Increasing the temperature at a certain period during the incubation of broiler eggs improves the carcass and breast yields without a negative impact on the meat quality

The aim of the present study was to investigate how a higher temperature at a comparable period during chicken incubation influences the muscle development and the meat quality in the animals post hatch. Therefore half of fertilized eggs of the broiler genetic Cobb were incubated between ED 7 to 10 at 38.5 °C instead of 37.5 °C (control group). At the day of hatch (Day 21) the hatch rate was 86.6 % for the normal temperated eggs (NTG) and 82.4 % for the higher temperated group (HTG). The animals were reared until day 35. The broilers (N=30 per sex and incubation group) were then slaughtered and the carcass, breast and leg weights were determined. The meat quality analysis includes the determination of the pH and electrical conductivity 24 h after slaughter and the colour (L*a*b*) 20 min and 24 h after slaughter. Comparing the results between the incubation groups no significant differences in the weight parameters were determined. With regard to the meat quality parameters also no significant differences could be presented. Considering also the gender the HTG cocks had significantly (P<0.05) higher carcass, breast, the leg weights were similar. This difference between the incubation groups could not be determined in the hens which had generally lower carcass, breast and leg weights than the cocks. With regard to the meat quality parameters no clear influence of gender and incubation group could be determined. From the presented results it could be concluded that between ED 7 and 10 of the incubation certain steps within the myogenesis are sensitive to a higher temperature. The higher temperature could either have a direct effect on myogenic regulatory systems, or an indirect by a general stimulation of the embryonic metabolism and/or activity. The gender dependence of these differences might be related to temporal differences in the embryonic muscle development of the cocks and hens.