Probiótico (Enterococcus faecium) adicionado a dietas estándar y con baja proteína para cerdos

Abstract

An experiment was conducted to evaluate the growth performance (average daily gain, ADG; average daily feed intake, ADFI; feed:gain ratio, FGR; fat free lean gain, FFLG), the carcass characteristics (Longissimus muscle area, LMA; backfat thickness, BFT; lean meat percentage, LMP), the plasma urea nitrogen concentration, and the fecal microbial population of 36 hybrid (Yorkshire×Duroc×Pietrain) barrows in nursery (11.10 ± 0.51 kg), growing (25.75 ± 1.13 kg), and finishing (51.03 ± 2.20 kg) phases of fattening in response to two levels of crude protein (CP; nursery: 20.5 and 16.0 %; growing: 16.0 and 14.5 %; and finishing: 14.0 and 12.5 %) and two levels of probiotic (PRO) Enterococcus faecium (0.0 and 1.0 kg t-1 of food at each stage) in sorghum-soybean meal diets, in a completely randomized design with 2×2 factorial arrangement, with 9 replicates per treatment. The energy remained constant at 3.265 Mcal kg-1. In nursery pigs, the addition of PRO reduced (p£0.05) LMA, but did not affect (p>0.05) other variables. The plasma urea nitrogen decreased (p£0.05) in pigs fed low-protein diets. In growing and finishing pigs, the reduction of CP decreased (p£0.01) plasma urea nitrogen concentration, but did not affect (p>0.05) other variables. The addition of PRO increased (p£0.05) the concentration of Enterococcus and total fecal bacteria at all stages. These results indicate that adding PRO increases the total microbial population and the population of Enterococcus, although it does not affect the growth performance, the carcass characteristics, and the concen-tration of plasma urea nitrogen of pigs fed standard or low-protein diets.