Growth, pork quality, and excretion characteristics of pigs fed Bt corn or non-transgenic corn

Two experiments (exp. 1 and exp. 2, respectively) were conducted to compare performance, pork quality, and excretion characteristics of pigs fed diets containing Bt 11 (Bt) or control corn (C: non-transgenic inbred lines for exp. 1, and a non-transgenic isoline for exp. 2). Experiment 1 involved barrows and gilts (total n = 64; initial BW = 64 kg and 60 kg), while in exp. 2, 120 barrows were used (initial BW = 17 kg). Pigs were allocated to pens, blocked by sex and BW. Isocaloric, isolysinic diets contained an indigestible marker in exp. 1. Feed disappearance and weight gain data, and excreta samples were collected weekly in exp. 1. Feed disappearance and weight gain data were collected weekly in exp. 2. No difference in ADG was observed, however, feed efficiency was greater for pigs fed the C diet. No corn effects were observed for hot carcass weight, loin eye area, or backfat depth. Hunter color ‘b’ values and values for chroma were significantly greater for pigs fed C diets (P = 0.02, < 0.01, respectiv...