Postprandial plasma and whole blood amino acids are largely indicative of dietary amino acids in adult dogs consuming diets with increasing whole pulse ingredient inclusion.

BACKGROUND: Pulse ingredients often replace grains in grain-free dog diets due to their high protein content. However, research to ascertain the benefit of this modification is limited. OBJECTIVE: To correlate food compounds in one corn-inclusive control diet (Ctl) and three grain-free diets with increasing inclusions of whole pulses (up to 45%; Pulse15, Pulse30, Pulse45), formulated to meet similar macro and micronutrient targets with postprandial amino acids (AA) in healthy dogs over 20-weeks. METHODS: Diets were analyzed for biochemical compounds using tandem-MS. Twenty-eight outdoor-housed, healthy, adult Siberian Huskies were allocated to diet and meal responses took place at baseline and weeks 2, 4, 8, 16 and 20 with samples collected at fasted and 15, 30, 60, 90, 120 and 180 minutes after meal presentation. Blood AAs were analyzed by UPLC and differences across week, treatment and time post-meal were analyzed in SAS Studio. Partial least squares regression was performed in SAS Studio using biochemical compounds in the diet as predictor variables and blood AAs as response variables. RESULTS: In plasma, Pulse45 had ∼32% greater postprandial Asn compared to Pulse15, and Ctl had ∼34% greater postprandial Leu and ∼35% greater Pro compared to Pulse15 (P < 0.05). In whole blood, Pulse30 had ∼23% greater postprandial Lys compared to Ctl, and Ctl had ∼21% greater postprandial Met and ∼18% greater Pro compared to Pulse45 and Pulse30, respectively (P < 0.05). Several phospholipids were correlated with postprandial AAs. Compounds in the 'urea cycle' and 'glycine and serine metabolism' were more enriched (P < 0.05) in plasma and whole blood, respectively. CONCLUSIONS: In macro and micronutrient balanced canine diets that differ in their inclusion of corn- versus pulse-derived ingredients, postprandial changes in circulating AAs are largely indicative of the dietary AAs. This helps further our understanding of AA metabolism in healthy dogs fed grain-free diets.

Effects of diets supplemented with bioactive peptides on nutrient digestibility, immune cell responsiveness, and fecal characteristics, microbiota, and metabolites of adult cats.

Bioactive peptides (BP) are recognized for their ability to function as antioxidants and maintain lipid stability. They may have positive health effects, including antihypertensive, anti-inflammatory, antimicrobial, osteoprotective, gut health, and immunomodulatory properties, but are poorly tested in cats. Our primary objective was to determine the apparent total tract digestibility (ATTD) of BP-containing kibble diets and assess how the fecal characteristics, metabolites, and microbiota were affected in adult cats. Our secondary objective was to test whether BP could impact blood oxidative stress markers and cytokine concentrations following transport stress. Twelve adult cats (4.83 ± 0.37 yr; 4.76 ± 0.14 kg) were used in a replicated 4 × 4 Latin square design to test four extruded kibble diets: Control (no BP), Chicken (4% chicken BP), Marine1 (2% marine BP), and Marine2 (4% marine BP). Each experimental period lasted 28 d, with a 20-d adaptation phase, 5 d for fecal collection, 2 d for blood collection, and 1 d for transport stress testing (driven in vehicle in individual carriers for 45 min). Salivary cortisol and blood oxidative stress markers and cytokines were measured after transport. Fecal microbiota data were evaluated using 16S rRNA gene amplicon sequencing and QIIME2. All other data were analyzed using the Mixed Models procedure of SAS, with P < 0.05 being considered significant and P < 0.10 considered trends. No differences were observed in animal health outcomes, with all cats remaining healthy and serum metabolites remaining within reference ranges. Cats fed the Marine2 diet had higher (P < 0.05) ATTD of dry matter (84.5% vs. 80.9%) and organic matter (88.3% vs. 85.8%) than those fed the control diet. The ATTD of protein and energy tended to be higher (P < 0.10) for cats fed the Marine2 diet. Fecal characteristics, metabolites, and bacterial alpha and beta diversity measures were not affected by treatment. However, the relative abundances of six bacterial genera were different (P < 0.05) and two bacterial genera tended to be different (P < 0.10) across treatments. Treatment did not alter salivary cortisol, blood oxidative stress markers, or blood cytokines after transport stress. Our data suggest that BP inclusion may increase nutrient digestibility and modify fecal microbiota and immune measures. More testing is required, however, to determine whether BP may provide additional benefits to cats.

Dietary bioactive peptides (BP) may have positive health effects, but are poorly tested in cats. Our primary objective was to determine the apparent total tract digestibility of BP-containing kibble diets and assess how fecal characteristics, metabolites, and microbiota were affected in adult cats. Our secondary objective was to test whether BP could impact blood oxidative stress markers and cytokines following transport stress. Adult cats were used in a replicated 4 × 4 Latin square design to test four extruded kibble diets containing different BP concentrations. After diet adaptation, fecal and blood samples were collected and transport stress testing was done in each experimental period. All cats remained healthy and serum metabolites remained within reference ranges. Cats fed one of the BP diets had higher dry matter and organic matter digestibilities and tended to have higher protein and energy digestibilities. Fecal characteristics, metabolites, and microbiota diversity measures were not different, but the relative abundances of eight bacterial genera differed or tended to differ across treatments. Treatments did not alter oxidative stress markers after transport stress. Our data suggest that BP inclusion may increase nutrient digestibility and modify fecal microbiota. Further testing is required to determine whether BP provides additional benefits to cats.

The Pulse of It: Dietary Inclusion of Up to 45% Whole Pulse Ingredients with Chicken Meal and Pea Starch in a Complete and Balanced Diet Does Not Affect Cardiac Function, Fasted Sulfur Amino Acid Status, or Other Gross Measures of Health in Adult Dogs.

BACKGROUND: Pulses are an attractive alternative protein source for all mammals; however, recent reports suggest that these ingredients may be related to developing dilated cardiomyopathy in dogs. OBJECTIVES: The primary objective of this study was to quantify the effects of dietary pulse intake by adult dogs on cardiac function using echocardiographic measurements and cardiac biomarkers N-terminal pro-B-type natriuretic peptide and cardiac troponin I (cTnI). Second, to investigate the effects of pulse consumption on plasma sulfur amino acid (SAA) concentrations as pulses are generally low in SAA and may limit taurine synthesis. Last, to assess the general safety and efficacy of feeding pulse-containing diets on canine body composition and hematological and biochemical indices. METHODS: Twenty-eight privately-owned domestic Siberian Huskies (13 females; 4 intact, and 15 males; 6 intact) with a mean age of 5.3 ± 2.8 y (± SD) were randomly assigned to 1 of 4 dietary treatments (n = 7/treatment), with equal micronutrient supplementation and increasing whole pulse ingredient inclusion (0%, 15%, 30%, and 45%) with pea starch used to balance protein and energy. RESULTS: After 20 wks of feeding, there were no differences (P > 0.05) in echocardiographic parameters, N-terminal pro-B-type natriuretic peptide, and cTnI concentrations among treatments or across time within treatment (P > 0.05), indicating no differences in cardiac function among treatments. Concentrations of cTnI remained below the safe upper limit of 0.2 ng/mL for all dogs. Plasma SAA status, body composition, and hematological and biochemical indices were similar among treatments and over time (P > 0.05). CONCLUSIONS: The results from this study suggest that increasing the inclusion of pulses up to 45% with the removal of grains and equal micronutrient supplementation does not impact cardiac function concurrent with dilated cardiomyopathy, body composition, or SAA status and is safe for healthy adult dogs to consume when fed for 20 wks.