Riddell C, Classen H L
Department of Veterinary Pathology, Western College of Veterinary Medicine, Saskatoon, Saskatchewan, Canada.
Avian Dis. 1992 Jul-Sep;36(3):491-8.
Male broiler chickens were raised to 63 days of age under different lighting and anticoccidial treatments. A constant-light program was compared with two interrupted and increasing-light programs in which the photoperiod length was 6 hours between 7 and 14 days of age and then increased gradually to continual light by 49 days of age in the first program and more gradually to 18 hours by 49 days of age in the second program. By 63 days of age, the increasing-light programs significantly increased body-weight gain and decreased feed/grain ratio, but not significantly. The increasing-light programs reduced the incidence of skeletal disease from 7.56% to 2.88% in the first program and to 3.53% in the second program, reduced the incidence of acute death syndrome from 5.94% to 3.37% in the first program and to 4.65% in the second program, and reduced total mortality from 18.81% to 11.71% in the first program and to 11.38% in the second program. The lighting programs had no effect on the incidence of ascites and right heart failure, the ratio of right ventricular weight to total ventricular weight, the incidence of clinical and subclinical tibial dyschondroplasia, and the number of cartilaginous and osseous nodules in the lungs. The anticoccidials compared were monensin and amprolium/ethopabate, from 0 to 35 days of age. These treatments had no significant direct effects on any of the parameters measured.
雄性肉鸡在不同光照和抗球虫处理条件下饲养至63日龄。将持续光照程序与两种间断性递增光照程序进行比较，在第一种程序中，7至14日龄时光照时长为6小时，然后逐渐增加，至49日龄时变为持续光照；在第二种程序中，至49日龄时更缓慢地增加到18小时光照。到63日龄时，递增光照程序显著提高了体重增加量，并降低了料肉比，但差异不显著。第一种递增光照程序将骨骼疾病发病率从7.56%降至2.88%，第二种降至3.53%；将急性死亡综合征发病率从5.94%降至3.37%，第二种降至4.65%；将总死亡率从18.81%降至11.71%，第二种降至11.38%。光照程序对腹水和右心衰竭发病率、右心室重量与总心室重量之比、临床和亚临床胫骨软骨发育不良发病率以及肺部软骨和骨结节数量均无影响。所比较的抗球虫药为0至35日龄期间使用的莫能菌素和氨丙啉/乙氧酰胺苯甲酯。这些处理对所测的任何参数均无显著直接影响。
