This experiment was conducted to determine the effects
of increasing, energy to protein ratio and partial decreasing of nutrient
contents of diet using different levels of fats on broiler chickens performance
and serum lipids. With addition of fats (Poultry oil, Soybean oil and
Tallow) in two levels (4 or 8%) to basal diet that was already balanced
on NRC (1994) recommendations, seven different non-isocaloric and non-isonitrogenic
diets were prepared (12 or 24% increasing of energy to protein ratio in
4 or 8% of fat level addition, respectively) and given ad libitum
between 22 to 49 day of age. The blood samples were collected at 35 and
49 day and weight of selected visceral organs were recorded at 49 day.
The results suggested that high fat intake had no significant effect on
Final Body Weight (FBW) and Feed Conversion Ratio (FCR). Numerically the
FBW was higher in all groups that received high fat levels than control
group. But abdominal fat deposition only in birds that was fed by additional
soybean oil and tallow in 4% level was constant. The liver weight significantly
decreased (p<0.01) and abdominal fat weight significantly increased
(p<0.05) by elevation of fat level. Serum lipids concentrations had
no significant difference in dietary treatments. Serum LDL concentration
showed significant elevation from 35 to 49 day (p<0.01), whereas serum
cholesterol concentration showed decline at the same times (p<0.05).
With increasing of dietary fat level from 4 to 8%, serum cholesterol had
showed elevation (p<0.05). Therefore, it seems that broilers are more
resistant against the high dietary fat intake and they can be effectively
used for nutritional and growth requirements promoting, without mortality.
Tohid Vahdatpour, Kambiz Nazer-Adl, Yahya Ebrahim-Nezhad, Naser Maheri-Sis and Sina Vahdatpour, 2008. The Effects of Energy Increasing and Protein Lowering by Addition of Fats to Diet on Broiler Chickens: Performance and Serum Lipids. Asian Journal of Animal and Veterinary Advances, 3: 286-292.