Availability of nutrients is influenced by extremes of age. For appropriate development of foods and nutritional management throughout lifestages of cats, we need a better understanding of the influence. This study investigated nutrient digestibility, mineral absorption, feces and urine production in three groups of six young, mature and old cats fed two diets containing different energy densities.
A quadratic relationship was detected between age and digestibility of dry matter, organic matter, crude protein, acid-hydrolyzed fat and starch in the low-energy diet. Starch digestibility showed the same response in the high-energy diet. Young adult cats had intermediate digestibility, mature cats the highest and old cats the lowest. Mineral absorption and urinary pH were not different among groups.
These findings confirm previous studies finding low digestibility of nutrients in some old cats and support evidence that this trend is even more important in less digestible dry foods. However, data suggest mineral formulations do not need to be varied in diets for adult cats of different ages.