What is the evidence that egg production is a cause of bone quality issues?
26 September 2022The belief that selection for increased egg production is a cause of bone quality issues in laying hens has been widespread. However, the evidence that there is a link between the rate of lay and bone quality does not support this. A number of pieces of evidence reinforce the need to find alternative explanations. Issues of bone quality, in particular, the keel have existed long before modern hybrid breeding.
Comparisons of high versus lower producing lines do not show a consistent trend in bone quality. Within line comparisons do not support egg laying number as a factor in bone quality nor did selection experiments. Problems with bone quality appear to be more likely earlier in a hens laying life, suggesting the issue is not with the number of eggs laid.
Other explanations for problems with bone quality need to be examined including the design of the housing, the level of activity, the control of puberty, enabling selection for skeletal quality and of course continually ensuring optimal nutrition during rearing and laying.