The effect of manipulations of incubation temperature on embryonic and post-hatching growth of native Saudi chickens

Embryonated egg is an ideal, environment in which to investigate the effects of incubation temperature on the development of the chick embryo. The objective of the current study were to investigate the effect of increasing the incubation temperature of chick embryo by 1.2 degrees C for 7 days (ED4 to ED11) on the body movement and mass of native saudi chick embryo. This objective was extended to examine the influence of pre-hatching temperature on post-hatching growth. Therefore, a total of 180 hatching egg of native Saudi chicken divided into two equal groups incubated at temperature 37.5 degrees C. The incubation temperature was raised to 38.7 degrees C from ED4 to ED11 in treated group before being returned to the control group incubation temperature (37.5 degrees C). The study revealed that elevating the incubation temperature of the eggs of native Saudi chicken by just 1.2 degrees C, from 37.5 to 38.7 degrees C, during embryonic days (ED) 4-11 causes significant increase in embryonic movement as demonstrated in day 8 in the chicks incubated at 38.7 degrees C together with an increase in embryonic development, the embryos incubated at higher temperature were heavier in weights and exhibit significantly longer legs than the controls in ED12 and 15. The increase in pre-hatching incubation temperature (38.7 degrees C) did not reveal any significant effects on post-hatching growth or of feed conversion efficiency.