This study focused on dietary crude fiber (CF) and macromineral (Na, K, Ca, P, Mg) composition and apparent digestibility (aD) of organic matter and macrominerals in rabbits (a total of 180 measurements with 12 individuals and 10 different diets) as compared to guinea pigs and horses.
Significant negative relationships between dietary crude fiber and aD of organic matter were obtained, but the significant difference in digestive efficiency between rabbits and guinea pigs reported from studies where both species had been investigated under identical conditions were not detectable in the larger data collection. However, the 95% confidence interval of the negative slope of the crude fiber-aD of organic matter relationship did not overlap between domestic horses on the one hand, and rabbits and guinea pigs on the other hand, indicating a less depressing effect of crude fiber in horses.
Akaike's information criterion indicated that aD of a macromineral did not only depend on its concentration in the diet, but also on the individual and various other diet characteristics and the presence of other macrominerals, indicating complex interactions. The data indicate similar mechanisms in the absorption of macrominerals amongst rabbits, rodents and horses, with the exception of Na and K in guinea pigs and Ca in chinchillas that should be further corroborated.
Source: K.B. Hagen et al., 2015. Organic matter and macromineral digestibility in domestic rabbits (Oryctolagus cuniculus) as compared to other hindgut fermenters. JAPAN online, April 2015. doi: 10.1111/jpn.12323.