Effects of asymmetrical intermittent lighting in the rearing and laying period on bodyweight development performance and egg quality traits in laying hens

In an experiment effects of asymmetrically intermittent lighting during the rearing and laying period on light weight (LSL) and medium weight laying strains (LB, ISA) were investigated. During the rearing and the laying period a total of 16 hours light and 8 hours darkness per day were applied in both lighting programmes. In the intermittent lighting programme additional darkness phases during the (physiological) 16-hours lightphase were integrated. The three factorial design comprised of strain, lighting programme during the rearing period, lighting programme during the laying period and their interactions as influence factors. The pullets were floor reared and kept in single cages thereafter from 18 to 72 wk of life. Intermittent lighting during the rearing period caused a development delay at the beginning but was fully compensated until the 16th week. At the end of the rearing period the pullets were significantly heavier under the intermittent programme. This weight difference remained unchanged until the end of the laying period. The feed conversion ratio based on body weight gain during the rearing period was positively influenced by the intermittent lighting. The intermittent lighting (rearing and laying period) caused a slight stimulating effect on sexual maturity, i.e. reducing the age at first egg. The effect of intermittent lighting during the laying period from 18 wk to the onset of lay was significant while the effect of intermittent lighting during the rearing period was not. Egg production was influenced positively by the intermittent lighting during the rearing period. In contrast intermittent lighting during the laying period did not have any influence on egg mass but significantly reduced feed intake and thus feed conversion ratio. Furthermore the intermittent lighting during the laying period caused a clearly lower bodyweight gain and a slight decrease of yolk percentage. Interactions between rearing and laying period lighting programme were insignificant.