Tissue mass dynamics during egg‐production in female Zebra Finches <i>Taeniopygia guttata</i> : dietary and hormonal manipulations
Bibliographic record
Abstract
Changes in tissue masses associated with egg production were investigated in female Zebra Finches Taeniopygia gutatta using dietary and hormonal manipulations. We tested three hypotheses: that changes in organ masses, (a) reflect utilisation of endogenous nutrient stores due to inadequate daily dietary intake, (b) involve changes in organ structure or ‘functional capacity’, and (c) are initiated by onset of reproductive development (e.g. elevated plasma estrogen or yolk precursor levels, oviduct growth). Pectoral muscle lean dry mass was 18–22% lower in breeding females at the 1‐egg stage compared to non‐breeders, and this was independent of nutritional plane, i.e. similar changes occurred in birds provided with supplemental protein or egg food. Heart lean dry mass was also lower (16%) in breeding females, but only in birds on a low‐quality seed diet, not in birds on supplemented diets. Decreases in total liver mass (14%) were due to changes in lipid content not lean dry mass, and were diet‐dependent. These results demonstrate that changes in organ masses associated with egg production are complex, and do not simply reflect a general mobilisation of stored protein. We discuss why there is no hypertrophy of biosynthetic or metabolic ‘machinery’ associated with egg production in birds (cf. reproducing mammals). Exogenous 17β‐estradiol induced plasma levels of yolk precursors typical of breeding birds, and initiated oviduct growth (to 31% of mature size). However, estradiol treatment caused no change in mass of pectoral muscle, heart or liver, demonstrating that there is no simple relationship between onset of reproductive development and associated tissue mass changes.
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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) | 0.001 | 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".