Glicerina de média pureza na terminação de bovinos em confinamento

Abstract

This work was carried out to study the medium purity glycerin as a corn replacement on animal performance, feed efficiency, apparent digestibility, ingestive behavior, carcass characteristics and meat quality in crossbreed bulls finished in feedlot. Fourty Purunã bulls with 208.8 ± 33.3 kg weight and 8 ± 0.9 months old. The bulls were randomly assigned to 1 of 4 diets containing 0, 6, 12 or 18% glycerine on a DM basis; which represented 18.3; 38.5; and 61.3% of corn replacing. The corn silage (53%) and concentrate mix (soybean meal, cracked corn, glycerin and mineral salt) composed the diets. The corn replacement did not affect the animal performance and carcass characteristics. However, intake of DM (%BW), EE, NDF (kg and %BW), total carbohydrates and feed conversion rates decreased linearly a glycerine levels. The apparent digestibility of nutrients increased linearly with increasing glycerin in the diet, with the exception of EE and NDF. Glycerine changed durations of the bull’s behavioral activities. The rumination frequency was reduced linearly with glycerine inclusion in the diet. However, frequency of other activities showed a quadratic effect with glycerine addition. Glycerine inclusion in the diet reduced duration in feed frequency, but the frequency duration for other activities increased linearly. The carcass traits, marbling, texture, color, thawing and cooking loss, sensory analysis and chemical compounds of Longissimus muscle were not modified by different glycerine levels it he diets. The saturated fatty acids (SFA) and n-6:n-3 ratio decrease with glycerine levels. On the other hand, unsaturated fatty acids (PUFA), n-6 and n-3 fatty acids, PUFA:SFA ratio increase in muscles of bulls fed on diets with glycerine. The medium purity glycerine is an energetic alternative to total diet replacement (18% of DM), principally the corn replacement (61.3% of DM), on crossbreed bulls finished in a feedlot.