Application of Encapsulated and Dry-plated Food Acidulants to Control Salmonella enterica in Raw Meat-based Diets for Dogs.

There is an increasing demand for raw meat-based diets (RMBDs) for dogs, but these foods cannot be heat-pasteurized. Thus, the objective of this study was to evaluate the antimicrobial efficacy of encapsulated and dry-plated glucono delta lactone (GDL), citric acid (CA), and lactic acid (LA) when challenged against Salmonella enterica inoculated in a model raw meat-based diet (RMBDs) for dogs. Nutritionally complete, raw diets were formulated with different levels (1.0, 2.0 and 3.0% (w/w)) of both encapsulated and dry-plated GDL, CA, and LA with both the positive (PC) and the negative controls (NC) without acidulants. The diets were formed into patties of ∼100 g and inoculated with 3-cocktail mixtures of Salmonella enterica serovars, excluding the NC to achieve a final concentration of ∼6.0 Log CFU/patty. Microbial analyses were performed on the inoculated diets and survivors of S. enterica enumerated. Both encapsulated and dry-plated CA and LA had higher log reductions compared to GDL (P < 0.05). However, encapsulated CA and LA at 1.0% (w/w) exhibited higher log reductions (P > 0.05) and preserved product quality compared to the dry-plated acidulants at 1.0%. We concluded that 1.0% (w/w) of encapsulated citric or lactic acids could be successfully applied as an antimicrobial intervention in raw diets for dogs.

Physicochemical Parameters of Raw Pet Food and Dehydrated Pet Treats Developed from Beef Processing Co-Products.

Pet humanization and premiumization of pet foods have led to significant changes in the co-product market, as pet food companies are looking for more profitable protein sources for their products. Co-products such as beef liver (BL) and beef heart (BH) can be combined to generate restructured pet foods rich in vitamins and nutrients. Sodium alginate and encapsulated calcium lactate (ALGIN) can improve the acceptability of meat pieces by transforming them into a singular shape. The objective of this experiment was to assess the physiochemical parameters of co-products for utilization in raw pet foods and restructured pet treats generated from BL and BH by using ALGIN as a structure-forming agent. Results demonstrated increased cooking loss as ALGIN inclusion decreased, but cooking loss decreased as BL proportions increased (p = 0.0056). Expressible moisture of raw pet food decreased as ALGIN inclusion increased, but more moisture was released from treats when BL proportions increased (p < 0.0001). Increasing ALGIN and BH led to increased water activity of cooked treats (p < 0.0001). Thus, we suggest that BL and BH combinations with ALGIN inclusion produces a viable platform for higher inclusions of co-products in pet treats. Additionally, these ingredients improved the finished product quality characteristics of raw pet foods.

Shelf-Life Evaluation of Ingredient Combinations and Technologies for Use in Pet Food Formulations.

Poultry co-product chicken frames (CF) and wooden breast (WB) along with ingredient technology use may bring enhanced value to the pet food industry. Therefore, the current study focused on evaluating CF and WB combinations along with sodium alginate and encapsulated calcium lactate pentahydrate (ALGIN) inclusion within a fresh pet food formulation under simulated shelf-life conditions. Fresh chicken frames (CF) and boneless-skinless wooden breast (WB) were ground and allocated randomly to one of ten treatment combinations with either 0.5 or 1.0% added ALGIN. Ground treatments were placed into a form and fill vacuum package and stored using a reach-in refrigerated case for 21 days. Packages were evaluated for instrumental surface color, lipid oxidation, water activity, and pH on days 1, 3, 7, 14 and 21 of the display. Packages of pet food were lighter, less red, and more yellow (p < 0.05) with increasing percentages of CF regardless of ALGIN inclusion, whereas pH was greater (p < 0.05) and lipid oxidation was less (p < 0.05) with increasing percentage of WB. Water activity increased (p < 0.05) when WB and ALGIN inclusion increased. The current results suggest that the use of ALGIN in a poultry co-product pet food formulation can improve shelf-life characteristics such as surface color and lipid oxidation in fresh pet food.

Effect of dietary fat source and exercise on odorant-detecting ability of canine athletes.

Eighteen male English Pointers (2-4 years of age, 23.94+/-0.54 kg body weight) were allotted to three diet and two physical conditioning groups to evaluate the effect of level and source of dietary fat on the olfactory acuity of canine athletes subjected to treadmill exercise. Diet groups (6 dogs/diet) consisted of commercially prepared diets (minimum of 26% crude protein) containing 12% fat as beef tallow (A), 16% fat provided by equivalent amounts of beef tallow and corn oil (B), or 16% fat provided by equivalent amounts of beef tallow and coconut oil (C). This dietary formulation resulted in approximately 60% of the total fatty acid being saturated for diets A and C, while approximately 72% of the total fatty acids were unsaturated in diet B. One-half of the dogs within each dietary group were subjected to treadmill exercise 3 times per week for 30 min (8.05 km/h, 0% grade) for 12 weeks. All dogs were subjected to a submaximal exercise stress test (8.05 km/h, 10% slope for 60 min) every four weeks beginning at week 0. Olfactory acuity was measured utilizing behavioral olfactometry before and after each physical stress test. Non-conditioned (NON) dogs displayed a greater decrease (P<0.05) in olfactory acuity following exercise, while physically conditioned (EXE) dogs did not show a change from pre-test values. A diet by treatment interaction (P<0.10) was detected over the course of the study. NON dogs fed coconut oil had decreased odorant-detecting capabilities when week 4 values were compared with week 12 values. Feeding a diet that is predominately high in saturated fat may affect the odorant-detecting capabilities of working dogs. Additionally, these data indicate that utilization of a moderate physical conditioning program can assist canine athletes in maintaining olfactory acuity during periods of intense exercise.

Effects of exercise on canine skeletal muscle proteolysis: an investigation of the ubiquitin-proteasome pathway and other metabolic markers.

The effects of long-term athletic training are associated with excessive skeletal muscle turnover attributable to increased rates of myofibrillar protein synthesis and proteolysis, which are mechanisms poorly understood in the athletic dog. A physiologic field study using 44 English pointers and Labrador retrievers that had been purposely bred for bird hunting and retrieving was conducted to examine changes in the ubiquitin-proteasome (UP) pathway, which has been implicated in exercise-induced proteolysis. Muscle biopsy samples were collected from all dogs in September (preseason, pretraining) and February (peak season, peak activity). Western blot analysis was used to assess changes in expression of various components of the UP pathway in the biopsy samples. Citrate synthase and glycogen levels were also measured in a subset of these samples. Results across the population indicated pronounced up-regulation of ubiquitinated conjugates and the p31 regulatory capping subunit during the peak hunting period compared with the preseason period. In contrast, the catalytic core of the proteasome (beta-subunits) showed no apparent up-regulation in response to increased physical activity. Increased physical activity during the hunting season was associated with increased muscle glycogen levels and citrate synthase activity in these dogs. Overall, up-regulation of specific components of the UP pathway was an indication that it plays a role in the proteolytic process associated with skeletal muscle turnover during long-term athletic training, as previously believed.