Estimativa da proteína bruta e da digestibilidade da dieta de ovinos com uso da técnica de espectroscopia e reflectância do infravermelho próximo (NIRS)

Abstract

Sheep farming presents itself as an important activity in Brazilian livestock, in semiarid regions sheep are traditionally raised extensively with the main food base in the native pastures of the Caatinga Biome, therefore, it is necessary to know the quality of the selected diet of small ruminants to so that possible corrections can be made in the diet and thus improve the productive indexes, in this way, the objective of this study was to use the technique of spectroscopy and near infrared reflectance (NIRS) in the determination of crude protein and digestibility of the diet of sheep, as well as the variation in pasture quality throughout the year. The experiment was carried out in the municipalities of Paulistana Piauí located in the Mesoregion of Southeast Piauí. For the accomplishment of the study, 20 pilot properties were pre-selected, of these 20 properties 5 were selected because they presented similarity between the NIR spectra in relation to the models database. Fecal collections were carried out from 10% of the total herd of small ruminants of the species Ovis aries (sheep) fed on native pasture, being property A; located in Paulistana Piauí, property B; located in Acauã Piauí, property C located in Paulistana Piauí, property D; located in Paulistana-PI, property E; located in Betânia Piauí. For the predictions of crude protein (CP) and digestibility (DVMO) and (DVMS) contents, fecal samples were collected in the rectal ampoule of 10% of the total herd of sheep raised on a native pasture diet. In view of this study, it is possible to verify the existing variation in the nutritional composition of forage species present in the Caatinga biome of Vale Itaim in the dry seasons and waters. Climatic conditions, mainly related to rainfall distribution, in the experimental period contributed to the variation of protein and digestibility indexes, affecting the nutritional quality of the native pasture. The NIRS technology proves to be an important tool for monitoring the diet of small ruminants in caatinga pastures.