Amino acid digestibility and nitrogen-corrected true metabolizable energy of mildly cooked human-grade vegan dog foods using the precision-fed cecectomized and conventional rooster assays

Vegan, mildly-cooked, and human-grade dog foods are becoming more popular, as beliefs and views of pet owners change. To our knowledge, however, dog studies have not examined the digestibility of commercial vegan diets. Therefore, the objective of this study was to determine the apparent total tract digestibility (ATTD) of mildly-cooked human-grade vegan dog foods and their effects on blood metabolites and fecal microbiota, characteristics, and metabolites of adult dogs consuming them. Three commercial dog foods were tested. Two were mildly-cooked human-grade vegan dog diets, while the third was a chicken-based extruded dog diet. Twelve healthy adult female beagles (7.81±0.65 kg; 7.73±1.65 y) were used in a replicated 3x3 Latin Square design. The study consisted of three experimental periods, with each composed of a 7-day diet adaptation phase, 15 days of consuming 100% of the diet, a 5-day phase for fecal collection for ATTD measurement, and 1 day for blood collection for serum chemistry and hematology. During the fecal collection period, a fresh sample was collected for fecal scoring and dry matter, pH, metabolite, and microbiota measurements. All data were analyzed using the Mixed Models procedure of SAS (version 9.4). All three diets were shown to be highly digestible, with all macronutrients having digestibility values above 80%. The vegan diets had higher (P<0.001) ATTD of fat, but lower (P<0.05) ATTD of organic matter than the extruded diet. Dogs consuming the vegan diets had lower circulating cholesterol (P<0.001), triglyceride (P<0.001), and platelet (P<0.009) concentrations and lower (P<0.010) blood neutrophil percentages than dogs consuming the extruded diet. Dogs consuming vegan diets had lower (P<0.001) fecal dry matter percentages, lower (P<0.001) fecal phenol and indole concentrations, and higher (P=0.05) fecal short-chain fatty acid concentrations than those consuming the extruded diet. Fecal bacterial alpha and beta diversities were not different (P>0.05) among diets, but dogs consuming vegan diets had altered (P<0.05) relative abundances of nearly 20 bacterial genera when compared with those consuming the extruded diet. In conclusion, the mildly-cooked human-grade vegan dog foods tested in this study performed well, resulting in desirable fecal characteristics, ATTD, and serum chemistries. The vegan diets tested also led to positive changes to serum lipids and fecal metabolites, and interesting changes to the fecal microbial community.

show abstract

Standardized amino acid digestibility and nitrogen-corrected true metabolizable energy of frozen and freeze-dried raw dog foods using precision-fed cecectomized and conventional rooster assays

Oba,

Utterback,

Parsons

et al. 2023

Journal of Animal Science

View full text Add to dashboard Cite

Commercial raw or minimally processed diets, often referred to holistically as raw-meat based diets (RMBD) represent a small portion of the pet food market, but the growth of this sector has been significant in recent years. While traditionally, high-moisture, frozen options were the standard format of commercially available raw diets, freeze-dried raw diets have become more prevalent as of late. Despite the increasing popularity of these commercial raw diet formats, there is a dearth of literature describing their nutritional properties, particularly regarding freeze-dried diets. Therefore, the objective of this experiment was to determine and compare the standardized amino acid (AA) digestibilities and nitrogen-corrected true metabolizable energy (TMEn) of raw frozen and freeze-dried dog foods using precision-fed cecectomized and conventional rooster assays. Three formats of frozen or freeze-dried raw diets provided by Primal Pet Foods (Fairfield, CA, USA) were tested: traditional freeze-dried nuggets (T-FDN), hybrid freeze-dried nuggets (H-FDN), and frozen nuggets (FZN). Diets were fed to cecectomized roosters (4 roosters/diet) to determine AA digestibilities, while conventional roosters (4 roosters/diet) were used to determine TMEn. In both cases, after 26 h of feed withdrawal, roosters were tube-fed 12-13 g of test diets and 12-13 g of corn. Following crop intubation, excreta were collected for 48 h. Endogenous corrections for AA were made using 5 additional cecectomized roosters. All data were analyzed using the Mixed Models procedure of SAS version 9.4. There were no significant differences in standardized AA digestibilities among diets, with digestibilities being high for all diets tested. For most of the indispensable AA, digestibilities were greater than or equal to 90% for all diets. Histidine and lysine were the exceptions, with digestibilities ranging from 82%-87% and 87-92%, respectively. Moreover, the reactive lysine:total lysine ratio, a measure of heat damage, ranged from 0.91 to 0.95. TMEn values were higher (P = 0.0127) in T-FDN (6.1 kcal/g) and FZN (5.9 kcal/g) than H-FDN (5.3 kcal/g) and were most similar to those estimated by Atwater factors. In general, all diets tested had high AA digestibilities and had TMEn values that were most similar to Atwater factors.

show abstract

Amino acid digestibility and nitrogen-corrected true metabolizable energy of mildly cooked human-grade vegan dog foods using the precision-fed cecectomized and conventional rooster assays

Cited by 5 publications

References 37 publications

Beyond the Bowl: Understanding Amino Acid Requirements and Digestibility to Improve Protein Quality Metrics for Dog and Cat Foods

Beyond the Bowl: Understanding Amino Acid Requirements and Digestibility to Improve Protein Quality Metrics for Dog and Cat Foods

Apparent total tract macronutrient digestibility of mildly cooked human-grade vegan dog foods and their effects on the blood metabolites and fecal characteristics, microbiota, and metabolites of adult dogs

Standardized amino acid digestibility and nitrogen-corrected true metabolizable energy of frozen and freeze-dried raw dog foods using precision-fed cecectomized and conventional rooster assays

Contact Info

Product

Resources

About