55 The Effects of Dietary Net Energy Levels on Grow-Finish Performance and Carcass Characteristics of Market Gilts Managed with Improvest
Bibliographic record
Abstract
Abstract Improvest is a gonadotropin releasing factor (GnRF) analogue-diphtheria toxoid conjugate injection approved for temporary suppression of ovarian function and estrus in market gilts (Zoetis Canada Inc.). Study objectives were to determine the effects of three different net energy levels (LOW – 2.216 Mcal/kg, MID – 2.341 Mcal/kg, or HIGH – 2.466 Mcal/kg) during the grow-finish period on live performance and carcass characteristics of market gilts managed with Improvest (IMP) compared with market gilts not managed with Improvest (CON). The study consisted of 1,008 market gilts (average starting weight of 30.8 kg) in 48 pens (21 pigs/pen) with experimental treatments arranged as a 2 × 3 factorial design with main effects of Improvest (IMP or CON) and net energy level (LOW, MID, or HIGH). An equal number of pigs were marketed from each of the six treatment groups on day-83 (21.9% of the population), day-90 (21.9% of the population), day-97 (21.9% of the population), and day-104 (34.3% of the population) of the experiment. The weighted average for time post-second Improvest injection to marketing was 39.8 days. Data were analyzed with PROC MIXED of SAS, with pen serving as the experimental unit, fixed effects of Improvest (IMP or CON), net energy level (LOW, MID, or HIGH) and their interaction, and a random effect of pen location. There were no significant interactions (P ≥ 0.20) for average daily feed intake (ADFI), average daily gain (ADG), Feed:Gain (F:G), hot carcass weight (HCW), dressing percentage, backfat thickness, or predicted lean yield. However, IMP gilts consumed more feed (6.8% greater ADFI; P < 0.01), grew faster (5.0% greater ADG; P < 0.01), were less efficient (1.5% greater F:G; P < 0.01), were heavier (3.5 kg HCW; P < 0.01), and were fatter (1.9 mm greater backfat thickness and 0.9% less predicted lean yield; P < 0.01) than CON gilts. No difference (P = 0.21) in carcass dressing percentage between IMP and CON gilts was detected (Table 1). There were significant effects (P < 0.05) of net energy level for ADFI, ADG, F:G, HCW, and dressing percentage. Pigs fed LOW diets had the greatest ADFI, slightly less ADG, the least efficient F:G ratio, the lightest HCW, and reduced dressing percentage compared with HIGH (P < 0.01). There were no differences (P > 0.05) for backfat thickness or predicted lean yield among dietary energy level treatments. Overall, these data indicate that typical Improvest response levels were sustained at each of the net energy levels evaluated in this study (response levels for HCW of 2.6 kg for LOW, 3.4 kg for MID, and 4.5 kg for HIGH); however, consideration should still be provided to the known production impacts of low net energy diets when market gilts are managed with Improvest.
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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".