Effect of group size-floor space allowance and floor type on growth performance and carcass characteristics of heavy pigs = Efecto del espacio de piso según el tamaño del grupo y el tipo de piso en el desempeño del crecimiento y las características de la canal en cerdos pesados = Effet de l’attribution de la superficie de plancher selon la taille du groupe et le type de plancher sur les performances de croissance et les caractéristiques des carcasses de porcs lourds

Objective: To evaluate the effects of group size-space allowance and floor type on growth performance and carcass characteristics in pigs slaughtered at 160 kg live weight (LW). Materials and methods: (Landrace × Large White) × Duroc pigs (N = 216), averaging 89.8 ± 0.4 kg LW at approximately 6 months of age, were evenly distributed among 18 pens (six pens per room, equal numbers of barrows and gilts per pen). Nine pens provided a low space allowance (LSA; k = 0.033; 1.0 m2 per animal; 126 pigs), and nine pens provided a high space allowance (HSA; k = 0.047; 1.4 m2 per animal; 90 pigs). After 90 days, six pigs per pen were slaughtered (total 108 pigs; 156 ± 1.4 kg LW). The proportion of floor contaminated with manure, urine, or both, and environmental parameters, were recorded during the observation period. Results: Pigs on all floor types tended to gain more weight with HSA than with ISA (P = .08) days 46 to 90. Average daily gain (ADG) and final LW were higher for barrows than gilts (P < .05). Feed conversion ratio tended to be lower (P < .10) for HSA than LSA animals. Backfat thickness was higher for HSA and rooms with totally slatted floors. Contaminated floor area was smaller with totally slatted floors. Implications: Increasing space allowance from k = 0.033 to k = 0.047 is associated with better ADG at LW > 120 kg, suggesting that this change might be of benefit to the heavy-pig industry.