Nutritional Value of Glycerin for Pigs Fed a Mixture or an On-Top Diet

Glycerin has a similar energy value to corn and can partially replace it. However, there is a need to find the ideal level for using glycerin in pig feed without negatively interfering with performance parameters. The objective of this study was to determine the digestibility of glycerin through a mixture (MIX) or inserted on top of feed (ONTOP) using chromium indicator (Cr) and total collection (TC) methods. Ten barrows weighed 42.63 ± 4.23 kg in a 2 × 2 + 1 factorial scheme, with two forms of inclusion of the test ingredient (MIX or ONTOP), two digestibility methods (Cr or TC), and a basal diet (BD). The experimental design was completely randomized, and the evaluation period was used as split-plots, with two repetitions per period, totaling four repetitions per diet. The DE and ME values for glycerin were 3443 and 3356 kcal/kg (by the TC method) and 3411 and 3293 kcal/kg (by the Cr method), respectively (p < 0.05). There was no difference in MIX or ONTOP (p > 0.05), except for the digestibility coefficient (DC) of ethereal extract (p < 0.05). The DC and energy values obtained by Cr were lower than those obtained by TC. The inclusion of the test ingredients in the MIX and ONTOP forms did not present any difference, whereas Cr depreciated the nutritional value of glycerin for pigs.