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AUTHOR(S):

Mohammad Sh., Al Sardary S.

 

TITLE

Effect of Thermal Manipulation During Embryogenesis on Thermotolerance and Hatched Broiler Performance

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KEYWORDS

Epigenetic adaption, Thermal manipulation, Early age heat conditioning, Performance, Thermotolerance

ABSTRACT

This study was conducted to investigate the effect epigenetic adaptation by thermal manipulation (TM) during different stages of embryogenesis broiler breeder eggs by using an intermittent temperature treatments with amplitude of 1 °C higher than the standard incubation temperature for 4 hours daily at embryonic days (ED): T1 (1-5), T2 (8-12), T3 (14-18), T4 (19-21) and T5 was control (no TM), also through early age thermal conditioning chicks by exposing them to 38.0 ± 2 °C for 12 hours/day at 5th and 7th days of age then from the beginning of 4th week and onward the birds acclimated to elevated heat of 26±2 °C, on post-hatch broiler productive performance, body temperature and carcass traits at 35 and 42 days of broiler age . Six hundred (600) day-old chicks were randomly assigned according to treatment groups during hatching process. Chicks were distributed into five treatments with four replicates/group, with thirty chicks per each replicate (15 for each sex), all treatment groups were subjected to 38 ±2 °C for 12 hrs/day at 5th and 7th days (d) post-hatching as thermal conditioning (TC). After each exposure body temperature of birds were measured. Live body weight, bodyweight gain, feed consumption, feed conversion ratio and mortality were recorded weekly. Production index, dressing percentage and carcass cuts percentages, were measured at 35 and 42 days of age of broiler chicks. The overall data showed that T1 and T3 showed significantly (p?0.05) higher relative growth percentage than control group. T3 showed significantly (p?0.05) lower rectal temperature than other thermally manipulated groups and control group at 42 days of age. T1 and T3 showed significantly better feed conversion ratio than the other thermally manipulated groups and control group during the period 1- 42 days. T2 showed significantly lowest cumulative mortality percentage than other thermally manipulated groups and control. T2 and T3 had the higher production index than other treated groups and control group at marketing age of 35 and 42 days, respectively. In conclusion, using of epigenetic adaptation to temperature lead to decrease cloacae temperature at 42 days of age than control which confirms the acquisition of thermotolerance in thermally manipulated groups.

Cite this paper

Mohammad Sh., Al Sardary S. (2016) Effect of Thermal Manipulation During Embryogenesis on Thermotolerance and Hatched Broiler Performance. Food and Nutrition Science - An International Journal, 1, 12-19