104 Effects of a fermentation extract additive on feedlot performance of Bos indicus cattle fed in tropical environment.

Abstract The study aimed to investigate the effect of a fermentation extract additive (VPT-VistaPre-T, AB Vista) on productive parameters of beef cattle finished on feedlot. Uncastrated yearling bulls (48 Bos indicus, Nellore [374.8 ± 13.2 kg], and 48 Bos indicus × Bos taurus, ½ Nellore × ½ Angus [358.4 ± 9.30 kg]), approximately 24 months old were divided into four pens, each equipped with electronically monitored feed bunks and scales to measure DMI (kg/d). Productive parameters evaluated were DMI, ADG and FC. A complete randomized design with a 2 x 2 factorial arrangement was used, and treatments were: i. Normal energy diet (formulated to provide nutrients for an ADG of at least 1.5 kg) without VPT (NENV); ii. Normal energy on diet plus 2g/head/day of VPT (NEWV); iii. Low energy (NE-240 Kcal/kg of DM) diet without VPT (LENV); and iv. Low energy diet plus 2g/head/day of VPT (LEWV). Six diets were fed: adaptation fed for 16d, growing fed for 27d and finishing fed for 75d x normal and low energy. Animals were fed twice daily at 0730 and 1400 h. Analyses were performed in SAS 9.4 (SAS Institute, 1995), animals were the experimental unit. Data was analyzed by two-way ANOVA using the MIXED procedure of SAS, with factors including energy, VPT and interaction. Means were separated using Student’s T-test, and differences deemed significant at P< 0.05 and regarded as tendencies when P > 0.05 and P ≤ 0.10. There was no effect from genetic groups, therefore it was not included in the model. There was an interaction between diet energy and VPT. Treatment effects was observed (P < 0.05) for DMI, in which LENV presented the greatest intake (12.31 kg/d), followed by LEWV (11.95 kg/d), NENV (11.35 kg/d) and lastly by NEWV (11.72 kg/d, figure 3). For the growing phase, NEWV presented the greatest intake (12.12 kg/d; P < 0.05) compared to LENV, LEWV and NENV (11.86, 11.75, 11.60, respectively). However, just dietary effect was detected during the finishing phase, whereas LENV and LEWV presented higher intakes (P < 0.05, 12.35 and 12.40 kg/d, respectively), compared to NENV (11.55 kg/d) and NEWV (11.55 kg/d). For ADG, differences were observed for all treatments (P < 0.05), in which LEWV presented the greatest (1.74 kg/d), followed by LENV (1.70 kg/d), NEWV (1.66 kg/d) and NENV (1.63 kg/d). Cattle supplemented with VPT presented greater ADG during adaptation, independently of the dietary program. Nevertheless, NEWV presented a lower ADG when compared with NENV (P < 0.05), during the growing phase. For the finishing phase, LEWV presented lower ADG (P < 0.05), when compared with LENV. Based on the results, the supplementation of VPT increases DMI and ADG when higher fiber/low energy diets are fed.