Assessing non-protein nitrogen sources in commercial dry dog foods
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Abstract Protein is a macronutrient required by dogs for growth and maintenance metabolism. However, a portion of the crude protein listed on pet foods may actually arise from non-digestible organic nitrogen or potentially toxic inorganic non-protein nitrogen sources. Neither non-protein source is retained or used by the animal. However, these compounds may result in adverse effects such as methemoglobin formation and increased oxidative stress or potentially beneficial effects such as improved vascular distensibility and decreased inflammation. To analyze nitrogen retention and screen for non-protein nitrogen, four commercial, dry kibble dog foods and one laboratory-made diet were evaluated and then fed to beagles during two separate feeding trials. During the first trial, dogs were randomly assigned each diet (n = 4 dogs/diet) and fed chromium oxide-coated diets for 48 h, followed by total urine and marked fecal collection, as well as plasma collection for total nitrogen, nitrate, ammonia, and urea determination. The amount of nitrogen retained (93%–96%) did not differ among commercial diets. Protein total tract apparent digestibility (TTAD) ranged from 69% to 84%, with the high protein diets significantly higher than the laboratory-made and mid-ranged diets (1-way ANOVA: P < 0.05). The high protein diet also contained the highest concentration of nitrate with subsequent elevations in plasma nitrotyrosine levels (indicator of oxidative stress). During the second trial, eight dogs (n = 8) were fed the same diets for 6 d, after which echocardiography was completed with blood, urine, and feces collected. For health end-points, methemoblobin, plasma nitrotyrosine, and C-reactive protein (CRP; indicator of inflammation) levels were measured. Methemoglobin levels were significantly lower in the high protein diet (P > 0.05), possible due to the stimulation of methemoglobin reductase while nitrotyrosine was unchanged and CRP was undetectable. Furthermore, there was a positive relationship between crude protein, crude fat (simple linear regression: P = 0.02, r2 > 0.6), price (P = 0.08, r2 > 0.6), and caloric density (P = 0.11, r2 > 0.6). There were no significant cardiovascular differences among any of the diets (P > 0.05). Ultimately, this study shows that in commercial diets, price does reflect protein content but that feeding dogs high protein diets for a long period of time may provide an excess in calories without a change in cardiovascular function or detectable increases in inflammation.
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.
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 | 0.000 |
| Open science | 0.000 | 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 it