The effect of diet that contained fish oil on performance, serum parameters, the immune system and the fatty acid composition of meat in broilers.

A study with a duration of 42 days was conducted to evaluate the influence of fish oil inclusion on performance parameters, serum lipid content, antibody responses to sheep red blood cells (SRBC) and the composition of antigen and meat fatty acids in broilers. Two hundred and sixteen 1-day-old broiler chicks from a commercial hybrid (Cobb 500) were allocated randomly to four groups, which received feed supplemented with 1.5%, 3.0% and 6% fish oil or feed that was not supplemented (control group). The differences among the groups were significant with regards to their performance, so that a low level of fish oil (1.5%) led to higher feed intakes and an improvement in the efficiency of feeding in comparison to the control group (p<0.01). The results of the omega-3 fatty acid evaluation indicated significant differences among groups (p<0.01) and the birds in the 6% fish oil-fed group had the highest level of n-3 fatty acid in their meat. The n-6:n-3 ratio of polyunsaturated fatty acids was lower in the fish oil-fed groups compared to the control group (p<0.01).Broilers that were fed with diets rich in omega-3 fatty acid had higher levels of anti-SRBC titers and lower levels of serum cholesterol and triglycerides than those fed with the control diet (p< 0.05).