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

Processing conditions, particularly temperature and duration of heating, impact pet food digestibility. Various commercial pet food formats are now available, but few have been tested thoroughly. The objective of this study was to determine the amino acid (AA) digestibilities and nitrogen-corrected true metabolizable energy (TMEn) values of frozen raw, freeze-dried raw, fresh (mildly cooked), and extruded dog foods using the precision-fed cecectomized and conventional rooster assays. The diets tested were Chicken and Barley Recipe [Hill's Science Diet, extruded diet (EXT)], Chicken and White Rice Recipe [Just Food for Dogs, fresh diet (FRSH)], Chicken Formula [Primal Pet Foods, frozen raw diet (FRZN)], Chicken and Sorghum Hybrid Freeze-dried Formula [Primal Pet Foods, hybrid freeze-dried raw diet (HFD)], and Chicken Dinner Patties [Stella & Chewy's, freeze-dried raw diet (FD)]. Two precision-fed rooster assays utilizing Single Comb White Leghorn roosters were conducted. Cecectomized roosters (n = 4/treatment) and conventional roosters (n = 4/treatment) were used to determine standardized AA digestibilities and TMEn, respectively. All roosters were crop intubated with 12 g of test diet and 12 g of corn, with excreta collected for 48 h. In general, FD had the highest, while EXT had the lowest AA digestibilities; however, all diets performed relatively well and few differences in AA digestibility were detected among the diets. Lysine digestibility was higher (P < 0.05) in FD and FRZN than EXT, with other diets being intermediate. Threonine digestibility was higher (P < 0.05) in FD than EXT, with other diets being intermediate. Digestibilities of the other indispensable AA were not different among diets. The reactive lysine:total lysine ratios were 0.94, 0.96, 0.93, 0.93, and 0.95 for EXT, FRSH, FRZN, HFD, and FD, respectively. TMEn was higher (P < 0.05) in FRZN than FD, FRSH, and EXT, higher (P < 0.05) in HFD than FRSH and EXT, and higher (P < 0.05) in FD than EXT. In conclusion, our results support the notion that AA digestibilities are affected by diet processing, with FD, HFD, FRZN, and FRSH diets having higher AA digestibility coefficients and greater TMEn values, than the EXT diet; however, other factors such as ingredient inclusion and macronutrient composition may also have affected these results. More research in dogs is necessary to test the effects of format on diet palatability, digestibility, stool quality, and other physiologically relevant outcomes.

Processing conditions, particularly temperature and duration of heating, impact pet food digestibility. This study tested the standardized amino acid (AA) digestibilities and nitrogen-corrected true metabolizable energy (TMEn) values of five commercial dog diets: extruded diet (EXT), fresh (mildly cooked) diet (FRSH), frozen raw diet (FRZN), hybrid freeze-dried raw diet (HFD), and freeze-dried raw diet (FD). The first study, to determine AA digestibility, used 20 roosters who had their ceca (the main site of microbial fermentation in chickens) surgically removed. The second study used 20 conventional roosters to determine the TMEn of the diets. In general, FD had the highest AA digestibilities, while EXT had the lowest AA digestibilities. True metabolizable energy concentration was higher in the FRZN diet than the FD, FRSH, and EXT diets, higher in the HFD diet than the FRSH and EXT diets, and higher in the FD diet than the EXT diet. Our results support the notion that differences in diet processing, as well as factors such as macronutrient composition, and ingredient source, characteristics, and inclusion may impact AA digestibility and TMEn of dog diets. More research should be conducted to determine exactly how, and to what extent, these different factors impact digestibility in dogs.

Nutrient profile, amino acid digestibility, true metabolizable energy, and indispensable amino acid scoring of whole hemp seeds for use in canine and feline diets.

The use of various hemp-derived products has been rapidly growing in the human nutrition industry and has sparked great interest in using these ingredients for companion animals as well. Thorough research is needed to determine the ingredient and safety standards required for AAFCO approval of hemp ingredients. In order to be effectively incorporated into pet food products, we must determine the nutrient content, quality, and utility of these ingredients in pet species. The objective of this study was to evaluate the nutrient composition of seeds from four different varieties of hemp, NWG 452, NWG 331, NWG 2730, X-59, and determine protein quality and true metabolizable energy using a cecectomized rooster model. The seeds were similar in macronutrient composition, with small variations in acid hydrolyzed fat, crude protein, total dietary fiber and gross energy content, as well as amino acid and long-chain fatty acid profiles. All essential amino acids were present in concentrations that exceeded the NRC (2006) recommended allowances for adult dogs and cats at maintenance with the exception of tryptophan. The long-chain fatty acid profile presented a favorable ratio of omega-6 to omega-3 fatty acids of close to 3.5:1. The results of the cecectomized rooster assay indicated no significant difference in the standardized amino acid digestibility of the indispensable amino acids among the seed varieties (P > 0.05). A significant difference in the true metabolizable energy corrected for nitrogen was observed among the seeds (P < 0.05), following the pattern of higher acid hydrolyzed fat and lower total dietary fiber content resulting in higher metabolizable energy. An adapted calculation of digestible indispensable amino acid score was made to determine protein quality of the hemp seeds using AAFCO nutrient profiles and NRC recommended allowances for adult dogs and cats at maintenance as reference points. The resulting scores determined tryptophan to be the first limiting amino acid and indicate that hemp seeds alone do not meet all the amino acid requirements for adult dogs and cats at maintenance, and would need a complimentary protein source for practical use in companion animal diets. The data from this study suggest that hemp seeds may provide a beneficial source of fat, protein, and dietary fiber, with consideration to differences in nutrient profile among seed varieties. However, further investigation in vivo is needed to determine the safety and efficacy of utilizing hemp in the diets of both canines and felines.

Hemp products have become popular in the human food and health industry over the past few years. Due to this, a growing interest in using hemp ingredients in animal products has developed as well. There is a need to investigate the nutritional properties and potential utility of hemp seeds in food products for companion animals in order for them to be consumed safely and effectively. Four different varieties of hemp seed were evaluated and found to have similar fat, fiber, and protein content as well as protein quality. The results indicate that hemp seeds may be an advantageous ingredient in the development of pet food products, but a more in depth evaluation using pet species is necessary to confirm this.

Chemical composition of selected insect meals and their effect on apparent total tract digestibility, fecal metabolites, and microbiota of adult cats fed insect-based retorted diets.

Insect meals are novel and potentially sustainable protein sources. The objectives of this study were to determine the chemical composition and standardized amino acid digestibility using the cecectomized rooster model of three selected insect meals (i.e., speckled cockroach [SC], Madagascar hissing cockroach [MC], and superworm [SW]) and to determine the effects of these insect meals on food intake, apparent total tract digestibility (ATTD) of macronutrients, fecal scores, and metabolites of adult cats fed insect- or chicken-based retorted diets. This study consisted of a complete randomized design, with 28 adult cats randomly assigned to one of the four experimental retorted diets: Control (chicken-based diet), SC diet, MC diet, or SW diet. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee. All diets were formulated to be complete and balanced and meet or exceed the nutritional requirements of adult cats. The experimental period was 28 d, with the first 7 d allotted for diet adaptation. The total fecal collection was completed during the last 4 d of the experimental period. On day 21, a fresh fecal sample from each cat was collected for the determination of fecal metabolites and microbiota. Food was offered twice daily to maintain body weight and body condition score. Among the three selected insect meals evaluated, oleic acid, palmitic acid, linoleic acid, and stearic acid were the most prevalent fatty acids. Branched-chain amino acids and arginine were the most preponderant indispensable amino acids in these insect meals. ATTD of dry matter, organic matter, acid-hydrolyzed fat, and crude protein did not differ among treatments (P > 0.05), and all diets were well digested by the cats. Similarly, fecal scores did not differ among the treatments and were within ideal range. No differences (P > 0.05) in fecal metabolite concentrations or microbiota diversity were observed among cats fed different experimental diets; only a few genera from Firmicutes and Bacteroidota phyla differ (P < 0.05) in cats fed SW diet in contrast to other dietary treatments. In conclusion, the selected insect meals evaluated herein are rich in linoleic acid, an essential fatty acid for cats. Insect-based retorted diets led to comparable results to those achieved with a chicken-based retorted diet, suggesting that these novel protein sources might be adequate alternative ingredients in feline diets.

Insect meals are novel and potentially sustainable protein sources. The objectives of this study were to determine the nutrient composition of speckled cockroach, Madagascar hissing cockroach, and superworm (SW) and to determine the effects of these insect meals on food intake, digestibility of macronutrients, fecal scores, metabolites, and microbiota of adult cats fed insect- or chicken-based wet pet foods. Among the three selected insect meals evaluated, oleic acid, palmitic acid, linoleic acid, and stearic acid were the most prevalent fatty acids. Branched-chain amino acids and arginine were the most preponderant indispensable amino acids in these insect meals. All diets were well digested by the cats with no differences observed on macronutrient digestibility. Similarly, fecal scores did not differ among the treatments and were within the ideal range. No differences in fecal metabolite concentrations were observed. Only a few genera from Firmicutes and Bacteroidota phyla differ in cats fed SW diet in contrast to other dietary treatments. Overall, the selected insect meals evaluated herein are rich in linoleic acid, an essential fatty acid for cats. Insect-based retorted diets led to comparable results to those achieved with a chicken-based retorted diet, suggesting that these novel protein sources might be adequate alternative ingredients in feline diets.

Evaluation of feeding various sources of distillers dried grains with solubles in non-feed-withdrawal molt programs for laying hens.

An experiment was conducted using 588 Hy-Line W-36 hens (68 wk of age) to evaluate if laying hens can be successfully molted by ad libitum feeding various levels of 3 sources of distillers dried grains with solubles (DDGS). Treatment 1 consisted of a 47% corn (C):47% soy hulls (SH) molt diet (C:SH) fed for 28 d (positive control). Treatments 2, 3, and 4 were molt diets containing 94% DDGS from the 3 sources fed for 28 d. Treatments 5, 6, and 7 were 32% C: 42% SH: 20% DDGS, from each of the 3 DDGS sources, also fed for 28 d. At the end of the 28-d molt period, all hens were fed a 16% CP corn-soybean meal layer diet. Body weight loss during the molt period was significantly greater (P < 0.05) for hens fed the C:SH diet (26%) than hens fed the diets containing DDGS, and the reduction in BW loss varied among DDGS sources. Feed intake was lower (P < 0.05) for the C:SH control treatment compared with most DDGS treatments. Hens fed the C:SH diet had egg production near 0% during the last 3 wk of the molt period. Hens on the other treatments did not have mean egg production below 17% during the molt period (wk 1 to 4), and the reduction in egg production varied among DDGS sources. Postmolt hen-day egg production (5-41 wk) did not significantly differ among treatments; however, egg mass and egg specific gravity were generally reduced (P < 0.05) for hens fed the 94% DDGS molt diets compared with hens fed the C:SH diet. This study showed that molt and postmolt performance responses varied among DDGS sources; however, none of the molt diets containing 20 to 94% DDGS yielded molt period reductions in BW or egg production similar to a 47% C: 47% SH diet.

Chemical composition and nutritional quality of soybean meals prepared by extruder/expeller processing for use in poultry diets.

This research examined variation in chemical composition and nutrient quality of soybeans (SBs) and soybean meals (SBMs) produced at seven commercial extruder/expeller plants in the United States (experiment 1), as well as differences in amino acid digestibilities when roosters were fed SBMs extruded at 121, 135, 150, or 160 degrees C at a U.S. pilot processing plant (experiment 2). In experiment 1, limited variation existed in the composition of SBs arriving at the plants, whereas substantial differences were noted in amino acid composition and protein quality of the resultant SBMs. In experiment 2, the SBMs extruded at 121 and 135 degrees C were underprocessed as noted by high urease activities and lower amino acid digestibilities. Soybean meals extruded at 150 and 160 degrees C resulted in higher amino acid digestibilities and lower urease activities, indicating adequate processing. Large variation exists in the nutritional quality of extruder/expeller SBMs currently in the marketplace. Optimal processing temperatures should be >135 degrees C, and temperatures as high as 165 degrees C do not result in overprocessing.