A total number of 144 hens and 12 cocks of 48 wk old from
Fayoumi strain were used to determine whether hatchability can be
improved by using folic acid or pyridoxine supplementation in diets
during the late stages of egg production. Birds were divided into 3 equal
groups (48 hens + 4 cocks each) of 12 replicates each. A corn-soybean
meal basal experimental layer diet was formulated of being 16.5% CP and
2700 kcal.ME/kg diet. Three dietary treatments were used:
unsupplemented corn-soybean meal basal diet; the basal diet
supplemented with 1 mg folic acid/kg; and the basal diet supplemented
with 6 mg pyridoxine/kg. Response criteria included egg production, egg
fertility and hatchability as well as egg quality traits. Weekly data
responses were averaged across 4-wk periods and recorded in three
grouped time periods over the production periods. The following results
were obtained: 1) Feeding pyridoxine-supplemented diet caused the
highest egg weight; however, feeding folic acid or pyridoxinesupplemented diets resulted in significantly higher egg number and egg
mass and better feed conversion ratio as compared to feeding control diet.
2) Feeding folic acid-supplemented diet caused the highest hatchability %
and salable chicks %; however, pyridoxine-supplemented diets caused the
highest chick weight. Moreover, feeding folic acid or pyridoxinesupplemented diets resulted in significantly higher fertility % as compared
to feeding control diet. 3) Feeding folic acid-supplemented diet caused the
highest egg shape index; however, feeding folic acid or pyridoxinesupplemented diets resulted in significantly higher yolk %, shell %, shell
thickness and yolk height as compared to feeding control diet. On the
other hand, albumin % and albumin height were not significantly affected
by different treatments. From the nutritional point of view, under the
present experimental conditions, it is advisable to add 1 mg folic acid or 6
mg pyridoxine /kg of aged Fayoumi laying hen diet. Such practice helps
in improving laying performance, fertility, hatchability and egg quality
and seems to be advantageous in decreasing chick abnormalities.