Effects of feeding lubabegron fumarate or ractopamine hydrochloride to beef × dairy crossbred steers raised under small-pen commercial feedlot conditions in western Canada
Bibliographic record
Abstract
This study evaluated the effects of feeding lubabegron fumarate compared with ractopamine hydrochloride in beef × dairy crossbred steers fed a corn-based diet in western Canada. Beef × dairy (Limousin × Jersey) crossbred steers (n = 760, initial BW = 530.0 ± 34.7 kg) were randomly allocated 80 d before slaughter to 1 of 2 experimental groups. A total of 20 replicates were allocated to the study, with each replicate comprising 1 pen from each experimental group (for a total of 40 pens) and 19 steers per pen. Pen was the experimental unit. Experimental groups consisted of either lubabegron fumarate (Experior 10, Elanco Canada Limited, Mississauga, Canada) fed at a target level of 3.5 mg/kg diet DM for 56 d before slaughter (EXP) or ractopamine hydrochloride (Optaflexx 100, Elanco Canada Limited) fed at a target level of 250 mg/steer daily the last 28 d before slaughter (RAC). Steers in the EXP group had lower DMI, greater carcass weight, and greater DP compared with steers in the RAC group. Steers in the EXP group had greater ADG and G:F on both a carcass weight and live weight basis compared with steers in the RAC group. Steers in the EXP group also had a greater proportion of YG Canada 1 carcasses, a lower proportion of QG Canada Prime carcasses, increased LM area, and a lower overall marbling score compared with steers in the RAC group. Feeding lubabegron fumarate increased feedlot performance, the proportion of YG Canada 1 carcasses, and LM area, but decreased the proportion of QG Canada Prime carcasses and overall marbling score compared with feeding ractopamine hydrochloride. Magnitude of improvement in G:F was greater on a carcass weight basis than on a live weight basis.
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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 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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".