Acute and chronic eggshell temperature manipulations during hatching term influence hatchability, broiler performance, and XXXX incidence.

@entity1573 @entity843
UNASSIGNED: The aim of the current study was to determine how a control temperature and acute and chronic high eggshell temperatures during the last three days of incubation, can affect hatchability, @entity1573 quality, and organ development on day of hatch as well as broiler performance and @entity843 incidence in later life. The eggshell temperature manipulations were applied during hatching term (days 19 to 21) as follows: control EST (37.3 to 38.0  C), acute high eggshell temperature manipulations (38.4- to 39.0  C for three hours daily) and chronic high eggshell temperature manipulations (38.4 to 39.0  C). The lowest hatchability and the highest cull @entity1573 rate were in the chronic high eggshell temperature manipulations group. Lower @entity1573 quality parameters correlated with lower @entity1573 weights and heavier residual yolk sac weights that were in the chronic high eggshell temperature manipulations group depending on hatch time. The live weights on the 1(st) day of the growing period were higher in the control and acute high eggshell temperature manipulations groups than the chronic high eggshell temperature manipulations group. At 6 wk of age, live weights of broilers were the highest in the control than in the acute and chronic high eggshell temperature manipulations groups. The total mortality was 2.5, 9.2, and 13.3%, the mortality due to @entity843 was 2.1, 8.3, and 12.9% in the control, acute ,and chronic high eggshell temperature manipulations groups, respectively. The right ventricular/total ventricular ratios for the control, acute and chronic high eggshell temperature manipulations groups were 0.22, 0.28, and 0.30%, respectively. In conclusion, short-term and long-term higher temperatures during the hatching term affect embryo development, incubation results, broiler performance, and @entity843 incidence. Although the acute high eggshell temperature manipulations did not affect the @entity1573 quality parameters at hatch, it negatively affected incubation results and broiler performance, especially mortality due to @entity843 .
