Methane production from dairy and beef heifers fed forages differing in nutrient density using the sulphur hexafluoride (SF<sub>6</sub>) tracer gas technique
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
The effects of cattle breed type [dairy (Holstein) versus beef (Charolais × Simmental)] and forage quality (high, medium and low) on methane production were measured under ad-libitum and restricted feeding conditions. The in vitro organic matter digestibility (IVOMD) of the forage diets was high = 61.5%, medium = 50.7% and low = 38.5%. Each hay diet was fed to four animals (two dairy and two beef heifers) in three periods of four 3 × 3 Latin squares. Each period consisted of 23 d during which heifers were individually fed their assigned forage for 14 d on ad-ibitum feeding. Following this, intake was restricted to 2% of body weight (BW) for 9 d. Methane production was measured for five 24-h intervals in each period at both levels of intake using the SF 6 gas technique. Methane production was not different (P > 0.05) between dairy (238.0 ± 6.9 L d -1 ) and beef cattle (228.6 ± 7.8 L d -1 ) under either level of feeding. Forage quality affected CH 4 (L d -1 ) output, with high = medium > low during ad-libitum feeding. This effect of forage quality on CH 4 production was absent during restricted feeding (P > 0.05). Day-to-day variation in CH 4 production was 26.9 and 27.1% on ad-libitum and restricted feeding respectively (P < 0.05), whereas animal-to-animal variation (P < 0.05) was 26.6% (ad libitum) and 25.3% (restricted). On ad-libitum feeding, dry matter intake (DMI) was strongly correlated (P = 0.0001; r = 0.8) with CH 4 production (L d -1 ), and accounted for 64% of daily variation in CH 4 production. Methane [L kg -1 digestible organic matter intake (DOMI)] was highest (P < 0.05) on low-quality diets under both feeding regimes, and was not influenced (P > 0.05) by cattle type. Methane production as a percent of gross energy intake (GEI) was not influenced by diet. It can be concluded that the SF 6 tracer technique provides a measure of enteric CH 4 production directly from animals under production conditions. There were no differences in CH 4 production between dairy and beef breeds, but the quality of forages affected CH 4 production under both ad-libitum and restricted feeding. Key words: Methane, SF 6 tracer technique, cattle breed type, forage quality, level of intake
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| 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 it