0123 Association of rumination time and health status with milk production in early lactation dairy cows
Bibliographic record
Abstract
The objective of this study was to characterize the associations of rumination time (RT) and health status with milk yield (MY) and milk composition in early lactation dairy cows. A total of 339 dairy cows (first lactation, n = 107; second lactation, n = 112; ≥ third lactation, n = 120) on 4 commercial dairy farms in Ontario, Canada, were monitored from 1 to 28 d in milk (DIM) for rumination behavior (24h/d using an automated system), milk composition (fat, protein, somatic cell count, and milk urea N 1×/wk), and hyperketonemia (HYK; blood β hydroxybutyrate ≥ 1.2 mmol/L, measured 1×/wk). Cows were milked 3 times/d at each farm; Two farms recorded milk weights at each milking to determine daily MY (n = 170). Cases of retained placenta, metritis, milk fever, or mastitis during the study period were recorded. Cows were categorized into 1 of 3 groups: healthy (HLT) cows had no HYK or any other recorded disease (n = 139); HYK cows with no other health problems during transition (n = 97); or hyperketonemic plus (HYK+) cows that had HYK and ≥1 other health problems (n = 53). Data were summarized by week and analyzed in repeated measures general linear mixed models. A positive association was found between weekly summarized RT and MY in first (+0.006 ± 0.003 kg milk/min RT, P = 0.04) and second lactation (+0.01 ± 0.004 kg milk/min RT, P < 0.01) cows from 4 to 28 DIM. A positive association was also seen in parity 3+ cows, however, the relationship between RT and MY differed (P < 0.01) across weeks (wk +1: +0.05 ± 0.007 kg/min RT; wk +2: +0.06 ± 0.008 kg/min RT; wk +3: +0.05 ± 0.011 kg/min RT; wk +4: +0.04 ± 0.014 kg/min RT). During wk +2 and +3, second lactation HYK cows had lower milk protein percentage compared with HLT cows (0.08 ± 0.043w/w% and 0.12 ± 0.041w/w%, respectively; P ≤ 0.05). Hyperketonemia+, second lactation cows also had lower milk protein content compared with HLT cows in wk +1, and +2, (0.14 ± 0.068w/w% and 0.20 ± 0.089w/w%, respectively; P ≤ 0.05). Over the 4 wk observation period, first lactation HYK+ cows tended to have lower protein compared with HLT cows (P = 0.1) and ≥ third lactation HYK and HYK+ cows produced less protein than HLT cows (P ≤ 0.03). Second lactation cows in HYK+ produced less milk than HLT cows during wk +1 (7.1 ± 2.9 kg/d, P = 0.02), +2 (14.2 ± 4.0 kg/d, P < 0.001), +3 (13.8 ± 4.5 kg/d, P = 0.003), and +4 (10.6 ± 5.3 kg/d, P = 0.05). Ketosis decreased MY and protein percentage variably with parity. Rumination time was shown to have a positive association with MY in early lactation dairy cows.
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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 | 0.001 |
| 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".