Effects of canola meal inclusion rate in starter mixtures for Holstein heifer calves on dry matter intake, average daily gain, ruminal fermentation, plasma metabolites, and total-tract digestibility
Bibliographic record
Abstract
The objective of this study was to determine the effects of the canola meal (CM) inclusion rate in pelleted starter mixtures for Holstein heifer calves on dry matter intake, average daily gain, ruminal fermentation, plasma metabolites, and total-tract digestibility. Fifty Holstein heifer calves were blocked by birth date and body weight and, within block, randomly assigned to 1 of 5 pelleted starter treatments with 0, 15, 30, 45, or 60% of the crude protein supplied by CM instead of soybean meal (SBM). Pellets were formulated to be similar in crude protein (24.3%), starch (26.6%), and neutral detergent fiber (17.8%) and were provided to calves starting on d 8 of age, with starter intake measured daily. From 8.0 ± 0.0 (mean ± standard deviation) d of age through d 35.3 ± 2.4, calves were fed milk replacer at 15% of body weight, offered in 3 equal feedings at 0600, 1500, and 2100 h. After that, a gradual 21-d step-down weaning process was imposed, where no further milk replacer was provided starting on d 57.0 ± 0.0. Data for milk replacer and starter intake were calculated to determine weekly averages. On d 62.2 ± 0.8 of age, blood was collected every 4 h and analyzed for glucose, β-hydroxybutyrate, insulin, and urea concentrations. From d 66.2 ± 0.8 of age and extending for 3 d, fecal samples were collected every 12 h with a 3-h daily offset, to estimate fecal nutrient output and to determine apparent total-tract digestibility. Additionally, ruminal fluid (d 70.2 ± 0.8 of age) was sampled at 1300 h through an esophageal tube connected to a vacuum pump. The pH of ruminal fluid was measured, and ruminal fluid was analyzed to determine short-chain fatty acid and ammonia concentrations. Data were analyzed with fixed effect of treatment and random effect of block. Polynomial contrasts were calculated to assess linear, quadratic, and cubic effects with repeated measures statement for variables analyzed over time. Starter intake, average daily gain, body weight, and feed efficiency did not differ among treatments. Crude protein and ether extract digestibility were affected in a cubic manner, where CP was greatest for CM0, CM30, and CM45, and ether extract digestibility was least for CM15 and CM60. The molar proportion of acetate responded cubically, but the proportions of propionate and butyrate did not differ among treatments. Ruminal ammonia and plasma urea concentrations were not affected by CM inclusion rate. In conclusion, CM can replace up to 60% of the CP provided from SBM without affecting starter intake and growth of calves.
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 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".