Uso de aditivos, isolados ou associados, na dieta de novilhas confinadas

Abstract

The objective of this work was to evaluate the parameters of dry matter intake, feed conversion, average daily gain and carcass yield of confined Nellore heifers receiving diets with a high proportion of concentrate and inclusion of additives, isolated or associated. The experiment was carried out on a rural property owned by Universidade Brasil, in the municipality of Descalvado. Twenty Nellore heifers, approximately 15 months old and 282.4 ± 18.8 kg of initial live weight, were randomly distributed into four groups containing five animals per treatment. The animals were housed in individual, covered pens, measuring 12 m2, with individualized feeders and drinkers and a concrete floor, and divided into four treatments: T1 – association of monensin and flavomycin, T2 – 1 gram of phytoactive blend; T3 – association of monensin, flavomycin and one gram of phytoactive blend; T4 – association of monensin, flavomycin and two grams of phytoactive blend. The phytoactive blend tested was made from cinnamon and oregano essential oils, turmeric extract and tannic acid. Adaptation to diet and facilities took 15 days. The experimental period was 125 days, with weighing at the beginning of the experiment and then every 30 days, totaling four weighings throughout the experiment. The diets were provided twice a day, at 07:00 and 17:00 hours, being weighed individually, as well as the leftovers, for individual control of consumption. At the end of the experiment, the animals were slaughtered in a commercial slaughterhouse. The hot carcass weight was used to determine the carcass yield. There were no differences (P>0.05) between the associations and proportions of the additives on the evaluated parameters. The use of phytoactive blends, in substitution or association with conventional additives, showed promising results and can be used for confined heifers with a high concentrate: forage ratio in the diet, without compromising performance and carcass characteristics.