Effect of glycerin on digestibility of diets for pigs determined with different methodologies

Abstract

Glycerin is a by-product from the biodiesel chain whose energy value can be beneficial to pig diets. In this study, eight barrows were distributed individually into metabolic cages in a completely randomized block design. The animals were fed diets containing 0, 5, 10 and 15% glycerin from soybean oil and subjected to the methods of total feces and urine collection and chromic oxide marker. We determined the digestibility coefficients (DC); the dietary levels of digestible dry matter (DM), organic matter (OM), crude protein (CP), mineral matter (MM), ether extract (EE), an neutral detergent fiber (NDF); digestible energy (DE); metabolizable energy (ME); and these last two variables corrected for the nitrogen content (DEn and MEn). Digestible OM values increased linearly with glycerin inclusion in the diets. The digestible CP of the diets showed an inversely proportional relationship with glycerin inclusion levels. Digestible MM decreased linearly when determined by the total collection method and quadratically when determined by the marker method. There was a linear increase in the digestible and metabolizable coefficients of energy, DE, DEn, ME and MEn of the diets as the glycerin inclusion level was increased. Inclusion of up to 15% glycerin obtained from soybean oil production increased the digestible fractions of organic matter and energy of the diets. Key words: Biodiesel. Digestibility. Glycerol. Marker. Metabolizability. Total feces collection. ResumoA glicerina é um coproduto oriundo da cadeia do biodiesel que possui valor energético capaz de contribuir favoravelmente em dietas para suínos. Neste estudo, foram utilizados oito suínos machos castrados, distribuídos individualmente em gaiolas de metabolismo em delineamento experimental de blocos ao acaso. Os animais foram alimentados com dietas contendo 0, 5, 10 e 15% de glicerina oriunda do óleo de soja, submetidos ao método de coleta total de fezes e urina e o indicador óxido crômico. Foram determinados os coeficientes de digestibilidade (CD); e níveis dietéticos digestíveis de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), matéria mineral (MM), extrato etéreo (EE) e and tallow; and 9.1% in units that use the soybean and cottonseed oils.