| Popis: |
Objective This study aimed to evaluate the effects of a combination of live yeast and yeast cell wall fed before weaning and through backgrounding on heifer growth performance, health, and body temperature. Materials and Methods Angus crossbred cow-calf pairs with heifer calves (n = 95; BW = 165 ± 27 kg) were stratified based on BW, birth date, sire, and dam parity and assigned randomly to pasture (10 pastures, 9 or 10 cow-calf pairs/pasture). Pastures were assigned randomly to treatments: (1) no yeast (CON) or (2) addition of 3 g of live yeast and 1 g of yeast cell wall (Y+CW; Phileo by Lesaffre) in a randomized design with 5 replicates. Calves were offered creep-feed at 0.5% of BW (as fed) for 35 d before weaning. Heifers remained in preweaning treatment groups and were fed 1.8 kg/d of a concentrate supplement while grazing bermudagrass (Cynodon dactylon) pastures for 42 d with Y+CW continuing to provide 4 g of Y+CW per day. Results and Discussion Average daily gain and creep-feed consumption before weaning did not differ (P ≥ 0.29) between treatments. However, CON heifers had greater (P = 0.01) ADG from weaning to the end of the backgrounding period compared with Y+CW heifers. Body temperatures were not affected (P ≥ 0.31) by treatment before or after weaning. White blood cell concentrations, serum haptoglobin concentrations, and the percentage of cells positive for phagocytic activity did not differ (P ≥ 0.15) between CON and Y+CW heifers. Implications and Applications Based on the results of this study, Y+CW supplementation before or following weaning was not efficacious. |
