EFFECT OF SPRAYING HATCHING EGGS OF JAPANESE QUAILS BY LIVE YEAST ON PHYSIOLOGICAL CHANGES IN THE EMBRYONIC DEVELOPMENT, HATCHABILITY AND TOTAL BACTERIAL COUNT

The present experiment was carried out to study the role of spraying hatching eggs with live yeast (Saccharomyces cerevisiae) (YC) on physiological changes in the embryonic development, hatchability rates and the bacterial load on eggshell surface of quail eggs, and post hatch chicks performance. Four hundred and twenty hatching eggs of Japanese quails were divided into four treatment groups. Eggs of first group was the control group without any treatment. Eggs of the second group was sprayed by water. Eggs of the third and the fourth groups were sprayed by 2.5% and 5% yeast solution respectively.
Results obtained are summarized as follows:
1-Embryo weight, body length, shank length as well as, chick weight, chick body length, chick shank length and hatchability of fertile eggs ratio tended to be higher significantly (P<0.05) for eggs treated by spraying with live yeast solution than those of control eggs. Hatch time, embryonic mortality decreased in eggs sprayed by live yeast solution compared to untreated.
2- The egg albumin weight ratio at ages of 10 and 14 days of incubation, egg weight losses ratio and egg shell thickness at the 14th day of incubation were significantly (P<0.05) decreased in eggs sprayed by live yeast solution compared to those for untreated.
3- Blood hematological parameters (RBCs, Hb, and PCV), hormones and calcium represented significant improve while WBCs improvement numericly response to spraying with live yeast solution.
4- Carcass constituents (liver, gizzard, heart and intestine) of chicks at hatch and growth performance (body weight, body weight gain, feed intake and feed conversion) of chicks at 21 d of Japanese quails revealed significant higher values in response to spraying with live yeast solution while yolk residual for chicks at hatch of eggs sprayed by 2.5 and 5% live yeast solution was lower than control group.
5- Application of yeast had significant influence on TBC and TSC compared to control untreated either at one week or after two weeks of incubation.Spraying Japanese quail eggs with live yeast solution (5%) pre- incubation may be a good way to improve embryonig development, hatchability, blood hematology and hormones of hatch chicks and lowering the bacterial load on eggshell surface of quail eggs.