Nutritional adequacy in terms of minimum nutrient requirements for dogs and cats is based on cumulated research and updated periodically in the National Research Council (NRC) Nutrient Requirements for Dogs and Cats1
. These recommendations are typically based on studies using purified diets rather than commercial diets. To compensate for potential reductions in bioavailability, the Association of American Feed Control Officials (AAFCO) publishes its own nutrient profiles for dogs and cats to account for these reductions and potential processing losses2
. The AAFCO nutrient profiles are published yearly and are what the pet food industry uses as guidelines in formulating dog and cat commercial diets.
Besides setting minimum nutrient requirements, nutritional adequacy claims for commercial pet foods are based on procedures and protocols established by AAFCO2
. One method of establishing an adequacy claim in the United States is to conduct a feeding trial following AAFCO established protocols. Adequacy claims can also be made from calculated nutrient content of diet formulas using a nutrient data bank or actual chemical analysis of the diets with or without feeding trials. The pet food industry though uses ingredients than can have a wide variation in actual nutrient content and bioavailability. Therefore, feeding protocols are considered the “gold standard” in evaluating pet food for nutritional adequacy. Because of the increased costs involved, not all pet food companies perform feeding trials on their foods.
Grain-free diets are one of the largest growing segments of the pet food market right now. More and more pet owners are buying into the concept that dogs are strict carnivores like their ancestor the wolf, and that feeding grains can be harmful to dogs. Contrary to popular opinion, recent studies have shown through genomic sequencing that dogs have adapted to a diet rich in starch compared to wolves, through selection of genes for starch digestion3
. There is no reliable evidence that it is harmful to feed grains to dogs. The majority of dogs and cats are very efficient at utilizing the nutrients provided in grains, including protein, vitamins, minerals, fiber and essential fatty acids4
Many pet food companies are substituting grains with legumes or pulses (beans, lentils, peas) or potatoes in their grain-free diets. In association with more and more dogs eating grain-free diets, the FDA has been investigating a link between dogs being fed these diets and dilated cardiomyopathy (DCM)5,6
. Diet-related DCM has also been traced to diets formulated for dogs with exotic ingredients (i.e. exotic meats, fruits or vegetables).
The purpose of this AAFCO Adult maintenance trial was to evaluate the nutritional adequacy of Freshpet’s Vital Grain Free Complete Meal Chicken, Beef, Salmon & Egg Recipe in a group of large breed dogs. In addition, an evaluation of both plasma and whole blood taurine status was done on all the dogs. Taurine deficiency has been found in some of the dogs that have developed diet-related DCM.
Eight healthy adult English Pointer dogs between the ages of 1 – 5 years old were used as the control group, and eight healthy Pointer dogs between the age of 1 – 5 years old were used in the test group. All dogs starting the protocol passed an initial physical examination by a veterinarian. The control group was fed a diet containing rice and oats, Purina One Smart Blend Chicken and Brown Rice canned, exclusively throughout the trial, and the test group was fed Freshpet Vital Grain Free Complete Meal Chicken, Beef, Salmon & Egg Recipe throughout the trial. See Table 1 for ingredient list and analysis. The control group dieta
had previously passed an AAFCO adult maintenance feeding protocol. The diets were the sole source of nutrients, except for water which was available at all times. All dogs were fed based on their current weight and energy needs and were kept within 15% of starting weights. To determine food intake, all food was weighed before and after each feeding and the difference determined. The feeding trial was run for 26 weeks, with individual body weight measured and recorded at the beginning, weekly, and at the end of the trial. To pass the feeding trial, no individual dog shall lose more than 15% of its initial body weight, and the average percent body weight change (final compared to initial) shall not be less than 10%.
An AAFCO Adult Maintenance trail requires hemoglobin, packed cell volume (PCV), albumin, and alkaline phosphatase be measured and recorded at the end of the feeding trial. The average final hemoglobin, PCV, albumin and alkaline phosphatase shall not be less the:
- Hemoglobin – 14.0 g/dL (no individual < 12.0 g/dL)
- PCV – 42% (no individual < 36%)
- Albumin – 2.8 g/dL (no individual < 2.4 g/dL)
- Alkaline Phosphatase – 150 IU/L (no individual >300 IU/L)
Whole blood was drawn at the end of the study for hemoglobin, PCV, Albumin and Alkaline phosphatase analysis. For taurine analysis, an additional 2.0 ml of whole blood was drawn with 1 ml placed in sodium heparin tube, and 1 ml placed in sodium heparin tube and centrifuged with the heparin plasma placed in another clean tube. Both whole blood and plasma tubes were immediately submitted to the Amino Acid Analysis Laboratory at the University of California/Davis for whole blood and plasma taurine analysis.
Here you will find
the results of this study.