Crude glycerin in the diets of confined lambs: performance, carcass traits and economic feasibility

The crude glycerin is a byproduct of the biodiesel industry which has high levels of glycerol and can be utilized by ruminants for obtaining energy. This research was conducted in order to evaluate the performance, carcass characteristics and economic feasibility of lambs fed diets containing crude glycerin replacing ground corn. 24 non-castrated lambs (Pantaneiro racial grouping) at 90 days of age and average body weight of 20.02 ± 1.5 kg were used. We evaluated diets containing 0, 2.5, 5.0 and 7.5% inclusion of crude glycerin on dry matter of the diet replacing ground corn. The parameters evaluated were the consumption of dry matter and nutrients, weight gain, feed conversion, biometric measurements in vivo and carcass characteristics, in addition to the cost of the diet based on the carcass production. Animals reduced dry matter intake as doses of crude glycerin were increased. However, no differences to the weight gain of the animals were observed. Thus, animals fed crude glycerin showed better feed conversion rates and lower feeding cost which contributed to higher profit margin of the diets with crude glycerin. It is concluded that at the doses tested, the crude glycerin can be used in the diet of finishing lambs, however only at the level of 7.5% becomes economically feasible.