Apparent and true digestibility of macro and micro nutrients in adult maintenance dog foods containing either a majority of animal or vegetable proteins1

by Selleckchem | Jan 31 2024

There is dearth of knowledge with regards to mineral digestibility of ingredients in canines, and current knowledge is focused on the digestibility of supplemented minerals, not on intrinsic mineral digestibility of ingredients. The objectives of the present study were to determine the apparent and true digestibility (TD) of macronutrients and micronutrients, and the total tract gastrointestinal endogenous nutrient outputs in canines fed either animal- or vegetable-based adult maintenance diets. Eight purpose bred Beagles (two intact males, six spayed females) of similar age (2.12 ± 0.35 yr, mean ± SD) and weight (9.92 ± 0.73 kg, mean ± SD) were pair housed in kennels but fed individually based on individual maintenance energy requirements. Two basal diets (animal and vegetable protein based) were formulated to meet nutritional requirements of adult canines. Two additional trial diets were created, using the basal diets, by diluting diets by 50% with anhydrous α-d-glucose to attempt to quantify endogenous mineral losses and enable calculation of TD. All diets contained titanium dioxide at 0.3% for calculations of nutrient digestibility. Dogs were provided with deionized water as their only source of water throughout the trial. Dogs in a specific kennel were randomly assigned to an experimental diet for 10 d (experimental period), and fecal samples were collected the last 4 d of each period. All dogs were fed all experimental diets in random order based on a 4 × 4 replicated Latin square design. Dogs fed intact diets had a higher apparent mineral digestibility compared to dogs fed diluted diets (P < 0.05). Apparent phosphorus digestibility was higher for dogs fed the diet 2 compared with the diet 1 (P = 0.01) and the diluted diets (P < 0.001). There was a trend towards a greater TD of Cu for dogs fed the diet 2 compared with the diet 1 (P = 0.08). P, Mg, Zn, and Mn true digestibilities were higher for dogs fed the diet 2 compared with the diet 1 (P < 0.05, P = 0.01, P = 0.02, P = 0.009, respectively). These results suggest that apparent and TD do not result in similar values. Further research should be conducted on TD in canines only if a better model is developed.

Comments:

This study delves into the digestibility of various nutrients in canines based on different diets, aiming to understand how animals process minerals and other nutrients. It seems they observed differences in apparent mineral digestibility between dogs fed intact diets and those fed diluted diets, indicating that the form and concentration of nutrients in the diet can impact how effectively the body absorbs these minerals.

Interestingly, the study found higher apparent phosphorus digestibility in one diet compared to another and also noticed trends in the true digestibility of copper, phosphorus, magnesium, zinc, and manganese. These differences emphasize the complexity of nutrient absorption and the need for a more comprehensive understanding of mineral digestibility in canine diets.

The distinction between apparent and true digestibility is crucial. Apparent digestibility considers all ingested nutrients, while true digestibility factors in endogenous losses (in this case, using glucose dilution to quantify losses) to provide a more accurate measure.

The suggestion for further research is quite important. Developing more precise models will help in understanding the intricacies of mineral digestion in canines, which could have implications for formulating more optimal and nutritious diets for our furry friends.