24 Effects of an accelerated adaptation protocol in conjunction with Lactipro on performance, carcass characteristics, and health of finishing steers.

Abstract Lactipro (Axiota Animal Health; Fort Collins, CO) delivers an immediate, viable population of Megasphaera elsdenii directly to the rumen, thereby reducing the time needed for the animal to adapt to a high starch diet. Yearling steers [n = 1000; initial body weight (BW) = 403 kg; SD = 30] were utilized to evaluate the effects of an accelerated adaptation program for finishing steers drenched with Lactipro NXT (1.0 x 1010 CFU) on d 1 on performance, carcass characteristics, and health. Treatments were designed to evaluate the length of an accelerated adaptation phase (0, 7, or 14-d) compared to a traditional adaptation (21-d). Dietary treatments included 1) traditional 21-d adaptation (TRAD-21; 100% finisher on d 21), 2) accelerated 14-d adaptation (ACC-14; 100% finisher on d 14), 3) accelerated 7-d adaptation (ACC-7; 100% finisher on d 7), 4) accelerated 0-d adaptation (ACC-0; 100% finisher on d 2), and 6) accelerated 0-d adaptation with intensive feed delivery (ACC-0+, 100% finisher on d 2). All cattle were fed 3 times daily during the adaptation phase, except cattle on the ACC-0+ treatment, which were fed 6 times daily for d 2-5. Dry matter delivery during the adaptation period was based on a percentage of maintenance energy requirement determined by bunk scores prior to feeding and cattle aggression scores at the time of the first feeding. Orthogonal contrasts defined linear and quadratic effects of TRAD-21, ACC-14, ACC-7 and ACC-0, the effect of ACC-0 vs. ACC-0+, and the effect of TRAD-21 vs. ACC-0+. Dry matter intake (DMI) responded quadratically (P = 0.01) with the greatest DMI observed at TRAD-21 and the least DMI at ACC-7. Cattle assigned to TRAD-21 and ACC-0 treatments gained faster and consequently had greater HCW compared to those in ACC-14 and ACC-7 treatments, which were similar, resulting in a quadratic response for both ADG and HCW (P = 0.01). The ACC-0+ treatment had similar ADG and HCW to the TRAD-21 and ACC-0 treatments (P ≥ 0.58) suggesting more frequent feed delivery during the initial days of the adaptation phase did not prove to be beneficial. Feed efficiency tended to respond quadratically (P = 0.07) with a reduction at ACC-14. Longissimus muscle area also tended to respond quadratically in a similar manner to HCW (P = 0.06). No other differences (P ≥ 0.16) were observed in carcass characteristics or health outcomes. These data suggest that when cattle are drenched with Lactipro NXT, an accelerated adaptation approach with 100% finisher from the beginning is suitable, likely by enhancing substrate availability, yielding results comparable to a traditional adaptation program. Moreover, this approach improves feedlot’s operational efficiency by improving mill efficiency with the need for less diets and reducing forage usage by 22%.