conservation in Georgia, this paper quantifies the sensitivity of welfare estimates to common variations in mixed logit specification and assesses practical implications for policy guidance. Results suggest that practitioners may wish to reevaluate modeling and reporting procedures to reflect the welfare and policy implications of common but often unnoticed variations in model specification.Willingness to Pay, Conservation Easement, PACE, Mixed Logit, Stated Preference, Environmental Economics and Policy, Land Economics/Use, Research Methods/ Statistical Methods, Q24, Q51,

Income Prospects and Age at Marriage

In an earlier paper Courtship as a Waiting Game, Mark Bagnoli and I proposed a theory that explained why it is the case that in almost every society and at almost all recorded times, the average age at marriage of men exceeds that of women. An additional prediction of this model was that men who married later in life would turn out to have higher incomes when they reach maturity than those who marry young. The current paper reviews this theory and tests it with U.S. data. Consistent with our theory, we find that there is a strong positive relationship for men between age at marriage and earnings in later life and that no such relationship exists for women.Center for Research on Economic and Social Theory, Department of Economics, University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/101096/1/ECON080.pd

A bridge between the RNA and protein worlds? Accelerating delivery of chemical reactivity to RNA and DNA by a specific short peptide (AAKK)4

AbstractBackground: RNA can catalyze diverse chemical reactions, leading to the hypothesis that an RNA world existed early in evolution. Today, however, catalysis by naturally occurring RNAs is rare and most chemical transformations within cells require proteins. This has led to interest in the design of small peptides capable of catalyzing chemical transformations.Results: We demonstrate that a short lysine-rich peptide (AAKK)4 can deliver a nucleophile to DNA or RNA and amplify the rate of chemical modification by up to 3400-fold. We also tested similar peptides that contain ornithine or arginine in place of lysine, peptides with altered stereochemistry or orientation, and peptides containing eight lysines but with different spacing. Surprisingly, these similar peptides function much less well, suggesting that specific combinations of amino acids, charge distribution, and stereochemistry are necessary for the rate enhancement by (AAKK)4.Conclusions: By appending other reactive groups to (AAKK)4 it should be possible to greatly expand the potential for small peptides to directly catalyze modification of DNA or RNA or to act as cofactors to promote ribozyme catalysis

OUTDOOR RECREATION TRENDS AND MARKET OPPORTUNITIES IN THE UNITED STATES

In 1994 and 1995, the National Survey of Recreation and Environment (NSRE) was accomplished by interviewing approximately 17,000 Americans over age 15 in random-digit-dialing telephone samplings. The primary purpose was to learn about the outdoor recreation activities of people over age 15 in the United States. They were asked about their participation in 62 specific recreation activities.Resource /Energy Economics and Policy,

Evaluation of modified potato starch in diets for the early-weaned pig

Two growth trials were conducted to compare the effectiveness of replacing either corn or lactose with modified potato starches in diets for conventionally and early-weaned pigs. In Exp. 1, 198 pigs (initially 9.4lb and 19 d of age) were used to determine if modified potato starch (potato starch 1) can replace a portion of the lactose in a high nutrient dense diet. Pigs were allotted by weight, gender, and ancestry to each of six dietary treatments with either five or six pigs per pen and six pens per treatment. The control diet contained 10% dried whey (7.2% lactose), 7.5% spray-dried porcine plasma, 2.5% select menhaden fish meal, and 1.75% spray-dried blood meal. Additional treatments were formulated by adding 7 or 14% modified potato starch or lactose in place of com. A positive control diet also was formulated containing 29% dried whey (providing the same amount of lactose as the 10% dried whey plus 14% lactose diet). All diets were formulated to contain 1.5% lysine, and .90% Ca, .80% P, and 17.88% soybean meal and were fed in a meal form. From day 0 to 14 postweaning, increasing dietary lactose tended to linearly improve ADG and ADFI. Added potato starch did not improve ADG compared with pigs fed the control diet, but ADFI increased linearly with increasing potato starch. In Exp. 2, 180 pigs (8.5 lb and 14 d of age) were used to evaluate the effects of two modified potato starches (potato starch 1 or potato starch 2,a further hydrolyzed potato starch with a greater percentage of sugars as either glucose or maltose as a replacement for either com or lactose in a segregated early-weaning diet (SEW). Pigs were fed a control diet containing 15% dried whey, 12% added lactose, 6% porcine plasma, and 6% select menhaden fish meal. Modified potato starch 1 or 2 (12 %) replaced either corn or the added lactose on an equal weight basis. From d 0 to 7 postweaning, pigs fed the modified potato starch 1 had greater ADG and ADFI than those fed modified potato starch 2. Pigs fed diets with either starch substituted for corn had greater ADG than those fed diets with either starch substituted for lactose. From d 0 to 14 and d o to 21, pigs fed diets containing either modified potato starch substituted for corn tended to have greater ADG than those fed the control diet. This appeared to be the result of greater feed intake of pigs fed the diets containing either starch substituted for corn compared with those fed the control diet or diets containing either starch substituted for lactose. Pigs fed diets with either modified starch substituted for lactose had similar ADG as those fed the control diet. In conclusion, these results suggest that potato starch can improve growth performance of pigs when substituted for corn and can replace a portion of the lactose in an SEW diet without adversely affecting performance.; Swine Day, Manhattan, KS, November 17, 199

Evaluating the impact of maternal vitamin D supplementation: I. Sow performance, serum vitamin metabolites, and neonatal muscle characteristics

Citation: Flohr, J. R., Woodworth, J. C., Bergstrom, J. R., Tokach, M. D., Dritz, S. S., Goodband, R. D., & DeRouchey, J. M. (2016). Evaluating the impact of maternal vitamin D supplementation: I. Sow performance, serum vitamin metabolites, and neonatal muscle characteristics. Journal of Animal Science, 94(11), 4629-4642. doi:10.2527/jas2016-0409In Exp. 1, 56 gestating sows (PIC 1050; 35 d postinsemination) were used in a 30-d trial to determine serum 25(OH)D-3 response to increasing concentrations of dietary vitamin D3. Sows were randomly allotted to 1 of 7 dietary D3 treatments (200, 800, 1,600, 3,200, 6,400, 12,800, or 25,600 IU of added D3 per kilogram of complete diet) with 8 sows per treatment. Increasing D-3 increased (quadratic; P < 0.001) serum 25(OH)D-3 with the response depicted by the prediction equation: serum 25(OH) D3, ng/mL = 35.1746 + (0.002353 x dietary D-3, IU/d)- (0.0000000156 x dietary D3, IU/d(2)). In Exp. 2, 112 sows and their litters were used to determine the effects of dietary vitamin D regimen on sow performance, subsequent preweaning pig performance, neonatal bone and muscle characteristics, and serum vitamin metabolites. Sows were allotted to 1 of 4 dietary treatments 3 to 5 d following breeding: 800, 2,000, or 9,600 IU of D-3 per kilogram of the diet or 50 mu g of 25(OH) D-3 (2,000 IU of D-3 equivalent from Hy- D, DSM Nutritional Products, Parsippany, NJ) per kilogram of diet. There were 25 to 27 sows per treatment. Increasing dietary D-3 increased (linear, P = 0.001) serum 25(OH) D-3 of sows on d 100 of gestation, at farrowing, and at weaning. Increasing D-3 in sow diets increased piglet serum 25(OH)D-3 at birth (linear, P = 0.001) and weaning (quadratic, P = 0.033). Sows fed 50 mu g of 25(OH)D-3/kg had intermediate (P < 0.004) serum 25(OH)D-3 concentrations on d 100 of gestation, at farrowing, and at weaning compared with sows fed 2,000 IU of D-3/kg and sows fed 9,600 IU of D3/kg. Pigs from sows fed 50 mu g of 25(OH) D3/ kg had greater serum 25(OH)D-3 compared with pigs from sows fed 2,000 IU of D-3/kg, but at weaning, serum 25(OH)D-3 concentrations were similar. Also, pigs from sows fed 9,600 IU of D-3/kg had greater (P = 0.011) serum 25(OH) D3 at birth and weaning compared with pigs from sows fed 50 mu g of 25(OH) D-3/kg. Maternal performance, litter characteristics, neonatal bone ash content, and neonatal muscle fiber characteristics were largely unaffected by the dietary vitamin D treatments. Overall, D3 and 25(OH) D3 are both useful at increasing serum 25(OH)D-3 concentrations, but more D3 (on an equivalent IU basis) is needed to achieve similar serum 25(OH)D-3 responses compared with feeding 25(OH)D-3. Concentration of maternal vitamin D supplementation in lactation impacted milk transfer of the vitamin more so than the form of the vitamin, as evidence by the weaned pig serum 25(OH)D-3 concentrations

Evaluating the impact of maternal dietary vitamin D supplementation on sow performance, serum 25OHD3, and subsequent pig performance

Citation: Flohr, J. R., Bergstrom, J. R., Woodworth, J. C., Tokach, M. D., DeRouchey, J. M., Dritz, S. S., & Goodband, R. D. (2016). Evaluating the impact of maternal dietary vitamin D supplementation on sow performance, serum 25OHD3, and subsequent pig performance. Journal of Animal Science, 94, 125-125. doi:10.2527/msasas2016-265A total of 104 sows (PIC 1050; mean parity 2.2 ± 0.3) in 4 farrowing groups (25–27 sows per group) were used to determine the effects of gestational and lactational vitamin D supplementation on sow performance and serum 25OHD3. Sows were allotted to 1 of 4 dietary treatments (800, 2000, or 9600 IU of D3, or 50 µg of 25OHD3 [equivalent to 2000 IU/kg D3, DSM Nutritional Products Inc., Parsippany, NJ] per kg of diet) in a CRD. There were 25 to 27 sows per treatment. Maternal performance was not impacted by treatments. Increasing dietary D3 increased (linear, P = 0.001) sow serum 25OHD3. Sows fed 50 µg/kg of 25OHD3 had greater (P < 0.001) serum 25OHD3 than sows fed 800 or 2000 IU/kg, but decreased (P < 0.004) serum 25OHD3 compared to sows fed 9600 IU/kg. At weaning, increased maternal D3 increased piglet serum 25OHD3 (quadratic, P = 0.033), and pigs from sows fed 50 µg/kg of 25OHD3 had greater (P = 0.001) serum 25OHD3 compared to pigs from sows fed 800 IU/kg D3, but lower (P = 0.001) than pigs from sows fed 9600 IU/kg of D3. A subsample population of pigs (n = 448; PIC 327 × 1050; initially 6.6 ± 0.3 kg; 21 d of age) from 52 litters (2 of 4 farrowing groups) were used in a split-plot design (maternal treatment = whole plot; nursery treatment = subplot) to determine the influence of maternal and nursery dietary vitamin D on postweaning growth. Once weaned, pigs were allotted to pens based on maternal treatment, maintaining pre-weaning BW differences, and pens were randomly assigned to 2 nursery diets (2000 IU D3/kg or 50 µg 25OHD3/kg). There were 12 and 9 pens/treatment in nursery and finishing, respectively. Pen was the experimental unit. Growth performance was not influenced by nursery vitamin D. In the nursery, pigs from sows fed increasing D3 had increased (quadratic, P < 0.003) ADG and ADFI. Throughout finishing, ADG and G:F increased (quadratic, P < 0.05) with increasing maternal D3. Pigs from sows fed 50 µg/kg 25OHD3 had increased (P = 0.002) ADG compared to pigs from sows fed 800 IU/kg D3. Overall, increasing maternal D3 increased serum 25OHD3 concentrations, but more D3 (on an equivalent IU basis) is needed to achieve similar serum 25OHD3 responses compared to feeding 25OHD3. Pigs from sows fed 2000 IU/kg D3 grew faster after weaning compared to pigs from sows fed 800 or 9600 IU/kg D3 and pigs from sows fed 25OHD3 had greater ADG compared to pigs from sows fed 800 IU/kg D3

Evaluating the impact of maternal vitamin D supplementation on sow performance: II. Subsequent growth performance and carcass characteristics of growing pigs

Citation: Flohr, J. R., Woodworth, J. C., Bergstrom, J. R., Tokach, M. D., Dritz, S. S., Goodband, R. D., & DeRouchey, J. M. (2016). Evaluating the impact of maternal vitamin D supplementation on sow performance: II. Subsequent growth performance and carcass characteristics of growing pigs. Journal of Animal Science, 94(11), 4643-4653. doi:10.2527/jas2016-0410A of subsample of 448 growing pigs (PIC 327 x 1050) weaned from 52 sows fed varying dietary vitamin D regimens were used in a split-plot design to determine the effects of maternal and nursery dietary vitamin D on growth performance. Sows were previously administered diets containing vitamin D as vitamin D-3 (800, 2,000, or 9,600 IU/kg) or as 25(OH) D3 (50 mu g [or 2,000 IU vitamin D equivalent]/kg from HyD; DSM Nutritional Products, Parsippany, NJ). Once weaned, pigs were allotted to pens on the basis of previous maternal vitamin D treatment, and then pens were randomly assigned to 1 of 2 nursery vitamin D dietary regimens (2,000 IU of vitamin D-3/ kg or 50 mu g 25(OH) D-3/kg). Pigs remained on nursery vitamin D treatments for 35 d, and then they were provided common finishing diets until market (135 kg). Growing pig serum 25(OH)D-3 suggested that maternal dietary vitamin D influenced (P < 0.001 at weaning) serum concentrations early after weaning, but nursery vitamin D regimen had a larger impact (P < 0.001) on d 17 and 35 postweaning. Overall growth performance was not influenced by nursery vitamin D dietary treatments. From d 0 to 35 in the nursery, pigs from sows fed increasing vitamin D3 had increased (quadratic, P < 0.003) ADG and ADFI, but G:F was similar regardless of maternal vitamin D regimen. Also, pigs from sows fed 50 mu g/kg of 25(OH) D-3 had increased (P = 0.002) ADG compared with pigs weaned from sows fed 800 IU of vitamin D3. Throughout finishing (d 35 postweaning until 135 kg), ADG was increased (quadratic, P = 0.005) and G: F was improved (quadratic, P = 0.049) with increasing maternal dietary vitamin D-3. Also, pigs from sows fed 50 mu g/kg of 25(OH)D-3 had increased (P = 0.002) ADG compared with pigs weaned from sows fed 800 IU of vitamin D-3. Carcass data were collected from a subsample population separate from that used for the growth performance portion of the study, and a total of 642 carcasses from progeny of sows fed the varying dietary vitamin D treatments were used. Live BW of pigs at marketing and HCW were heavier (P < 0.030) for pigs from sows previously fed 25(OH)D-3 compared with pigs from sows fed 9,600 IU of vitamin D-3. Overall, pigs from sows fed 2,000 IU of vitamin D-3 grew faster after weaning compared with pigs from sows fed 800 or 9,600 IU of vitamin D-3. Pigs from sows fed 25(OH)D-3 hag greater ADG compared with pigs from sows fed 800 IU of vitamin D-3, and they had increased final BW and HCW compared with pigs from sows fed 9,600 IU of vitamin D-3

The effects of experimental potato protein on starter pig growth performance

This study suggested that experimental potato protein can be an effective replacement for a portion of spray-dried animal plasma in starter diets. Pigs fed combinations of experimental potato protein and spray-dried plasma had greater ADG than those fed either protein source alone. In phase II diets, pigs fed experimental potato protein had similar ADG and FIG compared with those fed spray-dried blood meal and select menhaden fish meal.; Swine Day, Manhattan, KS, November 21, 199