Long-term effects of Buttiauxella sp. phytase on performance, eggshell quality, apparent ileal Ca and P digestibility, and bone properties of white egg layers
Bibliographic record
Abstract
Adequate dietary Ca and available phosphorus (avP) are essential to long-term egg production and bone health in laying hens. The effects of dietary Ca and avP levels and Buttiauxella sp. phytase (BSP) were studied in Lohmann LSL Lite hens from 30 to 70 wk of age (woa). Hens (n = 456; 4 per cage) were fed either a primary breeder recommendation-based diet (positive control; PC); the PC with avP and Ca levels reduced by 0.146 and 0.134% of the diet, respectively, without (NC) or with 300 FTU/kg BSP (NC+BSP). Egg production, BW, feed intake, FCR, and eggshell quality from 30 to 70 woa, and apparent ileal digestibility of P (AIDP) and Ca (AIDCa), and bone quality at 32, 48, and 70 woa were measured. The avP and Ca levels in the NC diet were not clinically deficient, as most parameters were unaffected by diet. Hen BW from 34 to 70 woa tended to be 2.9% greater (P = 0.076) for PC and NC+BSP compared to NC. Mid-diaphysis cortical bone mineral content (CBMC) tended to be 10% and 9% higher (P = 0.065) in the NC+BSP hens than in NC hens at 48 and 70 woa, respectively. AIDP of NC+BSP was 24% greater (P = 0.034) than of NC at 32 woa and tended to be 18% greater (P = 0.082) than AIDP of PC at 48 woa, and 25% lower than of NC and PC at 70 woa (P = 0.028). AIDCa was 25% lower for NC+BSP than PC at 48 woa only (P = 0.037). The avP and Ca sufficiency in the NC diet limited the opportunity to determine a phytase effect. Although the supplemental BSP tended to increase BW and 48 and 70 woa CBMC, and increased 32 woa AIDP, the efficacy of BSP could not be determined due to the lack of an NC effect on most parameters. Commercial laying hens can maintain health and productivity at lower than recommended levels of dietary Ca and avP; phytase supplementation may allow for even further reductions.
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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 | 0.001 |
| 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".