The spin-flip and change the movement of eggs during natural incubation by a brooding hen is a much-debated issue.

While some claim that the hen each day gives you back half full, others say that it doesn't make them give more than a 1/4 turn at a time and others that give 3/4.

These views also influence the practice of flipping in the artificial incubation. In which there are also differences of opinion, and while some will make a 1/2 turn, others turn 1/4 and 3/4.

To resolve the issue, a study of a similar nature was conducted, and to that end, we observed two nests, carefully noting what the brooding hens did with the eggs.

This also allows us to observe the change in the location of the eggs, that is, to see whether or not it is true that those in the center are moved to the periphery and those in the periphery are moved to the center.

The study was conducted on 15 eggs in each nest, and for this purpose, all the eggs were marked with a number. A mark was drawn on the larger end of each egg +, putting the letters to, b, c., d at each end of the cross.

This allows us to appreciate it, thanks to the remarkable research conducted by Professor J. L. Frateur of the Institute of Animal Science in Leuven (Belgium), the 1/8-turn approach.

The position of the eggs were scored every day, be practised in observation at eight in the morning, when he pulled the brooder to give you freedom and to eat.

The births took place normally at the start of the 22 days after starting the incubation.

Displacement centripetal and centrifugal eggs:

In other words, if I change location from the center to the periphery and from there to the center, it was determined in the tables they established, but the figures can only determine this approximately, because it is difficult to say whether an egg occupies exactly the periphery or the center.

To determine this more precisely, it is necessary to examine the diagrams showing the position of each egg on each of the 21 days of incubation; here we will look only at the position of two nests (1).

The examination of these paintings and engravings follows:

• 1. Throughout the incubation period, the eggs were regularly moved from the center to the periphery and from the periphery to the center.
• 2. Even though the eggs didn't move from their spot, they were always changing position.

Change the position of the eggs:

The engravings which illustrate this work show perfectly the change of position of the eggs, or in other words, the rotation about their axes.

A quick glance at the illustrations is enough to see that the change in position occurs almost exclusively through a rotational movement about the major axis. The tables that were compiled show the degree of rotation for each egg.

(1) Prof. Finleur’s report includes all 42 designs—21 for each nest—but because they would take up too much space, we are publishing only two for each nest as a representative sample.