Effects of Different Processed Diets on Growth Performance, Blood Parameters, Hair Quality and Fecal Microbiota in Ragdoll Cats.

In recent years, there has been ongoing debate about the dietary choices for pet cats, particularly regarding three options: extruded dry food, cooked meat, and raw meat. Determining which diet is most suitable for a cat's healthy growth still requires substantial empirical support. Our study aimed to evaluate the effects of feeding Ragdoll cats (n = 5/group) extruded dry food (ED), cooked meat (CM), and raw meat (RM) on their growth performance, apparent digestibility, fur condition, blood parameters, fecal scores, and gut microbiota composition. However, our results indicate that different types of diets did not significantly affect the daily weight gain of Ragdoll cats. The CM group showed a significant improvement in the digestibility of dry matter, fat and protein compared to the ED group (p < 0.05) but no improvement in that of fat compared to the RM group. Compared to the ED group, both the CM and RM groups showed significant improvements in fur condition while exhibiting a significant decrease in fecal scores (p < 0.05). The CM and RM groups exhibited enhanced serum antioxidant capacity (p < 0.05) and increased immunity in the cats (p < 0.05). Immunity enhancement in the CM group was significantly higher than that in the RM group(p < 0.05). The ED group showed an increase in the abundance of beneficial bacteria in Ragdoll cat intestines, while the CM and RM groups showed enhancements in the innate microbiota of feline animals. These data, to some extent, suggest that CM is the most suitable diet for Ragdoll cats, but further research on intestine microbiota is still needed. These study findings provide a reference for purebred pet breeding purposes.

Duckweed protein as an alternative plant-based protein source for dog and cat dry diets.

Duckweed has attracted increasing attention as a high-quality and sustainable novel plant-based protein source. However, little research has been conducted in dogs and cats. We evaluated the effects of inclusion of duckweed protein (Lemna; MCSelect; Parabel; Vero Beach, FL) primarily in replacement of pea protein in dog diets at 0%, 5%, and 10% and cat diets at %, 10%, and 15% on stool quality, nutrient digestibility, and palatability. We hypothesized that duckweed protein would be a viable protein source in both dog and cat diets by showing no detriment to nutritional outcomes. All feeding tests were conducted at an independent research facility (Susquehanna, PA). A standard 2-bowl palatability test over a 2-d period was conducted with adult animals (n = 30 each) to determine intake ratio between test diets (duckweed-containing diets) and control diets (0% duckweed protein). Apparent total tract nutrient digestibility was conducted with 18 adult dogs and 21 adult cats (n = 6 to 7 per diet) with 5 d of diet acclimation followed by 5 d of total fecal collection. Stool quality was evaluated on a 1 to 5 scale where 1 = non-formed or diarrhea and 5 = hard, formed. Palatability data were analyzed using paired t-test (daily consumption) and chi-square test (first choice). All other data were analyzed by ANOVA and contrast (SAS version 9.4). For cats, 10% duckweed had greater (P < 0.05) palatability than control, while no difference was observed between 15% duckweed protein and control. For dogs, 5% and 10% duckweed protein had (P < 0.05) lower palatability, demonstrating a preference to control. Both cats and dogs fed duckweed diets had acceptable stool quality (Mean = 3.4 and 3.3, respectively). No detriments in nutrient digestibility were observed in dogs fed 5% and 10% duckweed protein; however, cats fed 10% and 15% duckweed protein had (P < 0.05) lower dry matter, protein, and energy digestibility vs. control. In conclusion, the data collected indicate that duckweed can be a viable replacement for other plant-based proteins in dog diets at inclusion levels up to 10%; more development is needed for duckweed protein inclusion into cat diets.

Duckweed, an aquatic plant rich in protein, holds promise as a sustainable plant-based protein for companion animals. However, the potential of duckweed protein in dog and cat diets has been relatively unexplored. In our study, we assessed the viability of incorporating duckweed protein into dog and cat diets by examining nutrient digestibility, stool consistency, and diet palatability. Our findings indicate that including duckweed protein in dog diets maintains acceptable nutrient digestibility and improves stool quality, although it may impact diet palatability. For cats, duckweed protein inclusion led to reduced nutrient digestibility, looser stool, and lower diet palatability. While duckweed protein shows potential as a suitable plant-based protein source for dogs, further development is necessary before considering it for cat diets.

Effects of a Veterinary Gastrointestinal Diet on Fecal Characteristics, Metabolites, and Microbiota Concentrations of Adult Cats Treated with Metronidazole.

Antibiotics are used to treat gastrointestinal diseases or infections, but are known to negatively affect stool quality and gut microbiota in cats and dogs. Therefore, identifying dietary strategies that may aid in antibiotic recovery is of interest. The objective of this study was to determine how a veterinary gastrointestinal diet affected the fecal characteristics, metabolite and bile acid (BA) concentrations, and microbiota of cats recovering from metronidazole administration. Twenty-four healthy adult cats were used in an 8-wk completely randomized design study. During a 2-wk baseline, all cats consumed a leading grocery brand diet (GBD). Over the next 2 wk, cats consumed GBD and received metronidazole (20 mg/kg BW twice daily). At wk 4, cats were randomly allotted to one of two treatments [GBD; BLUE Natural Veterinary Diet GI Gastrointestinal Support (BB)] and fed for 4 wk. Fecal scores were recorded daily and fresh fecal samples were collected at wk 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter (DM) %, metabolites, and microbiota. Microbiota were analyzed by 16S rRNA gene sequencing and qPCR, which was used to calculate dysbiosis index. Data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, testing for effects of diet, time and diet*time. Metronidazole had dramatic effects on all outcomes, including increased fecal scores (looser stools), reduced fecal pH and DM%, reduced fecal short-chain fatty acid, branched-chain fatty acid, ammonia, phenol, and indole concentrations, and altered fecal BA concentrations (increased primary BA; reduced secondary BA). Metronidazole reduced fecal bacterial alpha diversity, increased dysbiosis index, and altered the relative abundance of 78 bacterial genera. Fecal outcomes partially recovered over the next 4 wk, with some being impacted by diet. Fecal acetate concentrations were higher after metronidazole in cats fed BB. Dysbiosis index and alpha diversity measures slowly recovered over 4 wk, without diet differences. Recovery of 16 bacterial genera were impacted by diet. Fecal BA profiles demonstrated a prolonged impairment of primary to secondary BA conversion, with cholic acid being lower after metronidazole in cats fed BB. In conclusion, our data demonstrate that metronidazole is a powerful antibiotic that has long-lasting effects on the fecal microbiota and metabolites of cats. Outcome variables slowly recovered over time, but a gastrointestinal diet may aid in recovery.

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.

Reporting perceived capability, motivations, and barriers to reducing treat feeding amongst dog and cat caregivers.

Obesity remains a significant concern for dogs and cats, and reducing or eliminating treats is commonly recommended as a strategy for weight management. Caregivers can struggle with adherence to such dietary recommendations. Previous research suggests caregivers are reluctant to reduce treats but there is limited understanding of the underlying factors contributing to these behaviours and decisions. The objective of this study was to explore caregivers' motivations and barriers to reducing treat feeding, and their reported capability to do so. An online questionnaire including multiple choice and Likert scale questions was disseminated to dog and cat caregivers (n=1053) primarily from Canada and the USA from September to November 2021. Caregivers commonly expressed a wide range of motivations to reduce treat feeding with their pet, though barriers to reducing treat feeding were less defined. Changing their pet's routine was a reported barrier by more than 30% of respondents and was predictive of caregivers finding reducing treat giving to be difficult (OR=1.67, p=0.017). Results from multivariable logistic regression also revealed that caregivers who consider their companion animal to be obese as more likely to perceive reducing treats to be difficult. The results highlight the role of treats in the relationship and routine of caregivers' and their pets, and the importance of considering the individualised needs and circumstance of the caregiver and pet in veterinary discussions surrounding reducing treat feeding. Identifying these perspectives can improve self-efficacy with veterinary nutrition recommendations surrounding treats.

Website Investigation of Pet Weight Management-Related Information and Services Offered by Ontario Veterinary Practices.

Pet owners rely on information and advice from their veterinary practice to effectively manage their pet's weight. This study investigated weight management information and services displayed on practice websites in Ontario, Canada. Information collected from the websites of 50 randomly selected small and mixed-animal practices included practice and staff demographics and the type of weight management services, products, and information advertised or displayed. The most frequently advertised weight management service and product were nutritional counselling (34%) and therapeutic diets (25%), respectively. Current bodyweight measurement was advertised on just over half of the websites (54%), while physical therapy counselling was the least-advertised service (16%). Further statistical analyses were performed in an exploratory fashion to determine areas for future research. Binary logistic regression analyses were used to investigate the association between practice demographics and the type of weight management information advertised online. A maximum of two predictor variables were included in each regression model. Exploratory analyses indicated that when controlling for the number of veterinarians in each practice, having a higher number of veterinary technicians was associated with increased odds of a practice website advertising current bodyweight measurement by 80.1% (odds ratio (OR) = 1.80, p = 0.05). Additionally, when controlling the number of veterinary technicians, having a higher number of veterinarians was associated with increased odds of a practice website advertising sales of therapeutic diets by 119.0% (OR = 2.19, p = 0.04). When using corporate practices as reference, independently owned practices had decreased odds of advertising sales of treats and weight management accessories on their practice websites by 78.7% (OR = 0.21, p = 0.03). These preliminary results suggest that advertising weight management information is not prioritized on veterinary practice websites in Ontario, especially those with lower staff numbers. The findings of this study raise awareness on the current state of weight management promotion for pets on veterinary practice websites and highlight ways to improve upon a practice's online presence.

Effects of weight loss and feeding specially formulated diets on the body composition, blood metabolite profiles, voluntary physical activity, and fecal metabolites and microbiota of overweight cats.

Feline obesity is a common and preventable disease, posing a myriad of health risks and detriments. Specially formulated diets and restricted feeding may serve as an intervention strategy to promote weight loss and improve feline health. In this study, our objective was to determine the effects of restricted feeding and weight loss on body composition, voluntary physical activity, blood hormones and metabolites, and fecal microbiota of overweight cats. Twenty-two overweight adult spayed female and neutered male cats [body weight (BW) = 5.70 ± 1.0 kg; body condition score (BCS) = 7.68 ± 0.6; age = 4 ± 0.4 yr] were used in a weight loss study. A control diet (OR) was fed during a 4-wk baseline to identify intake needed to maintain BW. After baseline (week 0), cats were allotted to OR or a test diet (FT) and fed to lose ~1.0% BW/wk for 24 wk. At baseline and 6, 12, 18, and 24 wk after weight loss, dual-energy x-ray absorptiometry scans were performed and blood samples were collected. Voluntary physical activity was measured at weeks 0, 8, 16, and 24. Fecal samples were collected at weeks 0, 4, 8, 12, 16, 20, and 24. Change from baseline data were analyzed statistically using the Mixed Models procedure of SAS, with P < 0.05 considered significant. Restricted feeding of both diets led to weight and fat mass loss, lower BCS, and lower blood triglyceride and leptin concentrations. Cats fed the FT diet had a greater reduction in blood triglycerides and cholesterol than cats fed the OR diet. Restricted feeding and weight loss reduced fecal short-chain fatty acid, branched-chain fatty acid, phenol, and indole concentrations. Fecal valerate concentrations were affected by diet, with cats fed the OR diet having a greater reduction than those fed the FT diet. Fecal bacterial alpha diversity was not affected, but fecal bacterial beta diversity analysis showed clustering by diet. Restricted feeding and weight loss affected relative abundances of 7 fecal bacterial genera, while dietary intervention affected change from baseline relative abundances of 2 fecal bacterial phyla and 20 fecal bacterial genera. Our data demonstrate that restricted feeding promoted controlled and safe weight and fat loss, reduced blood lipids and leptin concentrations, and shifted fecal metabolites and microbiota. Some changes were also impacted by diet, highlighting the importance of ingredient and nutrient composition in weight loss diets.

The objective of this study was to determine the effects of diet, restricted feeding and weight loss on body composition, voluntary physical activity, blood hormones and metabolites, and fecal metabolites and microbiota of overweight cats. Overweight cats were allotted to a control diet (OR) or weight loss diet (FT) and fed to lose ~1.0% body weight/week for 24 wk. Body weight, body composition, and voluntary physical activity were measured, while fecal and blood samples were collected over time. Restricted feeding led to weight and fat mass loss, and lower blood triglyceride and leptin concentrations. Cats fed FT had a greater reduction in blood triglycerides and cholesterol than cats fed OR. Restricted feeding reduced fecal metabolite concentrations and affected relative abundances of 7 fecal bacterial genera. Fecal bacterial beta diversity analysis showed clustering by diet. Dietary intervention affected change from baseline relative abundances of 2 fecal bacterial phyla and 20 fecal bacterial genera. Our data demonstrate that restricted feeding promoted controlled and safe weight and fat loss, reduced blood lipids and leptin concentrations, and shifted fecal metabolites and microbiota. Some dietary differences were noted, highlighting the importance of ingredient and nutrient composition in weight loss diets.

Effects of overfeeding on the digestive efficiency, voluntary physical activity levels, and fecal characteristics and microbiota of adult cats.

The incidence of feline obesity continues to rise despite it being a preventable disease. There are many risks and health perturbations associated with obesity, with several of those impacting a pet's quality of life, wellness, and longevity. Feline obesity is commonly studied, but most research has been focused on weight loss rather than weight gain. To our knowledge, feline studies have not examined the implications of overfeeding and weight gain on gastrointestinal transit time (GTT) nor the association it has with the fecal microbiota. Therefore, the objective of this study was to determine the effects of overfeeding and weight gain on apparent total tract digestibility (ATTD), GTT, blood hormones, serum metabolites, hematology, fecal microbiota populations, and voluntary physical activity of cats. Eleven lean adult spayed female cats [body weight (BW) = 4.11 ±â€…0.43 kg; body condition score = 5.41 ±â€…0.3; age = 5.22 ±â€…0.03 y] were used in a longitudinal weight gain study. After a 2-wk baseline phase, cats were allowed to overeat for 18 wk. A commercially available complete and balanced diet was fed during the baseline phase to identify the intake needed to maintain BW. Cats were then fed the same diet ad libitum to induce weight gain. Fecal samples, blood samples, and voluntary physical activity data were collected at baseline (week 0) and 6, 12, and 18 wk after weight gain. Fecal samples were collected for microbiota analysis, determination of ATTD, and GTT measurement while blood samples were collected for serum chemistry, hematology, and insulin and leptin measurements. Microbiota data were evaluated using QIIME2. All other measures were evaluated statistically using the mixed models procedure of SAS using repeated measures analysis, with time effects being the focus. A P < 0.05 was considered significant. The ATTD of dry matter (P = 0.0061), organic matter (P = 0.0130), crude protein (P < 0.0001), fat (P = 0.0002), and gross energy (P = 0.0002), and GTT (P = 0.0418) decreased with overfeeding and weight gain. Fecal bacterial alpha diversity measures were unchanged, but fecal bacterial beta diversity was impacted (P < 0.05) with overfeeding and weight gain. The relative abundances of 16 bacterial genera, including Bifidobacterium, Collinsella, Erysipelatoclostridium were affected (P < 0.05) by overfeeding and weight gain. In conclusion, overfeeding and subsequent weight gain reduced ATTD, reduced GTT, and caused changes to the fecal microbial community of adult cats.

Feline obesity continues to rise, impacting the wellness, quality of life, and longevity of cats. Understanding the metabolic and gastrointestinal changes that companion animals face with the onset of weight gain and obesity may help with future prevention and treatment plans. The implications of overfeeding and weight gain on gastrointestinal transit time (GTT) and its association with fecal microbiota populations have not been studied. Therefore, the objective of this study was to determine the effects of overfeeding and weight gain on apparent total tract digestibility, GTT, blood hormones, serum metabolites, hematology, fecal microbiota populations, and voluntary physical activity of cats. After a 2-week baseline phase, adult cats were allowed to overeat for 18 weeks. Fecal and blood samples were collected, and voluntary physical activity was measured using accelerometers over time. Dry matter, organic matter, protein, fat, and energy digestibilities and GTT were decreased with overfeeding and weight gain. Fecal bacterial beta diversity was impacted by overfeeding and weight gain, impacting the relative abundances of 1 bacterial phylum and 16 bacterial genera. In conclusion, overfeeding and subsequent weight gain reduced nutrient digestibility, reduced GTT and caused changes to the fecal microbial community of adult cats.

Dietary choline, but not L-carnitine, increases circulating lipid and lipoprotein concentrations, without affecting body composition, energy expenditure or respiratory quotient in lean and obese male cats during weight maintenance.

Introduction: Due to the involvement in one-carbon metabolism and lipid mobilization, choline and L-carnitine supplementation have been recommended to minimize hepatic lipid accumulation and support fat oxidation, respectively. This study investigated the lipotropic benefits of choline or L-carnitine supplementation in lean and obese cats maintaining body weight (BW). Methods: Lean [n = 9; body condition score (BCS): 4-5/9] and obese (n = 9; BCS: 8-9/9) adult male neutered colony cats were used in a replicated 3 x 3 complete Latin square design. Treatments included choline (378 mg/kg BW0.67), L-carnitine (200 mg/kg BW) and control (no supplement). Treatments were supplemented to the food for 6 weeks each, with a 2-week washout between treatments. Cats were fed once daily to maintenance energy requirements, and BW and BCS were assessed weekly. Fasted blood collection, indirect calorimetry, and dual-energy X-ray absorptiometry occurred at the end of each treatment period. Serum was analyzed for cholesterol (CHOL), high-density lipoprotein CHOL (HDL-C), triglycerides (TAG), non-esterified fatty acids (NEFA), glucose, creatinine (CREAT), urea, alkaline phosphatase (ALP) and alanine aminotransferase (ALT). Very low-density lipoprotein CHOL (VLDL) and low-density lipoprotein CHOL (LDL-C) were calculated. Data were analyzed using proc GLIMMIX, with group and period as random effects, and treatment, body condition, and their interaction as fixed effects, followed by a Tukey's post-hoc test when significance occurred. Results: Cats supplemented choline had lower food intake (P = 0.025). Treatment did not change BW, BCS and body composition (P > 0.05). Obese cats had greater ALP, TAG, and VLDL, and lower HDL-C compared to lean cats (P < 0.05). Choline resulted in greater CHOL, HDL-C, LDL-C and ALT (P < 0.05). L-carnitine resulted in lower CREAT (P = 0.010). Following the post-hoc test, differences between treatment means were not present for ALP (P = 0.042). No differences were found for glucose, urea or NEFA (P > 0.05). Obese cats had a lower fed respiratory quotient (RQ), regardless of treatment (P = 0.045). Treatment did not affect fed or fasted RQ and energy expenditure (P > 0.05). Discussion: Choline appeared to increase circulating lipid and lipoprotein concentrations regardless of body condition, likely through enhanced lipid mobilization and hepatic elimination. Neither dietary choline or L-carnitine altered body composition or energy metabolism in the lean or obese cats, as compared to control.

Comparing the standardized amino acid digestibility of an alternative protein source with commercially available protein-based ingredients using the precision-fed cecectomized rooster assay.

Using single-cell-based proteins in pet foods is of interest, but little testing has been done. Therefore, our objective was to determine the amino acid (AA) digestibilities, assess protein quality of a novel microbial protein (MP) (FeedKind), and compare it with other protein-based ingredients using the precision-fed cecectomized rooster assay. Test ingredients included: MP, chicken meal (CM), corn gluten meal (CGM), pea protein (PP), and black soldier fly larvae. Thirty cecectomized roosters (n = 6/ingredient) were randomly assigned to test ingredients. After 24 h of feed withdrawal, roosters were tube-fed 15 g test ingredient and 15 g corn, and then excreta were collected for 48 h. Endogenous AA corrections were made using additional roosters. Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality according to Association of American Feed Control Officials (AAFCO), The European Pet Food Industry Federation, and National Research Council reference values for growing and adult dogs and cats. Data were analyzed using the Mixed Models procedure of SAS 9.4, with P ≤ 0.05 being significant. All reactive lysine:total lysine ratios, an indicator of heat damage, were higher than 0.9, except for CM (0.86). Digestibility of indispensable and dispensable AA were >85% and >80% for MP, respectively, with indispensable AA digestibilities being >80% for all other ingredients. In general, CGM had the highest, while CM had the lowest AA digestibilities. Two exceptions were lysine and tryptophan. Lysine digestibility for MP was higher than that of all other ingredients, while tryptophan digestibility for MP was higher than that of CM, CGM, and PP. Threonine digestibility was highest for CGM and MP. Valine digestibility was highest for CGM, PP, and MP. DIAAS-like calculations identified limiting AA of each ingredient and depended on the reference used and life stage and species of animal. Using AAFCO guidelines, all DIAAS-like values for MP were >100 suggesting that it could be used as the sole source of protein in adult dog and cat diets; only methionine had DIAAS-like values <100 for growing kittens. For dogs, limiting AA was most commonly methionine, threonine, and tryptophan in the other protein sources. For cats, limiting AA was most commonly lysine and methionine. Lysine was severely limited in CGM across all life stages considered. Further research in dogs and cats is necessary, but our data suggest that the MP tested has high AA digestibilities and is a high-quality protein source that may be useful in pet foods.

Single-cell-based proteins are of interest for use in pet foods, but little testing has been done. The objective of this experiment was to compare the amino acid (AA) digestibilities and protein quality of a novel microbial protein (MP) (FeedKind) with chicken meal (CM), corn gluten meal (CGM), pea protein (PP), and black soldier fly larvae ingredients using the precision-fed cecectomized rooster assay. Cecectomized roosters were tube-fed the test ingredients and excreta were collected. All reactive lysine:total lysine ratios, an indicator of heat damage, were higher than 0.9, except for CM. Digestibility of indispensable and dispensable AA were >85% and >80% for MP, respectively, with indispensable AA digestibilities being >80% for all other ingredients. In general, CGM had the highest, while CM had the lowest AA digestibilities. Lysine and tryptophan were exceptions, being highest for MP. Threonine and valine digestibilities were also high for MP. Digestible indispensable AA score-like values identified limiting AA of each ingredient. Limiting AA was most commonly methionine, threonine, and tryptophan for dogs and lysine and methionine for cats. Our data suggest that the MP tested has high AA digestibilities and is a high-quality protein source that may be useful in pet foods.

Amino acid digestibility and protein quality of mealworm-based ingredients using the precision-fed cecectomized rooster assay.

Mealworms may serve as an alternative protein source for pet foods because of their high protein content and low environmental footprint. The amino acid (AA) content and protein quality of mealworm-based ingredients may vary depending on their composition and processing, however, so testing is required. Our objective was to measure the AA composition, AA digestibility, and protein quality of mealworm-based ingredients using the precision-fed cecectomized rooster assay. The University of Illinois Institutional Animal Care and Use Committee approved all animal procedures prior to experimentation. Sixteen cecectomized roosters (4 roosters per substrate) were randomly allotted to one of four test substrates: 1) whole lesser mealworm (A. diaperinus) meal (ADw); 2) defatted lesser mealworm (A. diaperinus) meal (ADd); 3) defatted yellow mealworm (T. molitor) meal (TMd); and 4) hydrolyzed T. molitor protein meal (TMh). Ingredients were provided by Ynsect, France. After 26 h of feed withdrawal, roosters were tube-fed test substrates. Following crop intubation, excreta samples were collected for 48 h. Endogenous loss corrections for AA were made by using five additional cecectomized roosters. All data were analyzed using SAS version 9.4. All substrates had high AA digestibilities, with all indispensable AA digestibilities being >90% with the exception of histidine (87.9% to 91.1%) and valine (77.9% to 79.7%). Amino acid digestibilities were not different among substrates (P > 0.05). Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality according to Association of American Feed Control Officials (AAFCO) nutrient profiles, The European Pet Food Industry Nutritional Guidelines (FEDIAF) nutritional guidelines, National Research Council (NRC) recommended allowances for adult dogs, adult cats, growing puppies, and growing kittens, and NRC minimal requirements for growing puppies and growing kittens. In general, TMh had the highest and TMd had the lowest DIAAS-like values for most indispensable AA. Methionine (TMh; TMd; ADw) and phenylalanine (ADd) were the first-limiting AA. Our results demonstrate that mealworm-based ingredients are high-quality protein sources. Further research in dogs and cats is necessary to confirm sufficient palatability and digestibility, but these data suggest that they are valuable sources of protein for pet foods.

Mealworms may serve as an alternative protein source for pet foods because of their high protein content and low environmental footprint. The amino acid (AA) content and protein quality of mealworm-based ingredients may vary depending on their composition and processing, however, so testing is required. Our objective was to measure the AA composition, AA digestibility, and protein quality of the following ingredients using the precision-fed cecectomized rooster assay: 1) defatted yellow mealworm (Tenebrio molitor) flour (TMd); 2) hydrolyzed T. molitor proteins (TMh); 3) whole lesser mealworm (Alphitobius diaperinus) flour (ADw); and 4) defatted lesser mealworm (A. diaperinus) flour (ADd). All ingredients had high AA digestibilities, with all indispensable AA digestibilities being >90% with the exception of histidine and valine. Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality for adult dogs, adult cats, growing puppies, and growing kittens. In general, TMh had the highest and TMd had the lowest DIAAS-like values for most indispensable AA. Methionine (TMh; TMd; ADw) and phenylalanine (ADd) were the first-limiting AA. Our results demonstrate that mealworm-based ingredients are high-quality protein sources. Dog and cat research is necessary, but these data suggest that they are valuable sources of protein for pet foods.

Circulating direct infusion MS and NMR metabolomic profiles of post-gonadectomy kittens with or without additional dietary choline supplementation.

Choline is beneficial for energy metabolism and growth in various species. Choline may work similarly in kittens at risk of obesity. Direct infusion MS (Di-MS) and NMR spectroscopy were used to investigate the metabolomic signatures of kittens supplemented with or without additional dietary choline for 12 weeks. Fifteen intact male kittens consumed a base diet (3310 mg choline/kg DM) to their daily metabolisable energy requirement (DER) over an 11-week acclimation. Kittens were gonadectomised and assigned, based on body weight, to the base diet (CONTROL, n 7) or the base diet with 300 mg/kgBW0·75 additional choline as choline chloride (CHOLINE, n 8) and offered three times their individual energy requirement divided into three meals. At weeks -1 and 12, fasted blood was sampled and serum analysed for 130 metabolites via Di-MS and fifty-one metabolites via NMR spectroscopy. Changes in fasted metabolites were assessed using a repeated-measures GLIMMIX procedure with time and group as fixed effects, and time as a repeated measure. Metabolites of one-carbon metabolism and lipids increased, and medium-chain acyl carnitines decreased from week -1 to 12 for CHOLINE (P < 0·05), but not CONTROL (P > 0·05). Increases in amino acid, biogenic amine and organic compound concentrations were observed in both groups (P < 0·05). The results suggest impacts of dietary choline at greater intakes than currently recommended on one-carbon metabolism and fatty acid oxidation, and these may promote healthy growth in post-gonadectomy kittens.

Dietary enrichment of resistant starches or fibers differentially alter the feline fecal microbiome and metabolite profile.

BACKGROUND: Cats are strict carnivores but possess a complex gastrointestinal (GI) microbial community that actively ferments dietary substrates that are not digested and reach the colon. The GI microbiota responses to dietary inclusion of resistant starches versus fibers have not been tested in cats. Thus, our objective was to evaluate the effects of diets enriched in resistant starch or fibers on the fecal characteristics, microbiome, and metabolite profiles of cats. Twelve healthy adult domestic shorthair cats (age = 9.6 ± 4.0 year; body weight = 3.9 ± 1.0 kg) were used in a replicated 3 × 3 Latin square design to test diets that were enriched with: (1) resistant starch (ERS), (2) a fiber-prebiotic-probiotic blend (FPPB), or (3) a fiber-prebiotic-probiotic blend + immune-modulating ingredients (iFPPB). In each 28-day period, 22 days of diet adaptation was followed by fecal and blood sample collection. Fecal samples were used for shotgun metagenomic sequencing. In addition, fecal and blood metabolite measurements and white blood cell stimulation was performed to assess immune function. RESULTS: A total of 1690 bacterial species were identified, with 259 species differing between fiber-rich and ERS treatments. In comparison with fiber-rich treatments that increased diversity and promoted Firmicutes and Bacteroidetes populations, resistant starch reduced microbial diversity and fecal pH, led to a bloom in Actinobacteria, and modified Kyoto Encyclopedia of Genes and Genomes orthology (KO) terms pertaining to starch and sucrose metabolism, fatty acid biosynthesis and metabolism, epithelial cell signaling, among others. Resistant starch also differentially modified fecal metabolite concentrations with relevance to GI and overall host health (increased butyrate; decreased propionate and protein catabolites - branched-chain fatty acids; phenols and indoles; ammonia) and reduced blood cholesterol, which correlated strongly with microbial taxa and KO terms, and allowed for a high predictive efficiency of diet groups by random forest analysis. CONCLUSION: Even though domestic cats and other carnivores evolved by eating low-carbohydrate diets rich in protein and fat, our results demonstrate that the feline microbiome and metabolite profiles are highly responsive to dietary change and in directions that are predictable.

Effect of Dietary Methylsulfonylmethane Supplementation on Growth Performance, Hair Quality, Fecal Microbiota, and Metabolome in Ragdoll Kittens.

Methylsulfonylmethane (MSM) is a natural sulfur-containing organic substance that has many biological functions, such as antioxidant, anti-inflammatory, skin nourishing, and hair growth-promoting effects. This study was conducted to determine the effect of MSM supplementation on growth performance, antioxidant capacity, and hair quality in kittens. A total of 21 Ragdoll kittens were assigned to three diets by initial body weight and gender: basal diet supplemented with 0%, 0.2%, and 0.4% MSM (CON, LMSM, and HMSM groups) for 65 days. During the whole period, the food intake of kittens in the MSM-treated groups tended to be higher (P < 0.10) compared with the CON group, and the average daily gain (ADG) had no significant difference when compared to the kittens in the CON group (P > 0.05). Antioxidant capacity had no significant difference (P > 0.05) among the groups. The scale thickness of hair tended to be smaller in the LMSM group compared to the CON group (P < 0.10) and decreased significantly (P < 0.05) over time from d 0 to d 65 in the LMSM group, indicating the improvement of hair quality. Besides, supplementation with LMSM increased bacterial diversity. Kittens fed MSM had no significant differences in fecal genus at the end of the study. No significant differences in fecal short-chain fatty acids were observed among groups. Fecal metabolomics analysis further revealed that MSM hardly affected the metabolites. Overall, dietary supplementation with 0.2% MSM can improve the hair quality of kittens. Furthermore, 0.2∼0.4% of MSM had no detrimental effects on serum biochemistry, growth performance, gut microbiota, and metabolome, which supports the safety inclusion of MSM to a certain degree in feline diets. To the best of our knowledge, this is the first study to investigate the effects of MSM supplementation in cats.

Dose-response relationship between dietary choline and serum lipid profile, energy expenditure, and respiratory quotient in overweight adult cats fed at maintenance energy requirements.

Choline is an essential nutrient linked to hepatic lipid metabolism in many animal species, including cats. The current study investigated the serum lipid profiles, serum liver enzymes, respiratory quotients, and energy expenditures of overweight cats fed maintenance diets, in response to graded doses of supplemental dietary choline. Overweight (body condition score [BCS]: ≥6/9) adult male neutered cats (n = 14) were supplemented with five choline chloride doses for 3-wk periods, in a 5 × 5 Latin square design. Doses were based on individual body weight (BW) and the daily recommended allowance (RA) for choline (63 mg/kg BW0.67) according to the National Research Council. Doses were control (no additional choline: 1.2 × RA, 77 mg/kg BW0.67), 2 × RA (126 mg/kg BW0.67), 4 × RA (252 mg/kg BW0.67), 6 × RA (378 mg/kg BW0.67), and 8 × RA (504 mg/kg BW0.67). Choline was top-dressed over the commercial extruded cat food (3,620 mg choline/kg diet), fed once a day at maintenance energy requirements (130 kcal/kgBW0.4). Body weight and BCS were assessed weekly. Fasted blood samples were taken and indirect calorimetry was performed at the end of each 3-wk period. Serum was analyzed for cholesterol, high-density lipoprotein cholesterol (HDL-C), triglycerides, non-esterified fatty acids, glucose, creatinine, blood urea nitrogen (BUN), alkaline phosphatase (ALP), and alanine aminotransferase. Very low-density lipoprotein cholesterol (VLDL) and low-density lipoprotein cholesterol were calculated. Data were analyzed via SAS using proc GLIMMIX, with group and period as the random effects, and treatment as the fixed effect. Statistical significance was considered at P < 0.05. Body weight and BCS did not change (P > 0.05). Serum cholesterol, HDL-C, triglycerides, and VLDL increased with 6 × RA (P < 0.05). Serum ALP decreased with 8 × RA (P = 0.004). Choline at 4 × and 6 × RA decreased serum BUN (P = 0.006). Fed or fasted respiratory quotient and energy expenditure did not differ among dietary choline doses (P > 0.05). These results suggest that dietary choline supplementation at 6 × RA may increase hepatic fat mobilization through increased lipoprotein transport and beneficially support hepatic health in overweight cats. Future studies that combine these results with existing knowledge of feline weight loss and hepatic lipidosis are warranted.

Choline is an essential nutrient important for lipid metabolism in the liver of many mammals. In the present study, fourteen overweight cats had their commercial extruded cat food top-dressed with different amounts of choline chloride supplement. The amounts of choline were based on the individual body weights and the published recommended allowance (RA) for dietary choline intake in adult cats. The choline treatments were control (no additional choline added, 1.2 × RA), 2 × RA, 4 × RA, 6 × RA, and 8 × RA. The cats were separated into five groups. Each group received the choline treatments once daily for 3 wk per treatment. Choline at 6 × RA increased serum cholesterol, triglycerides, and lipoproteins. There were no significant differences in respiratory quotient or energy expenditure with choline intake. The results of this study suggest that choline at 6 × RA increases the transport of lipids from the liver. This may be beneficial in supporting liver health in overweight cats. Future studies should investigate supplementing choline to cats undergoing weight loss and those at risk of developing fatty liver.

Effects of a high-protein, high-fiber diet rich in antioxidants and l-carnitine on body weight, body composition, metabolic status, and physical activity levels of cats after spay surgery.

Spay and neuter surgeries are useful in controlling pet populations, but increase obesity risk due to increased appetite, decreased metabolic rate, and decreased energy expenditure. Dietary management may help limit post-spay weight gain, but few research studies have been conducted in cats. Therefore, the objective of this study was to evaluate the effects of a high-protein, high-fiber diet (HPHF) compared to a moderate-protein, moderate-fiber diet (MPMF) in female cats following spay surgery. Twenty healthy female cats (9.5 ±â€…0.1 mo) were used. After a 4-wk baseline phase with cats fed MPMF to maintain body weight (BW), 16 cats were spayed and allotted to MPMF (n = 8) or HPHF (n = 8), with the remaining cats being sham-operated and fed MPMF (n = 4). Cats were fed to maintain BW for 12 wk and then allowed to eat up to twice that amount for another 12 wk. Daily food intake, twice weekly BW, and twice weekly body condition scores (BCS) were assessed. Back fat thickness (BF) using ultrasound, body composition using dual-energy X-ray absorptiometry (DEXA), feline body mass index (fBMI), body fat percentage estimates using zoometry measurements, serum metabolites, and voluntary physical activity levels were measured prior to spay (week 0) and every 6 wk post-spay. A treatment*time effect was observed for food intake (g/d), but not caloric intake (kcal ME/d). Caloric intake was affected by time and treatment, being reduced over the first 12 wk and reduced at higher amounts in HPHF and MPMF cats vs. sham cats. BW, BCS, and body fat percentage were affected over time. Treatment*time effects were observed for blood urea nitrogen, alkaline phosphatase, and fructosamine, whereas blood triglycerides, total cholesterol, creatinine, total protein, phosphorus, and bicarbonate were affected by time. Physical activity was reduced over time. Our results demonstrate that spay surgery affects food intake, BW, metabolism, and physical activity of cats. Dietary intervention in this study, however, led to minor changes.

Spay surgery helps control pet populations, but increases obesity due to increased appetite, decreased metabolic rate, and decreased energy expenditure. Our objective was to evaluate the effects of high-protein, high-fiber diet (HPHF), and moderate-protein, moderate-fiber diets (MPMF) in female cats following spay surgery. Of the 20 cats used, 16 were spayed and fed MPMF (n = 8) or HPHF (n = 8) and four were sham-operated and fed MPMF. Cats were fed to maintain body weight (BW) for 12 wk and then allowed to overeat for 12 wk. Food intake, BW, body condition scores (BCS), back fat thickness, body composition, feline body mass index, body fat percentage estimates, serum metabolites, and physical activity levels were measured. Over the first 12 wk, caloric intake was reduced at higher amounts in spayed versus sham cats. BW, BCS, body fat percentage, and physical activity levels were altered over time. Our results demonstrate that the diets tested had minor effects, but spaying affected cat food intake, BW, metabolism, and physical activity.

Palatability and apparent total tract macronutrient digestibility of retorted black soldier fly larvae-containing diets and their effects on the fecal characteristics of cats consuming them.

There is a growing interest in using black soldier fly larvae (BSFL) due to its supposed sustainability and nutritional qualities. Because little research has been conducted to evaluate the use of BSFL in cats, our objective was to determine the palatability and apparent total tract macronutrient digestibility (ATTD) of BSFL-containing canned diets and the fecal characteristics of healthy adult cats consuming them. First, three palatability tests were conducted to compare the following diets: 1) diet with poultry byproduct meal (PBPM) and chicken serving as the primary protein sources (control) vs. diet with BSFL meal replacing PBPM (BSFL meal); 2) control vs. diet with whole BSFL replacing some PBPM and poultry fat (BSFL whole); and 3) control vs. diet with BSFL oil replacing poultry fat (BSFL oil). All diets were formulated to meet Association of American Feed Control Officials nutrient profiles for adult cats and were produced using a still retort. A paired t-test was conducted to analyze data from each palatability test, with a higher (P < 0.05) consumption ratio being observed for BSFL meal (1.93:1), BSFL whole (2.03:1), and BSFL oil (1.57:1). Second, 32 adult cats (20 females and 12 males; BW: 4.19 ± 0.55 kg; age: 3.3 ± 0.38 yr) were used in a completely randomized design study composed of a 21-d baseline period and a 70-d experimental period. Cats consumed the control diet during the baseline and were then allotted to one of four experimental diets (n = 8 per group): 1) control, 2) BSFL meal, 3) whole BSFL, and 4) BSFL oil. Fecal samples were collected after baseline and experimental periods for ATTD and fecal characteristic analysis. Fecal output was higher (P < 0.05) and fecal dry matter percentage was lower (P < 0.05) in cats fed BSFL meal than those fed BSFL oil. Organic matter, crude protein (CP), and energy ATTD were lower (P < 0.05) in cats fed BSFL meal than those fed BSFL oil or control. CP and energy ATTD were lower (P < 0.05) in cats fed BSFL whole than those fed BSFL oil. A few serum metabolites were affected by diet (P < 0.05) but remained within reference ranges. Hematology was not affected by diet (P > 0.05). Overall, our results suggest that BSFL-containing diets are palatable and do not negatively affect fecal characteristics or serum chemistry but may have slightly lower nutrient digestibilities in adult cats.

The pet food industry is interested in black soldier fly larvae (BSFL) because of its supposed sustainability and nutritional qualities. BSFL has not been well tested in cats, so our objective was to determine the palatability and apparent total tract macronutrient digestibility (ATTD) of BSFL-containing canned diets and how they affected the fecal characteristics of adult cats. Palatability tests were conducted to compare diets containing BSFL meal, whole BSFL, or BSFL oil against a poultry-based control. Higher consumption ratios were observed for all BSFL-containing diets. A second study determined the digestibility of BSFL-containing diets and how they affected fecal characteristics. Cats were allotted to a control diet or diets containing BSFL meal, whole BSFL, or BSFL oil. Fecal output was higher and fecal dry matter percentage was lower in cats fed BSFL meal than those fed BSFL oil. Organic matter, crude protein (CP), and energy ATTD were lower in cats fed BSFL meal than those fed BSFL oil or control. CP and energy ATTD were lower in cats fed whole BSFL than those fed BSFL oil. Overall, BSFL-containing diets were shown to be palatable and did not negatively affect fecal characteristics, but reduced nutrient digestibilities in adult cats.

Case Report: A Case Series Linked to Vitamin D Excess in Pet Food: Cholecalciferol (Vitamin D3) Toxicity Observed in Five Cats.

Cholecalciferol (vitamin D3) toxicity caused by defective pet food formulations is a rare occurrence described in cats. Nevertheless, it poses a health risk, even though the affected pet food is not fed as the sole diet. Excessive vitamin D3 intake might cause hypercalcemia and soft tissue mineralization, which are findings that prompt clinicians to further investigate the feasible etiology. This case series describes the effects of an extremely high vitamin D3 intake in five young cats caused by the consumption of a fish-based complementary kitten pet food (KPF) that was fed to all of the cats as part of their diet (cases 1, 2, and 3) or eaten exclusively (cases 4 and 5). Due to the different amounts of vitamin D3 consumed, diagnostic examinations showed different degrees of severity of hypercalcemia and azotemia as well as different radiographic findings in cases where diagnostic imaging was performed (cases 2, 4, and 5). All of the cats were treated by withdrawing the affected food and providing medical management of the hypercalcemia. All of the cats recovered, except for two persistent azotemic cats, which developed chronic kidney disease. The goal of this case series is, therefore, to describe the occurrence and resolution of an acute vitamin D3 toxicity due to the highest amount of dietary vitamin D3 intake that has ever been described in domestic cats.

A Comparison of Key Essential Nutrients in Commercial Plant-Based Pet Foods Sold in Canada to American and European Canine and Feline Dietary Recommendations.

Plant-based foods intended for feeding dogs and cats are available in Canada, though few studies have examined the suitability of plant-based foods for dogs and cats. All commercial plant-based extruded and wet pet food products available in Ontario, Canada, in 2018 (n = 26) were acquired and analysed for energy, crude protein, crude fat, crude fibre, ash, amino acids, fatty acids, minerals and vitamins A, B12, D2 and D3. Results were compared with recommendations of the Association of American Feed Control Officials (AAFCO) and the European Pet Food Industry Federation (FEDIAF). Thirteen products were labelled for adult canine maintenance, four for canine all life stages, one for puppy growth, two for adult feline maintenance, three for feline all life stages, one for adult maintenance of dogs and cats and two for all life stages of dogs and cats. Four products met AAFCO and one product met FEDIAF nutrient recommendations for canine maintenance. No diets met AAFCO or FEDIAF recommendations for feline maintenance or growth for either species. Nutrients most commonly found insufficient were: sulfur amino acids, taurine, arachidonic acid, EPA and DHA, calcium phosphorus and vitamin D. There were no nutrients unable to be provided from non-animal sources. Compliance with labelling guidelines was also poor, similar to other findings with commercial animal-based pet products. The results from this study indicate areas where producers of plant-based pet foods must improve to meet the industry recommended nutrient profiles and labelling requirements.

Amino acid digestibility and digestible indispensable amino acid score-like values of black soldier fly larvae fed different forms and concentrations of calcium using the precision-fed cecectomized rooster assay.

Black soldier fly larvae (BSFL) are an alternative protein source for animals, including dogs and cats. Dietary calcium source is an essential nutrient for BSFL development in the pupal stage. Calcium carbonate (CaCO3) and calcium chloride (CaCl2) are common calcium sources but differ in solubility, acid-binding capacity, and calcium concentration. A high calcium concentration in BSFL may affect how well nitrogen and amino acids (AA) are digested by animals consuming them, thereby affecting feed conversion efficiency. Our objective was to determine the effects of dietary calcium form and concentration on nutrient composition, AA digestibility, and digestible indispensable amino acid score (DIAAS)-like values of BSFL intended for use in animal feeds using the precision-fed cecectomized rooster assay. All BSFL tested in this study were harvested at 18 d after hatch. Industry standard rearing conditions were maintained and a commercial layer ration was fed to all BSFL until 11 d post-hatch. From day 11 to 18, BSFL were fed a combination of distiller's dried grains with solubles from a distillery, bakery byproduct meal, and varied calcium sources. All BSFL diets contained 0.2% calcium in the basal diet plus additional calcium in the following amounts and forms: BSFLA: 1.2% CaCl2, BSFLB: 1.2% CaCO3, BSFLC: 0.75% CaCO3, and BSFLD: 0.6% CaCO3 + 0.6% CaCl2. On day 18, BSFL were washed and frozen. Prior to the rooster assay, BSFL were lyophilized and ground. In total, 16 cecectomized roosters (4 roosters per substrate) were randomly assigned to test substrates. After 24 h of feed withdrawal, roosters were tube-fed 20 g of test substrates. Following crop intubation, excreta were collected for 48 h. Endogenous corrections for AA were made using five additional cecectomized roosters. All data were analyzed using a completely randomized design and the GLM procedure of SAS 9.4. Nutrient and AA digestibilities were not different among substrates. DIAAS-like values were calculated to determine protein quality according to the Association of American Feed Control Officials nutrient profiles and National Research Council recommended allowances for dogs and cats. Although AA digestibilities did not differ, those containing CaCO3 generally had higher DIAAS-like reference values than the diet containing CaCl2 alone (BSFLA). Aromatic AA (Phe + Tyr) and sulfur AA (Met + Cys) were often first-limiting AA. Our results suggest that calcium sources fed to BSFL did not affect AA digestibility and protein quality.