The Impact of Lowering Floor Space Allowance and Dietary Energy Level on Finishing Pigs, from 65 Kg to Market, on Growth Performance

Abstract The objective of this experiment was to evaluate the impact of reducing floor space allowance in finishing hogs with a starting body weight (BW) of 65 ± 2 kg when fed high versus low energy diets on growth performance. Mixed-sex pens (n=88) with 24 ± 1 pigs per pen were blocked by starting BW to a randomized complete block design with eight treatments. These eight treatments formed a 2 x 4 factorial arrangement with 2 energy levels: low (LE, 3270 ±19 kcal/kg ME) vs. high (HE, 3392 ±19 kcal/kg ME) accomplished through fat inclusion; and 4 floor space allowances: 0.60, 0.63, 0.65, 0.67 m2 per pig. Assigned floor space was adjusted by moveable gates in the rear of the pen, which were corrected at each pig removal until the marketing phase. Pen weight and feed disappearance were measured for 2 phases at d 0, 29, and 48 to calculate average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (GF). Data were analyzed by pen (SAS 9.4, Cary, NC) with the repeated measure of phase, and the fixed effects of floor space allowance, dietary energy, and the interaction between. For the overall trial, decreased floor space had no effect (P > 0.1) on ADG, ADFI, or GF (0.36, for all). Energy had a significant effect (P < 0.01) on ADFI (3.17 vs 3.12 kg for LE and HE, respectively) and GF (0.35 and 0.36 for LE and HE, respectively), and tended to impact ADG (1.12 vs 1.13 kg, for LE and HE, respectively; P = 0.08). In conclusion, lowering floor space allowance from 0.67 m2 down to 0.60 m2 did not affect the growth performance of pigs starting at 65 kg. Pigs fed HE diets had 2.86% better GF compared with pigs fed LE diets, however had similar growth and body weight.