Growth performance and meat quality of buffalo young bulls: 1. Effect of group size

Aim of this study was to evaluate growth performance and meat quality of buffalo bulls maintained in different group sizes. Twentyone young buffalo bulls were assigned into two different sized groups of 7 (group LS) or 14 (group HS) individuals. The groups were homogenous for body weight (337±67 kg) and age (455±72 d). Total pen area (3.2 indoor + 3.2 outdoor m2/animal) was kept constant in the two groups. All animals were fed the same diet [CP 14.7% dry matter (DM); Milk FU 0.91/kg DM]. Average daily gain (ADG) was calculated every 2 weeks, along with DM intake (DMI), calculated on pen basis. On a subgroup of 4 individuals per groups, carcass traits were recorded at slaughter. Meat quality (hardness, cohesion, chewiness, WB shear force) and meat colour (L*, a*, b*) were evaluated on 7-day aged muscles (Longissimus dorsi, Semitendinosus, Semimembranosus). DMI and carcass traits were analyzed by one-way ANOVA; ADG, calculated only for 7 animals from group HS, and meat quality parameters were analyzed by a linear mixed model for repeated measures. There was no significant effect of group size on DMI (8.65 vs 8.51 kg DM/day for LS and HS animals, respectively; SE 0.41), ADG (0.89 vs 0.96 kg/d; SE 0.048), carcass weight (249 vs 260 kg; SE 8.13) and dressing percentages (50.6 vs 50.8%; SE 1.12). All carcasses from the two groups were classified O, for carcass conformation, and 4, for fat score, according to SEUROP grading system. There were no differences between the groups for the any meat quality traits, although hardness (3.92 vs 4.80; SE 0.48) and chewiness (2845 vs 3659; SE 4.77) tended to be higher in larger group. In conclusion, group size did not affect growth performance, although meat quality tended to be lower in the larger group.