Male broiler breeder fowl display high levels of aggression toward females
Bibliographic record
Abstract
Commercial broiler breeder males are reported to display high levels of aggression, often injuring and sometimes killing females. Aggression toward females by mature male domestic fowl is rare and may be regarded as aberrant behavior. The objective of this study was to determine the effects of genetic strain and feed restriction on the sexual and aggressive behavior of male domestic fowl. A 3 x 2 factorial design was used to compare the behavior of three genetic strains (two broiler breeder strains and one commercial laying strain) on two feeding regimens (one restricted and one fed ad libitum) between 25 and 37 d of age. At 22 wk of age, pairs of same-strain males were penned with 20 females of a broiler breeder strain. Behavior was sampled from each pen for six 10-min periods during Weeks 25, 27, 29, 33, and 37. Broiler breeder males displayed significantly more male-to-male (P < 0.0197) and male-to-female aggression (P < 0.0005) than laying strain males. Broiler breeder males chased females (P < 0.0001), forced more copulations (P < 0.0003), and displayed little courtship behavior (P < 0.0001) compared with laying strain males. There were no behavioral differences between broiler breeder strains. It was expected that feed restriction would result in increased aggression. However, males fed ad libitum displayed the most male-to-male (P < 0.0035) and male-to-female (P < 0.0273) aggression. Sexual behavior was not affected by feeding regimen. In conclusion, broiler breeder males display aberrant sexual behavior and extremely high levels of aggression, which are associated with genetic differences, not feed restriction.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.008 | 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 teacher head, 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".