The enrichment of eggs with polyunsaturated fatty acids (PUFA), particularly
with omega-3 fatty acids, has attracted the attention of both researchers and
the food industry, because these fatty acids are essential for normal body
development and play an important role in the prevention of heart diseases.
This experiment was conducted to evaluate the effect of four dietary oils on
selected blood metabolites in egg-type chickens. One hundred and five (105)
Isa Brown laying hens at 34 weeks of age were used and the study lasted for 6
weeks in a completely randomised design. Hens were randomly allotted to seven
dietary treatments namely: basal diet (T1), basal diet + 1.5% palm oil (T2),
basal diet + 1.5% soybean oil (T3), basal diet + 1.5% sesame seed oil (T4),
basal diet + 1.5% fish oil (T5), basal diet + 0.75% soybean oil + 0.75% fish
oil (T6) and basal diet + 0.75% sesame seed oil + 0.75% fish oil (T7). The
treatments had 5 replicates of 3 hens each. Blood samples (5mls) were
collected from the jugular vein of a bird per replicate for serum and
haematological parameters. There were no significant differences observed in
packed cell volume, haemoglobin, red blood cell, white blood cell,
lymphocyte, heterophils and basophils of birds on experimental diets but
diets had an influence (P<0.05) on the monocytes, eosinophils and platelets
of birds. Monocytes of birds on the control diet were similar to those of
birds on T3 (basal diet + 1.5% soyabean oil) but significantly (P<0.05)
higher than monocyte counts for birds on other diets. Eosinophils of birds on
the experimental diets were similar except for those on T4 (basal diet + 1.5%
sesame seed oil) with significantly higher eosinophil values compared with
others. A similar trend was observed in platelets of birds on the
experimental diets. There were no significant differences observed in
triglycerides, high density lipoproteins and cholesterol of birds on
experimental diets. Low density lipoprotein (LDL) of birds on the control
diet was similar to those recorded for birds on different dietary oils
supplemented diets except for those on T6 (basal diet + 0.75% soybean oil +
0.75% fish oil) with significantly (P<0.05) reduced LDL. It can be concluded
that dietary oils combination of 0.75% soybean oil + 0.75% fish oil could be
effective in reducing serum low density lipoprotein in laying birds.