maybe this will help you understand why u need to turn your hatching eggs. The developing embryo always rests on top of the yolk. When an egg is turned, the yolk turns in the albumen so the embryo is again positioned on top of the yolk. Nature probably does this so the embryo is always in the best position to receive body heat from the mother hen sitting on the eggs.
If the egg is not turned, the yolk tends to float upward toward the shell and pushes the embryo nearer the shell. If the yolk travels rises enough, the developing embryo is squeezed between the yolk and shell. The embryo can be damaged or killed. Turning the egg causes the yolk to be repositioned away from the shell, making it safe for the developing embryo until time to turn the egg again.
Strands of twisted albumen extend from the yolk into the albumen toward both the small and large ends of the egg. These strands are called chalazae. They help keep the yolk away from the shell. The chalazae hold the yolk firmly in the egg's center until egg quality begins to deteriorate, as when an egg is placed in a 100oF. temperature incubator.
As the albumen becomes more watery, the chalazae lose their ability to hold the yolk in place, making it more important to turn the egg often after incubation begins. In general, the need for turning begins when eggs are set and remains until two or three days before the eggs begin pipping.
In large commercial incubators the eggs are turned automatically each hour, 24 hours a day. Eggs in small incubators in the home sometimes get turned only twice a day, once in the morning and again in the evening. If manual turning, it is best to turn the eggs for an odd number of times each day (i.e., 3, 5 or 7 times). The longest period that the egg remains in one position is during the night hours. Turning an odd number of times will alternate the nights that the same side of the egg is uppermost.
