Abstract:
High cholesterol content in chicken egg has become a public concern and thus means
of reducing the cholesterol contents of chicken eggs are of importance. Rice bran (RB)
and RB oil have been found to reduce the cholesterol contents in many laboratory
animals and humans. Objective of this study was to evaluate whether increasing levels
of dietary RB in layer diets could be used as a means of reducing cholesterol levels of
chicken eggs. The experiment was a completely randomized design in 2*4 factorial
arrangements. Thirty six weeks old brown Keghom layer chicken (n=120) were
allocated in to 40 pens and fed one of the eight layer rations for 29 days after 14 days
of gradual acclimatization period for respective feeds. The treatment factors were two
dietary RB forms (dry and normal) and four dietaxy RB levels (10, 20, 30 and 40%).
Live weight, feed intake, egg production, shell weight, fresh yolk weight, diy yolk
weight and albumin weight were not affected by either dietary RB level or form or
their interaction. The egg weight of the layers fed normal RB (61.01 g) was
significantly (p<0.05) higher than the birds given dry RB (59.5g). Shell ash percentage
and shape index were affected by dietary RB level*form interaction (p<0.05). The
lowest yolk cholesterol content was reported by the birds given 40% RB in normal
form (174 mg/yolk) which was 21.5% lower than that of the birds fed 10% RB in
normal form (222.7 mg/yolk). The yolk cholesterol level was highest (271.9 mg/yolk)
when 10% RB was give in dry form. When dried RB was used, the lowest cholesterol
level was reported at 30% RB; which was a 28.61 % reduction compared to 10% RB in
dry form. Meanwhile when normal RB was used cholesterol level was lowest at 40%
RB. Cholesterol contents expressed as mg/g fresh yolk or mg/g dry yolks were also
showed a similar trend. There was a significant RB*form interaction with reference to
the serum cholesterol level. It was concluded that increasing dietary RB level either in
dry or normal form significantly reduced the cholesterol contents of chicken egg.
