ArticleLiterature Review

Myths and Misperceptions About Ingredients Used in Commercial Pet Foods

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Information and misinformation about pet nutrition and pet foods, including ingredients used in pet foods, is widely available through various sources. Often, this "information" raises questions or concerns among pet owners. Many pet owners will turn to their veterinarian for answers to these questions. One of the challenges that veterinarians have is keeping up with the volume of misinformation about pet foods and sorting out fact from fiction. The goal of this article is to provide facts regarding some common myths about ingredients used in commercial pet foods so as to better prepare veterinarians to address their client's questions.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Dry pet food contains products from animals, such as poultry by-product meal (Aldrich et al., 2007;Carciofi, 2008;Dozier et al., 2003;Kawauchi et al., 2014;Laflamme et al., 2014). This ingredient has high nutritional value and is rich in amino acids, fatty acids, and macro and micro minerals. ...
... This ingredient has high nutritional value and is rich in amino acids, fatty acids, and macro and micro minerals. However, this ingredient is highly susceptible to oxidative and microbial deterioration (Jayathilakan et al., 2012;Laflamme et al., 2014;Murray et al., 1997;Ockerman and Hansen, 1999). ...
... High processing temperature leads to overheating of the material (Awonorin et al., 1995;Ferroli et al., 2000) with consequent catalysis of oxidation reactions during the process and reduction of antioxidant concentrations in PBM (Tucker, 2004;Laflamme et al., 2014). The relationship between moisture and water activity with oxidation reactions in foods is not linear, but is instead quadratic. ...
Article
The current study aimed to investigate the relationship between oxidative stability and in vitro digestibility in the rendering process of poultry by-product meal (PBM). One hundred PBM batches were sampled from two integrated rendering plants (n = 50) and two independent rendering plants (n = 50). The parameters related to raw material, processing and finished product (PBM) were considered independent variables. In the PBM samples, the in vitro digestibility of organic matter (IVDOM) and the oxidative stability, measured as induction period (IP) by an oxygen bomb, were determined. These data were considered dependent variables for multivariate statistical analyses. Data from the independent variables were submitted to Exploratory Factorial Analysis (EFA). Subsequently, a hierarchical cluster was performed for the dependent variables. For oxidative stability, the samples were grouped into three clusters according to IP as follows: low (89 ± 12.2 min), medium (127 ± 9.7 min) and high (180 ± 13.3 min) (P = 0.001). Among the principal components (PC), the moisture (P = 0.009) and water activity (P = 0.039) were the factors related to the PBM that most influenced oxidative stability. The moisture content of 25 ± 12.4 g/kg and water activity of 0.24 ± 0.11 resulted in the lowest oxidative stability, indicating that excessive drying leads to less stable PBM. Oxidative stability was also influenced by synthetic antioxidants (P = 0.036). PBM samples were grouped into four clusters based on their in vitro digestibility of organic matter (IVDOM): very low (723 ± 14.6 g/kg), low (759 ± 9.7 g/kg), moderate (803 ± 3.3 g/kg), and high (848 ± 15.8 g/kg). Lower average (101 ± 2.05 °C, P = 0.022) and maximum (106 ± 1.02 °C; P = 0.004) processing temperatures led to higher PBM digestibility. Time to processing and rendering conditions directly affected PBM quality. Better standardization of those factors can favor the production of a nutritionally more suitable ingredient with longer oxidative stability.
... One claim is that corn and other grains cause allergies. Veterinary reports have shown that the main cause of allergies is peptides or glycoproteins, and that grains cause less than 1.5% of all food allergy cases (Laflamme et al. 2014). Some pet owners also have the perception that corn has no nutritional value, and that it is added to the food as a "filler" or as an ingredient to lower production cost. ...
... Verlinden et al. (2006) compiled data from seven studies and concluded that most food allergies were caused by animal protein (36% beef, 28% dairy, 10% egg, 9.6% chicken, 4% pork, 1% rabbit, and 1% fish), 15% were caused by wheat, and none by corn. More recently, Laflamme et al. (2014) reported that animal proteins were involved in most cases of food allergy in dogs, while wheat had a prevalence of 15%, and no cases (N ¼ 198) of food allergenicity were due to corn consumption. In France, Carlotti, Remy, and Prost (1990) gathered veterinarian reports of 33 cases of canine food allergy and, again, no dog on the research reviewed was allergic to corn. ...
Article
Full-text available
Corn is one of the largest cereal crops worldwide and plays an important role in the U.S. economy. The pet food market is growing every year, and although corn is well utilized by dogs, some marketing claims have attributed a negative image to this cereal. Thus, the objective of this work was to review the literature regarding corn and its co-products, as well as describe the processing of these ingredients as they pertain to pet foods. Corn is well digested by both dogs and cats and provides nutrients. The processing of corn generates co-products such as corn gluten meal and distillers dried grains with solubles that retain quality protein, and fibrous components that dilute dietary energy. Further, corn has much functionality in extrusion processing. It may yield resistant starch under certain processing conditions, promoting colonic health. Carotenoids in corn may enhance immune support in companion animals if concentrated. Mycotoxin contamination in grains represent a health hazard but are well controlled by safety measures. Genetically modified (GM) corn is still controversial regarding its long-term potential for mutagenicity or carcinogenicity, thus more long-term studies are needed. In conclusion, the negative perception by some in the pet food market may not be warranted in pet foods using corn and its co-products.
... The main limitations of use of poultry by-product meal are related to their quality due to being raw materials susceptible to oxidation process (Laflamme et al., 2014) and microbiological contamination (Jones-Ibarra et al., 2017), besides presenting wide variability in nutritional composition. Regarding this last-mentioned aspect, these by-products are made from a constant flow of waste, making it difficult to segregate the fresh materials from the slaughterhouse to maintain stability in chemical composition, which results in wide variability in nutritional content. ...
... This variability can affect digestibility and nutrient profiles such as amino acids, making it difficult to determine protein quality (Yamka et al., 2003). The different proportions of animal tissues and parts, as well as batch uneven and individual variations between process operators and production companies affect the quality and digestibility of PBM (Laflamme et al., 2014), an observation we were able to detect in the current study. ...
Article
Full-text available
The study aimed to measure variations in industrial process and nutritional variables of poultry by-product meal (PBM) in rendering plants from batch cookers. A total of 200 samples of low ash PBM with mineral matter (MM) content of 11% (LA, n = 104) or high ash with MM above 11% (HA, n = 96) were collected from 5 industrial processing plants. The highest coefficients of variation in chemical composition were for MM (LA - 19.70%; HA - 19.59%), ether extract (LA - 20.72%; HA - 14.86%), collagen (LA - 21.16%; HA - 30.00%) and water activity (LA - 24.54%; HA - 25.89%). However, the crude protein (LA - 5.07%; HA - 7.39%), dry matter (LA - 1.75%; HA - 2.90%) and organic matter digestibility (LA - 4.81%; HA - 6.78%) were lower. The variability of the data related to the process of PBM were: maximum process temperature (LA - 3.91%; HA - 3.56%), average process temperature (LA - 3.73%; HA - 4.71%) and processing time (LA - 27.37%; HA - 37.59%). This study evidenced that the corrective measures by limiting the amount of bones in the raw material, optimizing the pressing step for the poultry fat extraction, and also controlling the processing time of PBM may favor the production of more standardized PBM in terms of chemical composition and quality.
... An IVM course would be uniquely positioned to discuss current knowledge and controversies in raw diets, home-prepared diets, grain-free diets, and feline nutrition (Hewson-Hughes et al., 2011;Zoran and Buffington, 2011;Verbrugghe et al., 2012;Freeman et al., 2013;Shmalberg, 2013b;Laflamme et al., 2014). The concept of natural diets and the impact of new pet food formulations should be reviewed (Buff et al., 2014). ...
Article
Full-text available
Integrative veterinary medicine (IVM) describes the combination of complementary and alternative therapies with conventional care and is guided by the best available evidence. Veterinarians frequently encounter questions about complementary and alternative veterinary medicine (CAVM) in practice, and the general public has demonstrated increased interest in these areas for both human and animal health. Consequently, veterinary students should receive adequate exposure to the principles, theories, and current knowledge supporting or refuting such techniques. A proposed curriculum guideline would broadly introduce students to the objective evaluation of new veterinary treatments while increasing their preparation for responding to questions about IVM in clinical practice. Such a course should be evidence-based, unbiased, and unaffiliated with any particular CAVM advocacy or training group. All IVM courses require routine updating as new information becomes available. Controversies regarding IVM and CAVM must be addressed within the course and throughout the entire curriculum. Instructional honesty regarding the uncertainties in this emerging field is critical. Increased training of future veterinary professionals in IVM may produce an openness to new ideas that characterizes the scientific method and a willingness to pursue and incorporate evidence-based medicine in clinical practice with all therapies, including those presently regarded as integrative, complementary, or alternative. © 2016, Faculty of Veterinary Medicine, University of Tripoli and National Authority for Scientific Research. All rights reserved.
... The risk for developing cancer of the nasal cavity for example is increased up to 60% in animals that are kept by smokers in comparison to pets of non-smoking owners [55,56]. Although there are differences in the diet of humans and companion animals, many components such as meat, vegetables and carbohydrates are derived from the same sources and are consumed non-sterile as opposed to mice under SPF conditions [57]. Furthermore, studies have shown that the contact between owner and pet leads to a large overlap in the microbiome, the importance of which for human tumor development has come into focus recently [58]. ...
Article
Full-text available
The use of transgenic mouse models has revolutionized the study of many human diseases. However, murine models are limited in their representation of spontaneously arising tumors and often lack key clinical signs and pathological changes. Thus, a closer representation of complex human diseases is of high therapeutic relevance. Given the high failure rate of drugs at the clinical trial phase (i.e., around 90%), there is a critical need for additional clinically relevant animal models. Companion animals like cats and dogs display chronic inflammatory or neoplastic diseases that closely resemble the human counterpart. Cat and dog patients can also be treated with clinically approved inhibitors or, if ethics and drug safety studies allow, pilot studies can be conducted using, e.g., inhibitors of the evolutionary conserved JAK-STAT pathway. The incidence by which different types of cancers occur in companion animals as well as mechanisms of disease are unique between humans and companion animals, where one can learn from each other. Taking advantage of this situation, existing inhibitors of known oncogenic STAT3/5 or JAK kinase signaling pathways can be studied in the context of rare human diseases, benefitting both, the development of drugs for human use and their application in veterinary medicine.
... Humanization of pets has shifted the pet food industry toward a diet perceived as healthy for pet owners. Within these trends, the "grain-free" and the "ancient grain" claims have become popular as many pet owners consider traditional cereal grains to be unhealthy for their companion animals (Laflamme, 2014). Ancient grains are typically considered those that have been cultivated for centuries with little genetic modification, such as sorghum, millet, quinoa, chia, and spelt. ...
Article
The aim of this study was to evaluate the impact of ancient grain and grain free carbohydrate sources on extrusion process, nutrient utilization, and palatability by dogs. Two maintenance dog diets were formulated with same proportions of carbohydrates: 1) Ancient grain diet (AG) with spelt, millet and sorghum; and 2) Grain free diet (GF) which had potato, peas and tapioca starch. Experimental diets were extruded over five replicates in a completely randomized experimental design. Digestibility was carried out with twelve dogs in a switch back experimental design. The GF diet required 22.6% and 25.9% more (P < 0.05) specific mechanical energy and in-barrel moisture input, respectively, than AG to produce kibbles out of the extruder with similar bulk density (P > 0.05). After drying, GF kibbles were less dense and more expanded, but harder than AG kibbles (P< 0.05). Dogs preferred GF over AG in the palatability assessment of uncoated kibbles. Apparent nutrient digestibility of dry matter, organic matter, gross energy, crude protein, and crude fat were not affected by treatment (P > 0.05). However, total dietary fiber (TDF) digestibility was 31.9% greater for dogs fed GF (P < 0.05). Moreover, wet fecal output was higher, and fecal dry matter was lower for dogs under GF (P < 0.05). The results demonstrated that GF and AG diets behaved differently during extrusion, but were similarly utilized by dogs, with exception of TDF. Thus, fiber content of grain-free diets should be monitored to maximize fecal quality.
... Pet humanization has driven the pet food industry towards products perceived as healthy and natural by pet owners. Considering that grains have been perceived as unhealthy ingredients by some pet owners (LaFlamme, 2014), grain-free (GF) diets have become a major portion of the pet food industry. In 2017, this category represented more than 40% of the dog foods sold in the United States (Phillips-Donaldson, 2018). ...
Article
Full-text available
This study evaluated the effects of a grain-based (GB) and grain-free (GF) diet on protein utilization and taurine status in healthy Beagle dogs. Two practical dog diets sufficient in crude protein, sulfur amino acids, and taurine content were formulated with the same ingredients with exception of the carbohydrate sources. The GB contained sorghum, millet, and spelt while potatoes, peas, and tapioca starch were used in the GF. A total of 12 Beagle dogs were used in a completely randomized design with six replicates per treatment. The study consisted of an adaptation period of two weeks followed by an experimental period of 28 d in which GB and GF were fed to the dogs. At the end of the adaptation period and every two weeks after it (d 0, d 14, d 28), markers of taurine metabolism were analyzed in whole blood (taurine), plasma (taurine, methionine, and cystine), urine (taurine:creatinine), and fresh fecal samples (primary and secondary bile acids). Fecal samples were collected during the last 6 days of experimental period for digestibly assessment using titanium dioxide as an external marker. Taurine markers and digestibility data were analyzed in a repeated measures model and one-way ANOVA, respectively, using PROC GLIMMIX in SAS (version 9.4). Apparent crude protein digestibility was not affected by treatment, but dogs fed GF diet had lower apparent organic matter digestibility compared to those fed GB (P < 0.05). Greater plasma taurine concentrations were observed at d 14 and d 28 compared to d 0; wherein dogs fed GF exhibited greater increase compared to those fed GB (P < 0.05). Whole blood taurine concentrations, plasma methionine concentrations, and urinary taurine:creatinine were also greater at d14 and d 28 compared to d 0 (P < 0.05), but no effect of diet was observed. Total bile acid excretion was similar between GF and GB groups, but dogs fed GF excreted a higher proportion of primary bile acids compared to those fed GB (25.49 vs 12.09% at d 28, respectively). In summary, overall taurine status was not affected by dietary treatments, however, our results suggest that the higher content of oligosaccharides and soluble fibers in the GF diet may alter the composition of the fecal bile acid pool.
... Another current trend in pet food marketing is the development of "grain free" products. According to Laflamme et al. [19], cereals in pet food may give rise to food adverse reactions. However, according to our survey, this characteristic was not deemed a major priority by the Italian pet owners interviewed. ...
Article
Full-text available
Background: Over recent years, pet owners have started to demonstrate increased sensitivity toward their companion animals, which includes an increase in the attention paid towards their nutrition, seen as a way of safeguarding their pets' welfare. The aim of this study was to identify how pet food quality traits are perceived as being the most important by dog and cat owners. To this end, a survey of dog and cat owners was conducted by means of a questionnaire distributed in pet stores and trade fairs throughout Italy. Results: A total of 935 surveys were collected; 61.8% of which were compiled by female pet owners. The respondents were relatively homogeneously distributed between cat (30.8%), dog (39.4%), and cat and dog (29.8%) owners. A quarter of the owners (25.5%) reported to have asked their veterinarian for advice on which pet food to buy, and almost a third (30.4%) trusted the advice posted on the web sites of well-known brands. "Contains natural ingredients" was the characteristic that obtained the highest mean score (4.3 out of 5). Elderly owners (> 65 years) placed most importance on whether a product had a high price, and least on feed appearance, animal satisfaction, and stool quality. Young owners (< 35y) paid most attention to the stool quality, the percentage of protein in the feed, and the presence of recyclable packaging, and least attention to feed appearance, smell, and animal satisfaction. Feed appearance, smell, a higher cost, and certain label indications (protein content, presence of fresh meat, grain free) were mostly important among the buyers of wet pet food. Some specific differences also emerged between dog, cat, and dog and cat owners. Conclusions: In this survey of Italian pet food buyers, the presence of "natural" ingredients was considered to be the most important indicator of pet food quality, whereas characterized by a high price was considered least important. The data obtained from this survey could be used to help pet food companies identify which pet food quality traits are perceived as important by dog and cat owners.
... The increasing pet food production is even greater in the 'premium' category as pet owners are getting more concerned about the composition of the food offered to their pets [4]. Labelling is an important factor in consumer choices, since there is a preference for ingredients resembling human diets [11,12]. Due to flawed regulations, the pet food industry in Brazil is allowed to include words or pictures referring to high quality animal protein (e.g. ...
Article
Full-text available
Considering the increasing pet owner's concern about the food their pets are consuming, in this study we investigated the origin of the main ingredients in wet and dry foods produced in Brazil using stable isotope ratios of carbon and nitrogen. We concluded that chicken and pork seem to be the dominant ingredients in most of the samples, with larger proportions in wet cat food. Even in pet foods showing 'beef' as the main ingredient on the label, we found a low proportion of bovine products in both wet and dry cat foods. Comparing the contribution of plant-derived products (C 3 and C 4 plants) and animal-derived products (chicken-pork, bovine and fish), approximately 21 % of cat foods had more than 30 % of ingredients with plant origin in their composition. The high amount of plant-derived products in cat foods found here raises the question whether this should be mentioned on package labels. ARTICLE HISTORY
... Keeping in mind that animals have nutrient and not ingredient requirements (Laflamme et al., 2014), the possibility of feeding cats on a plant-based diet should not be discharged as impossible: critical attention should be put on its correct formulation and furthermore on how feline's physiology answers to it. ...
Article
A topical subject in human nutrition is the steadily growing number of people choosing to limit or completely avoid all animal‐derived food products either for moral dilemma, health concerns or both. To meet people's will of applying their dietary choices to their domestic animals, the pet food industry answered by launching on the market some plant‐based diets. This leads to concerns about whether these diets are adequately formulated to satisfy the target species nutritional requirements, especially for cats which are still considered strict carnivores. This case report follows a 2‐year‐old male neutered Main Coon and a 1‐year‐old female spayed Domestic Shorthair cat, presented to the nutrition service of the University of Toulouse, France. Reason for consultation was lethargy with in anamnesis a recent dietary transition to a plant‐based pet food. Dysorexia, lethargy and muscle waste were present at first consultation. Progressive weight loss developed during follow‐ups. A macrocytic, non‐regenerative anaemia with serum folates below reference were the main clinical features. Analysis of pet food showed multiple nutrients below minimum recommendation at the average daily intake of both cats. Folic acid supplementation improved dysorexia, and subsequent reintroduction of animal‐derived ingredients in the diet restored appetite, weight and a normal mentation in both cases.
... Most research on dog diet and nutrition deals with improving food palatability (39,40), modifying stool quality and nutrient absorption (41), all while meeting the daily caloric requirements. Little consideration of disease prevention has been reported in the literature (42). It has been well-established that a healthy diet in humans contributes to an increased health span and that an unhealthy diet increases the risk of many pathologies (43)(44)(45). ...
Article
Full-text available
Background: While anecdotal evidence has long claimed that a raw meat–based diet (RMBD) improves the metabolic health of canines, no rigorous scientific study has clarified this issue. Canine atopic dermatitis (CAD) has also been linked to metabolic health, but its relation to diet remains poorly understood. This study investigates whether dietary choice is linked to metabolic health in healthy and CAD-diagnosed canines via targeted serum and urine metabolomic analysis of polar, non-ionic metabolites, as well as whether the underlying CAD condition modulates the response to nutritional intake. Materials and Methods: Serum metabolites of client-owned Staffordshire bull terriers, divided into CAD-diagnosed (n = 14) and healthy (n = 6) cohorts, were studied. Urine metabolites of a subset of the CAD-diagnosed canines (n = 8) were also studied. The canines were split into two cohorts based on diet. The first cohort were fed a commercially available high-fat, moderate-protein, low-carbohydrate RMBD (n = 11, CAD diagnosed n = 8, healthy n = 3). Those in the second cohort were fed a commercially available moderate-fat, moderate-protein, high-carbohydrate kibble diet (KD) (n = 9: CAD diagnosed n = 6, healthy n = 3). The diet intervention period lasted approximately 4.5 months (median 135 days). Statistical analyses of the serum profiles across all dogs (n = 20) and the urine profiles of the CAD-diagnosed subset (n = 8) were performed. Results and Discussion: The KD cohort was found to have higher concentrations of methionine than the RMBD cohort, both in serum (all dogs, p < 0.0001) and in urine (CAD-only cohort, p < 0.0002), as well as cystathionine and 4-pyridoxic acid. Methionine plays important roles in homocysteine metabolism, and elevated levels have been implicated in various pathologies. The CAD (n = 14) cohort dogs showed starker metabolic changes in response to diet regarding these pathways compared to the healthy (n = 6) cohort. However, there was no significant change in CAD severity as a result of either diet. Likely due to the higher meat content of the RMBD, higher concentrations of several carnitines and creatine were found in the RMBD cohort. Citrulline was found in higher concentrations in the KD cohort. Our findings provide insight into the relationship between diet and the serum and urine metabolite profiles of canines. They also suggest that neither diet significantly affected CAD severity.
... Consumer uncertainty about what passes as "by-products" may lead pet owners to perceive them as poor-quality ingredients [3]. Processed animal proteins are, in fact, widely used in the pet food industry and provide an excellent source of protein, energy, and minerals [4,5], however, misperceptions about their origin and content make fresh meat the more desirable ingredient. ...
Article
Fresh mechanically deboned meat (MDM) is usually claimed as high-quality ingredient on dry pet food recipes and this aspect may positively influence consumer choice. It is important to determine the scientifically sustainability of this claim and to assess the microbiological safety of MDM inclusion in dry pet food. Objectives were: 1) to evaluate the effect of inclusion of MDM in dry dog food on fatty acid profile and in vivo and in vitro digestibility, proposing a new system (DaisyII Incubator) to measure the in vitro digestibility for dogs; 2) to compare palatability of dry dog food containing MDM with dry dog food in which meat by-products (MBP) are the only animal protein sources; 3) to determine, whether or not, the inclusion of that ingredient changes the microbiology and the storage quality. Results indicated that MDM product was characterized by significant higher nutritional value in terms of fatty acids profile, in vitro digestibility (HV-IVD method) and lower palatability than the MBP product. Microbiological risk assessment showed no microbiological hazards for either product. After 6-months storage, the total mesophilic bacterial count ranged between 1.77 and 2.09 log CFU/g feed, while polyamine values were higher in the MDM (0.37 g/kg) than in the MBP (0.27 g/kg). The DaisyII Incubator was found to be a valid instrument for studying in vitro digestibility also for dogs, providing data simply, quickly, with less variability and costs than in vivo trials. In conclusion, MDM inclusion in dry dog food is microbiologically safe and it can improve its nutritional quality, at the expense of a reduced palatability. The higher polyamine levels fount in MDM-enriched petfood after 6-months storage, however, may represent a possible hazard, and further studies are still warranted.
... It is necessary to point out that the current survey only included those feeding a dry food (kibble) diet and these data may be quite different if owners who feed a different dietary format are included. People who allocate more points to the importance of the ingredients in a pet food and people who look for the terms, 'no fillers' and 'no by-products' were more likely to select 'no grain' when choosing a pet food, supporting the statement by LaFlamme et al. [13] that grains are often considered 'fillers' by pet owners. In addition, Conway & Saker [14] reported that respondents in a survey often selected that grain-free diets were "diets free of fillers and byproducts". ...
Article
Full-text available
Grain-free pet food options abound in the pet food market today, representing more than 40% of available dry dog foods in the United States. There is currently a dearth of information about the factors that contribute to a dog owner’s choice of a grain-free dry dog food and if those factors are similar among countries. Therefore, the primary objective of the current survey was to identify the variables that are predictive of a dog owner’s choice of a grain-free dry food across North America (Canada and the United States) and Europe (France, the United Kingdom and Germany). The survey consisted of 69 questions, took less than 15 minutes to complete and was distributed virtually via Qualtrics (Qualtrics XM, Utah, USA). A total of 3,298 responses were collected, equally distributed between countries. Multinomial logistic regression was performed in SPSS Statistics (Version 26, IBM Corp, North Castle, New York, USA). Male respondents, people from France, people who ranked the importance of ingredients in a pet food in the lower quartiles and people who do not rotate their dog’s diet to provide variety were less likely to select ‘no grain’ when choosing a pet food. In contrast, people who believe that their dog has a food allergy, follow more than 5 specific dietary routines in their own diet, do not try to include grains in their own diet, get their information about pet food from online resources or pet store staff and look for specific claims on pet food (such as ‘no fillers’), were all more likely to select ‘no grain’ when choosing a pet food. This survey provides insight into the similarities and differences in decision making among dog owners in North America and Europe and should be considered when exploring the effects of grain-free dog foods on canine health and well-being.
... For example, sometimes the fact that cats are strict carnivores is interpreted as meaning that cats can only obtain their nutritional requirements through consuming animal tissue. This is incorrect from a nutritional perspective as animals, including cats, need nutrients and not specific ingredients [7]. The fact that cats evolved consuming low-carbohydrate prey and the increased understanding of the unique feline carbohydrate metabolism has led to speculations that high-carbohydrate diets could be detrimental to feline health. ...
Article
Full-text available
The domestic cat’s wild ancestors are obligate carnivores that consume prey containing only minimal amounts of carbohydrates. Evolutionary events adapted the cat’s metabolism and physiology to this diet strictly composed of animal tissues and led to unique digestive and metabolic peculiarities of carbohydrate metabolism. The domestic cat still closely resembles its wild ancestor. Although the carnivore connection of domestic cats is well recognised, little is known about the precise nutrient profile to which the digestive physiology and metabolism of the cat have adapted throughout evolution. Moreover, studies show that domestic cats balance macronutrient intake by selecting low-carbohydrate foods. The fact that cats evolved consuming low-carbohydrate prey has led to speculations that high-carbohydrate diets could be detrimental for a cat’s health. More specifically, it has been suggested that excess carbohydrates could lead to feline obesity and diabetes mellitus. Additionally, the chances for remission of diabetes mellitus are higher in cats that consume a low-carbohydrate diet. This literature review will summarise current carbohydrate knowledge pertaining to digestion, absorption and metabolism of carbohydrates, food selection and macronutrient balancing in healthy, obese and diabetic cats, as well as the role of carbohydrates in prevention and treatment of obesity and diabetes mellitus.
... However, regulatory guidelines forbid the inclusion of ingredient quality indicators on pet food labels. In fact, actual properties of finished product depend on selection of commodities providing the nutritional features [6]. ...
Article
Full-text available
Selected quality and oxidative stability parameters of the lipid fraction were analyzed in four complete dry dog foods with different main animal-derived ingredients. The measurements were taken at the time of bag opening and repeated after 7 months of continuous storage in normal room conditions. Fatty acid (FA) content and acid value (AV) were determined, followed by subsequent pressure differential scanning calorimetry (PDSC) measurements. From the resulting PDSC exotherms, maximum induction time (smax) was determined and used for assessing the oxidative stability. The study revealed changes in lipid quality and oxidative stability of dry dog foods that appeared during storage. Results of FA and AV assays showed specificity and marked quality differences of lipid ingredients declared as used in the production process. Product with the lowest content of polyunsaturated FA had the highest oxidative stability. PDSC appeared to be an effective method for the analysis of lipid oxidation in pet foods.
... Humanization of pets has shifted the pet food industry toward a diet perceived as healthy for pet owners. Within these trends, the "grain-free" and the "ancient grain" claims have become popular as many pet owners consider traditional cereal grains to be unhealthy for their companion animals (Laflamme, 2014). Ancient grains are typically considered those that have been cultivated for centuries with little genetic modification, such as sorghum, millet, quinoa, chia, and spelt. ...
Article
The aim of this study was to evaluate the impact of ancient grain and grain-free carbohydrate sources on extrusion process, nutrient utilization, and palatability by dogs. Two maintenance dog diets were formulated with same proportions of carbohydrates: 1) ancient grain diet (AG) with spelt, millet, and sorghum; and 2) grain-free diet (GF) which had potato, peas, and tapioca starch. Experimental diets were extruded over 5 replicates in a completely randomized experimental design. Digestibility was carried out with 12 dogs in a switch-back experimental design. The GF diet required 22.6 and 25.9% more (P < 0.05) specific mechanical energy and in-barrel moisture input, respectively, than AG to produce kibbles out of the extruder with similar bulk density (P > 0.05). After drying, GF kibbles were less dense and more expanded, but harder than AG kibbles (P < 0.05). Dogs preferred GF over AG in the palatability assessment of uncoated kibbles. Apparent nutrient digestibility of dry matter, organic matter, gross energy, crude protein, and crude fat were not affected by treatment (P > 0.05). However, total dietary fiber (TDF) digestibility was 31.9% greater for dogs fed GF (P < 0.05). Moreover, wet fecal output was higher, and fecal dry matter was lower for dogs under GF (P < 0.05). The results demonstrated that GF and AG diets behaved differently during extrusion, but were similarly utilized by dogs, with exception of TDF. Thus, fiber content of grain-free diets should be monitored to maximize fecal quality.
Article
Full-text available
strong>PICO question In adult cats, does feeding grain free maintenance diet reduce the risk of obesity compared to feeding a maintenance diet containing grains? Clinical bottom line There is no evidence showing feeding grain free maintenance diet reduces the risk of obesity compared to feeding a maintenance diet containing grains. <img src="https://www.veterinaryevidence.org/rcvskmod/icons/pr-icon.jpg" alt="Peer Reviewed" /
Preprint
The objectives of this study were: (a) to evaluate the effect of inclusion of mechanically separated chicken meat (MSCM) in dry dog food on fatty acid profile, in vivo and in vitro digestibility, and palatability as compared with dry dog food containing meat by-products (MBP); (b) to determine, whether or not, the inclusion of the one or the other ingredient changes the microbiology and the storage quality of the two food products; (c) to propose a new system (DaisyII Incubator) to measure the in vitro digestibility of the two products. Their similar chemical composition notwithstanding, the MSCM product had lower palatability but better nutritional quality (with higher polyunsaturated fatty acid [PUFA] content and lower saturated fatty acid [SFA] content) than the MBP product. Microbiological risk assessment showed no microbiological hazards for either product. After 6 months storage, polyamine values were found to be higher in the MSCM than in the MBP. Finally, the DaisyII Incubator proved a valid instrument for the study of in vitro digestibility also for dogs; since it provided data simply, quickly with less variability and cost than obtained with in vivo trials, it could represent the future for pet food digestibility studies. Our results indicate that inclusion of MSCM or MBP as the main protein ingredient in extruded pet food may be used advantageously in product formulations.
Article
Full-text available
Dry pet food, made of fresh meats and especially meat meals, represents one of the main types of complete food available on the market by virtue of its practicality and long shelf life. The kibble production process includes mixed thermal and mechanical treatments that help to improve the palatability and durability of the final product but may have undesirable effects on nutrient bioavailability and digestibility. An analysis of the protein and lipid content of different dry pet food formulations, together with an in vitro digestibility analysis, can reveal which formulation can provide a more nourishing diet for pets. In this study, a quantitative and qualitative analysis was performed on three different formulations of chicken-based dry pet food, consisting of fresh meats, meat meals, or a mix of these two. The soluble protein concentration was determined by the Bradford assay, while the crude protein content was assessed through the Kjeldahl method. Quadrupole time-of-flight liquid chromatography/mass spectrometry (Q-TOF LC/MS) was used to analyze the amino acid (AA) and lipid compositions. Finally, a gastric and small intestinal digestion simulation was used to determine the in vitro digestibility. The results show that dry pet food consisting only of chicken fresh meats has the highest content of soluble protein; it also contains more Essential AAs, Branched-Chain AAs, and Taurine, as well as a greater quantity of monounsaturated and polyunsaturated fatty acids. In addition, its in vitro digestibility was the highest, exceeding 90% of its dry weight, in agreement with the soluble protein content. These findings thus make the fresh-meat-based formulation a preferable choice as dry pet food.
Article
Consumption of grain-free (GF) diets has recently been linked to canine dilated cardiomyopathy in selected dog breeds. Soluble fiber present in GF carbohydrate sources may be contributing to taurine depletion, thus affecting heart health. The objective of this study was to evaluate the effects of different carbohydrate sources on taurine status in healthy Beagle dogs. Two practical diets sufficient in sulfur-amino acids and taurine were formulated with the same proportion of carbohydrate sources: a grain-based (GB) containing sorghum, millet, and spelt, and a GF containing peas, potatoes and tapioca starch. Twelve Beagle dogs were fed experimental diets for 4-wk in a randomized complete block design. The morning prior to feeding experimental diets (baseline) and two and four weeks after, markers of taurine metabolism were analyzed in blood, urine, and fresh fecal samples. Data were analyzed as a change from baseline in a repeated measures model by GLIMMIX (SAS, version 9.4) in which the main effects of time, diet, and their interaction were evaluated. Greater concentrations of taurine in plasma (158 vs. 117 nmol/mL) and whole blood (254 vs. 234 nmol/mL) were observed during experimental period compared to baseline. An increase in plasma methionine was also observed during experimental period compared to baseline (64 vs. 57nmol/mL). Dogs fed GF exhibited higher plasma taurine concentration compared to those fed GB (181 vs. 138 nmol/mL). There were no significant effects of diet, time, or their interaction on plasma cystine concentration, urinary taurine:creatinine ratio, or total fecal bile acid (BA) excretion (P > 0.05). However, dogs fed GF had greater fecal primary BA (26 vs 14%) as a proportion of total BA compared to those fed GB. This study suggests that GF diets do not impair taurine blood concentration, but the increased proportion of fecal primary BA may decrease recycling of taurine through enterohepatic circulation.
Article
Commercial pet food in the United States includes a diverse range of products. There is a tremendous amount of variation among companies regarding the financial resources invested into producing their products, research, and marketing. Commercial pet food is a regulated industry at both the state and federal levels, and many of the same standards applied to the human food industry apply to pet food. Many foods that both pets and people consume are processed; however, the type and extent of processing do not correlate with the nutritional value. Commercial pet food does not meet the needs of every pet.
Article
The evaluation of the quality of commercial diets is a topic of interest to dog owners and veterinarians. The aims of the study were to determine proximate analysis, metabolizable energy and some amino acids in dry dog diets for different ages, divided into three groups G1 (low price, grains included), G2 (medium price, grains included) and G3 (high price, grain‐free). The hypothesis was tested that there are significant differences in the analysed values between dry dog diets from different price categories and between grain‐free and grain‐containing diets. Furthermore, the analysed values were compared with AAFCO and FEDIAF recommendations and with label values guaranteed by manufacturers to see whether there are any deviations. We analysed 60 samples of complete dry dog diets purchased in the Czech Republic, using the standard AOAC methods of proximate analysis. Metabolizable energy was calculated using the NRC equation, and 30 samples were analysed for selected amino acids. The results showed that there are significant differences in protein and amino acid contents between grain‐free (G3) and grain‐containing (G1,2) dog diets. G3 diets had significantly (p < 0.01) higher crude protein and essential amino acid contents. No significant differences were found between grain‐containing diets G1 and G2. The results may indicate a higher proportion of animal components and a lower content of carbohydrates in G3 diets. Most of the tested dog diets met the AAFCO and FEDIAF recommendations. There were only a few deviations in threonine in G1 and G2 diets for growing dogs.
Article
Full-text available
RESUMEN El objetivo del estudio fue determinar la calidad nutricional de tres alimentos comerciales «Premium» para cachorros fabricados y comercializados en el Ecuador, así como determinar la sensibilidad de la técnica de espectroscopía por infrarrojo cercano (NIRS) para la valoración de los macronutrientes de estos alimentos. Se analizaron las características nutricionales de tres marcas de alimento, tomándose muestras de cuatro lotes por marca. Se determinaron los macronutrientes (proteína, grasa, fibra, almidón, cenizas y humedad) mediante la técnica NIRS, prueba que fue duplicada en dos laboratorios con diferentes equipos. Además, se determinó el perfil de aminoácidos mediante cromatografía líquida (HPLC). En el análisis proximal, los tres alimentos cumplen con los requerimientos de macronutrientes mínimos para garantizar el desarrollo y la salud de los cachorros, aunque uno de ellos presentó una mejor composición nutricional. La técnica de NIRS como prueba rápida es estable para analizar los componentes de los alimentos secos para mascotas; sin embargo, presentó variabilidad al medir principalmente la concentra-ción de grasa (p=0.029) en los tres alimentos, aunque también ocurrió en uno de los
Article
A survey was conducted among first‐opinion practices in Germany and Austria on dog nutrition consultation, food sold in the practice, recommendations given to owners, most commonly encountered consequences of malnutrition, need for further education and feeding of own dogs. Of the 169 participants, one third was from Austria, two thirds from Germany. Most practiced in the countryside or in suburbs, were female and between 36 and 55 years old. The majority felt that nutrition has become an important topic, and that “feeding myths” were on the rise. However, only in 18% of the practices at least one staff member had further education in nutrition, while none of the participants had a national or international degree. Only half of our participants felt qualified to give nutrition advice. A nutritional assessment was not regularly performed, and the Body Condition Score was not regularly assessed, often only when health problems were obvious. If a homemade diet was requested, practitioners rather referred to a nutritionist, while 25% left it up to the owners. Most relied on traditional premium diets for their patients and also for their own dogs. Feeding myths seemed to be widespread among veterinarians, too; even Biologically Appropriate Raw Feeding and diets not complying with EU legislation were recommended. There is obvious need for further education and specialization to establish nutrition consultation as a profitable service in small animal practice.
Article
Full-text available
Objectives-To determine whether there is a relationship between species-specific mitochondrial DNA (mtDNA), especially canine and feline mtDNA, and detectable amounts of pentobarbital in previously analyzed dog food samples. Sample Population-31 dog food samples previously analyzed for pentobarbital (limit of detection, 1 mug/kg). Procedure-Polymerase chain reaction (PCR) analysis was performed on dog food samples by use of PCR primers specific for either canine, feline, equine, bovine, porcine, ovine, or poultry mtDNA: Results-PCR amplicons specific for feline or canine mtDNA at a 0.007% (70 mug/g [wt/wt basis]) or 0.0007% (7 mug/g) level, respectively, were not found in the 31 dog food samples. Most of the 31 dog food samples had a PCR amplicon on PCR analysis when a PCR primer set capable of simultaneously detecting mtDNA of cows, pigs, sheep, goats, deer, elk, and horses was used. Results of PCR analysis by use of primers specific for bovine, swine, sheep and goat, or horse mtDNA revealed amplicons specific for bovine or swine mtDNA only in 27 of the 31 samples. Analysis of the remaining 4 samples failed to yield amplicons for any mammalian mtDNA. Pentobarbital was detected in 2 of these 4 samples. Results of PCR analysis correlated with the stated ingredient list for most, but not all samples. Conclusions and Clinical Relevance-Because canine and feline mtDNA were not found in a set of retail dog food samples, these results indicate that the source of pentobarbital in dog food is something other than proteins from rendered pet remains.
Article
Full-text available
Obesity and age are risk factors for feline diabetes. This study aimed to test the hypothesis that age, long-term obesity, and dietary composition would lead to peripheral and hepatorenal insulin resistance, indicated by higher endogenous glucose production (EGP) in the fasted and postprandial state, higher blood glucose and insulin, and higher leptin, free thyroxine, and lower adiponectin concentrations. Using triple tracer-(2)H(2)O, [U-(13)C(3)] propionate, and [3,4-(13)C(2)] glucose infusion, and indirect calorimetry-we investigated carbohydrate and fat metabolic pathways in overnight-fasted neutered cats (13 young lean, 12 old lean, and 12 old obese), each fed three different diets (high protein with and without polyunsaturated fatty acids, and high carbohydrate) in a crossover design. EGP was lowest in fasted and postprandial obese cats despite peripheral insulin resistance, indicated by hyperinsulinemia. Gluconeogenesis was the most important pathway for EGP in all groups, but glycogen contributed significantly. Insulin and leptin concentrations were higher in old than in young lean cats; adiponectin was lowest in obese cats but surprisingly highest in lean old cats. Diet had little effect on metabolic parameters. We conclude that hepatorenal insulin resistance does not develop in the fasted or postprandial state, even in long-term obese cats, allowing the maintenance of euglycemia through lowering EGP. Glycogen plays a major role in EGP, especially in lean fasted cats, and in the postprandial state. Aging may predispose to insulin resistance, which is a risk factor for diabetes in cats. Mechanisms underlying the high adiponectin of healthy old lean cats need to be further explored.
Article
Full-text available
The domestic hypercarnivores cat and mink have a higher protein requirement than other domestic mammals. This has been attributed to adaptation to a hypercarnivorous diet and subsequent loss of the ability to downregulate amino acid catabolism. A quantitative analysis of brain glucose requirements reveals that in cats on their natural diet, a significant proportion of protein must be diverted into gluconeogenesis to supply the brain. According to the model presented here, the high protein requirement of the domestic cat is the result of routing of amino acids into gluconeogenesis to supply the needs of the brain and other glucose-requiring tissues, resulting in oxidation of amino acid in excess of the rate predicted for a non-hypercarnivorous mammal of the same size. Thus, cats and other small hypercarnivores do not have a high protein requirement per se, but a high endogenous glucose demand that is met by obligatory amino acid-based gluconeogenesis. It is predicted that for hypercarnivorous mammals with the same degree of encephalisation, endogenous nitrogen losses increase with decreasing metabolic mass as a result of the allometric relationships of brain mass and brain metabolic rate with body mass, possibly imposing a lower limit for body mass in hypercarnivorous mammals.
Article
Full-text available
Experiments were conducted to evaluate amino acid digestibility of 32 commercial meat and bone meals (MBM) varying in raw material source and produced in seven different commercial cooking systems and at two processing temperatures (low vs high) that differed by 15 to 20 C. Raw material sources included all beef, all pork, mixed species, and high bone MBM. True digestibilities of amino acids were determined using the precision-fed cecectomized rooster assay. Protein efficiency ratio (PER) of six MBM varying greatly in amino acid digestibility was determined with chicks fed 10% CP diets containing a MBM as the sole source of dietary protein. The 32 MBM samples averaged 53.2% CP, 2.73% Lys, 0.6% Cys, and 0.75% Met on a DM basis. True digestibility averaged 82% for Lys, 87% for Met, and 47% for Cys. True digestibilities of amino acids varied substantially among processing systems and temperatures, particularly for Lys and Cys. For example, Lys and Cys digestibility ranged from 68 to 92% and from 20 to 71%, respectively, among different MBM. The higher processing temperature generally yielded lower amino acid digestibility than did the low processing temperature. A smaller, less consistent, effect was observed for raw material source. The PER values of the six selected MBM varied from 0.97 to 2.68 and were highly correlated with amino acid digestibility. These results indicated that very high amino acid digestibility MBM can be produced in commercial rendering systems. However, differences in processing systems and temperatures can cause substantial variability in amino acid digestibilities.
Article
Full-text available
Egg proteins contribute substantially to the daily nitrogen allowances in Western countries and are generally considered to be highly digestible. However, information is lacking on the true ileal digestibility of either raw or cooked egg protein. The recent availability of stable isotope-labeled egg protein allowed determination of the true ileal digestibility of egg protein by means of noninvasive tracer techniques. Five ileostomy patients were studied, once after ingestion of a test meal consisting of 25 g of cooked 13C- and 15N-labeled egg protein, and once after ingestion of the same test meal in raw form. Ileal effluents and breath samples were collected at regular intervals after consumption of the test meal and analyzed for 15N- and 13C-content, respectively. The true ileal digestibility of cooked and raw egg protein amounted to 90.9 +/- 0.8 and 51.3 +/- 9.8%, respectively. A significant negative correlation (r = -0.92, P < 0.001) was found between the 13C-recovery in breath and the recovery of exogenous N in the ileal effluents. In summary, using the 15N-dilution technique we demonstrated that the assimilation of cooked egg protein is efficient, albeit incomplete, and that the true ileal digestibility of egg protein is significantly enhanced by heat-pretreatment. A simple 13C-breath test technique furthermore proved to be a suitable alternative for the evaluation of the true ileal digestibility of egg protein.
Article
Full-text available
The effect of ash concentration on amino acid (AA) composition, true AA digestibility, and protein efficiency ratio (PER; weight gain per unit of protein intake) of meat and bone meal (MBM) was evaluated. Commercially rendered MBM samples containing 16 to 44% ash were obtained from two sources. Additional samples of MBM varying in ash from 9 to 63% were obtained by chloroform floatation or lab screening of a beef crax sample. Protein quality of selected MBM samples was assessed by determining true AA digestibility using the precision-fed cecectomized rooster assay and by a PER chick growth assay wherein chicks were fed 10% CP diets containing a MBM as the only source of dietary protein from 8 to 18 d of age. Increases in Ala, Pro, Gly, and Arg as a percentage of CP were observed in all MBM samples as ash percentage increased, with Pro and Gly accounting for most of the increase. In contrast, the levels (% of CP) of all essential AA, other than Arg, decreased as ash level increased. For example, Lys concentrations per unit of CP decreased from 5.7 to 4.0% as ash increased from 9 to 63%. There was little or no effect of ash content on AA digestibility of MBM varying in ash from 9 to 44%. The PER of MBM markedly decreased from 3.34 to 0.72 as ash increased from 16 to 44%, and most of the effects of ash on PER were not due to differences in dietary Ca and P levels. The results indicate that the reduction in protein quality of MBM as ash content increases is almost entirely due to a decrease in analyzed essential AA per unit of CP, not a decrease in digestibility of AA.
Article
Full-text available
Cats have a requirement for dietary protein two to three times that of omnivores and herbivores. This was reported to be due to the hepatic catabolic enzymes of this species being set to a permanently high level and, therefore, showing little adaptation to low dietary protein. A major mechanism for adapting to dietary protein in other species is amino acid oxidation (hereafter referred to as protein oxidation), and the objective of this study was to determine whether protein oxidation in cats was correlated with protein intake. Net protein and net fat oxidation in six adult cats were studied directly from gas exchanges using indirect calorimetry, after feeding moderate protein (MP; 35% energy) and high protein (HP; 52% energy) diets. Protein oxidation was significantly higher (P < 0.05) when cats were fed the HP diet (28.4 plus minus 0.7 mg/min) rather than the MP diet (20.4 plus minus 0.8 mg/min). Fat oxidation was significantly higher (P < 0.05) when cats consumed the MP diet (9.0 plus minus 0.7 mg/min) rather than the HP diet (4.7 plus minus 0.5 mg/min). Protein oxidation was significantly correlated (linear regression, R(2) = 46.0, P < 0.05) with protein intake such that the mean ratio of 18-h oxidation: 18-h intake was 1.2 on both diets. Fat oxidation was significantly correlated (linear regression, R(2) = 18.9, P < 0.05) with fat intake such that the mean ratio of 18-h fat oxidation: 18-h fat intake was 1.1 (MP) and 0.9 (HP). This study demonstrated that cats adapt net protein oxidation at these levels of protein intake, and the reason for the high dietary protein requirement of this species is, therefore, unclear.
Article
Full-text available
The cat (Felis silvestris catus) has a higher dietary protein requirement than omnivores and herbivores, thought to be due to metabolic inflexibility. An aspect of metabolic flexibility was examined with studies of whole-body protein turnover at two levels of dietary protein energy, moderate protein (MP; 20 %) and high protein (HP; 70 %), in five adult cats in a crossover design. Following a 14 d pre-feed period, a single intravenous dose of [15N]glycine was administered and cumulative excretion of the isotope in urine and faeces determined over 48 h. N flux increased (P<0.005) with dietary protein, being 56 (se 5) mmol N/kg body weight (BW) per d for cats fed the MP diet and 146 (se 8) mmol N/kg BW per d for cats fed the HP diet. Protein synthesis was higher (P<0.05) on the HP diet (75 (se 10) mmol N/kg BW per d; 6.6 (se 1) g protein/kg BW per d) than the MP diet (38 (se 5) mmol N/kg BW per d; 3.4 (se 0.4) g protein/kg BW per d). Protein breakdown was higher (P<0.05) on the HP diet (72 (se 8) mmol N/kg BW per d; 6.3 (se 0.7) g protein/kg BW per d) than the MP diet (44 (se 3) mmol N/kg BW per d; 3.9 (se 0.3) g protein/kg BW per d). Compared with other species the rate of whole-body protein synthesis in the well-nourished cat (9.7 (se 1.3) g protein/kg BW0.75 per d) is at the lower end of the range. These results show that feline protein turnover adapts to dietary protein as has been shown in other species and demonstrates metabolic flexibility. Further work is required to determine exactly why cats have such a high protein requirement.
Article
Full-text available
To determine whether there is a relationship between species-specific mitochondrial DNA (mtDNA), especially canine and feline mtDNA, and detectable amounts of pentobarbital in previously analyzed dog food samples. 31 dog food samples previously analyzed for pentobarbital (limit of detection, 1 microg/kg). Polymerase chain reaction (PCR) analysis was performed on dog food samples by use of PCR primers specific for either canine, feline, equine, bovine, porcine, ovine, or poultry mtDNA. PCR amplicons specific for feline or canine mtDNA at a 0.007% (70 microg/g [wt/wt basis]) or 0.0007% (7 microg/g) level, respectively, were not found in the 31 dog food samples. Most of the 31 dog food samples had a PCR amplicon on PCR analysis when a PCR primer set capable of simultaneously detecting mtDNA of cows, pigs, sheep, goats, deer, elk, and horses was used. Results of PCR analysis by use of primers specific for bovine, swine, sheep and goat, or horse mtDNA revealed amplicons specific for bovine or swine mtDNA only in 27 of the 31 samples. Analysis of the remaining 4 samples failed to yield amplicons for any mammalian mtDNA. Pentobarbital was detected in 2 of these 4 samples. Results of PCR analysis correlated with the stated ingredient list for most, but not all samples. Because canine and feline mtDNA were not found in a set of retail dog food samples, these results indicate that the source of pentobarbital in dog food is something other than proteins from rendered pet remains.
Article
Full-text available
Corn is a commonly used ingredient in dry pet foods because there is a stable supply and it is a relatively inexpensive source of nutrients. Corn hybrids are available that are higher in CP and amylose and lower in phytate concentration than conventional hybrids. Approximately 500 mg of high-protein (HP), high-protein, low-phytate (HPLP), and high-amylose (HA) corn were compared with conventional (CONV) corn and amylomaize starch (AM) in triplicate and exposed to pepsin/hydrochloric acid and pancreatin to simulate hydrolytic digestion. Substrate remaining after this was used to determine in vitro colonic fermentation. Organic matter disappearances as a result of hydrolytic digestion were >80% for CONV, HP, and HPLP, whereas HA (60.7%) and AM (43.7%) were lower (P < 0.05). Total digestion (TD) values after hydrolytic digestion and 8 h of fermentation using canine fecal inoculum were greater (P < 0.05) for CONV, HP, and HPLP vs. HA and AM. The residue left after hydrolytic digestion of all substrates was poorly fermented. Five ileal-cannulated dogs were fed each corn hybrid at approximately 31% of the diet in a 5 x5 Latin square design. Dogs fed diets containing HP corn had higher (P < 0.05) ileal OM digestibility (70.3%) and tended (P < 0.10) to have higher DM digestibility (64.6%). Ileal starch digestibilities were lower (P < 0.05) for dogs fed HA (64.0%) and AM (63.0%). Ileal digestibilities of essential (71.2%), nonessential (67.4%), and total (69.0%) AA tended to be higher (P < 0.10) for HP diets compared with CONV (66.4, 62.4, and 64.0%, respectively). Total-tract DM, OM, CP, and GE digestibilities (77, 82, 77, and 84%, on average, respectively) were higher (P < 0.05) for dogs fed CONV, HP, and HPLP than for those fed AM (66.9, 71.6, 72.6, and 76.5%) and HA (60.6, 65.7, 69.7, and 71.5%). Total-tract fat digestibilities were lower (P < 0.05) for dogs fed HA diets (86.6%) than for all other treatments (91.0%, on average). Total-tract starch digestibilities were higher (P < 0.05) for dogs fed CONV, HP, and HPLP (98%, on average) compared with HA (72.8%) and AM (76.5%). No differences were detected among treatments in fecal bifidobacteria, lactobacilli, or Clostridium perfringens concentrations. The experiments demonstrated that HP and HPLP corn had hydrolytic digestion and fermentation characteristics similar to those of CONV corn, whereas HA resulted in similar responses to AM, a well-established resistant starch ingredient.
Article
Full-text available
To evaluate the effect of dietary fat and energy density on body weight gain, body composition, and total energy expenditure (TEE) in neutered and sexually intact cats. 12 male and 12 female cats Male cats were castrated (castrated male [CM]) or underwent no surgical procedure (sexually intact male [IM]). Female cats underwent ovariectomy (spayed female [SF]) or laparotomy and ligation of both uterine tubes without ovary removal (sexually intact female [IF]). Cats were fed either the low-fat (LF) or high-fat (HF) diet for 26 weeks, with the final allocation consisting of 8 groups: IF-LF IF-HE SF-LF, SF-HF IM-LF, IM-HF, CM-LF, and CM-HF. Mean food intake for each group was recorded daily, and body weight was monitored weekly throughout the study. Body composition and TEE were measured before surgery in week 0 and at the end of the study (week 26) by isotope dilution (double-labelled water). N eutered cats gained significantly more body fat and body weight (53.80+/-5.79%) than sexually intact cats (27.11+/-5.79%) during the study. Body weight gain of neutered cats fed the HF diet was greater than those fed the LF diet. Following correction for body composition, TEE was similar in all groups and no pattern towards increased food intake was evident. Weight gain in neutered cats was decreased by feeding an LF, low energy-dense diet. To prevent weight gain in cats after neutering, a suitable LF diet should be fed in carefully controlled meals rather than ad libitum.
Article
Full-text available
A high concentration of dietary carbohydrate is suggested to increase the risk of obesity and diabetes mellitus in domestic cats. To evaluate this, food intake, body weight, fat mass and circulating adiposity-related factors were determined in twenty-four sexually mature (9-12 months) cats assigned to four six-cat dietary groups balanced for body weight and sex. The effect of dietary fat in exchange for carbohydrate at 9, 25, 44 and 64 % of metabolisable energy (ME) in a purified diet of constant protein:ME ratio was studied 13 weeks before and 17 weeks after gonadectomy (GX). Body weight did not significantly change among the cats before GX except for an increase of 17 (sem 5) % in cats given the highest-fat diet. Following GX, all groups gained body weight, and body fat mass was positively correlated (r 0.50; P < 0.04) with dietary fat percentage. Post-GX weight gains were much greater for females (+39 (sem 5) %) than males (+10 (sem 4) %). Plasma ghrelin concentration negatively correlated (P < 0.02) with dietary fat percentage and, before GX, was greater (P < 0.05) in females than males. Plasma insulin concentration increased with weight gain induced by high dietary fat. Plasma glucose, TAG and leptin concentrations were not affected by dietary fat percentage, GX or weight gain. These data provide evidence that in cats, high dietary fat, but not carbohydrate, induces weight gain and a congruent increase in insulin, while GX increases sensitivity to weight gain induced by dietary fat.
Article
Full-text available
The cooking of food is hypothesized to have played a major role in human evolution partly by providing an increase in net energy gain. For meat, cooking compromises the structural integrity of the tissue by gelatinizing the collagen. Hence, cooked meat should take less effort to digest compared to raw meat. Likewise, less energy would be expended digesting ground meat compared to intact meat. We tested these hypotheses by assessing how the cooking and/or grinding of meat influences the energy expended on its digestion, absorption, and assimilation (i.e., specific dynamic action, SDA) using the Burmese python, Python molurus. Pythons were fed one of four experimental diets each weighing 25% of the snake's body mass: intact raw beef, intact cooked beef, ground raw beef, and ground cooked beef. We measured oxygen consumption rates of snakes prior to and up to 14 days following feeding and calculated SDA from the extra oxygen consumed above standard metabolic rate. Postprandial peak in oxygen consumption, the scope of peak rates, and SDA varied significantly among meal treatments. Pythons digesting raw or intact meals exhibited significantly larger postprandial metabolic responses than snakes digesting the cooked ground meals. We found cooking to decrease SDA by 12.7%, grinding to decrease SDA by 12.4%, and the combination of the two (cooking and grinding) to have an additive effect, decreasing SDA by 23.4%. These results support the hypothesis that the consumption of cooked meat provides an energetic benefit over the consumption of raw meat.
Article
Full-text available
The effects of six extruded diets with different starch sources (cassava flour, brewer's rice, corn, sorghum, peas or lentils) on dog total tract apparent digestibility and glycemic and insulinemic response were investigated. The experiment was carried out on thirty-six dogs with six dogs per diet in a completely randomized design. The diets containing brewer's rice and cassava flour presented the greatest digestibility of dry matter, organic matter and gross energy (p < 0.05), followed by corn and sorghum; pea and lentil diets had the lowest. Starch digestibility was greater than 98% in all diets and was greater for brewer's rice and cassava flour than for lentils and peas diets (p < 0.05). Dogs' immediate post-prandial glucose and insulin responses (AUC < or = 30 min) were greater for brewer's rice, corn, and cassava flour diets (p < 0.05), and later meal responses (AUC > or = 30 min) were greater for sorghum, lentil and pea diets (p < 0.05). Variations in diet digestibility and post-prandial response can be explained by differences in chemical composition of each starch source including fibre content and starch granule structure. The nutritional particularities of each starch ingredient can be explored through diet formulations designed to modulate glycemic response. However, more studies are required to support these.
Article
Full-text available
Cats require more dietary protein than noncarnivorous species. Earlier work showed that cats lack the ability to regulate hepatic urea cycle enzymes in response to dietary protein concentration. We thus hypothesized that cats are unable to fully adapt protein oxidation to protein intake, particularly at low-protein concentrations. We used indirect respiration calorimetry to assess cats' ability to adapt substrate oxidation to diets containing different concentrations of protein, including 1 below their protein requirement. Nine cats (5 males and 4 females; 2.7 +/- 0.5 y; 4.49 +/- 0.19 kg) consumed each of 4 semipurified diets containing 7.5% [low protein (LP(3))], 14.2% [adequate protein (AP)], 27.1% [moderate protein (MP)], and 49.6% [high protein (HP)] of metabolizable energy from protein in a modified crossover design, beginning with the MP diet and then consuming the remaining diets in random order. After adaptation to each diet, cats completed a 5-d nitrogen balance trial and at least 2 12-h indirect calorimetry measurements. There was a significant effect of diet on protein oxidation (P < 0.0001), which measured 10.4 +/- 0.5, 14.1 +/- 1.0, 25.0 +/- 1.7, and 53.2 +/- 1.7% of total energy expenditure for the LP, AP, M,P and HP diets, respectively. The ratio of protein oxidation:protein intake was higher with the LP diet (1.39 +/- 0.07) than the other 3 diets (AP, 1.00 +/- 0.07; MP, 0.93 +/- 0.06; HP, 1.07 +/- 0.03; P < 0.0001), indicating a net loss of protein with the LP diet. Thus, cats are able to adapt protein oxidation to a wide range of dietary protein concentrations, provided their minimum protein requirement is met.
Article
Full-text available
The effects of diets with different starch sources on the total tract apparent digestibility and glucose and insulin responses in cats were investigated. Six experimental diets consisting of 35% starch were extruded, each containing one of the following ingredients: cassava flour, brewers rice, corn, sorghum, peas, or lentils. The experiment was carried out on 36 cats with 6 replications per diet in a completely randomized block design. The brewers rice diet offered greater DM, OM, and GE digestibility than the sorghum, corn, lentil, and pea diets (P < 0.05). For starch digestibility, the brewers rice diet had greater values (98.6%) than the sorghum (93.9%), lentil (95.2%), and pea (96.3%) diets (P < 0.05); however, starch digestibility was >93% for all the diets, proving that despite the low carbohydrate content of carnivorous diets, cats can efficiently digest this nutrient when it is properly processed into kibble. Mean and maximum glucose concentration and area under the glucose curve were greater for the corn-based diet than the cassava flour, sorghum, lentil, and pea diets (P < 0.05). The corn-based diets led to greater values for the mean glucose incremental concentration (10.2 mg/dL), maximum glucose incremental concentration (24.8 mg/dL), and area under the incremental glucose curve (185.5 mg.dL(-1).h(-1)) than the lentil diet (2.9 mg/dL, 3.1 mg/dL, and -40.4 mg.dL(-1).h(-1), respectively; P < 0.05). When compared with baseline values, only the corn diet stimulated an increase in the glucose response, occurring at 4 and 10 h postmeal (P < 0.05). The corn-based diet resulted in greater values for maximum incremental insulin concentration and area under the incremental insulin curve than the lentil-based diet (P < 0.05). However, plasma insulin concentrations rose in relation to the basal values for cats fed corn, sorghum, pea, and brewers rice diets (P < 0.05). Variations in diet digestibility and postprandial response can be explained by differences in the chemical composition of the starch source, including fiber content and granule structure, and also differences in the chemical compositions of the diets. The data suggest that starch has less of an effect on the cat postprandial glucose and insulin responses than on those of dogs and humans. This can be explained by the metabolic peculiarities of felines, which may slow and prolong starch digestion and absorption, leading to the delayed, less pronounced effects on their blood responses.
Article
Feed comprises the biggest cost in intensive fish farming and the quality of feed is therefore important. A vast body of research has been carried out in order to investigate nutritional quality of alternative ingredients. Effects of ingredients on physical quality are seldom included in these investigations. Physical quality of feed varies with ingredient composition and processing condition and may interfere with feed intake, nutrient digestibility and therefore growth performance of the fish. In this review, physical quality of extruded, high energy feed, and how ingredient composition and processing conditions affect the quality will be addressed. Various pellet properties will be discussed and methods used to evaluate physical quality will be reviewed.
Article
Reviews of the most recent literature on amino-acid and nitrogen requirements have shown that the minimal protein requirement (using a protein with a high NPU) of the growing kitten is about 20 per cent of the diet whether the requirement is based on the nitrogen content of the protein or upon its essential amino-acid content. Although this is higher than that required by the growing dog, rat or man, the difference is not as great (65 per cent higher) as the differential found for adult animals of these same species. That is, the adult cat requires 12–15 per cent dietary protein for maintenance compared with about 4–5 per cent for the adult rat, man and dog.
Article
Extrusion cooking, as a multi-step, multi-functional and thermal/mechanical process, has permitted a large number of food applications. Effects of extrusion cooking on nutritional quality are ambiguous. Beneficial effects include destruction of antinutritional factors, gelatinisation of starch, increased soluble dietary fibre and reduction of lipid oxidation. On the other hand, Maillard reactions between protein and sugars reduce the nutritional value of the protein, depending on the raw material types, their composition and process conditions. Heat-labile vitamins may be lost to varying extents. Changes in proteins and amino acid profile, carbohydrates, dietary fibre, vitamins, mineral content and some non-nutrient healthful components of food may be either beneficial or deleterious. The present paper reviews the mechanisms underlying these changes, as well as the influence of process variables and feed characteristics. Mild extrusion conditions (high moisture content, low residence time, low temperature) improve the nutritional quality, while high extrusion temperatures (200 °C), low moisture contents (<15%) and/or improper formulation (e.g. presence of high-reactive sugars) can impair nutritional quality adversely. To obtain a nutritionally balanced extruded product, careful control of process parameters is essential.
Article
While cooking has long been argued to improve the diet, the nature of the improvement has not been well defined. As a result, the evolutionary significance of cooking has variously been proposed as being substantial or relatively trivial. In this paper, we evaluate the hypothesis that an important and consistent effect of cooking food is a rise in its net energy value. The pathways by which cooking influences net energy value differ for starch, protein, and lipid, and we therefore consider plant and animal foods separately. Evidence of compromised physiological performance among individuals on raw diets supports the hypothesis that cooked diets tend to provide energy. Mechanisms contributing to energy being gained from cooking include increased digestibility of starch and protein, reduced costs of digestion for cooked versus raw meat, and reduced energetic costs of detoxification and defence against pathogens. If cooking consistently improves the energetic value of foods through such mechanisms, its evolutionary impact depends partly on the relative energetic benefits of non-thermal processing methods used prior to cooking. We suggest that if non-thermal processing methods such as pounding were used by Lower Palaeolithic Homo, they likely provided an important increase in energy gain over unprocessed raw diets. However, cooking has critical effects not easily achievable by non-thermal processing, including the relatively complete gelatinisation of starch, efficient denaturing of proteins, and killing of food borne pathogens. This means that however sophisticated the non-thermal processing methods were, cooking would have conferred incremental energetic benefits. While much remains to be discovered, we conclude that the adoption of cooking would have led to an important rise in energy availability. For this reason, we predict that cooking had substantial evolutionary significance.
Article
The present study aimed to evaluate the digestion rate and nutritional quality of pig muscle proteins in relation to different meat processes (aging, mincing, and cooking). Under our experimental conditions, aging and mincing had little impact on protein digestion. Heat treatments had different temperature-dependent effects on the meat protein digestion rate and degradation potential. At 70 °C, the proteins underwent denaturation that enhanced the speed of pepsin digestion by increasing enzyme accessibility to protein cleavage sites. Above 100 °C, oxidation-related protein aggregation slowed pepsin digestion but improved meat protein overall digestibility. The digestion parameters defined here open new insights on the dynamics governing the in vitro digestion of meat protein. However, the effect of cooking temperature on protein digestion observed in vitro needs to be confirmed in vivo.
Article
The objectives of this study were to determine differences in apparent total tract energy and macronutrient digestibility, fecal and urine characteristics, and serum chemistry of domestic cats fed raw and cooked meat-based diets and extruded diet. Nine adult female domestic shorthair cats were utilized in a replicated 3 × 3 Latin square design. Dietary treatments included a high-protein extruded diet (EX; 57% CP), a raw beef-based diet (RB; 53% CP), and a cooked beef-based diet (CB; 52% CP). Cats were housed individually in metabolic cages and fed to maintain BW. The study consisted of three 21-d periods. Each period included diet adaptation during d 0 to 16; fecal and urine sample collections during d 17 to 20; and blood sample collection at d 21. Food intake was measured daily. Total feces and urine were collected for determination of nutrient digestibility. In addition, a fresh urine sample was collected from each cat for urinalysis, and a fresh fecal sample was collected from each cat for determination of DM percentage and ammonia, short-chain fatty acid (SCFA), and branched-chain fatty acid (BCFA) concentrations. All feces were scored after collection using a scale ranging from 1 (hard, dry pellets) to 5 (watery, liquid that can be poured). Blood was analyzed for serum metabolites. Apparent total tract DM, OM, CP, fat, and GE digestibilities were greater (P ≤ 0.05) in cats fed RB and CB than those fed EX. Total fecal SCFA concentrations did not differ among dietary treatments; however, molar ratios of SCFA were modified by diet, with cats fed RB and CB having an increased (P ≤ 0.05) proportion of fecal propionate and decreased (P ≤ 0.05) proportion of fecal butyrate compared with cats fed EX. Fecal concentrations of ammonia, isobutyrate, valerate, isovalerate, and total BCFA were greater (P ≤ 0.05) in cats fed EX compared with cats fed RB and CB. Our results indicated that cooking a raw meat diet does not alter apparent total tract energy and macronutrient digestibility and may also minimize risk of microbial contamination. Given the increasing popularity of feeding raw diets and the metabolic differences noted in this experiment, further research focused on the adequacy and safety of raw beef-based diets in domestic cats is justified.
Article
Every clinician is asked "What should I feed my pet?" Understanding the ingredients in pet food is an important part of making the best recommendation. Pet food can be as simple as one ingredient or as complicated as containing more than 60 ingredients. Pet food and its ingredients are regulated by the Food and Drug Administration and state feed officials. Part of that regulation is the review and definition of ingredients. Existing ingredients change and new ingredients become available so the need for ingredient definitions grows. Ingredients for product formulations are chosen based on their nutrient content, digestibility, palatability, functionality, availability, and cost. As an example, a typical, nutritionally complete dry dog food with 42 ingredients is examined and the ingredients are discussed here. Safe, healthy pet food starts with safe ingredients sourced from well-monitored suppliers. The ultimate goal of both veterinarians and pet food manufacturers is the same--long healthy lives for dogs and cats.
Article
Groups of three or four male and female beagle dogs were maintained for 6 months on diets containing BHA at concentrations of 0 (control group), 0.25, 0.5 and 1.0% (w/w). The average daily intake of BHA was about 60 mg/kg body weight in the 0.25% group, 110 mg/kg in the 0.5% group and 220 mg/kg in the 1.0% group. All animals survived the entire experimental period without showing signs of toxicity other than a dose-related retardation of growth. Serum biochemical examinations conducted at 1, 3 and 6 months revealed a slight decrease in albumin concentration and an elevation of alkaline phosphatase and leucine aminopeptidase activity in the higher dose groups. Histopathological and histometrical examination showed no evidence of mucosal alteration in the stomach, oesophagus or duodenum attributable to the administration of BHA. The mitotic index in the squamous epithelium of the distal oesophagus was comparable in the control and BHA-treated groups. Liver weights were increased in BHA-treated groups, but there were no related histopathological changes. From these data it is concluded that feeding of BHA-supplemented diets at palatable concentrations for 6 months has no pathological effects on the stomach, oesophagus, duodenum or liver of beagle dogs.
Article
The pathology lesions from three studies, two with butylated hydroxyanisole (BHA) and one with butylated hydroxytoluene (BHT), are reviewed. When BHA was fed at 0.5 and 2.0% of the diet to F344 rats for two years, there was an increase in epithelial hyperplasia of the forestomach at both treatment levels. Papilloma and squamous-cell carcinoma of the forestomach were increased at the 2.0% level. When BHA was fed to beagle dogs at 1.0 and 1.3% of the diet for 180 days, no lesions/tumours of the distal oesophagus or stomach could be identified either at gross necropsy or by light or electron microscopy. The BHT was fed to Wistar rats at 0, 25, 100 and 250 mg/kg body weight. At the highest dose there was an increase in the number of rats with hepatocellular adenoma and with hepatocellular carcinoma.
Article
1.1. The hydrolysis of disaccharides by homogenates of small intestinal mucosa from five carnivorous mammals was investigated. Maltase, sucrase and lactase activities were present in the small intestine of the domestic cat, lion, ferret, dog and polar bear. Trehalase activity was absent from the intestine of the domestic cat and lion, but was present in the other carnivores.2.2. A detailed investigation was made of intestinal lactase levels in cats of various ages. Lactase activity was high at birth and decreased to relatively low levels in the adult animal. The decline in activity occurred most rapidly during 4–7 weeks of age, which coincides with the weaning period.3.3. Evidence for the existence of at least two intestinal β-galactosidases in the domestic cat was obtained. One is a soluble enzyme which hydrolyses ortho-nitrophenyl β-galactoside but not lactose; the other is a particulate enzyme which catalyses the hydrolysis of both substrates.
Article
The effect of starch and sugars on blood sugar level and renal excretion of sugars and galactitol was investigated. Fifty-nine adult cats were divided into seven dietary groups (carbohydrate content in dry matter): STARCH (29-37% starch, decomposed or raw), SUC (36% sucrose), LAC1 and LAC2 (11 and 28% lactose, respectively), GLUC (40% glucose), GAL (39% galactose) and a carbohydrate-free control diet, FAT. Diet STARCH did not significantly influence postprandial blood glucose level (3.65 +/- 0.68 mmol/l +/- SD, n = 16) compared with diet FAT (3.20 +/- 0.77 mmol/l, n = 14) 1, 3 or 6 h after feeding (weighted means). Diet GLUC led to a steep rise in blood glucose concentration 1 h after feeding (5.08 +/- 0.69 mmol/l, n = 6). Diet SUC induced a mild persistent hyperglycemia without marked postprandial changes (4.52 +/- 0.52 mmol/l, n = 15, weighted mean of 0, 3 and 6 h post-prandially). Diet GAL induced persistent hypoglycemia before and after feeding (2.58 +/- 0.38 mmol/l, n = 13) and considerable postprandial galactosemia (3.26 +/- 1.38 mmol/l, n = 7). In the groups STARCH and FAT, glucose was only detectable in traces in urine, whereas all diets containing sugars led to glucosuria. In group SUC, fructose and sucrose were found in urine and in both lactose groups galactose and lactose were found. Diet GAL led to galactosuria (140 mmol galactose/l). In group LAC1, and especially in group GAL, galactitol was detected in urine. These results point to a rather limited capacity of the cat to metabolize sugars.
Article
Two chick growth experiments and a precision-fed cockerel digestibility assay were conducted to evaluate the effect of extrusion and expelling on the nutritive value of conventional (CSB) and Kunitz trypsin inhibitor-free (KFSB) soybeans. In the first experiment, performance of chicks fed CSB or KFSB autoclaved at 121 C was similar to that of chicks fed CSB or KFSB extruded at 138 C. The effect of extrusion temperature on protein quality of the soybeans was evaluated in the second experiment. Eleven corn-soybean diets were formulated to contain one of the following: CSB extruded at 104, 121, 138, or 154 C; KFSB extruded at 104, 121, or 138 C; CSB extruded at 121, 138, or 154 C followed by processing through an expeller; and commercial dehulled solvent-extracted soybean meal (SBM). All diets contained 20% crude protein and the same amount of soybean oil and were fed to chicks from 7 to 21 days of age. The CSB extruded at 104 or 121 C and KFSB extruded at 104 C yielded depressed growth and feed efficiency compared with SBM. Performance of chicks on the other treatments was similar to that of chicks fed SBM. Pancreas weight (as a percentage of BW) decreased as extrusion temperature increased, with the response being greater for CSB. Growth performance was greater and pancreas weights were lower for chicks fed KFSB extruded at 104 or 121 C compared with those of chicks fed CSB extruded at the same temperatures. Expelling improved weight gain and feed efficiency when CSB was extruded at 121 C. A 48-h digestibility assay with cecectomized cockerels indicated that digestibility of amino acids in CSB and KFSB increased as extrusion temperature increased and that digestibilities of amino acids in CSB extruded at 104 or 121 C were lower than those in KFSB extruded at the same temperatures. Results of this study indicated that extrusion of CSB at 138 to 154 C or extrusion of KFSB at 121 to 138 C yields protein quality similar to that of SBM.
Article
We conducted experiments to determine amino acid (AA) digestibility of nine animal by-product meals using precision-fed cecectomized roosters and ileally cannulated dogs. The products initially evaluated in roosters were meat and bone meals (MBM) containing 24 or 34% ash, poultry by-product meals (PBP) containing 7 or 16% ash, lamb meals (LM) containing 15 or 24% ash, a LM analog containing a mixture of LM and turkey meal, and two MBM processed at either a low or high temperature. The MBM and PBP differing in ash, low-ash LM, and low-temperature MBM then were incorporated into extruded dry dog foods and evaluated in cecectomized roosters and ileally cannulated dogs. True digestibility of total AA in roosters averaged 76% for the nine meals fed alone, with the low-temperature MBM being highest at 84% and the low-ash LM being lowest at 66% (P < .05). No consistent differences in rooster AA digestibility were observed between pairs of meals differing in ash content. Digestibilities of AA were higher in the low-temperature MBM than in the high-temperature MBM. Differences in rooster AA digestibility values among the six extruded dog foods containing selected animal meals were similar to those observed when the animal meals were fed alone. The ileally cannulated dog assay yielded results for AA digestibilities that were highly correlated (r = .87 to .92) with those of the rooster assay, whereby the high-ash MBM and low-temperature MBM foods had the highest mean AA digestibility at 82% and the low-ash LM food had the lowest mean AA digestibility at 62% (P < .05). Again, no consistent differences in AA digestibilities for dogs were observed between pairs of dog foods containing MBM or PBP differing in ash content. Results of this study indicated that processing temperature influenced AA digestibility of MBM, but species raw material source and ash content had no consistent effect on AA digestibility. Results also indicated that the precision-fed cecectomized rooster assay could be used to predict differences in AA digestibility among animal by-product meals for dogs.
Article
Approximately 25 to 40% of the DM in premium dog diets is animal by-product. However, limited information is available regarding the compo- sition and digestibility of these by-products, especially small intestinal digestibility. The effects of raw and rendered animal by-products incorporated into dog diets on nutrient digestion at the ileum and in the total tract were studied in this experiment. Diets fed contained various animal by-products including a rendered beef meat and bone meal (RMBM); fresh beef (FB); poultry by-product meal (PBPM); fresh poultry (FP); a plant-based control protein source, defatted soy flour (DS); and an animal-based control protein source, dehydrated whole egg (WE). The diets were extruded and kibbled. By-products varied widely in concentrations of OM, CP, amino acids, and fat. Nutrient intakes were numerically higher for FB than for all other treatments. All nutrient intakes were higher ( P < .03) for the FB treatment than for the RMBM treatment. Digestibilities of DM, OM, CP, fat, and GE at the ileum were higher ( P < .06) when dogs were fed diets containing FP than when fed diets containing PBPM. Amino acids were highly digestible at the ileum; however, digestibilities of all amino acids except cystine were higher ( P < .04) for the diets incorporating FP vs PBPM. Total tract digestion was different among treatments for DM ( P < .02), OM ( P < .01), and GE ( P < .02), and diets containing animal by-products were similar in total tract digestibility, greater than the DS control, and lower than the WE control. Rendering of poultry, but not beef, seemed to have a slight negative influence on small intestinal, but not total tract, digestibility by dogs.
Article
Cereal grains represent 30 to 60% of the DM of many companion animal diets. Once incorporated into a diet, the starch component of these grains can provide an excellent source of ME. However, crystallinity and form of starch are variable and can cause incomplete digestion within the gastrointestinal tract. Diets fed in this experiment included one of six high-starch flours as the main source of carbohydrate. The flours originated from barley, corn, potato, rice, sorghum, and wheat. The diets were extruded and kibbled. Starch fraction concentrations of flours consisted of nearly 100% rapidly digestible starch (RDS) and slowly digestible starch (SDS) combined. Starch fraction concentrations of diets paralleled concentrations in flours. Flours varied widely in concentrations of CP, fat, starch, and total dietary fiber. Ileal OM and CP digestibilities were lowest for the potato flour treatment (74 and 64%, respectively). Ileal and total tract starch digestibilities were different (P<.05) among treatments; however, the starch component of all diets was nearly completely digested (>99%). Total tract digestibility of DM and OM was lowest for sorghum (80 and 84%, respectively) compared to all other diets. Crude protein digestibility was highest for corn (87%). Wet fecal weights tended (P<.08) to be greatest for dogs fed the barley treatment (175 g/d). However, dry fecal weights (dried at 55 degrees C) were greatest for dogs consuming the sorghum diet (51 g/d). Fecal scores were consistently greater (i.e., looser stools) for the barley treatment. Any of these flours could be used without negative effects on digestion at either the ileum or in the total tract. Fecal consistency data for dogs consuming the barley treatment indicate that diets containing large amounts (>50%) of barley may not be advantageous for dog owners who house their animals indoors for most of the day.
Article
Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are widely used antioxidant food additives. They have been extensively studied for potential toxicities. This review details experimental studies of genotoxicity and carcinogenicity which bear on cancer hazard assessment of exposure to humans. We conclude that BHA and BHT pose no cancer hazard and, to the contrary, may be anticarcinogenic at current levels of food additive use.
Article
To establish a model for inheritance of gluten-sensitive enteropathy (GSE) in Irish Setters. 44 dogs of a 6-generation family of Irish Setters with GSE and 7 healthy Irish Setters. Phenotype of each dog was determined after oral administration of gluten in the weaning diet, using morphometric evaluation of jejunal biopsies (all generations) and measurement of small intestinal permeability by use of a lactulose-rhamnose permeation test (generations 1, 2, and 3). Overall probability for each of 4 genetic models of inheritance (autosomal recessive, autosomal dominant, sex-linked recessive, and sex-linked dominant) accounting for segregation of partial villus atrophy within the entire family was calculated. The autosomal recessive model was most tenable and was 56,250 times more likely to account for segregation of partial villus atrophy than the autosomal dominant model, assuming disease prevalence of 0.8%. Both sex-linked models were untenable. These conclusions were robust to the error attached to estimation of disease prevalence. High intestinal permeability without morphometric jejunal abnormalities in 4 of 20 dogs in the 3 youngest generations suggested heterogeneity of lesions associated with GSE. Genetic transmission of GSE is under the control of a single major autosomal recessive locus.
Article
To elucidate the impact of dietary influence on carbohydrate and lipid metabolism and on the development of diabetes mellitus in the carnivorous cat, a 3 weeks feeding trial was carried out on six sexually intact and six neutered adult male cats. The effects of two isonitrogenic diets, differing in carbohydrate and fat content, were investigated on plasma metabolite levels in a 24-h blood sampling trial. Plasma leptin concentrations were also determined at the beginning and at the end of the 24-h trial. Glucose and insulin response was measured in an i.v. glucose tolerance test. A 5 days long digestion trial was also performed, which revealed a high digestion capacity of both fat and carbohydrates in cats. The high fat diet induced a significant rise in the plasma triglyceride, FFA, beta-hydroxybutyrate and cholesterol concentration, while the elevation in the glucose level did not reach significance. In the glucose tolerance test no significant difference was found between the neutered and intact cats. However, independently of the sexual state, the cats on the high fat diet showed a slightly elongated glucose clearance and reduced acute insulin response to glucose administration. This is indicative of diminished pancreatic insulin secretion and/or beta-cell responsiveness to glucose. The results of this preliminary study may be the impetus for a long-term study to find out whether it is rather the fat rich ration than carbohydrate rich diet that is expected to impair glucose tolerance and thus might contribute to the development of diabetes mellitus in cats. Whether the alteration in glucose metabolism is due to altered leptin levels remains to be determined.
Article
Food allergy (FA) is defined as "all immune-mediated reactions following food intake," in contrast with food intolerance (FI), which is non-immune-mediated. Impairment of the mucosal barrier and loss of oral tolerance are risk factors for the development of FA. Type I, III, and IV hypersensitivity reactions are the most likely immunologic mechanisms. Food allergens are (glyco-)proteins with a molecular weight from 10-70 kDa and are resistant to treatment with heat, acid, and proteases. The exact prevalence of FA in dogs and cats remains unknown. There is no breed, sex or age predilection, although some breeds are commonly affected. Before the onset of clinical signs, the animals have been fed the offending food components for at least two years, although some animals are less than a year old. FA is a non-seasonal disease with skin and/or gastrointestinal disorders. Pruritus is the main complaint and is mostly corticoid-resistant. In 20-30% of the cases, dogs and cats have concurrent allergic diseases (atopy/flea-allergic dermatitis). A reliable diagnosis can only be made with dietary elimination-challenge trials. Provocation testing is necessary for the identification of the causative food component(s). Therapy of FA consists of avoiding the offending food component(s).
Article
The effect of meat cooking was measured on myofibrillar proteins from bovine M. Rectus abdominis. The heating treatment involved two temperatures (100 degrees C during 5, 15, 30, and 45 min and 270 degrees C during 1 min). Protein oxidation induced by cooking was evaluated by the level of carbonyl and free thiol groups. Structural modifications of proteins were assessed by the measurement of their surface hydrophobicity and by their aggregation state. With the aim of evaluating the impact of heat treatment on the digestive process, myofibrillar proteins were then exposed to proteases of the digestive tract (pepsin, trypsin, and alpha-chymotrypsin) in conditions of pH and temperature that simulate stomach and duodenal digestion. Meat cooking affected myofibrillar protein susceptibility to proteases, with increased or decreased rates, depending on the nature of the protease and the time/temperature parameters. Results showed a direct and quantitative relationship between protein carbonylation (p<0.01) and aggregation (p<0.05) induced by cooking and proteolytic susceptibility to pepsin. However, no such correlations have been observed with trypsin and alpha-chymotrypsin.
Is carbohydrate essential for pregnancy and lactation in dogs Nutrition of the dog and cat: Waltham symposium No. 7. Cambridge (United Kingdom): Cambridge Uni-versity Press
  • Blaza
  • Booles D Se
  • Burger
  • Ih
Blaza SE, Booles D, Burger IH. Is carbohydrate essential for pregnancy and lactation in dogs?. In: Burger IH, Rivers JP, editors. Nutrition of the dog and cat: Waltham symposium No. 7. Cambridge (United Kingdom): Cambridge Uni-versity Press; 1989. p. 229–42.
A simple method for estimating the metab-olizable energy content of dry cat foods
  • G Kuhlman
  • Laflamme Dp
  • Ballam
  • Jm
Kuhlman G, Laflamme DP, Ballam JM. A simple method for estimating the metab-olizable energy content of dry cat foods. Fel Pract 1993;21:16–20.
NOVA: Can I eat that? " aired on NOVA on PBS channels
  • Hamilton D J Sweet
Hamilton D, Sweet J. " NOVA: Can I eat that? " aired on NOVA on PBS channels. Transcript. WGBH Educational Foundation. 2012. Available at: http://www.pbs. org/wgbh/nova/body/can-i-eat-that.html. PBS airdate October 31, 2012.
Corn: chemistry and technology St Paul (MN): Am Assoc Cereal Chemists
  • White
  • Pj
  • La Johnson
White PJ, Johnson LA. Corn: chemistry and technology. 2nd edition. St Paul (MN): Am Assoc Cereal Chemists; 2003.