Taurine balance is different in cats fed purified and commercial diets.
Ileal fluxes, urinary losses and taurine balance were determined in six taurine-replete and four taurine-depleted cats. Digesta samples collected at the terminal ileum were used to assess ileal flux of taurine. Four diets were tested: a commercial diet in two forms (heat-processed and frozen) and two purified diets containing either 1225 or 0 mg taurine/kg diet. Five-day balance trials were performed on d 3-7 with measurement of food intake and taurine in urine and ileal digesta. Substantially greater quantities of total taurine (free + bound) were found in ileal digesta from cats fed the heat-processed rather than the frozen preserved diet (205 vs. 101% of the average daily taurine intake, respectively), with calculated taurine balances of -609 vs. -212 mumol/d, respectively. The quantity of taurine in ileal digesta from taurine-replete cats fed the 1225 or 0 mg taurine/kg purified diets was not significantly different, indicating that taurine found at the terminal ileum is mostly of endogenous origin. Taurine-depleted cats had significantly lower amounts of taurine in ileal digesta, with a taurine balance of -77 mumol/d. These results demonstrate that a heat-processed diet causes substantially greater losses of taurine from the intestine than does a frozen diet. This phenomenon may explain the inability of some heat-processed diets to maintain normal plasma taurine concentrations in cats.
Hickman
M A
MA
Department of Physiological Sciences, School of Veterinary Medicine, University of California, Davis 95616.
Rogers
Q R
QR
Morris
J G
JG
D000821:Animal Feed; D000818:Animals; D002415:Cats / Q000378:metabolism*; D015925:Cryopreservation; D005511:Food Handling; D005519:Food Preservation; D006358:Hot Temperature; D007082:Ileum / Q000737:chemistry / Q000378:metabolism; D008297:Male; D011897:Random Allocation; D013047:Specific Pathogen-Free Organisms; D013654:Taurine / Q000008:administration & dosage / Q000096:biosynthesis / Q000378:metabolism*
D013654:Taurine