Author : Chamnian Yosraj

Summary : An experiment was conducted to evaluate the effect of additional photoperiod to the normal day length in Thailand (NDL, approximately 12 hrs.) in Thailand on the laying performance of ducks. Four levels of additional photoperiod (2, 4, 8, and 12 hours) were applied at 3 levels of light intensities (5.38, 10.76, and 21.52 lux) conducted on a 4 x 3 factorial experimental design. A total of 468 ducks and 78 drakes were used that constituted 13 treatment combinations including the NDL as control. Data were analyzed as cases of completely randomized design (CRD), randomzied complete block design (RCBD), and RCBD's factorial designs. A second experiment was conducted to compare and verify the effect of the housing conditions used in the raising of ducks in Thailand. Results indicated that the 14-hour day length (NDL + 2) had a significant higher egg production rate than the other levels of added photoperiods. Ducks in treatment with added light hours reached sexual maturity significantly earlier than the NDL control group. The longer photoperiods also significantly influenced earlier oviposition time shortly after midnight. The various levels of light intensities did not significantly affect average egg production rate, weight of eggs, feed consumption, feed conversion ratio, body weight, mortality, and incidence of prolapse. The 5.38-lux treatment generally elicited better responses favorable to egg laying performance than the brighter light intensity levels. Data also showed some interactions between age of sexual maturity and light intensity. Results of Experiment indicated that the set of housing conditions were used in Experiment 1 was significantly inferior to the conventional housing conditions used for duck raising in Thailand.