49 The Effect of Increasing Standardized Ileal Digestible Methionine Intake During Lactation on Whole-Body Nitrogen Utilization of Primiparous Sows
Bibliographic record
Abstract
Abstract Seventy-five primiparous Yorkshire × Landrace and Yorkshire sows were used to determine the effect of increasing dietary standardized ileal digestible (SID) methionine (Met) intake on whole-body nitrogen (N) utilization during lactation. Upon farrowing (190.2 ± 18.0kg initial body weight), sows were assigned to 1 of 7 dietary SID Met levels (n = ~10), ranging from 70% to 130% of estimated SID Met requirements (0.182 to 0.338% SID Met) via the addition of DL-Met. All other indispensable amino acids were supplied above estimated requirements (1.19% SID lysine, 19.74% crude protein) and additional cysteine was supplied to minimize Met utilization for transsulfuration. Litters were standardized to 13 ± 2 piglets within 48 hours of birth and feed was offered according to a standard feeding curve (NRC, 2012). The N balance periods were between days 5 to 9 (early; N1) and 17 to 21 (Peak; N2) of lactation where total urine was collected via urinary catheters and feces was grab-sampled; titanium dioxide was used as an indigestible marker for determining apparent total tract N digestibility. In N1 and N2, 5.22 and 6.87 kg/d of experimental diet was offered in three equal meals at 0830, 1200, and 1530 h to each sow. Milk N output (g/d) was calculated using estimated milk yield based on litter growth rate and size and analyzed milk N concentration. Contrast statements were used to assess linear and quadratic effects of dietary SID Met level. During N1, N intake increased and then decreased when dietary SID Met content surpassed 0.286% (quadratic; P < 0.05). Similar relationships were observed for total N excretion (urine + fecal N; P < 0.05) resulting in no SID Met effect on N retention (77.1 ± 6.6, -12.5 ± 10.4, and 89.5 ± 8.9 g/d for total, maternal, and true milk protein N retention, respectively) or apparent N utilization efficiency (N retention/N intake×100; 53.2 ± 3.4%). During N2, as SID Met increased, N intake tended to increase (205.5 to 210.2 ± 5.7g/d; linear; P = 0.078), total N excretion tended to decrease (87.3 to 78.7 ± 6.2 g/d; linear; P = 0.087), and total N retention increased (117.9 to 131.4 ± 8.0g/d; linear; P < 0.05). True milk protein N output increased with SID Met (100.3 to 112.5 ± 8.1 g/d; linear; P < 0.05) and maternal N retention decreased and then increased when dietary SID Met content surpassed 0.260% (quadratic; P < 0.05). Apparent N utilization efficiency increased with increasing dietary SID Met (57.5 to 62.5 ± 1.2%; linear; P< 0.05). Therefore, in early lactation, SID Met intake had minimal effects on N utilization, indicating that the requirement for lactating primiparous sows may be equal to or less than 0.182% SID Met. During peak lactation, the supply of SID Met needed to maximize true milk protein N and apparent N utilization efficiency may be greater than 0.338%, which does not take into consideration the non-protein partitioning of dietary Met.
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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) | 0.001 | 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".