Nutrient digestibility, but not mineral absorption, is age-dependent in cats

Abstract

Availability of nutrients is influenced by extremes of age, and a better characterization of this influence is necessary for appropriate development of foods and nutritional management throughout life stages of cats. This study investigated nutrient digestibility, mineral absorption, faeces and urine production in three groups of six young, mature and old cats fed two diets containing different energy densities. Apparent digestibility and mineral absorption were calculated by total collection method and values were tested with anova and regression analysis. A quadratic relationship was detected between age and digestibility of dry matter, organic matter, crude protein, acid-hydrolysed 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 (calcium, phosphorus, magnesium, sodium, potassium and chloride) and urinary pH were not different among groups. These findings confirm previous studies that found low digestibility of nutrients in some old cats, and support evidence that this trend is even more important in less digestible dry foods. On the contrary, data suggest that mineral formulations do not need to be varied in diets for adult cats of different ages.

Seasonal and age effects on energy requirements in domestic short‐hair cats (Felis catus) in a temperate environment

“…In this study, old cats showed a marked reduction in the digestibility of dry matter, protein, and energy, consistent with results from other studies (Taylor et al., 1995; Peachey et al., 1999a; Teshima et al., 2010). A reduction in energy digestibility in older cats may partly explain the larger energy intake and expenditure (Harper, 1998).…”

“…The reasons for reductions in nutrient digestibility are, however, unclear. Intestinal transit time appears to be unaffected by age (Peachey et al., 2000), although older cats appear to have increased variation in both nutrient digestibility and transit time compared with younger cats (Peachey et al., 2000; Teshima et al., 2010). In the current study, the coefficient of variation for dry matter, protein and energy digestibility in young and old cats was similar.…”

“…In the current study, the coefficient of variation for dry matter, protein and energy digestibility in young and old cats was similar. While the effects of ageing on the morphology of the intestinal tract in cats is unclear (Teshima et al., 2010), ageing does affect the morphology of the intestine in dogs (Kuzmuk et al., 2005). A recent study has shown that, in the dog, ageing increases the expression of genes involved in inflammation and stress response (Kil et al., 2010).…”

“…(Scarlett et al., 1994; German, 2006). Companion animals are also living longer (Teshima et al., 2010), so the accurate assessment of the nutrient requirements for older pets is an area of increasing importance. Published data on the energy requirements of older cats is contradictory.…”

Sodium in feline nutrition

“…Subsequently, Teshima et al. () reported sodium digestibilities of 78% in low‐energy diets (13.7 MJ ME/kg) and 89.5% in high‐energy diets (16.8 MJ ME/kg). In all studies, apparent sodium absorption rate increased with sodium intake, but sodium faecal output was not significantly affected by dietary sodium content or total sodium intake, suggesting nearly 100% absorption of ingested sodium.…”