Use of dietary mannanoligosaccharides during rabbit fattening period: effects on growth performance, feed nutrient digestibility, carcass traits, and meat quality.

This study was conducted to compare the effects of mannanoligosaccharides (MOS) and antibiotics as a dietary supplement on ADG, ADFI, G:F, and feed nutrient digestibility of rabbits during the fattening period, as well as on carcass traits and meat quality. A total of 512, sixty-day-old hybrid Hyla rabbits were randomly divided into 4 treatment groups based on BW and sex. The 4 treatment groups consisted of a control group and 3 MOS groups. The control group was fed a diet that contained apramycin (50 mg/kg), but diets for the 3 MOS groups contained 0.5, 1.0, or 1.5 g/kg of MOS instead of apramycin. The rabbits were fed experimental diets for 22 d and all rabbits were slaughtered at the end of the experiment when they were 82 d old. Individual BW and feed intake per cage were recorded weekly for 32 cages randomly chosen per group (64 rabbits) to calculate ADG, ADFI, and G:F. The apparent digestibility values of OM, CP, ether extract, crude fiber, NDF, ADF, cellulose, and hemicellulose were measured using AIA as an inert marker. Carcass data were collected from 16 randomly chosen rabbits (8 males and 8 females) per group. The control group had less G:F (P < 0.001) than the MOS groups and a linear increase (P < 0.001) in G:F was observed as the concentration of MOS increased from 0.5 to 1.0 and 1.5 g/kg. The apparent digestibility of DM, OM, crude fiber, NDF, ADF, cellulose, and hemicellulose increased (quadratic, P < 0.05) as the concentration of MOS in the diets increased. The apparent digestibility of DM, OM, CP, crude fiber, NDF, ADF, cellulose, and hemicellulose was also greater (P < 0.05) in the diets containing MOS than in the control diet and the digestibility of these nutrients was greater (P < 0.05) in the diet containing 1.5 g/kg of MOS compared with the control diet. The concentration of palmitic acid, stearic acid, and SFA was greater (P < 0.05) in the meat from rabbits fed the control diet than rabbits fed the MOS diets. The concentration of stearic acid decreased (quadratic, P < 0.05) in the meat of rabbits as the concentration of MOS in the diet increased. Meat from rabbits fed diets containing MOS also had greater contents of oleic acid (P < 0.05) and MUFA (P < 0.001) than those rabbits fed the diet containing apramycin. The thrombogenic index was greater (P < 0.05) in the meat from the control group rabbits than the MOS group rabbits. In conclusion, the inclusion of MOS in diets fed to rabbits during the fattening period may improve G:F and modify the fatty acid profile of meat.