The study was carried out as a split-plot design with a 2 x 6 factorial arrangement of treatments (two genders and six wheat varieties). A three-phase dietary program was used; all diets were formulated with a fixed level of wheat inclusion (70%, 80% and 85% for the Grower, Finisher I and Finisher II phases, respectively). A total of 240 commercial hybrid pigs (equal numbers of barrows and gilts) were grown from 29.5±0.29 to 114.5±2.23 kg live weight in single-gender pens (barrows or gilts) of five pigs (eight pens per dietary treatment) with ad libitum access to feed and water throughout the study. At the end of each dietary phase and of the test period, ultrasound measurements were taken at the 10th rib. Animals from the transgenic and non-transgenic treatments were harvested at the end of the study and carcass and meat quality measurements were taken. Pigs fed the six wheat varieties had similar (P>0.05) feed intake, live weight gain, gain:feed ratio and ultrasound measures of backfat thickness and longissimus muscle area. There was a wheat variety x gender interaction (P<0.05) for longissimus fat content. Gilts fed the transgenic wheat had higher (P<0.05) longissimus fat content than those fed the non-transgenic control wheat; however, for barrows there was no effect (P>0.05) of wheat variety on longissimus fat content. However, there was no effect (P>0.05) of wheat variety on other longissimus muscle quality or composition measures. Gilts had lower (P<0.01) feed intake, growth rate and backfat thickness, and similar gain:feed ratio (P<0.05) compared to barrows.
This study, with growing–finishing swine, suggests that the genetically modified wheat resulted in equivalent animal performance to conventional wheat.
BA Peterson, Y Hyun, EP Stanisiewski, GF Hartnell and M Ellis. 2008. Animal. 2(11):1602–1609.