2005 Poultry Science Association, Inc. Effect of Supplementary Tryptophan Prior to Marketing on Carcass Quality in Broilers1

Three experiments were conducted to examine the effect of supplemental Tryptophan on carcass quality of broilers. The first experiment utilized 49-d-old broilers with half of the birds crop intubated with 2 tablets, each containing 500 mg of Trp, compared with an equal number of birds not crop intubated, with processing occurring 14 h after intubation. For the second experiment, broilers were taken off feed on d 49, weighed, and allotted to either normal drinking water or offered a Trp-saturated solution containing 5 g of Trp per 1,000 mL of water for 4 h in pens during feed withdrawal until cooping for 14 h prior to processing. In the third experiment, a withdrawal feed was formulated with standard or high dietary Trp (2 × requirement, 0.33 vs. 0.18%) and fed to broilers from 46 to 49 d of age. Our results suggest that supplemental Trp, whether in an intubated tablet, water, or final feed, was insufficient to have any meaningful effect on broiler carcass defects. Supplementation of Trp in the water did reduce water consumption compared with birds offered the control water (42.1 vs. 88.9 mL, respectively). Consequently, until the level and length of Trp supplementation can be determined to alleviate contradictory findings and inconsistent results reported in the literature, determination of the genuine effects of supplemental Trp on behavior modification and carcass quality improvements in broilers ar