Comparative digestible energy requirements of adult beagles and domestic cats for body weight maintenance.

Digestible energy (DE) needs for body weight maintenance (BWM) of six adult Beagles and six domestic cats were comparatively assessed by using data from thirteen 14-day and nine 21-day consecutive apparent digestibility trials, respectively. In each trial the Beagles and cats were given different commercial foods, and feces were quantitatively collected excluding the first 7 days. The relationship between mean daily body weight change (delta BW) per trial and DE intake was examined by regression analysis of data for individual animals. Pooled mean (n = 6) data from 223 Beagle and 143 cats digestibility trials were analyzed by the same method. Significant (P less than 0.05) linear regressions between delta BW and DE intake were obtained (R2 = 0.43-0.93) for all individual Beagles, five of six cats and pooled mean data for both Beagles and cats. Mean (range) daily DE needs for BWM of six individual Beagles were 70 (63-78), 140 (127-146) and 173 (156-187) kcal for data scaled to kilograms, kilograms0.75 and kilograms0.67 BW, respectively. Respective values for six individual cats were 76 (56-89), 104 (86-114) and 114 (95-122) kcal. Analysis of group mean data for Beagles and cats generated daily DE costs for BWM of 76 and 66 kcal/kg, respectively, equivalent to 148 and 95 kcal/kg0.75. Thus adult cats had significantly (P less than 0.001) lower energy costs of BWM than Beagles when scaled to metabolic BW (kilograms0.75 or kilograms0.67), but not on an absolute BW basis.