Date of this Version
This experiment was conducted to evaluate growth performance and carcass quality measurements in growing-finishing pigs fed diets containing either Corn Root Worm Protected Corn (CRW0586), the parental control corn (RX670), or two commercial sources of non-genetically modified corn (DK647 and RX740). The experiment used 72 barrows and 72 gilts with an average initial body weight of 50 lb. The pigs were allotted to a randomized complete block design with a 2 x 4 factorial arrangement of treatments (two sexes x four corn hybrids). The experiment continued until the average body weight was 260 lb, at which time all pigs were slaughtered. Real-time ultrasound measurements were taken on the final day of the experiment. Carcass quality measurements were made 24 hours postmortem. Corn hybrid did not affect average daily gain (ADG) or average daily feed intake (ADFI), but there was an effect of sex, with barrows having greater (P<0.01) ADG and ADFI than gilts. Feed efficiency was not affected by the different corn hybrids, but gilts had improved (P<0.01) feed efficiency compared to barrows during Finisher 1 (0.37 versus 0.35) and Finisher 2 (0.32 versus 0.30). Real-time ultrasound measurements were similar corns; however, a sex effect was detected for backfat (BF) depth, with gilts having less (P<0.01) BJ than barrows (0.78 versus 0.98 in). There were no differences in carcass midline BF measurements among corns, but there was a significant difference between barrows and gilts, with gilts having less (P<0.05) BF than barrows. Hot carcass weight was greater (P<0.01) in barrows than gilts (210 versus 190 lb). Also, the percent carcass lean was greater (P<0.01) in gilts than barrows (51.7 versus 49.5%). Longissimus muscle quality scores were similar among corns and between barrows and gilts. Analysis of longissimus muscle composition revealed no main effect of corn (P>0.20) or sex (P>0.30) for protein, fat, and water percentages. However, Corn Root Worm Protected Corn (73.1%) differed (P<0.04) from parental control corn (73.6%) but not commercial corns (73.3 and 73.3%) in longissimus water content. In summary, there were no differences in growth performance or carcass measurements in growing-finishing pigs fed diets containing either Corn Root Worm Protected Corn, the parental control corn, or two commercial sources of non-genetically modified corn. Thus, the replacement of non-genetically modified corn. Thus, the replacement of non-transgenic corn with Corn Root Worm Protected Corn in growing-finishing diets will result in similar growth performance and(or) carcass measurements.