Precision-fed Cecectomized Rooster Assay Research Articles

PSI-16 Evaluation of protein quality of defatted black soldier fly (Hermetia illucens) larvae meal compared with traditional protein sources for dogs and cats

Abstract There is increased interest in the use of insects, such as black soldier fly (Hermetia illucens) larvae meal (BSFLM), as an alternative protein source in pet foods. However, additional information is needed to determine how BSFL protein quality compares with traditional pet food protein sources. Thus, the objectives of this study were to determine the chemical composition, amino acid digestibility, and protein quality of defatted BSFLM in comparison with whole egg powder (WEP) and chicken meal (CM) using the precision-fed cecectomized rooster assay. Fifteen cecectomized roosters (n = 5 per substrate) were randomly allocated to the test substrates BSFLM, CM, and WEP. After 26 h of feed withdrawal, 20 g of substrates were crop-fed and excreta were collected for 48 h. Digestible indispensable amino acid score (DIAAS)-like values were calculated using the Association of American Feed Control Officials (AAFCO), The European Pet Food Industry Federation (FEDIAF), and National Research Council (NRC) reference values for different life stages of dogs and cats. Data were analyzed using SAS Proc Mixed 9.4 with P ≤ 0.05 significance. On a dry matter basis, CM had the greatest crude protein (70.2%), followed by BSFLM (59.8%), and WEP (51.2%). In general, WEP had greater amino acid digestibility than BSFLM and CM. BSFLM (84%) and CM (84%) had comparable arginine digestibility, but less than WEP (92%). Lysine digestibility was greater for BSFLM (80%) in contrast with CM (74%), but less than WEP (91%). DIAAS-like values were calculated, revealing methionine + cysteine as the first limiting amino acids for growing puppies and adult dogs in BSFLM according to AAFCO, FEDIAF, and NRC, whereas for CM threonine was the first limiting amino acid based on AAFCO, and phenylalanine + tyrosine based on NRC and FEDIAF. NRC identified methionine and cysteine as limiting for all test substrates in adult dogs. Methionine and cysteine were limiting for growing kittens for BSFLM among AAFCO, FEDIAF, and NRC. For CM and WEP, phenylalanine and tyrosine was the first-limiting amino acid by NRC and FEDIAF. For adult cats, phenylalanine and tyrosine were the limiting amino acid for BSFLMand CM according to AAFCO and FEDIAF, with NRC identifying it as limiting across all protein sources. In summary, methionine and cysteine and/or phenylalanine and tyrosine were the primary limiting amino acids among the protein sources evaluated. In general, BSFLM had comparable indispensable standardized amino acid digestibility to CM.

304 Amino acid digestibility and protein quality of fermented soybean-based ingredients using the precision-fed cecectomized rooster assay

Abstract Fermented soybean-based ingredients may serve as an alternative protein source for pet foods because of their high-quality protein content. The amino acid (AA) content and protein quality of fermented soybean-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 fermented soybean-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. Cecectomized roosters (n = 36; six roosters per substrate) were randomly allotted to one of five test substrates: 1) autoclaved soybean (ASB); 2) fermented soybeans (FSB); 3) fermented soybeans with probiotics (FSBP); 4) fermented soybean meal (FSBM); 5) fermented soybean meal with probiotics (FSBMP). After 26 h of feed withdrawal, roosters were tube-fed test substrates. Following crop intubation excreta samples were collected 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 increased AA digestibilities, with all indispensable AA digestibilities being >80% except for lysine (78.1% to 86.9%). Tryptophan digestibility was less (P < 0.05) in FSB than other substrates, but other AA digestibilities were not different. Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality according to nutritional guidelines for adult dogs, adult cats, growing puppies, and growing kittens. The most limiting AA was the same for all ingredients. In adult dogs, methionine was the most limiting AA based on National Research Council (NRC; DIAAS: 33.4-35.1), European Pet Food Industry Nutritional Guidelines (FEDIAF; DIAAS: 49.6-52.1), and Association of American Feed Control Officials (AAFCO; DIAAS: 60.2-63.2) guidelines. In adult cats, phenylalanine was the most limiting AA (DIAAS: 59.5-63.2) when using NRC guidelines, but DIAAS were above 100 for FEDIAF and AAFCO guidelines. In growing puppies, methionine was most limiting according to NRC (DIAAS: 56.7-59.6) and FEDIAF (DIAAS: 78.8-82.7) guidelines, but threonine was most limiting according to AAFCO (DIAAS: 68.8-72.3) guidelines. In growing kittens, methionine was most limiting according to NRC (DIAAS: 70.9-74.4) and AAFCO (53.4-56.0) guidelines, but phenylalanine was most limiting according to FEDIAF (DIAAS: 66.7-70.8) guidelines. Our results demonstrate that fermented soybean-based ingredients are high-quality protein sources. Even though they have one or more limiting AA, they would serve as strong complementary proteins for pet foods. 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 food.

PSXIII-27 Evaluation of Protein Quality of Select Chicken-Based Protein Sources Using the Precision-Fed Cecectomized Rooster Assay

Abstract The objective of this experiment was to determine and compare the standardized amino acid (AA) digestibility of chicken-based protein sources using the precision-fed cecectomized rooster assay. Four ingredients were tested: spray-dried chicken protein hydrolysate (CPH), spray-dried chicken meat (CC), spray-dried chicken broth (CB), and chicken meal (CM). All animal care procedures were approved by the University of Illinois Institutional Animal Care and Use Committee before experimentation. Sixteen cecectomized roosters (4 roosters per substrate) were randomly assigned to the four test substrates. After 24 h of feed withdrawal, roosters were tube-fed 12 g of test substrates and 12 g of corn. Following crop intubation, excreta (urine and feces) 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. Generally, CC had the greatest (P < 0.05) standardized digestibility for AA, followed by CPH. Methionine, phenylalanine, and valine had greater (P < 0.05) digestibility in CC and CPH compared with CB and CM. Digestibility of isoleucine and leucine were greater (P < 0.05) in roosters fed CC, followed by CPH, CM, and CB. Greater digestibility (P < 0.05) of lysine was observed in roosters fed CC and CPH, followed by CM and CB. Histidine and threonine had the least digestibility (P < 0.05) in CB compared with all other ingredients. In contrast, digestibility of tryptophan was greatest (P < 0.05) in CC, followed by CPH and CB, while CM had similar (P > 0.05) digestibility to CC and CPH. Amino acid digestibility for most indispensable AA was above 80% for all ingredients, except for histidine, lysine, and threonine, which were exceptions only for CB (68%, 73%, and 74%, respectively). For selected dispensable AA, amino acid digestibility was above 60% for all ingredients, except for aspartic acid in CB and CM, and serine in CB, which were exceptions (43, 68% and 66%, respectively). In general, the least DIAAS values were observed in roosters fed CB, followed by CPH, CM, and greatest in CC. Overall, CC and CPH have comparable indispensable AA digestibility, and tryptophan or phenyl alanine+tyrosine were, generally, the first limiting AA.

186 Amino Acid Digestibility of Various Protein-Based Ingredients Using the Precision-Fed Cecectomized Rooster Assay

Abstract Given their high protein quality and sustainable production practices, there is growing interest in using single cell-based proteins in pet foods. Because there has been a lack of testing on these proteins, the objective of this experiment was to determine the amino acid (AA) digestibilities of a single cell protein and other protein-based ingredients using the precision-fed cecectomized rooster assay. Test ingredients included: Calysta microbial protein (MP), chicken meal (CM), corn gluten meal (CGM), pea protein (PP), and black soldier fly larvae (BSFL). All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. Thirty cecectomized roosters (n = 6/ingredient) were randomly assigned to test ingredients. After 24 h of feed withdrawal, roosters were tube-fed 15 g of test ingredient and 15 g of corn. Following crop intubation, excreta were collected for 48 h. Endogenous corrections for AA were made using 5 additional cecectomized roosters. Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality according to AAFCO nutrient profiles, FEDIAF nutritional guidelines, and NRC recommended allowances for adult dogs, adult cats, growing puppies, and growing kittens. Data were analyzed using the Mixed Models procedure of SAS 9.4, with P < 0.05 being significant. All of the reactive lysine:total lysine ratios, an indicator of heat damage, were greater than 0.9 except for CM (0.86). All indispensable AA had digestibilities >85% for MP, with indispensable AA digestibilities being >80% for all ingredients. In general, CGM had the greatest AA digestibilities, while CM had the least AA digestibilities. Two exceptions were the digestibilities of lysine and tryptophan, which were greatest in MP. Lysine digestibility for MP (92.3%) was greater (P < 0.01) than that of all other ingredients. Tryptophan digestibility for MP (97.2%) was greater (P < 0.0001) than that of CM, CGM, and PP. Threonine and valine digestibilities were also greater for MP. Threonine digestibility was greatest for CGM (91.0%) and MP (88.6%), being greater (P < 0.0001) than that of the other ingredients. Valine digestibility was greatest for CGM (93.3%), PP (89.3%), and MP (89.3%), being greater (P < 0.001) than that of CM. DIAAS-like calculations estimated the protein quality of each ingredient, with the limiting AA of each depending on the reference used (NRC; AAFCO; FEDIAF) and life stage (growing; adult) and species (dog; cat) of animal in question. For dogs, limiting AA were most commonly methionine, threonine, and tryptophan. For cats, limiting AA were most commonly lysine and methionine. Further research in dogs and cats is necessary to confirm sufficient palatability and digestibility. However, our data suggest that the MP tested is a high-quality protein source with high AA digestibilities, and may serve as a valuable protein alternative for pet foods.

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.

PSIII-15 Standardized Amino Acid Digestibility and Protein Quality of Mealworm-Based Ingredients Using the Precision-fed Cecectomized Rooster Assay

Abstract Mealworms may serve as an alternative protein source for pet foods because of their high protein content. 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. 12 cecectomized roosters (4 roosters/substrate) were randomly assigned to one of three test substrates: 1) whole buffalo mealworm meal (BMW); 2) defatted yellow mealworm meal (YMW); and enzymatically hydrolyzed mealworm powder (HYD). After 24 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 5 additional cecectomized roosters. All data were analyzed using SAS version 9.4. All substrates had high AA digestibilities, with all indispensable AA digestibilities being &amp;gt;90% with the exception of histidine (87.9-91.1%) and valine (77.9%-79.7%). AA digestibilities were not different among substrates. Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality according to AAFCO nutrient profiles, FEDIAF nutritional guidelines, and NRC recommended allowances for adult dogs, adult cats, growing puppies, and growing kittens. In general, HYD had the highest and YMW had the lowest DIAAS-like values for most indispensable AA. Methionine (HYD; YMW) and tryptophan (BMW) 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 will be valuable sources of protein for pet foods.

104 Standardized Amino Acid Digestibility of Three Formats of Freeze-Dried dog Foods Using the Precision-fed Cecectomized Rooster Assay

Abstract Freeze-dried pet foods represent a small segment of the pet food market, but its growth has been significant in recent years. Despite their increasing popularity, freeze-dried diets have not been well tested. Therefore, the objective of this experiment was to determine and compare the standardized amino acid (AA) digestibilities of freeze-dried dog foods using the precision-fed cecectomized rooster assay. Three formats of freeze-dried diets provided by Primal Pet Foods (Fairfield, CA) were tested: traditional freeze-dried nuggets (FDN), low-temperature freeze-dried nuggets (LTN), and a hybrid freeze-dried nugget (HN). All animal care procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. Twelve cecectomized roosters (4 roosters per substrate) were randomly assigned to the three test substrates. After 24h of feed withdrawal, roosters were tube-fed 12-13g of test substrates and 12-13g of corn. Following crop intubation, excreta (urine and feces) were collected for 48h. 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 tested. For most of the indispensable AA, digestibilities were greater than 90% for all diets (arginine: 94.1%-95.6%; isoleucine: 91.2%-93.1%; leucine: 92.4%-95.3%; methionine: 92.8%-94.9%; phenylalanine: 90.8%-93.6%; tryptophan: 96.2%-98.6%; valine: 90.2%-92.9%). Histidine, lysine, and threonine were the exceptions, with digestibilities ranging from 81.7%-86.6%, 86.7%-91.7%, and 89.6%-91.7%, respectively. Moreover, the reactive:total lysine ratio, a measure of heat damage, ranged from 0.91 to 0.95. In general, the low-temperature nugget had thegreatest numerical AA digestibilities, likely due to reduced heat damage, but all diets performed very well.

119 Awardee Talk: A Matter of the Heart: The Use of Pulses in Canine and Feline Nutrition

Abstract In the pet food industry, the popularity of plant-based protein sources has risen as consumer demand for grain-free and novel protein sources increase. However, minimal research has been conducted as regards use of pulses and their effects on acceptability and digestibility in canine and feline nutrition. In addition, market shift towards grain-free and pulse-rich diets has presented concerns about the suitability of pulses as viable protein sources. In July 2018, the FDA published a press release discussing a potential link between diets containing legumes and the development of dilated cardiomyopathy (DCM) in dogs. As such, part of our research program has focused on the 1) characterization of the macronutrient composition and protein quality of plant-based protein sources, 2) evaluation of the effects of plant-based protein sources in extruded canine and feline diets on macronutrient digestibility, and modulation of fecal microbiota and metabolites, and 3) determination of the longitudinal effects of high pulse inclusion in diets on taurine status in dogs. Pulse ingredients contained approximately 20% crude protein, and had methionine or tryptophan as the first-limiting amino acids using the precision-fed cecectomized rooster assay. When incorporated in canine and feline diets, pulses did not result in negative effects on macronutrient digestibility or fecal scores. However, shifts in fecal microbial and metabolites were observed in animals fed pulse-based in contrast with animal-based protein diets. The inclusion of 45% green lentils in extruded diets did not cause decreased plasma or whole blood taurine or methionine levels. Additionally, excess taurine was not depleted from these animals in the urine or feces. Taurine status was considered normal in these dogs, despite changes in fecal bile acid concentrations and microbiota. Although we are currently carrying out further research projects investigating potential association of pulse rich diets and canine DCM. Current research findings from our laboratory suggest the inclusion of pulses may not be the causative factor. The use of plant-based proteins as ingredients in canine and feline diets not only meet consumer demand but also provide a valuable, safe, and nutritionally adequate alternative to traditional protein sources.

110 Evaluation of Macronutrient Composition and Amino Acid Digestibility of Select Novel Dietary Proteins for Use in Canine and Feline Nutrition

Abstract Demand for the inclusion of high-quality protein in companion animal diets has increased as owners have become more invested in the health of their pets. There is very little information on the nutrient content of novel proteins needed for a properly balanced diet, so as a result the objectives of this study were to determine the chemical composition, standardized amino acid digestibility using the precision-fed cecectomized rooster assay, and protein quality using digestible indispensable amino acid score (DIAAS like) of raw chicken, spirulina, cricket meal, and fish (carp) slurry. Raw chicken has the lowest crude protein concentration (45.6%) on dry matter (DM) basis, whereas fish slurry had the highest (75.3%). All amino acids were moderately to highly digestible (70.2% to 98.8%, dry matter basis) with differences (P &amp;lt; 0.05) in all but arginine, phenylalanine, threonine, cysteine, serine, and tyrosine. The limiting amino acid based on DIAAS-like values for adult dogs compared with the Association of American Feed Control Officials (AAFCO) recommended values were tryptophan for raw chicken and methionine for cricket meal. Comparing DIAAS-like values for adult dogs to National Research Council (NRC) recommended allowances, the limiting amino acids were the same where raw chicken and fish slurry still had tryptophan and spirulina and cricket meal had methionine as the first limiting amino acids. The DIAAS-like values for adult cats compared to AAFCO and NRC values were all above 100% with the lowest being threonine for chicken (123.65%) compared to AAFCO nutrient profile for adult cats and histidine for spirulina (123.13%) compared to NRC for cats at maintenance. Based on the data gathered in this study, the novel dietary protein sources evaluated are of similar or superior protein quality compared with raw chicken; a traditional protein source widely used in pet foods.

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.

Use of the precision-fed cecectomized rooster assay to determine standardized amino acid digestibility, true metabolizable energy content, and digestible indispensable amino acid scores of plant-based protein by-products used in canine and feline diets.

Traditionally, protein by-products from oil seeds and cereal grains have been used in pet foods as sustainable, inexpensive, and protein-rich ingredients. However, the on-going demonization of soy- and corn-based ingredients continue to hinder their use in pet food and treat formulations. Ideally, the further demonstration of their protein quality and nutrient composition may encourage their favorable return as acceptable ingredients in pet foods and treats. Therefore, the objectives of this study were to determine the macronutrient composition, indispensable amino acid profile, standardized amino acid digestibility, true metabolizable energy content corrected for nitrogen (TMEn), and digestible indispensable amino acid scores (DIAAS-like) of soy flakes (SF), peanut flour (PF), soybean meal (SBM), and corn gluten meal (CGM). Standardized amino acid digestibility was assessed using the precision-fed cecectomized rooster assay. All test ingredients demonstrated a profile of highly digestible indispensable amino acids except for lysine in PF, which was lowest (P < 0.05) at 45.5%. The SBM and CGM had the highest (P > 0.05) digestibilities of indispensable amino acids. A DIAAS-like value was calculated for each ingredient using either AAFCO (2020) recommended values or NRC (2006) recommended allowances as the reference protein pattern. For adult dogs compared to AAFCO recommended values, the first-limiting amino acid was lysine for PF and CGM but it was methionine for SF and SBM. For adult cats compared to AAFCO recommended values, the first-limiting amino acid was lysine for PF and CGM but it was threonine for SF. There was no first-limiting amino acid in SBM for cats as DIAAS-like values were over 100% for all indispensable amino acids. The TMEn values were highest (P < 0.05) for PF and CGM (4.58 and 4.31 kcal/g [dry matter basis], respectively). The protein quality of these plant-based protein by-products reflects their value as nutritional ingredients for canine and feline diets. However, the prior processing of these by-products must be considered before exposing them to additional processing methods, such as extrusion. Additionally, the inclusion of complementary proteins or supplemental amino acids will be needed to meet all indispensable amino acid requirements for a portion of nutritionally complete and balanced pet food.

Use of precision-fed cecectomized rooster assay and digestible indispensable amino acid scores to characterize plant- and yeast-concentrated proteins for inclusion in canine and feline diets.

Increased consumer interest in high-quality and novel protein sources has driven the demand for the inclusion of protein-rich ingredients in companion animal diets. Novel protein concentrates, with protein contents of at least 50%, have been used to satisfy these consumer demands. However, minimal information is available regarding the macronutrient composition and protein quality of these ingredients that is needed for proper formulation of pet foods. Therefore, the objectives of this study were to determine the macronutrient and amino acid compositions, standardized amino acid digestibility according to the precision-fed rooster assay, and protein quality using digestible indispensable amino acid score (DIAAS like) of pea protein (PP), potato protein (POP), faba bean protein (FBP), soy protein concentrate (SPC), and dried yeast (DY). Precision-fed rooster assays were conducted using cecectomized roosters to calculate standardized amino acid digestibility and true metabolizable energy corrected for nitrogen (TMEn). For all five protein concentrates, all essential amino acids were highly digestible (88.0% to 96.3%, dry matter basis) with differences (P < 0.05) in only lysine, methionine, and tryptophan digestibilities. The TMEn values were highest for POP (4.22 kcal/g) and DY (3.61 kcal/g). The DIAAS-like values for adult dogs indicated that methionine was the first-limiting amino acid in all protein concentrates except POP, where the first-limiting amino acid was tryptophan. Using Association of American Feed Control Officials (AAFCO)-recommended values for adult cats, DIAAS-like values for methionine were lowest (P < 0.05) for FBP at 81.5%, with all other amino acids for all protein concentrates over 100%. The National Research Council (NRC)-recommended allowances for adult cats indicated that DIAAS-like methionine values for PP (92.7%) and FBP (73.8%) were significantly lower (P < 0.05) with these being the first-limiting amino acids, with the remaining amino acids above 100% for the other protein concentrates. The protein quality and high essential amino acid digestibility of these protein concentrates indicate that they would be viable protein sources in canine and feline diets. However, additional complementary protein sources should be included to meet the requirements of all essential amino acids.

True nutrient and amino acid digestibility of dog foods made with human-grade ingredients using the precision-fed cecectomized rooster assay.

For a pet diet to be labeled as human-grade, every ingredient and the finished food must be stored, handled, processed, and transported according to the current good manufacturing practices for human edible foods. Human-grade dog foods are now available and increasing in popularity, but little research has been conducted to test the digestibility of these foods. For this reason, the objective of this experiment was to determine the true nutrient and amino acid (AA) digestibilities of dog foods formulated with human-grade ingredients using the precision-fed cecectomized rooster assay. Six commercial dog foods were tested, including the Beef & Russet Potato (BRP), Chicken & White Rice (CWR), Fish & Sweet Potato (FSP), Lamb & Brown Rice (LBR), Turkey & Whole Wheat Macaroni (TWM), and Venison & Squash (VSR) formulas provided by Just Food For Dogs LLC (Irvine, CA). Before analysis, all foods were lyophilized and ground. A precision-fed rooster assay using cecectomized roosters was conducted to determine the true nutrient digestibility and standardized AA digestibilities of the foods tested. Conventional roosters were used to determine the nitrogen-corrected true metabolizable energy (TMEn) of the foods. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. The substrates and rooster excreta were analyzed for macronutrient and AA composition. All data were analyzed using the Mixed Models procedure of SAS (version 9.4; SAS Institute, Cary, NC). In general, all foods tested were highly digestible. Dry matter digestibility was similar among CWR, LBR, and TWR foods, and greater (P < 0.0001) than that of FSP and VSR foods. Organic matter digestibility was highest (P = 0.0002) for CWR and lowest (P = 0.0002) for VSR. For the majority of indispensable AA, digestibilities were greater than 85%, with some being greater than 90%. TMEn was higher (P < 0.0001) for BRP than the other foods, which were similar to one another. Also, TMEn values were much higher than what would be estimated by using modified Atwater factors and often above the predictive equations for metabolizable energy (ME) recommended by the National Research Council or by using Atwater factors. Although statistical differences were observed among foods, they all performed well and the foods tested had very high AA digestibilities. Additionally, the TMEn data suggest that existing methods and equations for ME prediction underestimate the energy content of the foods tested.

240 True nutrient and amino acid digestibility of black soldier fly larvae differing in life stage using the precision-fed cecectomized rooster assay

Abstract Edible insects such as black soldier fly larvae (BSFL) are alternative protein sources for animal feeds due to their high protein content and low environmental footprint. However, protein quality and amino acid (AA) content may vary across insect species and life stage. Our objective was to determine the effects of life stage on true nutrient and AA digestibility of BSFL intended for use in animal feeds using the precision-fed cecectomized rooster assay. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. 24 cecectomized roosters (4 roosters/substrate) were randomly assigned to test substrates [BSFL0= day 0 (day of hatch); BSFL11= day 11; BSFL14= day 14; BSFL18= day 18; BSFL23= day 23; BSFL29= day 29]. After 24h of feed withdrawal, roosters were tube-fed 20g of test substrates. Following crop intubation, excreta were collected for 48h. Endogenous corrections for AA were made using 5 additional cecectomized roosters. All data were analyzed using SAS 9.4. True dry matter, organic matter, and nitrogen digestibilities were not different among substrates, but acid-hydrolyzed fat tended to be greater (P &amp;lt; 0.10) for BSFL23 and BSFL29 than BSFL14 and BSFL18. Although all substrates had a high digestibility, BSFL0 and BSFL11 had the lowest (P &amp;lt; 0.05) digestibilities for most indispensable and dispensable AA. Digestible indispensable amino acid score (DIAAS)-like values were calculated to determine protein quality according to AAFCO nutrient profiles and NRC recommended allowances for dogs and cats. In general, BSFL18 had the highest and BSFL11 had the lowest DIAAS-like values for most indispensable AA. Threonine, methionine, and arginine were often the first-limiting AA. Our results suggest that BSFL are a high quality protein and amino acid source, but that life stage can affect the AA digestibility and protein quality of this novel protein source.

PSIII-24 True nutrient and amino acid digestibility of commercial pork-based extruded dog foods using the precision-fed cecectomized rooster assay

Abstract Pork-based dog foods are increasing in popularity, but there has been a lack of research conducted on these diets, including information about their digestibility. Therefore, the objective of this experiment was to determine the true nutrient and amino acid (AA) digestibilities of commercial pork-based extruded dog foods using the precision-fed cecectomized rooster assay. Four commercial extruded diets were tested in this study, including three pork formulas (PF1; PF2; PF3) with varying levels of legume content, and a multi-protein formula (MPF), all provided by Champion Petfoods (Alberta, Canada). A precision-fed rooster assay utilizing cecectomized roosters was conducted to determine the true nutrient digestibility and standardized AA digestibilities of the diets tested. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. 16 cecectomized roosters (4 roosters/substrate) were randomly assigned to test substrates. After 24h of feed withdrawal, roosters were tube-fed 30g of test substrates. Following crop intubation, excreta (urine and feces) were collected for 48h. Endogenous corrections for AA were made using 5 additional cecectomized roosters. All data were analyzed using the Mixed Models procedure of SAS 9.4. There were no significant differences in true macronutrient digestibilities among diets tested. For most of the indispensable AA, digestibilities were greater than 80%, with some being greater than 90%. For the majority of indispensable and dispensable AA, MPF had higher (P &amp;lt; 0.05) AA digestibilities than the other diets tested. For the majority of indispensable AA, PF1 had the lowest AA digestibilities. In general, the diet containing a mixed protein source had the greatest AA digestibilities, but all diets including those based on pork protein performed well.

PSIII-26 True nutrient and amino acid digestibility of black soldier fly larvae fed different forms and concentrations of calcium using the precision-fed cecectomized rooster assay

Abstract Black soldier fly larvae (BSFL) is an alternative protein source for animals, including dogs and cats. The larval diet may affect their nutrient composition and overall nutritional value. Calcium carbonate (CaCO3) and calcium chloride (CaCl2) are common Ca sources, but differ in solubility (CaCO3 is insoluble; CaCl2 is soluble), so their intestinal absorption may differ. In addition, the Ca form and concentration may decrease mineral utilization and nitrogen digestibility, thereby affecting feed conversion efficiency. Our objective was to determine the effects of different forms and concentrations of Ca on true nutrient and amino acid (AA) digestibility of BSFL intended for use in animal feeds using the precision-fed cecectomized rooster assay. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. 16 cecectomized roosters (4 roosters/substrate) were randomly assigned to test substrates. All contained 0.2% Ca in the commercial diet and additional Ca in these amounts and forms: BSFLA: 1.33% CaCl2; BSFLB: 1.0% CaCO3; BSFLC: 0.6% CaCO3; BSFLD: 0.5% CaCO3 + 0.7% CaCl2. After 24h of feed withdrawal, roosters were tube-fed 20g of test substrates. Following crop intubation, excreta was collected for 48h. Endogenous corrections for AA were made using 5 additional cecectomized roosters. All data were analyzed using SAS 9.4. True macronutrient and AA digestibilities were not different among substrates. Digestible indispensable amino acid score (DIAAS)-like values were calculated to determine protein quality according to AAFCO and NRC recommended allowances for dogs and cats. Although AA digestibilities did not differ among groups, those containing CaCO3 generally had higher DIAAS-like values than the diet containing CaCl2 alone (BSFLA). Threonine, methionine, and arginine were often the first-limiting AA. Our results suggest that Ca source fed to BSFL did not affect AA digestibility and protein quality, despite affecting total calcium content of the BSFL.

241 True nutrient and amino acid digestibility of human-grade dog foods using the precision-fed cecectomized rooster assay

Abstract Human-grade dog foods are now available and increasing in popularity, but little research has been conducted to test the digestibility of these foods. The objective of this experiment was to determine the true nutrient and amino acid (AA) digestibilities of human-grade ingredient-based dog foods using the precision-fed cecectomized rooster assay. Six commercial dog foods were tested, including the Beef &amp; Russet Potato (BRP), Chicken &amp; White Rice (CWR), Fish &amp; Sweet Potato (FSP), Lamb &amp; Brown Rice (LBR), Turkey &amp; Whole Wheat Macaroni (TWM) and Venison &amp; Squash (VSR) formulas provided by Just Food For Dogs (Irvine, CA). Before analysis, all diets were lyophilized and ground. A precision-fed rooster assay utilizing cecectomized roosters was conducted to determine the true nutrient digestibility and standardized AA digestibilities of the diets tested. Conventional roosters were used to determine the nitrogen-corrected total metabolizable energy (TMEn) of the diets. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. The substrates and rooster excreta were analyzed for macronutrient profile and AA composition. All data were analyzed using the Mixed Models procedure of SAS 9.4. In general, all diets tested were highly digestible. Dry matter digestibility was similar among CWR, LBR and TWR diets, and greater (P &amp;lt; 0.0001) than that of FSP and VSR diets. Organic matter digestibility was highest (P = 0.0002) for CWR and lowest (P = 0.0002) for VSR. TMEn value was highest for BRP. For the majority of indispensable AA, digestibilities were greater than 85%, with some being greater than 90%. Although statistical differences were observed among diets, they all performed very well. The diets tested had very high AA digestibilities, being digested at levels exceeding that usually observed with extruded diets.

Nutrient and AA digestibility of black soldier fly larvae differing in age using the precision-fed cecectomized rooster assay1.

Edible insects such as black soldier fly larvae (BSFL) are alternative protein sources for animal feeds due to their high-protein content and potential low environmental footprint. However, protein quality and AA content may vary across insect species and age. Our objective was to determine the effects of age on nutrient and AA digestibility of BSFL intended for use in pet foods using the precision-fed cecectomized rooster assay. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee prior to experimentation. Twenty-four cecectomized roosters (four roosters per substrate) were randomly assigned to test substrates [BSFL0 = day 0 (day of hatch); BSFL11 = day 11; BSFL14 = day 14; BSFL18 = day 18; BSFL23 = day 23; BSFL29 = day 29]. 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. DM and OM digestibilities were not different among substrates, but acid-hydrolyzed fat digestibility tended to be greater (P < 0.10) for BSFL23 and BSFL29 than BSFL14 and BSFL18. Although all substrates had a high digestibility, BSFL0 and BSFL11 had the lowest (P < 0.05) digestibilities for most indispensable and dispensable AA. Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality according to AAFCO nutrient profiles and NRC recommended allowances for dogs and cats. In general, BSFL18 had the highest, and BSFL11 had the lowest DIAAS-like values for most indispensable AA. Threonine, methionine, and tryptophan were often the first-limiting AA. Our results suggest that BSFL are a high-quality protein and AA source, but that age can affect the AA digestibility and protein quality of this alternative protein source.

Chemical composition, true nutrient digestibility, and true metabolizable energy of chicken-based ingredients differing by processing method using the precision-fed cecectomized rooster assay1

Chicken-based ingredients are commonly used in pet food products, but vary greatly in nutrient composition and processing conditions that may affect their protein quality and digestibility. Testing the quality of protein sources undergoing different processing conditions provides important information to pet food producers. The objective of this study was to determine the chemical composition, nutrient digestibility, protein, and AA digestibility scores, and nitrogen-corrected true metabolizable energy (TMEn) of chicken-based ingredients that had undergone different processing conditions (i.e., chicken meal, raw chicken, retorted chicken, and steamed chicken) using the precision-fed cecectomized rooster assay. True nutrient digestibility was variable among the protein sources (60% to 76% of DM, 66% to 81% of OM, 83% to 90% of AHF, 50% to 95% of AA and 73% to 85% of TMEn/GE). In general, the chicken meal had a lower (P < 0.05) nutrient digestibility than other ingredients tested, including DM, OM, and most indispensable and dispensable AA, with most having a true digestibility between 75% and 85%. The steamed chicken had the highest indispensable AA digestibilities, with all having a true digestibility greater than 88% and most being over 90%. TMEn value and digestible indispensable AA scores (DIAAS)-like values were higher (P < 0.0001) in the less processed chicken-based ingredients in comparison to chicken meal. Although animal proteins are often considered to be complete proteins, DIAAS-like values <100% suggest that ingredients like chicken meal may not provide all indispensable AA when included at levels to the meet minimal crude protein recommendation. Although raw protein sources are often touted as being the most digestible and of the highest quality, the steamed chicken had the highest (P < 0.0001) DIAAS-like values in this study. This study demonstrates the considerable variability that exists, not only in the chemical composition but also in the true nutrient digestibility among chicken-based ingredients undergoing different processing conditions. These data justify more in vivo testing and the use of DIAAS-like values that consider AA profile, in vivo digestibility, and species-specific recommendations, to evaluate protein-based ingredients intended for use in dog and cat foods.

228 Chemical composition, nutrient digestibility, and true metabolizable energy of differentially processed chicken-based pet food ingredients using the precision-fed cecectomized rooster assay

228 Chemical composition, nutrient digestibility, and true metabolizable energy of differentially processed chicken-based pet food ingredients using the precision-fed cecectomized rooster assay