PSXIV-27 Effects of an immunomodulatory feeding program on performance for Bos indicus-influenced cattle in a commercial feedlot.

Abstract Transportation, deworming, dietary changes, and social interactions in a new environment can induce physiological stress in cattle. Therefore, strategies to mitigate stress during the initial feeding phase are essential for optimizing health and performance throughout the full feeding period. The use of nutritional additives that enhance the physiological status of the animals, may play an important role. The objective of this study was to evaluate the effects of a nutritional product (NutraGen®) during the adaptation period (26 days) on the performance of Nelore bulls over an entire feedlot period. A total of 3,107 Nelore bulls (30 months old, initial body weight: 473 ± 31.8 kg) were blocked and randomly assigned to one of two treatments: Control (no additives) or NutraGen® (7 g/100 kg BW). After a total period of 91 days, performance parameters assessed included final body weight (FBW), average daily gain (ADG), feed efficiency (FE), carcass dressing percentage (CDP), carcass weight (CW), and dry matter intake (DMI). Data were analyzed using the PROC MIXED procedure in SAS, with animal as a random effect and treatment as a fixed effect. Bulls fed NutraGen® during adaptation period showed improved ADG (1.10 kg vs. 1.40 kg; P < 0.004), DMI as a percentage of body weight (2.23% vs. 2.36%; P < 0.04), and FE (0.093 vs 0.113; P< 0.005) compared to the control group, while no differences were observed in FBW (577.6 kg vs. 587.8 kg; P < 0.19), and CW (331.5 kg vs 334.3 kg; P < 0.55). In conclusion, bulls supplemented with NutraGen® during the adaptation period phase (26 days) showed enhanced performance traits throughout the 91-day finishing period, demonstrating potential as a nutritional strategy to help improve feedlot cattle productivity.