EFFECTS OF THERMAL MANIPULATION OF JAPANESE QUAIL EMBRYO ON POST-HATCH CARCASS TRAITS, WEIGHT OF INTERNAL ORGANS, AND BREAST MEAT QUALITY
Authors: El-Shater Saad Nazeh , Khalil * Karim Mohamed , Rizk Hamdy Mahmoud , Zaki Hamdy , Abdelrahman Hisham Ahmed , Abozeid Hassanein , Khalifa Elsayed Fath 
Published: July 2023

Embryonic thermal manipulation was known as an effective protocol for improving post-hatch growth performance and thermotolerance acquisition among avian species. Previously, we evaluated the impact of embryonic thermal manipulation of Japanese quail on embryonic development, hatchability, and post-hatch performance. We conducted the current study to furtherly elucidate the effects of thermal manipulations of Japanese quail embryos on internal organ weights, carcass traits, and meat quality parameters at post-hatch day 35. Quail eggs of control group were incubated at 37.7 °C and relative humidity (RH) 55%. Three thermally manipulated groups of quail eggs were incubated intermittently at 41°C and 65% RH intermittently (3 hours/day): the early embryonic group (TM1) was thermally challenged at embryonic day (ED6) to ED8, the late embryonic group (TM2) was thermally challenged at ED12-14, and early/late embryonic group (TM3) was thermally challenged in both time windows. Quail meat quality parameters, carcass traits, and internal organ weights were evaluated at post-hatch day 35. The results revealed that early embryonic thermal manipulation (TM1 group) is an effective protocol for decreasing fat pad accumulation. The pH value of breast meat in all TM treatments revealed significant (P < 0.05) decreases by 5% in comparison with that of control without any negative effects on breast meat composition or sensory criteria. Early embryonic thermal manipulation would be recommended as an enhanced protocol that can be used to reach the favored lucrative effects of the thermal treatment in meat-type quail.
UČINKI TOPLOTNE MANIPULACIJE ZARODKOV JAPONSKIH PREPELIC NA LASTNOSTI TRUPA PO IZVALITVI, TEŽO NOTRANJIH ORGANOV IN KAKOVOST PRSNEGA MESA
Izvleček: Toplotna manipulacija zarodka različnih vrst ptic je znana kot učinkovit protokol za izboljšanje rasti po izvalitvi in pridobivanje odpornosti na povišano temperaturo. Predhodno smo ocenili vpliv embrionalne toplotne manipulacije zarodkov japonskih prepelic na embrionalni razvoj, valilnost in uspešnost po izvalitvi. V tej študiji smo natančneje pojasnili učinke toplotne manipulacije zarodkov japonskih prepelic na težo notranjih organov, lastnosti trupa in parametre kakovosti mesa na 35. dan po izvalitvi. Jajca prepelic kontrolne skupine so bila inkubirana pri 37,7 °C in 55-odstotni relativni vlažnosti. Tri preiskovane skupine prepeličjih jajc so bile občasno izpostavljene temperaturi 41 °C in relativni vlagi 65 % (3 ure/dan): zgodnja embrionalna skupina (TM1) je bila izpostavljena toploti 6.– 8. embrionalni dan (ED), pozna embrionalna skupina (TM2) 12.–14. ED, zgodnja/pozna embrionalna skupina (TM3) pa v obeh časovnih intervalih. Parametre kakovosti mesa prepelic, lastnosti trupa in težo notranjih organov smo ocenili na 35. dan po izvalitvi. Rezultati so pokazali, da je toplotna manipulacija v zgodnjem embrionalnem obdobju (skupina TM1) učinkovit protokol za zmanjšanje kopičenja maščobnih blazinic. Vrednost pH prsnega mesa pri vseh toplotno manipuliranih skupinah se je znatno (P < 0,05) znižala za 5 % v primerjavi s kontrolno skupino, brez negativnih učinkov na sestavo prsnega mesa ali senzorične kriterije. Zgodnjo embrionalno toplotno manipulacijo bi bilo priporočljivo uporabiti kot izboljšan protokol, s katerim bi bilo mogoče doseči prednostne donosne učinke pri mesnih prepelicah.
Ključne besede: Coturnix japonica; mesna prepelica; lastnosti prsnega mesa; toplotna biologija