Effect of ractopamine on whole body and splanchnic energy metabolism in Holstein steers
Bibliographic record
Abstract
This study was designed to examine the influence of ractopamine (RAC) on whole-body and splanchnic energy balance. Six growing Holstein steers [body weight (BW) = 402 ± 39.5 kg] surgically fitted with an arterial and portal, hepatic, and mesenteric venous indwelling catheters were used in a repeated measures study. Treatments were a basal diet of alfalfa cubes fed at approximately 1.5&times maintenance energy requirements (days 1-21) and basal plus RAC (430 mg head d -1 ; days 22-42). On day 14 of each period, splanchnic and portal-drained viscera (PDV) energy balances were determined as the product of arterio-venous O 2 difference and blood flow. Blood flow was determined using down-stream dilution of p-aminohippuric acid. Whole-body energy balance was determined on days 15-21 of each period, which included 7 d total excreta collection and 3 d of respiratory gas exchange measurements. Body weight and DM intake were greater (P < 0.05) for steers receiving RAC compared with those receiving the control diet; however, no difference was observed in either BW or DMI when expressed on a BW 0.75 basis. Similarly, as a function of BW 0.75 , whole-body heat production (691 kJ kg BW 0.75 d -1 ; P = 0.96) and retained N (0.85 g kg BW 0.75 d -1 ; P = 0.34) and energy (298 kJ kg BW 0.75 d -1 ; P = 0.71) were unaffected by RAC. In contrast, RAC tended to decrease (P = 0.09) energy use by splanchnic tissues (191 vs. 156 kJ kg BW 0.75 d -1 ), largely due to a reduction (P = 0.12) in energy use by the PDV (100 vs. 86 kJ kg BW 0.75 d -1 ). These data indicate that although whole-body energy use is not affected by RAC, energy use by splanchnic tissues is decreased, thereby increasing energy use by peripheral tissues.Key words: Bovine, ractopamine, beta-agonist, energy balance, metabolism
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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".