Stocking density and feeder space effects on growth and carcass quality of PIC359 sired pigs

Abstract Text: A grow – finish trial using 1,895 PIC359 x Camborough pigs was conducted to investigate the effects of varying stocking densities and feeder space allowances on growth rate, feed conversion, and carcass quality. Seventy pens with 17.13 m² of floor space were stocked with 23, 26, or 29 pigs at 56.6 d of age. Floor space allowances were 0.75, 0.66, or 0.59 m² / pig at placement. Each pen had two cup waterers and a four-hole dry feeder that was 142.2 cm long. Custom-built steel plates were used to block pig access to two holes on 36 feeders.  Pigs were marketed at an average weight of 132.8 kg at a commercial pork processing plant.  Carcass backfat thickness and loin depth were measured with an optical probe. Carcass lean percentage was estimated from the backfat and loin depth measurements. Average daily gain was 0.042 kg / d (0.76 vs. 0.802) and 0.06 kg / d (0.76 vs. 0.82) slower for pens with 29 pigs compared to pens with 26 or 23 pigs (P < 0.05).  Daily feed intake was 0.08 kg / d (2.0 vs. 2.08) and 0.11 kg / d (2.0 vs. 2.11) lower for pens stocked with 29 pigs compared to pens with 26 or 23 pigs, respectively (P < 0.05). Pens of pigs with two feeder holes grew 0.024 kg / d (0.782 vs. 0.806) slower than pigs from pens with four feeder holes (P < 0.03). Daily feed intake was 0.04 kg / d (2.04 vs. 2.08) lower for pens of pigs allowed access to only two feeder holes (P < 0.06). Pigs sold as light-weight culls was 1.4 % higher for the two feeder hole treatment (3.0 % vs. 1.6 %; P < 0.05).  Carcass lean was 0.5 % higher when 29 pigs were placed in a pen compared to 23 pigs per pen (56.0 % vs. 55.5 %; P < 0.02). The feeder hole treatment was not different for any of the carcass traits (P > 0.60). A floor space by feeder space interaction was detected for gain : feed and kg of gain : Kcals ME (P< 0.05). Restriction of feed intake by restricting floor space / pig or reducing cm of feeder space / pig adversely affected growth rate and feed intake, but not feed conversion. Restricting floor space improved carcass lean via a reduction in feed intake.

Keywords: pigs, growth feed intake