EFFECT OF HEAT TREATMENTS DURING HATCHING EGGS STORAGE ON HATCHABILITY TRAITS AND CHICK QUALITY

Abstract

The purpose of this study was to investigate the efficacy of short periods of incubation during egg storage (SPIDES) on hatchability, embryonic mortality, incubation time and chick quality of broiler breeder hatching eggs stored for 15 days. A total of 15510 hatching eggs were collected from 49-wk-old Arbor Acres broiler breeders flock. Eggs were divided into four groups. First group was stored for 5 days without heat treatment (Fresh eggs). Second group was stored for 15 days and heated one time at the fifth day of storage (SPIDES1). Third group was stored for 15 days and heated two times, on fifth and tenth days of storage (SPIDES2). Forth group was stored for 15 days without heating, a negative control. Heat treatment was at 32oC and 55 – 60% relative humidity for 6 hours. Results indicated that prolonged storage reduced hatchability, and visible fertility of untreated eggs. Heat treatments improved early embryonic mortality, hatchability and visible fertility. When eggs were exposed two times to heat treatment the hatchability was significantly improved as compared to those exposed one time only. Incubation time of the negative control was significantly increased as compared to the fresh eggs group or both heat treatment groups. No differences were observed between groups in live pipped or culled percentages. Relative yolk sac weight of newly hatched chicks increased significantly with the length of the pre-incubation storage period. However, both heat treatments restored this percentage to that of the fresh eggs. Chick quality traits (Tona score, chick weight, relative chick weight and chick length\weight) of the negative control group had lowest values as compared to other groups. However, SPIDES treatments slightly improved chick qualities. In conclusion, the present study revealed that SPIDES is an effective method to ameliorate the detrimental effects of long storage period on hatchability and chick quality.