Abstract
Six experiments were conducted to study the effects of supplementing diets with different types of oils on the
production performance of broilers and fatty acid profile of abdominal fat with a view to find a least cost energy
supplement to broiler ration in Bangladesh. The aim was further extended to select the appropriate dietary levels of
oil and its probable consequence on lipid profile of mice fed with abdominal fat from the broilers fed with such feeds.
In experiment-1, a total of 600 day-old broilers were randomly distributed in four groups, each having three
replications. Each of the replication was having 50 broilers. Four rations were formulated with no oil, 2.5% soybean
oil, 2.5% palm oil and 2.5% fish oil and were supplied randomly to those groups of broilers. Blood was collected
from the broilers every week to analyze the lipid profile. Body weight was taken weekly. Broiler was slaughtered
from each replication to examine carcass quality. Abdominal fat was collected from slaughtered broilers to analyze
fatty acid profile. Results showed that body weight differed significantly (p<0.05) among treatment groups at 3-6
weeks. Supplementation of diets with soybean oil, palm oil and fish oil significantly (p<0.05) increased live weight at
3 weeks of age. Similar results were observed at 4, 5 and 6 weeks of age. Live weight gain differed (p<0.05) among
the treated groups at 6 weeks. Feed consumption was better (p<0.05) in oil supplemented groups than without oil
group. Supplementation of diets with different types of oil revealed no impact on feed conversion (FC) up to 5 weeks
but had a better effect(p<0.05) than non-oil supplemented group. FC was better (P<0.05) in soybean oil
supplemented group of broilers than those of other groups at 6 weeks. Among carcass parameters, only feather,
dressed, digestive tract and head weight differed (P<0.05) among supplemented groups at 4 weeks of age of broilers.
Total serum cholesterol (mg/dl) level of broilers varied (p<0.05%) between oil supplemented and non oil
supplemented groups at 4th week. High density lipoprotein (HDL) cholesterol level of blood varied (p<0.05) at 3, 5
and 6 weeks. At 5 week of age, HDL cholesterol of the broilers of marine fish oil group was higher (p<0.05) than
soybean oil group. Dietary supplementation had significant (p<0.05) effect on LDL-cholesterol level at 4 and 6
weeks of age of broilers. In experiment-2, irrespective of age, supplementation of diets with different levels of fish
oil (2.5, 3.0 and 3.5%) improved live weight gain of broilers. There was no significant effect of the level of fish oil
on the FC of broilers at 5 weeks of age. In experiment-3, regardless of age, supplementation of diets with different
levels of Palm oil (2.5, 3.0 and 3.5%) improved live weight gain of broilers. Among the supplemented groups, that
consuming 3.5% palm oil was showed better (p<0.05) results than those consuming 2.5% and 3.0% levels.
Supplementation of palm oil did not have marked effect on FC up to 3 weeks but it increased FC at 5 weeks of age of
broilers. Results of Experiment-4 showed that feed cost (Tk/broiler) increased (p<0.01) due to supplementation of
different oil. In terms of profit, net profit (Tk./broiler) differed significantly (p<0.05) and mean values were 16.50,
16.03, 15.41 and 14.17 for 3.0% palm oil, 3.0% fish oil, without oil and 3.0% soybean oil supplemented groups
respectively. In experiment-5, a positive correlation was observed between lean meat yield and FC irrespective of all
dietary treatments: 0% palm oil, 2% palm oil, 3% palm oil, 4% palm oil and 5% palm oil. As the amount of lean
meat yield increased FC value increased simultaneously. The correlation coefficient 'r' for lean meat and FC were
0.12, 0.20, 0.37, 0.61 and 0.73 for 0, 2, 3, 4 and 5% palm oil groups. These results indicate that as the level of
supplemental oil increased from 0-5% the correlation coefficient for lean meat yield and FC increased linearly from
0.12 to 0.73. A negative relationship was observed between lean meat yield and deposition of abdominal fat. It
appeared from the results of experiment-6, where four groups of mice were fed diets supplemented with abdominal
fat from broilers fed with diets having 0% oil, 2.5% soybean oil, 2.5% palm oil and 2.5% fish oil, that there was a
tendency of lowered cholesterol level in blood of mice due to supplementation of oil in birds' ration. However,
triglyceride level was significantly (p<0.01) higher in mice due to feeding fats of broilers fed oil containing diets.
Although there was no effect on HDL level but LDL of mice was significantly (p<0.01) lower due to feeding
abdominal fat from the broilers fed supplemental oils and in this case palm oil fat gave the lowest LDL among all. It
may be concluded from the above findings that oil supplementation tended to decrease serum cholesterol of broilers
but significantly (p<0.05) decreased triglyceride level in blood. It had no effect on saturated and unsaturated fatty
acids in blood of broilers. Supplementation of palm oil at 3.5% level in broiler ration might be the best for production
performance of broiler and the use of palm oil in broiler ration is cost effective than soybean and fish oil. Although
abdominal fat of oil supplemented diets caused higher triglyceride level but it lowered down the LDL cholesterol in
mice. Finally, soybean oil could be replaced by palm oil in the broiler diet.