How can housing system affect growth and carcass traits, meat quality and muscle fiber characteristics in biceps femoris and mineral content of tibia and femur bones in growing rabbits?

Abstract

The aim of this study was to evaluate the effect of housing system (cages with wire mesh floor and pens with plastic mesh floor) and gender on growth performance, carcass and physical traits, muscle fibers and bone characteristics of growing rabbits. 160 rabbits were assigned to 4 groups by housing system and by gender. Sixty rabbits were kept in cages (0.15 m2 per rabbit; 90 × 50 × 45 cm; 3 rabbits/replicate; 10 replicates/gender), the other rabbits in pens (0.15 m2 per rabbit; 25 rabbits/replicate; 2 replicates/gender). Significant housing system (HS) × gender (G) interaction (P = 0.029) was found for dressing percentage, when pen housed females showed higher values compared to pen housed males. There was a higher percentage of hind part to reference carcass in pen housed than in cage housed rabbits (P = 0.001). The fiber cross-sectional area of αW (white fast twitch) was higher in pen housed (P = 0.009) than in cage housed rabbits in biceps femoris (BF). Pen housed males had larger diameter (P = 0.001) of BF muscle fibers in comparison with pen housed females. Additionally, pen housed rabbits had larger diameter (P = 0.001) of BF muscle fibers in comparison with cage housed rabbits. Moreover, significant interactions between HS × G were found in dry matter (P = 0.010), calcium (P = 0.024) and phosphorus (P = 0.049) content in tibias. Pen and cage housed males had higher content of dry matter compared to pen and cage housed females. Regarding calcium results, the highest values were observed in males and females from cages and from penned females, while penned males had the lowest values. The same results were found for phosphorus values. Furthermore, significant HS × G interaction was reported in dry matter content (P = 0.009), where the highest values were in pen housed males and the lowest in pen housed females in femurs. Additionally, the higher fracture toughness was found in pen housed rabbits.