Rumen and liver measurements of lambs fed with high inclusions of crude glycerin in adaptation and finishing period of feedlot

Abstract Crude glycerin is the main by-product of biodiesel industry and has great potential for reducing the feed costs in ruminant feedlot systems without affecting animal health and performance, mainly as a replacement for corn grain. The objective of this study was to evaluate the effects of increasing inclusions of crude glycerin (up to 30%) in diets for crossbred feedlot lambs in two different periods (adaptation and finishing) on the rumen morphometric and liver variables. Fifty-five 3-month-old crossbred lambs were randomly allocated in individual pens indoors, assigned to a complete randomized block design and fed with four experimental diets, containing 0, 10, 20 or 30% crude glycerin. Three animals were slaughtered at the end of the pre-adaptation period (d0), twelve at the end of the adaptation period (d14), and the remaining (n = 40) when they reached approximately 35 kg BW. After slaughtered, the stomach compartments and liver were collected and evaluated. All stomach compartments, number of rumen papillae and mitotic index were higher for the finishing period (P