The current study was part of a larger investigation (Dobenecker, 2002). The apparent digestibility of protein, fat, nitrogen-free extract (N-free extract) and organic matter as well as energy of a tripe and rice-based diet supplemented either with normal calcium or excess calcium was determined in growing dogs of two breeds, Beagles and Foxhound-Boxer-Ingelheim Labrador crossbred dogs (FBIs).

Apparent energy digestibility was significantly impaired by excess calcium in both breeds, with the effect stronger in FBIs than in Beagles. The same was true for organic matter, N-free extract, crude protein and fat. The decrease in protein and fat digestibility was significant in FBIs but not Beagles. By contrast, the apparent digestibility of ash was lower in FBIs than in Beagles.

The results of the current study suggest excess dietary calcium may be associated with systematic differences in nutrient digestibility by different breeds of dogs.

Source : B. Dobenecker et al., 2010. High calcium intake differentially inhibits nutrient and energy digestibility in two different breeds of growing dogs. JAPAN online June 2010. doi: 10.1111/j.1439-0396.2010.00989.x