Waddington D, Perry M M, Gilbert A B, Hardie M A
J Reprod Fertil. 1985 Jul;74(2):399-405. doi: 10.1530/jrf.0.0740399.
Diets containing 3.5, 1.0 and 0.1% calcium were fed from the age of 42 weeks to individually caged laying hens. Ovaries were examined at 46-49 and 70 weeks of age for changes in the follicular population corresponding to the lowered egg production rates of birds given calcium-deficient diets (1.0% and 0.1%) and older birds given a normal diet (3.5%). Growth rates of follicles from 3.5 mm diameter to ovulation were not changed by the level of dietary calcium in 46-49-week-old birds. The number of atretic small follicles (less than or equal to 8 mm diam.) increased in old and calcium-deprived birds, resulting in lower numbers of viable follicles in the intermediate stages of growth (3-8 mm diam.). There was also an increase in the number of small follicles (1-2 mm diam.) starting to grow in 70-week-old birds which may have partly compensated for the increased loss by atresia. Birds of all ages on all diets were able to produce large follicles up to ovulable size. The main feature of poor laying birds was a reduction in the ovulation rate due to the loss of large follicles (greater than 8 mm diam.) by atresia, an event seen rarely in the birds with good laying performance. As atresia is the normal fate of most of the small follicles, the mechanisms controlling atresia in the small follicles and the large follicles appear to be independent.
从42周龄开始，给单独笼养的产蛋母鸡饲喂钙含量分别为3.5%、1.0%和0.1%的日粮。在46 - 49周龄和70周龄时检查卵巢，以观察卵泡数量的变化，这些变化与饲喂缺钙日粮（1.0%和0.1%）的母鸡产蛋率降低以及饲喂正常日粮（3.5%）的老龄母鸡产蛋率降低相对应。在46 - 49周龄的母鸡中，日粮钙水平并未改变直径从3.5毫米到排卵的卵泡生长速率。老龄和缺钙母鸡中闭锁小卵泡（直径小于或等于8毫米）的数量增加，导致生长中期（直径3 - 8毫米）的存活卵泡数量减少。70周龄母鸡中开始生长的小卵泡（直径1 - 2毫米）数量也有所增加，这可能部分补偿了闭锁造成的卵泡损失增加量。所有日粮组各年龄段的母鸡都能够产生可排卵大小的大卵泡。产蛋性能差的母鸡的主要特征是由于闭锁导致大卵泡（直径大于8毫米）损失，从而排卵率降低，而这种情况在产蛋性能良好的母鸡中很少见。由于闭锁是大多数小卵泡的正常归宿，控制小卵泡和大卵泡闭锁的机制似乎是相互独立的。
