Effect of Thermal Manipulation during Incubation on Some Incubation Indicators and BroilerChick Quality

Abstract

The research was carried out on 355 fertilized eggs from 50-week Ross 308 broiler breeder. Eggs were distributed into 4 groups: the control (37.8ºc during incubation and 37.5ºc during hatching), group 2 (41ºc/3 h/d, during 14-16 of incubation), group 3 (41ºc/3 h/d, during 14-15 of incubation) and group 4 (41ºc/3 h/d, during 14-16 and 18-19 of incubation). Results illustrated a decline in hatchability in group 2 and 4 by (17.13% and 23.35%), respectively compared to control. Hatchability from total eggs was also decreased in groups 2,3, and 4 by 20.96%, 10.23% and 14.17%, respectively comparing to that of control. A rise was observed in the total late embryonic mortality and during-experiment embryonic mortality, respectively in groups, 2 (37.04%, 17.28%), 3 (38.20%, 16,67%) and 4 (31.71%, 14.63%) compared to control (13.92%, 2.53%). Resultsalso showed a reduction in saleable hatchling percentage in group 3 (80.00%) compared to (100%, 97.30% and 95.24%) in control, group2 and 4, respectively, whereas both groups 3 and 4 have exceeded control’s average of hatchling body weight by (1.77 g and 2,75 g), respectively.