Evaluation of feed restriction and abomasal infusion of resistant starch as models to induce intestinal barrier dysfunction in healthy lactating cows
Bibliographic record
Abstract
Intestinal hyperpermeability and subsequent immune activation alters nutrient partitioning and thus, decreases productivity. Developing experimental models of intestinal barrier dysfunction in heathy cows is a prerequisite in identifying nutritional strategies to mitigate it. Six cannulated Holstein cows (mean ± standard deviation, 37 ± 10 kg/d milk yield; 219 ± 97 d in milk; 691 ± 70 kg body weight) were used in a replicated 3 × 3 Latin square design experiment with 21-d periods (16-d wash-out and 5-d challenge) to evaluate either feed restriction or hindgut acidosis as potential models for inducing intestinal hyperpermeability. Cows were randomly assigned to treatment sequence within square and treatment sequences were balanced for carryover effects. Treatments during the challenge were (1) control (CTR; ad libitum feeding); (2) feed restriction (FR; total mixed ration fed at 50% of ad libitum feed intake); and (3) resistant starch (RS; 500 g of resistant starch infused in abomasum once a day as a pulse-dose 30 min before morning feeding). The RS (ActiStar RT 75330, Cargill Inc.) was tapioca starch that was expected to be resistant to enzymatic digestion in the small intestine and highly fermentable in the hindgut. Blood samples were collected 4 h after feeding on d 13 and 14 of the wash-out periods (baseline data used as covariate), and on d 1, 3, and 5 of the challenge periods. Fecal samples were collected 4 and 8 h after the morning feeding on d 14 of the wash-out periods and d 5 of the challenge periods. By design, FR decreased dry matter intake (48%) relative to CTR and RS, and this resulted in marked reductions in milk and 3.5% FCM yields over time, with the most pronounced decrease occurring on d 5 of the challenge (34 and 27%, respectively). Further, FR increased somatic cell count by 115% on d 5 of the challenge relative to CTR and RS. Overall, FR increased nonesterified fatty acids (159 vs. 79 mEq/L) and decreased BHB (8.5 vs. 11.2 mg/dL), but did not change circulating glucose relative to CTR. However, RS had no effect on production or metabolism metrics. Resistant starch decreased fecal pH 8 h after the morning feeding (6.26 vs. 6.81) relative to CTR and FR. Further, RS increased circulating lipopolysaccharide binding protein (4.26 vs. 2.74 µg/mL) compared with FR only on d 1 of the challenge. Resistant starch also increased Hp (1.52 vs. 0.48 µg/mL) compared with CTR, but only on d 5 of the challenge. However, neither RS or FR affected concentrations of serum amyloid A, IL1β, or circulating endotoxin compared with CTR. The lack of consistent responses in inflammatory biomarkers suggests that FR and RS did not meaningfully affect intestinal barrier function. Thus, future research evaluating the effects of hindgut acidosis and FR using more intense insults and direct metrics of intestinal barrier function is warranted.
Stored with the screening record, where it is evidence for the labels above.
How this classification was reachedexpand
The three-model screen
all 5,600 screened works →All three models called this out of scope.
Evaluation of experimental models for inducing intestinal barrier dysfunction in cows; bench/animal model development, not metaresearch.
The experiment evaluates models of intestinal dysfunction in cows, not research itself.
Dairy-cow experimental models of intestinal barrier dysfunction; animal science.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".