Effect of reducing milk production using a prolactin-release inhibitor or a glucocorticoid on metabolism and immune functions in cows subjected to acute nutritional stress
Bibliographic record
Abstract
When cows are unable to consume enough feed to support milk production, they often fall into severe negative energy balance. This leads to a weakened immune system and increases their susceptibility to infectious diseases. Reducing the milk production of cows subjected to acute nutritional stress decreases their energy deficit. The aim of this study was to compare the effects on metabolism and immune function of reducing milk production using quinagolide (a prolactin-release inhibitor) or dexamethasone in feed-restricted cows. A total of 23 cows in early/mid-lactation were fed for 5 d at 55.9% of their previous dry matter intake to subject them to acute nutritional stress. After 1 d of feed restriction and for 4 d afterward (d 2 to 5), cows received twice-daily i.m. injections of water (control group; n=8), 2mg of quinagolide (QN group; n=7), or water after a first injection of 20mg of dexamethasone (DEX group; n=8). Feed restriction decreased milk production, but the decrease was greater in the QN and DEX cows than in the control cows on d 2 and 3. As expected, feed restriction reduced the energy balance, but the reduction was lower in the QN cows than in the control cows. Feed restriction decreased plasma glucose concentration and increased plasma nonesterified fatty acid (NEFA) and β-hydroxybutyrate (BHB) concentrations. The QN cows had higher glucose concentration and lower BHB concentration than the control cows. The NEFA concentration was also lower in the QN cows than in the control cows on d 2. Dexamethasone injection induced transient hyperglycemia concomitant with a reduction in milk lactose concentration; it also decreased BHB concentration and decreased NEFA initially but increased it later. Feed restriction and quinagolide injections did not affect the blood concentration or activity of polymorphonuclear leukocytes (PMN), whereas dexamethasone injection increased PMN blood concentration but decreased the proportion of PMN capable of inducing oxidative burst. Incubation of peripheral blood mononuclear cells in serum harvested on d 2 of the restriction period reduced their ability to react to mitogen-induced proliferation, and injection of quinagolide or dexamethasone could not alleviate this effect. This experiment shows that prolactin-release inhibition could be an alternative to dexamethasone for reducing milk production and energy deficit in cows under acute nutritional stress, without disturbing immune function.
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 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".