Effect of rumen protected carbohydrate supplementation on performance, blood and plasma metabolites in growing heifers.

J. P. RUSSI; PERUZZO E.J.; DI LORENZO N; A. E. RELLING,

Orlando

Congreso; Joint Annual Meeting 2015; 2015

American Society of Animal Science y American Society of Dairy Science

The objective of this study was to evaluate the inclusion of a rumen protected carbohydrate (RUPCA) (US Patent # 8,507,025) on performance, blood and plasma metabolites in growing heifers. Crossbred heifers (n=135; 136 ± 14kg) were used in an 84-d experiment. Heifers were blocked by initial BW, placed into 15 pens and fed a diet comprised of (DM basis) 38.8% corn silage, 41.5% dry corn, 2% minerals and vitamins mix, and 17.7% supplement or RUPCA, which varied depending on treatments. The supplement and RUPCA consisted of the same ingredients (58.1% soybean meal, 38.9% soluble carbohydrates, 2% urea and 1% mineral salt), differing in the processing of the carbohydrate (i.e., protected or not from ruminal degradation). Heifers within blocks were randomly assigned to three treatments: T0) 17.7% supplement (100% unprotected carbohydrate), T1) 8.85% supplement and 8.85% RUPCA, and T2) 17.7% RUPCA (100% protected carbohydrate). Body weight was measured on d 0, 21, 42, 63, and 84. Pen DMI was measured weekly from d 21 to 84. Blood samples were taken on d 0, 42, 63, and 84 from jugular vein prior morning feeding and analyzed for glucose, insulin, urea and NEFA concentrations. Data were analyzed as a randomized complete block design with repeated measures using a mixed model of SAS. Treatment *d interaction were found for DMI (P=0.02), ADG (P