PSX-26 Effect of physically effective neutral detergent fiber and starch inclusion on ruminal motility for feedlot cattle.
Bibliographic record
Abstract
Abstract This study was designed to evaluate the effects of physically effective neutral detergent fiber (peNDF) and starch inclusion rate on ruminal motility, pool sizes, and ruminal neutral detergent fiber (NDF) turnover rate in finishing cattle. Eight ruminally cannulated Nellore steers (468.6 ± 87.5 kg), were housed in individual pens (21 m2) and assigned to a replicated 4×4 Latin square design, balanced for carryover effects. The experiment followed a 2×2 factorial arrangement of treatments, with two levels of peNDF (low: 8.5% of diet dry matter (DM) vs. high: 10.3% of diet DM) and two levels of starch inclusion (22.5% vs. 45.0% of diet DM). Concentrate feedstuffs were ground through a 4-mm sieve, and all ingredients were included in the peNDF calculation. Each period consisted of 21 days, including 14 days for adaptation and 7 days of sampling. Corn silage was harvested from a single field and chopped to a theoretical chop length of 2.0 (low peNDF) or 9.0 mm (high peNDF), and included at 20% of DM in all diets. In addition, diets contained finely ground corn grain, soybean hulls, soybean meal, citrus pulp, mineral, urea, and sodium monensin. Dry matter intake, expressed in kg/d and as a percentage of body weight, was not affected by peNDF, starch, or the interaction (P≥0.15). The peNDF inclusion did not affect (P≥0.11) neutral detergent fiber (NDF), and undigested NDF (uNDF) intake. However, feeding high peNDF increased peNDF intake (high: 1.4 vs. low: 1.1 kg; P=0.05). In contrast, feeding high starch decreased NDF (high: 3.0 vs. low: 5.2 kg; P< 0.01), peNDF (high: 2.1 vs. low: 2.3 kg; P=0.05), and uNDF intake (high: 1.4 vs. low: 1.7 kg; P< 0.01). Cattle fed low peNDF and high starch had greater rumen contraction frequency (interaction, P=0.05) when compared with the other treatments. Cattle fed low starch had greater time between contractions (high: 7.7 vs. low: 7.2 s; P=0.03), contraction duration (high: 4.3 vs. low: 3.8 s; P< 0.01), and contraction amplitude (high: 2.8 vs. low: 2.0 mmHg×s; P=0.05). Total ruminal digesta pool size (kg as is), DM, NDF, uNDF, potentially degradable NDF, and NDF passage rate were not affected by peNDF, starch, or the interaction (P≥0.14). Feeding low starch inclusion increased the NDF degradation rate (low: 3.5 vs. low: 1.0 %/h; P< 0.01). Thus, increasing theoretical chop length, a practical approach to manipulate peNDF while keeping the same dietary NDF from roughage had minimal effects on ruminal motility. However, low starch inclusion increased contraction duration, amplitude, and NDF degradation rate. These findings suggest that starch level exerts a stronger influence on ruminal motility in feedlot Nellore cattle than peNDF, with potential implications for ruminal health and nutritional strategies.
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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 | 0.000 |
| 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) | 0.002 | 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".