The search to find food alternatives for corn and feeding alternatives that reduce the cost of production has been constant. The use of oleaginous grains to produce ethanol and biodiesel has produced an excess of byproducts, especially biodiesel which produces crude glycerin. The objective of this study was to evaluate the effect of including crude glycerin on the ingestive behavior of crossbred heifers supplemented with pasture. Thirty-six crossbred heifers with an initial mean weight of 301.5 ± 31 kg were distributed in a completely randomized design with four treatments and nine replicates per treatment. The animals were kept in a Brachiaria brizantha (Hochst. ex A. Rich.) Stapf ’Marandu’ pasture in a rotational-grazing system. The treatments tested were 0.0%, 3.33%, 6.66%, and 9.99% crude glycerin included in total DM to replace corn (Tea mays L.) Including crude glycerin reduced the time for grazing and eating at the trough and increased idle time. Rumination was quadratically influenced. Eating time (min kg-1 DM and neutral detergent fiber [NDF]) was reduced, while rumination time (min kg-1 DM and NDF) was quadratically affected by adding glycerin. The variables, time spent per ruminated bolus and the number of chews per day, were not affected. The number of boluses per day showed a quadratic effect. The number of grazing, idle, ruminating, and eating at the trough periods were not affected by including crude glycerin; means were 15.1, 24.9, and 13.3 and 3.71 periods d-1, respectively. Feed and rumination efficiency (kg h-1 DM and NDF) increased when crude glycerin was included in the diet. Including crude glycerin promotes feed and rumination efficiency in grazing heifers.

The objective of this study was to evaluate the economic returns of crossbred calves grazing on pastures formed by Urochloa brizantha fed crude glycerin as a supplement. Thirty-six crossbred calves with initial average weight of 301.5 kg were distributed in a completely randomized design with four treatments and nine replicates per treatment. The animals were maintained on rotational grazing production of Urochloa brizantha cv. Marandu. The tested treatments were 0.0, 3.33, 6.66 and 9.99% inclusion of crude glycerin in the total dry matter as a substitute for corn. The production of meat was not altered by the inclusion of glycerin in the diet. The inclusion of glycerin caused a reduction of up to 14.93% in the price of the concentrate. There was a significant increase in the total balance, which rose from 3.76 to 91.89 R$/ha with the inclusion of glycerin. The inclusion of crude glycerin in the supplement was capable of raising the net present value and the internal rate of return, proving to be an alternative to reduce the cost of production of supplemented pastured animals.