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Whitehead reported that chicken bone begins to weaken from the time 200 eggs are produced, corresponding to 50-52 weeks of age.
The chicken’s reproductive system has four components:
Hypothalamus
Responsible for directing hormonal operations, assisted by the adenohypophysis.
Ovary
Initial motor of the formation of the egg – since the follicles that will transform to yolks develop there – requires the constant supply of fatty acids from the liver
Oviduct & Medullary bone
The shell formation requires a great partner: the medullary bone. If the cells of the uterus in charge of mineralizing the shell get minerals from the cortical bone, the bird is losing the fight in the game of bone formation: osteoblasts versus osteoclasts.
It is important to plan wisely:
The activities to be carried out
Management and nutrition practices to guarantee the development, growth and maintenance of the hen’s bones, especially if more than 380 eggs are desired; or to reach one hundred weeks in a production cycle without molting.
Van Sickle, more than 30 years ago, described the important aspects to keep in mind from the first day of a chick’s age until the adult hen is removed:
Growth: relative rates with other organs and with respect to bone components.
Development of structural and functional components of bone: related to endochondrial and intramembrane growth.
Control of bone growth
The first two points of this proposal are not simple to carry out on a commercial farm since they are related to research centers.
However, what can be done is to construct a standard bone growth and development curve to assess the bone behavior of the birds. This is an additional variable to those who normally use metrics such as body weight, consumption, etc.
Importance of bone measurement
The importance of bone measurement is to indicate:
Table 1 details the effect of three measurements on the femur and its correlation with two variables in the egg, production and body weight. The cortical area has a significant and inverse effect on:
Specific gravity
Egg weight
Production
The medullary area presents a direct and highly significant relationship on the specific gravity and weight of the egg.
More area means more space for calcium fixation in the medullary bone, and from there the bird will mobilize it to mineralize the shell.
To achieve a positive effect on the variables of the egg, the work is carried...
