A trial was performed to study the effect of increasing dietary crude
fiber level on the performance, blood serum and yolk cholesterol
concentrations of Dandarawi laying hens. A total of one hundred twenty,
32 weeks old Dandarawi laying hens were randomly assigned to four
dietary treatments of 30 hens each (three replicate of 10 hens each).
Diets were formulated to have 3.01, 4.42, 6.52, and 8.46% crude fiber
(CF). The experiment prolonged for 3 months results indicated that
increasing dietary CF significantly increased feed efficiency while feed
Assiut Vet. Med. J. Vol. 54 No. 117 April 2008
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consumption was decreased. Dietary CF levels had no significant effect
on weight gain; egg mass, egg production, albumen and yolk weight.
Shell weight, percent and thickness were significantly decreased as
dietary CF increased. Milligrams yolk cholesterol per g of yolk
decreased as hens were fed increasing dietary CF levels. Total
cholesterol per yolk decreased by 5.06, 8.62 and 9.7 % at feeding CF
levels of 4.42, 6.52 and 8.46%, respectively; as compared to the control
diet (3.01CF). Serum cholesterol was significantly decreased when the
dietary CF was increased; the lowest reduction (29%) of cholesterol in
serum was found in hens fed diet contained 8.46% CF. In conclusion,
data reported in this study indicated that yolk and serum cholesterol was
reduced by increasing levels of CF. Furthermore, feeding clover hay as
fiber source in diet of Dandarawi laying hens reduced yolk cholesterol
without adversely affecting either egg production or egg mass
furthermore, feed efficiency was significantly improved.