Neonatal handling permanently alters hypothalamic-pituitary- adrenal axis function, behaviour, and body weight in boars
Bibliographic record
Abstract
Neonatal handling permanently alters hypothalamic- pituitary-adrenal axis (HPA) function in rats. In the rat, this treatment increases hippocampal glucocorticoid receptors (GR) and dampens plasma ACTH and corticosterone responses to stressors. The objectives of this study were to determine whether neonatal handling of pigs would effect permanent changes in plasma corticosteroid binding capacity (CBG), basal or stressor-induced plasma cortisol and ACTH concentrations, brain or pituitary GR levels, dexamethasone suppression of plasma cortisol and ACTH concentrations, behaviour in an open field-test pen, and body weights. Twelve litters of pigs were randomly assigned to either neonatal handling or no disturbance. Handled litters were removed from the farrowing crate for 10 min per day for the first 14 days of life. Male pigs were kept for the study and the boars were weighed monthly. At 7 months of age, boars were tested for locomotory behaviour in an open field-test pen. The boars were implanted with indwelling ear-vein catheters and blood samples were obtained basally, during and after application of a nose snare, and after 0.04 mg/kg dexamethasone. Boars were killed and blood samples were obtained and the brain and pituitary glands collected. Handled boars had greater (P<0.05) plasma CBG binding and lower basal total (P<0.05) and calculated free (P<0.03) plasma cortisol concentrations. No significant differences between treatments were found in plasma ACTH or cortisol responses to a nose-snare stressor; however, when killed, handled boars had greater (P<0.02) plasma ACTH concentrations. Handled and non-handled boars did not differ in plasma ACTH or cortisol responses to dexamethasone. There was no treatment effect on GR expression in the pituitary gland, frontal cortex, hippocampus, or hypothalamus. Behaviourally, the handled boars had higher (P<0.03) locomotor scores over inner squares and a lower (P<0.05) ratio of outer:inner squares entered in open field-tests. During the first 7 months of life, body weights were lower (P<0.004) for handled boars. In conclusion, neonatal handling permanently altered HPA function in pigs, but in a manner dissimilar to that found in the rat. These changes induced in the pig were not beneficial for commercial production with respect to body weight.
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 | 0.000 | 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 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".