PSXIV-16 Evaluation of alternative titanium dioxide dosing method to predict dry matter intake.

Abstract Titanium dioxide is an external marker that is commonly dosed via gelatin capsules to measure fecal output, and ultimately diet intake, of beef cattle indirectly. However, the capsule dosing method is restrictive, alters normal animal behavior, and not always practical in all research setting The objective of this experiment was to validate an alternative titanium dioxide dosing method to determine intake of beef cattle. To accomplish this goal, beef heifers (n=10, BW= 299 ± 0.09kg) were stratified by bodyweight (BW) and assigned to 1 of two treatment groups. Treatments consisted of control (CON) where titanium dioxide was dosed via 10 g gelatin capsules and the treatment (SUP) where titanium dioxide was dosed via 2 automated supplement feeders (SmartFeed Pro, C-Lock, Inc.) using a protein supplement containing 2% titanium dioxide. Animals were able to consume ~0.5 kg of supplement per day, at their own choosing. Heifers were fed a total mixed ration and intake was measured out of 2 additional SmartFeed Pro feeders. Control cows were sorted from treatment heifers and provided the titanium dioxide bolus each morning at approximately 0700 for all 21 d of the experiment., with the exception of d 10-12. Fecal samples were collected at 0700 and 0400 on d 9, 10, 18, 19, 20, and 21. A two one-sided T-test revealed that DMI estimates were similar to actual DMI (P < 0.02, P =.09, for the SUP and CON, respectively), but the SUP heifers had greater variability relative to CON. This data suggests an alternative dosing method, such as an automated feed intake system may be used to accurately predict dry matter intake of beef cattle.