Effects of altering growth curve and age at photostimulation in female broiler breeders. 1. Reproductive development
Bibliographic record
Abstract
An experiment was conducted to evaluate the effect of differences in growth curve and age at photostimulation on carcass traits and ovarian morphology in broiler breeder hens at photostimulation and at sexual maturity. Pullets were grown on one of three growth curves STD (standard), LOW (150 g lighter than STD) and HIGH (150 g heavier than STD), and were photostimulated at either 19 wk of age (19WK) or 21 wk of age (21WK). Weekly blood samples were taken between photostimulation and sexual maturity for determination of estradiol-17β concentration. Twelve birds per interaction were processed at photostimulation for determination of carcass and reproductive morphology, followed by an additional 10 birds per interaction at sexual maturity. Unless otherwise stated, all significance was assessed at the P < 0.05 level. At photostimulation, the HIGH birds were larger and had more carcass lipid (7.44%) than the LOW birds (6.22%). By sexual maturity, carcass lipid as a percentage of BW was similar among the growth curve groups, as were the weights of most carcass parameters measured relative to BW. The large yellow follicle content of ovaries from LOW, STD, and HIGH birds were not different. Ovaries from HIGH birds had 48.2% of large yellow follicles arranged in multiple sets (large yellow follicles weighing within 1 g) compared to 29.5% in STD birds. Birds photostimulated earlier took longer to lay their first egg after photostimulation (19WK = 41.3 d, 21WK = 35.1 d), although this still occurred at a younger age (19WK = 174.3 d of age, 21W K = 182.1 d of age). The profile of plasma estradiol-17β concentration of the 19WK birds appeared to increase more slowly than for the 21WK pullets. As plasma estradiol-17β concentration will increase at a regular rate once it begins to increase, the flatter summary profile of 19WK pullets may be indicative of a less-uniform response to photostimulation. Based on the BW growth curves used in this trial and data collected at photostimulation and sexual maturity, there was no advantage of early photostimulation, and ovarian morphology may be negatively affected by moderate increases in rearing growth curve. Key words: Broiler breeder, sexual maturity, ovarian morphology, growth curve, body weight
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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) | 0.000 | 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".