1315 Effect of increasing doses of abomasally infused linseed oil on animal performance and oxidative stability of milk in Holstein dairy cows
Bibliographic record
Abstract
To evaluate the effect of increasing doses of post-ruminal supply of linseed oil (LO), as a source of polyunsaturated fatty acids (PUFA), on animal performance and oxidative stability of milk, five Holstein dairy cows (36 ± 2 DIM, 38.7 ± 4.7 kg milk/d; Mean ± SD) were randomly distributed in a 5 × 5 Latin square design (14-d periods; 11 d of adaptation). All cows were fed the same ration and LO was abomasally infused continuously at 0, 75, 150, 300, and 600 g/d using peristaltic pumps. Oxidation measurements were done on fresh non-homogenized milk and on homogenized milk stored at 4°C during 11 d under fluorescent light. Data were analyzed using a mixed model including the random effects of period and cow, and the fixed effects of treatment, time and their interaction in the repeated measures analyses. A peroxidability index (PI) was calculated as: 0.025×Monoenoates + 1×Dienoates + 2×Trienoates + 4×Tetraenoates + 6×Pentaenoates + 8×Hexaenoates, to account for individual oxidation sensitivity of FA. Dry matter intake and yield of energy corrected milk decreased linearly with increasing dose of LO (P < 0.05). Milk fat concentration decreased quadratically (P < 0.05) reaching a nadir at 300 g of LO/d, whereas the yields of fat and protein decreased linearly (P < 0.05). The concentration and yield of lactose were not different among treatments. The concentration of PUFA increased linearly with LO dose (P < 0.001). Accordingly, the PI of fresh milk increased linearly with dose from 2.0 mg/g milk in the control, to 10.8 mg/g milk at the highest dose (P < 0.001). Conjugated diene hydroperoxides in fresh milk increased linearly with dose (P < 0.001), whereas conjugated triene hydroperoxides and redox potential were not affected. Volatile lipid oxidation products such as propanal, hexanal, trans-2-hexenal/hex-cis-3-enal, and hept-cis-4-enal increased linearly with dose (P < 0.001), whereas 1-octen-3-one was not affected, and trans-2, cis-6-nonadienal and trans-2, trans-4-nonadienal were not detected in fresh milk. During storage, similar increasing trends were observed across treatments for propanal, hexanal, trans-2-hexenal/hex-cis-3-enal, hept-cis-4-enal, and trans-2, cis-6-nonadienal in homogenized milk (time P < 0.001). Treatment by time interactions were detected for 1-octen-3-one and trans-2, trans-4-nonadienal. In conclusion, increasing doses of abomasally infused LO negatively affected animal performance. Despite small differences among individual oxidation products, overall, a linear increase in milk PUFA led to a quadratic response in total identified volatile compounds which tended to reach a plateau at 300 g of LO/d.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 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".