Uso de aditivos em diferentes dias de confinamento para bovinos de corte

Abstract

The objective of this study was to evaluate feedlot days and food additives, under performance and carcass attributes. 224 Nellore steers were used, with a live weight of 374.68±4 kg, distributed in a 2x2 factorial arrangement, in a completely randomized block design. The animals were fed a feedlot diet with a high concentrate content (R:C, 10:90), containing the following treatments: 1) BEO89: composed of essential oils (Crina® Ruminantes 90 mg/kg DM) + chromium and zinc carbo-amino-phospho-chelate (0.4 and 60 mg/kg DM, respectively) + 25-OH-Vitamin D3 (Hy-D®, 1 mg/animal/day); 2) MON89: sodium monensin (26 mg/kg DM); 3) BEO114: composed of essential oils (Crina® Ruminantes 90 mg/kg DM) + carbo-amino-phospho-chelate of chromium and zinc (0.4 and 60 mg/kg DM, respectively) + 25-OH-Vitamin D3 (Hy-D®, 1 mg/animal/day); 4) MON114: sodium monensin (26 mg/kg DM). Treatments 1 and 2 were slaughtered after 89 d of confinement, while 3 and 4 were slaughtered after 114 d. The additives were available from DSM Nutritional Products. The data were subjected to analysis of variance using PROC MIXED from SAS and the interactions were evaluated using the PDIFF command. Steers supplemented with BEO had higher DMI (P <0.01; kg/d and %BW). Steers supplemented with BEO for 114 days showed higher (P ≤ 0.048) final BW, ADG, BWW and carcass gain compared to the others. Animals supplemented with BEO had higher dry matter intake (kg/d), regardless of the days of feedlot. Animals fed BEO had a higher feed conversion ratio at 89d, but did not differ at 114d from the MON group (P <0.01). Steers supplemented with BEO showed greater (P=0.045) biological efficiency compared to animals supplemented with MON, with better results after 89 days of feedlot. The gain performance of animals that received BEO at 84d and 114d were higher than those in the MON group (P ≤ 0.002). Positive effect on meat quality (better shear strength, water retention capacity and better fatty acid profile in 114 days of feedlot) and lower cooking losses for BEO. Supplementation with BEO associated with 114 days of confinement promotes better performance by increasing the final weight and carcass gain of finishing animals in feedlot.