Beneficial effects of alternative lighting schedules on the incidence of ascites and on metabolic parameters of broiler chickens.
The beneficial effects of different lighting programmes on the incidence of ascites was investigated in an experiment with 360 three-day-old male broiler chickens. At 3 days of age, chicks were randomly divided over three rooms in a high-altitude farm, 2000 m above sea level. During days 14 to 28 ambient temperature decreased during the night but the minimum temperature did not descend below 15 degrees C. In the first room the continuous lighting schedule (CL, 23L:1D) was maintained and in the second room an intermittent lighting schedule (IL, 1L:3D), repeated six times daily, was imposed from 3 days of age. In the third room, an increasing photoperiod schedule (IP, 4 to 14 days, 6L:18D; 15 to 21 days, 10L:14D; 22 to 28 days, 14L:10D; 29 to 35 days, 18L:6D; 36 to 42 days, 23L:1D) was provided. Mortality associated with right ventricular failure and ascites was numerically lower in birds reared under the IL and IP schedules compared to birds reared under the CL schedule, which can be attributed to the temporary reduction in relative growth and feed intake in IL and IP birds. It was concluded that the beneficial effect of lighting schedules could be due to a reduced metabolic rate as a consequence of the altered growth trajectory, as also reflected in the lower haematocrit and plasma T3 levels of IL and IP birds compared to CL birds.
Hassanzadeh
M
M
Department of Poultry Diseases, Faculty of Veterinary Medicine, University of Tehran, PO Box 14155-6453, Tehran, Iran. Mhzadeh@Chamran.ut.ac.ir
Fard
M H Bozorgmehri
MH
Buyse
J
J
Decuypere
E
E
D000821:Animal Feed; D000818:Animals; D001201:Ascites / Q000517:prevention & control / Q000662:veterinary*; D002645:Chickens / Q000097:blood / Q000254:growth & development*; D002149:Energy Intake; D006400:Hematocrit / Q000662:veterinary; D006799:Housing, Animal; D015994:Incidence; D008029:Lighting; D008297:Male; D011201:Poultry Diseases / Q000097:blood / Q000517:prevention & control*; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D014284:Triiodothyronine; D013974:Thyroxine