The impact of dark exposure on broiler feeding behavior and weight of gastrointestinal tract segments and contents
Bibliographic record
Abstract
Ross 308 broilers were observed at 2 ages to quantify how duration of darkness affects behavior and alters the gastrointestinal tract (GIT, segment and content weights) over 24 h. Four treatments provided 1 (1D), 4 (4D), 7 (7D), or 10 (10D) h of darkness. Birds (n = 4000) were housed in 8 rooms with 8 pens per room (2 replications per treatment and 4 replications per gender per room). The GIT data were collected on day 27 to 28 (6 males per treatment, euthanized at 2 h intervals for 24 h) and expressed as a percentage of body weight. Data were analyzed as a completely randomized design, with treatment nested within room. Production data were analyzed as a 4 (dark) x 2 (gender) factorial arrangement and GIT data as a 4 (dark) x 12 (time) factorial arrangement. Regression analyses established relationships between darkness and dependent variables. At 31 d, regression analyses showed no effect on body weight. The highest feed consumption was observed under 4D. Mortality was lowest under 10D. Birds on 10D were the most feed efficient and had the heaviest crops. Crop content interacted with time of day, with peaks prior to dark under 4D, 7D, and 10D. Empty gizzard weight increased linearly as dark increased (P < .01). Behavior was examined as a 4 (dark) x 2 (age) x 2 (gender) factorial arrangement of treatments. Five birds per gender per room were focally observed for 24 h. Dark data were examined using regression analyses and an analysis of variance assessed age and gender data. As dark increased, feeding bout frequency increased and total time spent at the feeder decreased linearly (P = 0.01 and P < .01, respectively). As birds aged, feeding frequency decreased and feed bout length increased. Males visited the feeder more frequently. Birds anticipated dark periods >4 h and increased feeding activity prior to dark. Broilers adapt their feeding behavior in response to dark exposure, which alters GIT segment and content weight and likely feed passage rate.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".