as to exclude a large percentage of the light rays, but still provide for 

 ventilation. Two reflector-type floodlight bulbs of either 75, 150 or 300 

 watts were used in each pen to provide light. The wattage and height of 

 the bulb from the floor enabled the various foot candle intensities to be 

 maintained. The two bulbs were located on a line equidistant from each 

 side wall and one third of the distance from the front and rear of each 

 pen. Feeding space per chick of 1" for day old to 2 weeks, 2" to 6 weeks 

 and 3" to completion was provided by using hoppers of 3 different sizes. 

 A one gallon glass waterer was used for the first two weeks in each pen. 

 This was replaced with a three foot trough and a Fox-type valve providing 

 a continuous supply of water. 



Stock for every experiment was purchased from a large breeder hatchery, 

 which was in position to help us obtain stock with similar breeding for 

 all trials. The bird used was a crossbred, widely used in the broiler indus- 

 try, with Cornish blood on the male side. 



New England College Conference Rations were used throughout the ex- 

 periment. Only slight modifications were made in these formulae from year 

 to year. 



Measurement of Light Intensity 



A Weston Illuminator Meter — Model 756, with Viscor filter — was 

 used to determine the foot candles. This instrument indicates the illumi- 

 nation in foot candles based on the New Candle, on the surface of the light 

 target, or lumens, per square foot evenly distributed. The target was placed 

 on a piece of 2" x 4" lumber on edge beside the feeder. 



Outline of Experiments 



The study was divided into two parts. The purpose of the first part was 

 to determine the influence of light intensity and daily light dosage on 

 feather condition, body weight, feed conversion, and mortality rate in 

 broilers at 10 weeks of age. 



The purpose of the second part was to determine the effect of the feed 

 form and floor space allotment in combination with high and low light in- 

 tensity on feather condition, body weight, feed conversion and mortality 

 rate in broilers at 10 weeks of age. 



In the first part, three levels of light intensity and two of daily dosage 

 of light were used. The two dosages of light were 12 and 24 hours, and 

 the levels of light intensity were 15, 60, 120 foot candles. The layout of 

 each experiment followed a randomized block design. Each treatment com- 

 bination was replicated three times. A 2 x 3 factorial analysis was used. 

 In two out of the three experiments a natural daylight pen was added to 

 each replicate. Chicks were randomized from the shipping boxes to each 

 pen so that each pen received an equal number of chicks from each box. 

 Thirty male and thirty female day old chicks were placed in each pen. 



The dates for the three experiments in Part 1 were as follows: 

 Experiment I — August 23, 1956, to November 1, 1956 

 Experiment II — May 17, 1957, to July 26, 1957 

 Experiment III — February 10, 1958, to April 21, 1958 



The following data were obtained: 



1. Individual weight at 10 weeks of age. 



2. Individual feather score at 10 weeks of age (based on 



