Comparing responses of dairy cows to short-term and long-term heat stress in climate-controlled chambers
Bibliographic record
Abstract
Heat stress (HS) in dairy cows can be classified into short-term heat stress (STHS) and long-term heat stress (LTHS) according to the number of consecutive days in HS. The comparative study of these 2 types of HS is limited in terms of their effects on the production and energy metabolism of cows. In this study, 4 lactating Holstein cows (102.5 ± 12 days in milk, 605 ± 22 kg of body weight, second parity) fitted with rumen fistulae were randomly assigned to 1 of 2 groups in a 2 × 2 crossover design and allocated to 1 of 2 climate-controlled chambers. This study contained 2 periods, each with a control phase and a HS phase. There was a recovery phase between 2 periods. The HS phase comprised either STHS (3 d) or LTHS (7 d) treatments. Data collected from the 3 d of STHS and the last 3 d of LTHS were compared. The chambers were set at thermal neutral conditions (20°C, 50% humidity) during the control and recovery phases or cyclical HS conditions (26-38°C, 50% humidity) during the HS phase. Compared with STHS, LTHS decreased milk yield by 17.2% and dry matter intake by 12.6%, indicating that LTHS caused a more severe decline in milk production and feed intake. In addition, LTHS decreased milk protein concentration by 6.8% and milk protein yield by 22.4%. In comparison with STHS, LTHS decreased rumen liquor volatile fatty acid (29.7%), blood glucose (11.6%), and nonesterified fatty acid (13.6%) concentrations, but increased milk urea nitrogen by 15.1%, blood urea nitrogen by 8.6%, and creatine concentrations by 15.4%. Our results suggest that although reduced feed intake may be mainly responsible for reduced milk production during STHS, impaired rumen metabolism and suppressed mobilization of adipose tissue could be the main reasons for further reduction in milk yield during LTHS.
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.
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 | 0.001 |
| 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".