Growth Responses of Broiler Chicks to Different Levels of Threonine and Tryptophan in Chemically-Defined Diets
Bibliographic record
Abstract
In Experiment 1 three semi-purified diets were formulated using isolated soy protein and crystalline amino acids (AA) to contain three profiles of essential amino acids (EAA) based on NRC (1994; Diet 1), Illinois Ideal Chick Protein (IICP; Diet 2) and Blair et al. (1977; Diet 3), respectively, and were fed to male broiler chicks from 0 to 14d of age. Mean body weight gain at 2 w of age was 132.7, 145.0 and 192.8g (P<0.05) and mean daily feed intake 169.4, 173.9 and 240.4g (P<0.05), respectively, for the NRC, Illinois and PRC diets. Mortality with Diet 3 was significantly higher (P<0.05) than with the other two diets, due mainly to an increased incidence of gizzard impaction. In Expt. 2, three levels (90%, 100% and 110% of NRC, 1994) of threonine (Thr) and tryptophan (Trp) were arranged in a 3×3 factorial manner in a modified Diet 3 to give nine purified diets containing crystalline AA as the only source of AA. Broiler chicks were fed a commercial diet during the first w of age and experimental diets were fed from 1 to 3w of age. Weight gain was significantly lower (P<0.05) at the highest levels of both AA (110% Thr and 110% Trp) suggesting that that the diets became imbalanced at high levels of both Thr and Trp. The results of Experiment 2 suggest that dietary levels of Thr and Trp should be targeted at 65% of lysine (equivalent to 0.63% of digestible Thr) and 16% of lysine (equivalent to 0.16% of digestible Trp), respectively, for starting broilers. The results of this study suggest that the requirements for digestible Thr and Trp are no more than 7.2 and 1.8g/kg diet, respectively.
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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 | 0.001 | 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".