Effect of ahemeral light:dark cycles on egg production in early photostimulated brown-egg pullets.
A laying trial was conducted to determine the effect of an ahemeral lighting program on early photostimulated brown-egg pullets (DeKalb Sex-Sal). All birds received 24 h of light/day (24L:0D) to 3 days of age followed by 8 h of light (8L:16D) to 8 wk of age. From 8 to 16 wk the birds received 10 h of light daily. At 16 wk, the control group (CON) received 11 h of light and 13 h of darkness (11L:13D) followed by a weekly 1-h increase in photoperiod to 14L:10D at 19 wk, which was maintained for the duration of the trial (59 wk of age). Birds on the ahemeral (AHM) schedule were exposed to a 26-h schedule of 11L:15D at 16 wk with a weekly 1-h increase in the photoperiod to 14L:12D at 19 wk. The AHM schedule (14L:12D) was maintained from Weeks 19 to 30 at which time birds were returned to a 24-h cycle of 14L:10D and kept on this schedule for the remainder of the trial. Egg weight was significantly increased by the AHM treatment for 27 to 30 wk; however, there was no cumulative (Weeks 19 to 59) effect on egg weight. Percentages of eggs per hen per day (%HDP) were significantly reduced by the AHM treatment for the periods 23 to 26 wk and 31 to 34 wk. This reduction caused a significant cumulative effect on %HDP (68.9 for CON versus 66.2 for AHM).(ABSTRACT TRUNCATED AT 250 WORDS)
Hawes
R O
RO
Department of Animal, Veterinary, and Aquatic Sciences, University of Maine, Orono 04469.
Lakshmanan
N
N
Kling
L J
LJ
D000821:Animal Feed; D000818:Animals; D002645:Chickens / Q000502:physiology*; D004435:Eating; D004531:Eggs / Q000592:standards*; D005260:Female; D008027:Light; D010058:Oviposition / Q000502:physiology* / Q000528:radiation effects; D010507:Periodicity