Canadian National Dairy Study: Heifer calf management
Bibliographic record
Abstract
In the past decade, substantial changes have occurred in the way dairy heifer calves are managed. The objectives of this study, part of phase I of the 2015 Canadian National Dairy Study, were to examine heifer calf health and adoption of rearing practices, and to explore factors associated with different rearing strategies on Canadian dairy farms. The questionnaire was open to all licensed dairy producers in Canada and had a 12% response rate (n = 1,373). Fifty-one percent of respondents reported never allowing heifer calves to nurse their dam, and 17% always removed calves within 30 min of birth. Sixty-seven percent reported always feeding heifer calves 4 L of colostrum within 12 h of birth; 17% always fed colostrum between 2100 and 0400 h; 5% pasteurized all colostrum fed on farm. Seventy-seven percent of respondents reported calving and stillbirth information for 2014; the mean reported stillbirth rate was 4.9% (SD = 3.3). Forty percent housed calves in individual pens, 34% in group pens, 21% in individual hutches, 2% reported tethering calves, and 1% used group hutches. Of those who housed calves in groups, 59% reported a maximum group size of 3 to 10 calves, 31% reported a pair (2) of calves per pen or hutch, and 10% reported a group >10 calves. The maximum amount of milk offered to calves per day during the preweaned period was a mean of 8 L (SD = 3). Fifty percent of respondents reported mortality data for 2014; mean preweaning mortality was 6.4% (SD = 8.3), and postweaning mortality was 2.4% (SD = 4.4). Over 95% of producers reported disbudding practices; 86% used cautery, 11% used surgical amputation, and 9% used caustic paste. Twenty-eight percent reported disbudding at less than 3 wk of age, 60% at 3 to 8 wk, and 22% at 8 to 16 wk; 5% of respondents reported dehorning at more than 16 wk of age. Sixty-six percent of cautery users reported use of local anesthetic, 33% used sedation, and 25% used a nonsteroidal anti-inflammatory drug (NSAID). Multivariable regression models showed that the use of local anesthetic when disbudding calves was associated with social media activity (odds ratio = 2.3) and high-speed internet access (odds ratio = 2.0), whereas sedation was associated with geographic region, and NSAID use was associated with disbudding at more than 3 wk of age. Exploring heifer rearing management practices, including adoption of best practices, may help focus future education and extension efforts. Poor reporting of mortality data may reflect a lack of recordkeeping on farm.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".