Farm factors associated with increased free fatty acids in bulk tank milk
Bibliographic record
Abstract
Elevated concentrations of free fatty acids (FFA) in bulk tank milk are a milk quality concern in the dairy industry.Hydrolysis of triacylglycerols (TAG) yields FFA, and milk with ≥1.20 mmol FFA/100 g of milk fat is associated with undesirable characteristics, such as off-flavor, rancidity, reduced foam stability, and inhibited cheese-milk coagulation.Research on FFA is limited and absent in North America, but research out of European regions indicates that high FFA are multifactorial.This study aimed to identify farm-level FFA risk factors in Canadian dairy herds.A cross-sectional study was conducted on 293 Canadian dairy farms in Ontario (n = 238) and British Columbia (n = 55).Over 2 yr, selected farms were visited once to complete a survey, assess milking systems, and gather data on the diet of lactating cows.Bulk tank FFA values for each farm 15 d before and 15 d after the research visit were obtained from the corresponding province's milk marketing board.Using these values, a monthly FFA average was calculated for each farm and used as the outcome variable.Seventy-one farms were tiestall, 109 were freestall with milking parlors, and 113 were freestall with automated milking systems (AMS).The mean bulk tank FFA was 0.84 mmol/100 g of fat (SD = 0.40, range 0.26 to 3.67), and 10% (n = 29) of herds had an elevated monthly average FFA (≥1.20 mmol/100 g of fat).In the final multivariable linear regression model, milking frequency ≥3×/d (times per day) compared with <3×/d was associated with a greater FFA concentration in AMS (β = 0.27, 95% CI: 0.12, 0.41) and tiestall milking systems (β = 1.17, 95% CI: 0.76-1.59).Regardless of milking frequency, none of the parlor farms visited had FFA ≥1.20 mmol/100 g of fat.For farms milking ≥3×/d, not changing the milk filter at least 2×/d was associated with greater FFA concentrations (β = 0.27, 95% CI: 0.10, 0.44).The absence of pre-cooling was also associated with higher FFA levels (β = 0.16, 95% CI: 0.02, 0.3).The final model adjusted R 2 of 29% indicates that more factors associated with bulk tank milk FFA still need to be identified, which may include seasonal, milk composition, and individual cow factors.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 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 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".