Calcium and phosphorus dynamics in commercial laying hens housed in conventional or enriched cage systems
Bibliographic record
Abstract
Calcium (Ca) and phosphorus (P) dynamics in Shaver White hens (19-63 wk of age) were compared between enriched (EC) and conventional cage (CC) systems. Calcium and P intake and their levels in egg components and excreta were considered. Using commercial levels of production (4,836 hens), 10 test cages/system (24 hens/test cage) were used as replicate units. Enriched cages provided a nesting area, scratch pad, perches, and more floor space (643 cm(2)/hen ) than CC (468 cm(2)/hen). All birds were offered similar phase-fed diets based on wheat-soybean formulation and housed under semicontrolled environmental conditions for 11 periods (28 d each). Egg weight, production, and shell quality indices (egg specific gravity, shell weight, thickness, and percentage shell) were also measured. Data were analyzed as a repeated measures design using the MIXED procedure of SAS. Egg production, weight, and shell quality measurements were not significantly different between the 2 systems. On a DM basis, EC hens exhibited lower feed disappearance than CC hens (92.5 vs. 95.0 ± 0.61 g/hen per day, respectively; P < 0.01), and lower Ca and P excretions in manure compared with CC hens (Ca: 2.11 vs. 2.29 ± 0.04 g/hen per day, respectively; P: 0.619 vs. 0.643 ± 0.005 g/hen per day, respectively; P < 0.01). Even though eggs from EC compared with CC had lower Ca deposition (2.07 vs. 2.13 ± 0.01 g/hen per day, respectively; P < 0.0001) and output (38.3 vs. 38.8 ± 0.15 mg/g of egg, respectively; P < 0.05), both EC and CC systems exhibited similar Ca outputs in eggs when expressed as a proportion of Ca intake (56.5 vs. 56.6 ± 0.51% Ca intake, respectively). The overall mean P retention between EC and CC hens was not significantly different (-7.22 vs. -7.45 ± 0.71% P intake, respectively), but Ca retention was higher in EC than CC hens (-1.37 vs. -4.76 ± 0.89% Ca intake, respectively; P < 0.05). In addition to providing environmental enrichment, EC systems may help to reduce Ca and P excretions when compared with CC systems, thereby improving the utilization of these nutrients.
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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 | 0.000 |
| 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 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".