Seventy-two-week-old Single Comb White Leghorn hens were induced to molt by 11 different methods 1) to determine the utility of molt-inducing procedures that employ full feeding, limited feeding, and fasting and 2) to determine the postmolt performance of hens induced to molt by fasting to varying degrees of body weight reduction (BWR) then fed postfast, prelay (PF-PL) diets varying in nutrient density. Induced molt treatments were full feeding of 10 and 15% guar meal diets to 30% BWR; limited feeding by withholding feed to 30% BWR, except for 6-hr feeding periods on every 3rd, 4th, and 5th recurring day; fasting to 25, 30, or 35% BWR then feeding either a pullet developer ration or a fortified molt ration (FR) for 21 days. Egg production, egg weight, shell quality, Haugh unit, feed consumption, and mortality were recorded for 33 weeks. Molt treatments produced few significant differences; nonmolted control hens had overall poor performance. Full feeding of the 15% guar meal diet caused a slow cessation and reinitiation of lay with acceptable lay performance. The 10% guar meal diet reduced livability. All recurring day, limited-feeding treatments conserved feed during the first 35 days of molt induction. The 3rd and 5th recurring day-feeding treatments were particularly effective and had acceptable lay performance and feed efficiency. Neither level of BWR nor type of PF-PL diet significantly affected postmolt performance. The 30% BWR-FR induced-molt method produced superior (but not significantly) postmolt lay performance.

Two experiments were conducted to detennine broiler growth and electricity use for illumination utilizing six light sources and three photoperiods as well as high energy (HE) and low energy (LE) diets. In each experiment, 3,600 Hubbard males were placed in six rooms, each containing 12 floor pens, metered separately for electricity use for illumination. Diets in each trial were similar. A 3,157 to 3,306 kcal/ kg ME three-phase HE program was compared with an LE 3,051 to 3,215 kcal/kg ME four-phase LE program.In Experiment 1, with 23 h of light (L) per day and 1 h of darkness (23L: ID), broilers fed LE were heavier (P<05) at 28,35, and 42 days than those on HE. All four light sources [low pressure sodium, circle soft white fluorescent (SWF), tube-type daylight (DLF) and pencil U tube fluorescent] gave BW and feed conversion (FCV) equal to that obtained with incandescent bulbs (IN) while using from 41 to 62% less electricity. In Experiment 2, broilers reared under SWF and DLF (1L:2D) and SWF (1.3L:2.7D) programs weighed significantly more, and all five treatments had (P<05) better FCV than the SWF (23L:1D) control. Broilers fed the HE dietary program had heavier BW and lower FCV than the LE diet Electric energy use for lights with the SWF (1L:2D) intermittent photoregimen was reduced to 17% of that used with the IN treatment (23L: ID), while resulting in superior BW and FCV. (

Two adjoining rooms in a light-tight, fan-ventilated, insulated house were used for a study involving 320 Single Comb White Leghorn hens, 60 wk of age, placed two per cage. These hens were subjected to an induced molt which compared two lighting programs, two molt rations, two levels of total sulfur amino acids (TSAA), and two levels of ascorbic acid (AA) in a factorial arrangement. There were four treatments. Treatment 1 compared the Washington lighting program (WSU), consisting of an 8-h light photoperiod for 28 days beginning 7 days before fast with the North Carolina program (NCSU), consisting of a 24-h light photoperiod for 7 days prior to fast followed by 12 h light/day for 21 days. After 28 days, light duration was increased to 16 h/day in stages for both programs. Treatment 2 consisted of feeding cracked corn (CC) or 16% protein molt ration (MR) for 2 weeks: Treatment 3, feeding of 14% layer mash with either .60% or .65% TSAA; and Treatment 4, addition of either 0 or 50 ppm AA to the 14% layer mash. After molting, egg production was increased in the NCSU lighting program and .65% TSAA treatments. Feed conversion was improved by the NCSU lighting treatment. Deaths were fewer in diets with 50 ppm AA. Egg weight, specific gravity, and shell weight were not affected by any treatment. A significant light X molt diet interaction occurred due to better performance of MR birds compared with CC birds in the NCSU lighting program, whereas on the WSU lighting program, CC produced better performance. These data indicated that combining features of various molt programs may not produce optimum results.

No abstract