Aspectos nutricionais de dietas para ovinos contendo fontes de óleos

Abstract

The aim of this study was to evaluate the inclusion of vegetable oils in diets for sheep on intake, digestibility, ruminal fermentation parameters, and microbial protein synthesis. The experiment was carried out at the UFGD small farm, using 12 lambs of mixed breed, not castrated (45.00 ± 8 kg body weight, 9 ± 0.5 months old), distributed in a 4x4 Latin square, triple, where the inclusion of 2% in DM of one of the three sources of vegetable oils: soybean, sunflower, and residual frying oil, and an additional treatment without a source of oils as a control, were tested. Each experimental period lasted 20 days, with 15 days of adaptation and 5 days of data collection. The following parameters were measured: intake and digestibility of nutritional components, ingestive behavior, food selection index, rumen fermentation parameters, nitrogen balance, and microbial protein synthesis. There was no effect of the different oil sources on the DM and NDF selection index in any of the feed particle sizes. However, there was effect (P=0.072) for the NDF selection index on the short particle size (<8, >1.18mm), where the control diet had a lower index, indicating that there was greater rejection of particles in this size when compared to the oil sources. As the feeding and rumination parameters did not change with the oil sources, it was reflected in the pH and NH3, which were also not affected by the action of the oil sources, but remained within desirable limits. There was a reduction in DM intake of around 11% when comparing vegetable oil sources with the oil-free diet. There was a reduction in the digestibility of CP and NDF, by 5 and 8%, respectively, when comparing the oil sources with the control diet. There was an effect on microbial protein synthesis, where diets with soybean oil, sunflower, and residual frying oil had greater efficiency and greater synthesis of microbial protein. It is concluded that vegetable oil sources can be used in diets for growing lambs without causing damage to the ruminal environment or interfering with microbial growt.