To estimate the relationship between heat stress during the last 60 days prepartum, body condition score and certain reproductive traits in the subsequent lactation of Holstein cows, 564 multiparous cows and 290 primiparous cows from four dairy herds were used in a hot, humid region. Maximum prepartum degree days were estimated to quantify the degree of heat stress. Multiple regressions analyses and logistic regression analysis were performed to determine the effect of prepartum heat stress and body condition change on reproductive parameters, which were obtained from DHIA forms at the end of the lactation. Multiparous and primiparous cows which gained body condition score from calving to 60 d postpartum exhibited 28 and 27 fewer days open (P < 0.05), respectively, than cows not gaining. There was no effect (P > 0.05) of heat stress measurement on days open or services per conception in either multiparous or primiparous cows. During hotter months of calving, multiparous cows showed higher services per conception and primiparous cows showed higher days open and services per conception (P < 0.05). Maximum prepartum degree-days were positively associated (P < 0.05) with calving difficulty score. Multiparous cows with high body condition score at calving were 1.47 times more likely to present a very difficult calving than cows that calved in October (P < 0.05). Collectively, these results suggest that reproductive performance was not affected by cumulative prepartum heat stress although it was associated with very difficult calving score.

Carry-over effects of late gestation heat stress on postpartum productive and reproductive traits were estimated from DHI records using 341 lactations from six sites in Mississippi. Climatological data were gathered from records of weather stations near the sites. Using multiple linear regression analyses, predictor variables for lactations were age at calving, lactation number, maximum degree-days (above 32.2 degrees C) during the periods 30 and 60 d prepartum, and precipitation 30 and 60 d prepartum. Months and sites were indicator variables. Dependent variables included milk and fat production during early, mid, and late lactation; days to peak lactation; days open; services per conception; and body weight. Age at calving affected milk and fat production in mid and late lactation and services per conception. Degree-days for 60 d prepartum had the greatest negative influence on production variables; its statistical significance was shown in predictions of milk and fat production in early and midlactation. Days open were higher for July than for cows calving in August or September. Sites had effects on many milk and fat measurements and some reproductive traits. These results indicate that heat stress in the last 60 d of gestation has negative effects on some production variables.

Data obtained through a contingent-valuation survey were used to analyze preferences for wetland-loss prevention in coastal Louisiana. Results indicate a strong preference for a short-run program over a long-run program or no action. Respondents that had higher incomes, were white, had prior knowledge of ongoing restoration efforts, and had confidence in government were more likely to vote yes relative to no action, as were those citing hurricane, environmental, or climate-change protection as their primary concern. Turnbull Lower-Bound median willingness to pay (willingness to accept compensation) was estimated at $3,547 ($5,313) per household for the short-run program and $2,765 ($5,101) per household for the long-run program.

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. A B S T R A C TA nationwide survey was conducted to estimate welfare associated with large-scale wetland restoration in coastal Louisiana. Binary-and multinomial-choice survey instruments were administered via Knowledge Networks, using the latter to estimate willingness to pay (WTP) for increments in three ecosystem services:wildlife habitat provision, storm surge protection, and fisheries productivity. Results indicate that confidence in government agencies, political leanings, and "green" lifestyle choices were significant explanatory factors.All three ecosystem services significantly affected project support, with increased fisheries productivity having the largest marginal effect, followed by improved storm surge protection and increased wildlife habitat. Mean household WTP, in the form of a one-time tax, is estimated to be $909 (confidence interval $732-$1,185), with resource users being willing to pay substantially more. This figure implies a mean aggregate willingness to pay of $105 billion (confidence interval $84-$136 billion) in excess of the State of Louisiana's estimated $50 billion cost for a statewide restoration program similar to the hypothetical restoration in this study.

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