I. Evaluation of the impact of alternative light technology on male broiler chicken growth, feed conversion, and allometric characteristics.

This study evaluates the impact of light-emitting diode (LED), cold cathode fluorescent (CCFL), and incandescent lamps on broiler performance. Male Ross 708 broilers (n=672) were raised to 6 wk age in 8 black-out modified large colony houses, under identical intermittent lighting conditions using 4 unique types of lamps, which were gradually dimmed throughout the study. Incandescent lamps served as the control; experimental technologies tested included CCFL and 2 different LED lamps. Each technology was tested in duplicate for each of 4 trials (8 replications total per technology) conducted across the course of one year to account for seasonal variance. Live performance for each technology was evaluated using live broiler body weight (BW), weight gain, feed conversion, and mortality. Birds were removed from each house at 7, 14, 35, and 42 d to be humanely euthanized, weighed, and necropsied for allometric tissue sample analysis. Relative to the technologies tested, results indicate that birds raised under incandescent lamps had significantly higher BW by 42 d, compared to birds raised under CCFL lamps, which had poorer BW performance (P=0.03). Birds raised under both LED technologies grew to final BWs similar to those raised under incandescent light, with significant differences in neither feed conversion nor mortality.

II. Evaluation of the impact of alternative light technology on male broiler chicken stress.

This study evaluates the impact of light-emitting diodes (LEDs), cold cathode fluorescent lamps (CCFLs), and incandescent lamps on broiler welfare in response to recent interest in the agriculture industry to transition to more energy-efficient lighting technologies. Male Ross 708 broilers (n=672) were raised to 6 wk age in 8 light-tight modified large colony houses under identical intermittent lighting conditions using 4 unique types of lamps, which were gradually dimmed throughout the study. Incandescent lamps served as the control; experimental technologies tested were a CCFL, and 2 different LED lamps. Each technology was tested in duplicate for each of the 4 trials (8 replications total per technology) conducted across the course of one year to account for seasonal variance. Birds were removed from each house at days 7, 14, 35, and 42 to be humanely euthanized and weighed for necropsy evaluation and comparison of body mass. Blood collection via cardiac puncture was performed to obtain heterophil to lymphocyte (H:L) ratios for evaluation of environmental stress. Birds raised under CCFLs had significantly lower body weights (2,871 g±53) than the control (3,000±33 g) by 42 d. Birds raised under CCFLs additionally had significantly higher H:L ratios (0.68±0.06) than the control (0.53±0.03), indicating that these birds may have been chronically stressed (P=0.03). There were not significant differences in the H:L ratio between LED technologies at α=0.05. A significant age and seasonal correlation in H:L ratios was observed across all technologies, along with significant differences among birds raised under the experimental technologies. This study indicates that variation in broiler body weight and stress may be attributed in part to lighting technologies implemented in broiler houses.

Negative attitudes toward physical activity: measurement and role in predicting physical activity levels among preadolescents.

OBJECTIVES: To describe the development and validation of a measure of negative attitudes toward physical activity and examine the association between these attitudes and self-reported physical activity among preadolescents. METHOD: A school-based sample of 382 fifth and sixth graders (mean age = 10.8) completed measures of attitudes toward physical activity and self-reported physical activity. Body mass index data for the participants was collected as a part of a standard school health assessment. Exploratory factor analysis, confirmatory factor analysis, and structural equation modeling were utilized to test the factor structure and predictive value of attitudes toward physical activity. RESULTS: Results supported the reliability and concurrent validity of the negative attitudes measure and found a significant association between negative attitudes and physical activity. Negative attitudes was found to be a stronger predictor of physical activity than positive attitudes, which have been the focus of previous research in this area. CONCLUSIONS: The results suggest that negative attitudes toward physical activity can be reliably measured and may be an important target for intervention efforts to increase physical activity among children and adolescents.

Repressive adaptation in a nonclinical sample: consistent and inconsistent reports of child psychosocial functioning across informants.

Using multiple indicators (self-report, parent report, school grades, and disciplinary referrals), we compared the psychosocial functioning of children across Weinberger's (1990) and Weinberger, Schwartz, and Davidson's (1979) repressive adaptive style (RAS) groups. Participants included 134 children ages 10 to 13 years that were recruited from public schools and 117 of their caregivers. Relative to nonrepressors, we hypothesized repressors to evidence lower levels of self-reported distress but higher parent-reported distress on the Behavior Assessment System for Children (BASC; Reynolds & Kamphaus, 1992). Summary scores from the BASC self-report differed significantly between repressors and nonrepressors in the expected directions. No significant group differences in parent-reported distress or school functioning emerged. Consistent with Phipps (2005), results question the predominant assumption that the RAS is associated with risk of psychosocial difficulties in children.

Associations between the repressive adaptive style and self-reported hope in Mexican American and Euro-American children.

A large literature has examined the associations between Weinberger, Schwartz, and Davidson's (1979) repressive adaptive style (RAS) construct and various self-report measures of distress or unpleasant emotional states in adults and children. Fewer investigations have examined the role of RAS in self-reported positive psychology constructs. In this investigation, we used Weinberger et al.'s (1979) categorical typology to examine the associations between adaptive style and hope in Euro-American (n = 60) and Mexican American (n = 49) children (M age = 11.4 years) who were students at 1 of 3 parochial schools in a large Midwestern city. Partially supporting the hypotheses, a univariate 2 (ethnic group) x 2 (repressor group) analysis of variance indicated a significant main effect for adaptive style group but no significant main effect for ethnic group and no significant interaction effect. Results extend the literature on the associations between adaptive style and self-report instruments and indicate that (similar to self-reported measures of distress) self-reported hope may be subject to social desirability bias.

Evaluation of Two Compressed Air Foam Systems for Culling Caged Layer Hens.

Outbreaks of avian influenza (AI) and other highly contagious poultry diseases continue to be a concern for those involved in the poultry industry. In the situation of an outbreak, emergency depopulation of the birds involved is necessary. In this project, two compressed air foam systems (CAFS) were evaluated for mass emergency depopulation of layer hens in a manure belt equipped cage system. In both experiments, a randomized block design was used with multiple commercial layer hens treated with one of three randomly selected depopulation methods: CAFS, CAFS with CO2 gas, and CO2 gas. In Experiment 1, a Rowe manufactured CAFS was used, a selection of birds were instrumented, and the time to unconsciousness, brain death, altered terminal cardiac activity and motion cessation were recorded. CAFS with and without CO2 was faster to unconsciousness, however, the other parameters were not statistically significant. In Experiment 2, a custom Hale based CAFS was used to evaluate the impact of bird age, a selection of birds were instrumented, and the time to motion cessation was recorded. The difference in time to cessation of movement between pullets and spent hens using CAFS was not statistically significant. Both CAFS depopulate caged layers, however, there was no benefit to including CO2.