Avaliação de pastagem nativa e comportamento ingestivo de bovinos em área de várzea

Abstract

In regions of the lower and middle Amazon, cattle raising is divided into two distinct systems, livestock in the floodplain area and upland, the floodplain ecosystem in turn apparently presents an environment conducive to the exploitation of livestock, however, it is necessary to carry out specific studies to find its real benefit. Thus, this work aims to evaluate parameters related to pasture in a floodplain area in the Caburi agrovila region (Parintins-AM), for this, 160 heifers with an average age between 10 and 24 months, with an initial body weight of 293.72 ± 101.79 kg and a body condition score (BCS) of 3 ± 0.5. The experimental design adopted for conducting the experiment was completely randomized blocks. Blocking was performed based on weight, age and body condition score of heifers. The treatments corresponded to two types of forage offer, the high offer group was housed in a paddock that had forages of greater height and with greater mass and the low offer group that was housed in a paddock that had forage of lower height and lower mass. For the evaluation of the parameters related to the pasture, the forage collection was carried out when the animals entered the experimental paddocks, for this, the direct method was used: The direct method is based on cutting the forage, removing it from a certain sample area (frame of metal, wood, plastic, or other materials of known area) or total area to be assessed. Afterwards, the fresh sample is weighed and dried at 65 °C for 72 hours, and then the dry mass is weighed and the available forage mass per unit area is estimated. For ingestive behavior, five animals from each group were selected, as a selection criterion, the coat and characteristics of the animal were used, animals that are easier to identify were used to collect information on this variable. The bromatological evaluation of the forage identified significant differences for some variables between the two experimental areas, while in the ingestive behavior the idle variable obtained a significant difference between the treatments (P<0.05).