SID tryptophan levels and B6 vitamin supplementation do not change blood parameters, organ weights, carcass traits, and meat quality of barrows (70–100 kg)

This study evaluated the effects of standardized ileal digestible (SID) tryptophan and B6 on blood parameters, organ weights, carcass traits, and longissimus lumborum quality of barrows (70–100 kg). Sixty-four crossbred barrows averaging 70.77 ± 2.07 kg were distributed in a 4 × 2 factorial with four SID tryptophan levels (0.130, 0.155, 0.180, and 0.205%) and two B6 levels (1 and 5 mg/kg) in eight replicates of one animal each. The meat lightness degree answered linearly (P = 0.015) to SID tryptophan levels and the shear force answered quadratically (P = 0.050), with estimates of a higher value (31.67 N) at 0.163% SID tryptophan. Although B6 showed positive effects (P < 0.05) on hot and cold carcass yields and pH 24, it resulted in a negative effect (P < 0.05) on ham weight and yield, and increased the drip loss and cooking fluid. The dietary SID tryptophan requirement for barrows (70–100 kg) was not higher than 0.130% (4.07 g/day) and did not change due to B6.