Characterizing biosecurity, health, and culling during dairy herd expansions.

Our objectives were to investigate strategies for biosecurity, expansion, and culling for expanding dairy herds in the Upper Midwest. Eighteen dairies in Iowa and Wisconsin were visited, and dairy managers and veterinarians were interviewed to characterize five biosecurity practices, herd culling practices, vaccines administered, and ensuing disease status for the herds. The majority of herds that were interviewed failed to employ comprehensive biosecurity programs for incoming cattle. Nearly 60% of herds obtained cattle from sources for which it was difficult to document genetic backgrounds and health histories, fewer than half required health testing for incoming cattle, and approximately 50% quarantined new cattle on arrival. Despite high rates of vaccination for bovine viral diarrhea, all herd owners and managers indicated that herd biosecurity was compromised as a result of expansion. Half of the interviewed herds indicated that bovine viral diarrhea and papillomatous digital dermatitis were notable disease problems. Herds that obtained cattle with unknown backgrounds and health status experienced the largest number of diseases. Before expansion, the most frequently cited reasons for culling were reproductively unsound; low milk production; mastitis, poor udder health, and high SCC; during expansion, the strategic decision to cull cows for low milk production was used less often. In addition, the stochastic simulation model, DairyORACLE, was used to evaluate economic outcomes for several expansion alternatives. Five model scenarios studied were: base scenario (herd size was maintained) and four expansion scenarios--all paired combinations of heifer quality (high, low) and voluntary culling (implemented, not implemented). Culling for low milk production yielded an additional $23.29 annually (6-yr annuity) per cow, but on the basis of purchased replacements, no voluntary culling was most profitable. Purchasing high versus low quality replacement heifers for expansions returned an additional $113.54 annually ($681.24 total net present value) per heifer purchased. Many opportunities exist to improve cattle-related factors for dairy herd expansions, including the use of comprehensive biosecurity programs, realistic planning and budgeting for cattle purchases, and cost effective purchase and culling practices.

Force-proportional reinforcement: pimozide does not reduce rats' emission of higher forces for sweeter rewards.

A two-step force-proportional reinforcement procedure was used to assess the efficacy of a sucrose reward under neuroleptic challenge. The force-proportional reinforcement method entails an increase in the quality of reward contingent upon higher force-emission. This paradigm was conceived as a rate-free means of addressing the putative anhedonic effects of dopaminergic receptor-blocking agents. Results failed to support the anhedonia interpretation of neuroleptic-induced response decrements: Pimozide did not diminish the ability of a high-concentration sucrose solution to maintain elevated response forces. Alternatives to the anhedonia interpretation were discussed with emphasis on the drug's motor effects in the temporal domain.

Behavior-decrementing effects of low doses of haloperidol result from disruptions in response force and duration.

By using a factorial experimental design, the joint effects of two levels of sucrose reward, two levels of required force, and four levels of haloperidol dose (0. 0.04, 0.08, 0.16mg/kg) were examined for three measures of operant response: peak force, duration, and interresponse time. Even though a 24% sucrose reward led to more rapid acquisition of the operant than an 8% concentration during the drug-free response shaping period, neither the reward nor the required-force manipulations interacted with haloperidol dose during subsequent testing. Haloperidol had significant elevating effects on peak force and duration of response, while lengthening interresponse time. A within-session analysis revealed drug-related slowing of both response duration and interresponse time as the operant session progressed. Finally, dose effects on peak force and duration were apparent from the beginning of the session, but effects on interresponse time reached significance later in the session. Taken together the results downplay the importance of stimulus efficacy, anhedonia and required effort in accounting for haloperidol's behavior-decrementing effects. Instead, the results raise the possibility that the haloperidol-treated rats experienced difficulty in sensorimotor control of the operant response.

Selecting and recruiting health programs for the School Health Education Evaluation.

The School Health Curriculum Project (SHCP) and three promising health education approaches, Project Prevention, 3 Rs and High Blood Pressure (HBP), and Health Education Curriculum Guide, were the curricula used in the School Health Education Evaluation (SHEE) project. This paper contains program descriptions of each, and a brief description of the process that led to their selection. Inclusion of the School Health Curriculum Project (SHCP) was mandated by the use of government funds to support the SHEE. The three alternative curricula, Project Prevention, 3 Rs and High Blood Pressure, and Health Education Curriculum Guide, were selected on the basis of a protocol devised jointly by contractors, government project officers, and the project advisory panel.

Comprehensive school health education: a practical definition.

This article identifies 10 essential elements of comprehensiveness related to school health education that have been agreed upon by key personnel long involved in one or more of the four school health curriculum programs studied in the School Health Education Evaluation (SHEE) study. Each element is briefly described and followed with one or two examples of practical applications selected from the four curricula. The authors further concur with the concept that a Consumer Reports type of reporting of school health curriculum models might be useful in further SHEE data analysis and that the "elements of comprehensiveness" concept might be a valuable adjunct to such reporting.