Short communication: thermotolerance and residual feed intake in <i>Bos-indicus</i> crossbred beef heifers
Bibliographic record
Abstract
ABSTRACT This study investigated the relationship between thermotolerance and residual feed intake (RFI) in Bos indicus crossbred replacement beef heifers. In the summer of 2019, vaginal body temperatures were recorded from 654 heifers to identify the most and the least heat-tolerant animals based on changes in body temperature throughout the day. From this group of heifers, 27 were ranked in the summer as either heat-tolerant (n = 14; thermotolerant) or least heat-tolerant (n = 13; non-thermotolerant) to enroll in a 42-d feed efficiency test conducted in the fall. The maximum body temperature minus the 0700 h body temperature difference between the groups was 0.19 °C for thermotolerant and 1.2 for non-thermotolerant heifers (P < 0.01). In the fall, selected heifers (398 ± 11.3 kg of body weight [BW]; approximately 720 d of age) were randomly allocated into four concrete-floored pens, each with two GrowSafe feed bunks, and fed a common ad libitum total mixed ration (16.9% crude protein, 52% total digestible nutrients on a DM basis) for a 56-d period (14 d of adaptation followed by 42 d of evaluation). Body weight was collected on d -1, 0, 14, 28, 41, and 42, while fall body temperature was recorded (10 min intervals for 4 consecutive d) from d 29 to 32 of the study, using temperature probes placed intravaginally with a hormone-free controlled internal drug release device. Final BW, average daily gain (ADG), dry matter intake (DMI), DMI as a percentage of BW, RFI, and body temperature were analyzed as a completely randomized design. Final BW, ADG, DMI, and body temperature collected during the feeding period were not affected by thermotolerance phenotype (P ≥ 0.42); however, heifers previously classified as thermotolerant had decreased RFI (P = 0.01; -1.32 vs. 1.27 ± 3.31 kg, respectively) and DMI as a percentage of BW (P = 0.01) when compared with non-thermotolerant heifers. In conclusion, Bos indicus crossbred replacement beef heifers previously classified as thermotolerant based on multiple body temperature measurements collected throughout the summer had decreased RFI when measured in the fall, indicating the potential of feed efficiency in heat-tolerant beef heifers.
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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".