Effect of lighting program and nutrition on feather replacement of molted single comb White Leghorn hens

This experiment concerned the induced molt of 320 60-wk old Single Comb White Leghorn hens placed two per cage in two adjoining sections of a light-tight, fan-ventilated poultry building. Treatments compared were: 1) lighting program: Washington (WSU) vs. North Carolina (NCSU). The WSU program used 8 h light/day for 28 days beginning 7 days before fast. The NCSU program used continuous light for 7 days prior to fast, followed by 12 h light/day for 21 days. The light portion of the photoperiod was then increased in steps in both treatments to 16 h. 2) Molt diet: cracked corn (CC) vs. 16% protein molt ration (MR) for 14 days. 3) Laying diet. A 14% protein mash calculated to contain .60% or .65% total sulfur amino acids (TSAA) or ascorbic acid (AA) at 0 or 50 ppm added to the laying mash. Day 1 was designated as the first day of photoperiod modification. Primary and secondary feather loss and subsequent primary feather growth were all significantly increased by the WSU light program at 56, 84, and 112 days. Total and average growth of new primaries was significantly increased by MR at 56 days and total primary feather growth by .65% TSAA at 112 days. No effects due to AA were observed. Photoperiod had the greatest effect on molt per se, with MR and .65% TSAA increasing early and late growth, respectively.