This study was conducted to evaluate the effects of including two types of crude glycerin (CG) in feed on plasma parameters, quantitative and qualitative carcass characteristics, and the fatty acid profile of the Longissimus dorsi pig muscle. Sixty-three commercial line pigs were used, with an average weight of 30.53 ± 1.59 to 59.55 ± 4.27 kg in the growing phase and 60.35 ± 2.25 to 89.91 ± 5.23 kg in the finishing phase. The pigs’ diet included two sources of CG (vegetable and mixed) at four inclusion levels (3%, 6%, 9% and 12%). One CG was derived from soybean oil (VCG) and the other from 80% animal fat + 20% soybean oil (MCG). The control diet contained 0% glycerin. Blood samples were collected at the beginning, middle and final phases of the trial. In addition, at the end of the finishing phase, the animals were fasted for 12 h and then sacrificed to measure the quantitative and qualitative carcass characteristics and the fatty acid profile of the Longissimus dorsi. The results indicate that in both phases there was a quadratic effect on plasma triglycerides. There was no effect on carcass parameters. A quadratic behaviour for pH24 h was obtained, with the lowest value attained at 1.05% CG inclusion. There was an interaction between the type of glycerin and the inclusion level in the diets for polyunsaturated fatty acids. VCG and MCG can be used at up to 12% inclusion because they cause no negative effects on carcass characteristics and pig meat quality.