求翻译：试验选取160只1日龄初生重相近、发育正常、健康无病的AA雏鸡为实验对象，随机分为4组，每组设2个重复，每重复20只。是什么意思？

The test selected 160 birth weight is similar to 1-day-old normal development, health and disease-free aa chicks as experimental subjects, randomly divided into four groups, each group of two, each repeated 20.

Only 160 pilot selection 1 day-old newborn to similar, developmental disease-free normal, healthy chicks for the AA object of the experiment, the random is divided into 4 groups, each group has 2 repeats, only 20 per repeat.

The experiment selects the AA young chicken which 160 on 1st the age newborn heavy close, the growth normal, the health not gets sick is the experimental object, divides into 4 groups stochastically, each group supposes 2 repetitions, duplicates 20 every time.

Test select 160 1st age similar to the birth weight, normal, healthy disease-free chickens AA as the subject, randomly divided into 4 groups, 2 repeat for every group, every repeated 20.

正在翻译，请等待...