Abstract: High eggshell temperatures: a matter of life and death

Presented On The IFRG In Norwich 7-8 July 2009 (www.ifrg.org), By Roos Molenaar

R. Molenaar*, R. Meijerhof*, B. Kemp‡, R. Hulet.†, H. van den Brand‡

*HatchTech Incubation Technology, PO Box 256, 3900 AG Veenendaal, The Netherlands; ‡ Wageningen University, Adaptation Physiology Department, PO Box 338, 6700 AH Wageningen, The Netherlands; † Penn State University, Poultry Science Department, 222 Henning Bldg, University Park, PA, USA

In practice, eggshell temperatures often increase at the end of the incubation process, when greater heat production occurs in the eggs. Problems with cooling and air velocity in incubators can be the reason for this increase in eggshell temperature. It is critical that eggshell and, therefore, embryo temperature is not too high.

Regulation of embryo or eggshell temperature during incubation can be beneficial in both practical and scientific situations. Different studies have shown that high eggshell temperatures (38.9ºC) compared with normal eggshell temperatures (37.8ºC) from the first or second week of incubation till the end of incubation decrease embryonic development and chick quality in broiler embryos, expressed by a lower chick length, a lower yolk free body mass, a higher residual yolk and a poorer navel condition. One of the reasons for impaired development with high eggshell temperatures might be the reduced incubation time.