Effects of diets containing linseed oil and supplemented with grain amaranth (Amaranthus caudatus) on growth performances, oxidative status and serum biochemical parameters in broilers

The high fat content of the diet contributes to the pathogenesis of the most common human chronic diseases. The major nutritional causes of these metabolic alterations and damage to the body have always been considered the saturated fatty acids. Therefore, nutritionists suggest to replace in part the saturated fats with polyunsaturated fatty acids (PUFAs). However, PUFAs are subject to lipid peroxidation, in the absence of antioxidant protection. The objective of this work was to evaluate the effects of supplementing with different levels of grain amaranth (Amaranthus caudatus) on the growth performances, oxidative status and serum biochemical parameters in broilers fed diets rich in linseed oil. A total of 132 female broilers were randomly divided into three equal groups (44 broilers/group, 11 broilers/cage, 4 cages/treatment). Animals were fed for 5 weeks with three diets containing 5% linseed oil and supplemented with 0%, 5% and 10% of amaranth grain, respectively. To allow the assessment of oxidative status was measured the level of serum lipid peroxidation and the level of serum antioxidant capacity using LP-cholox test and anti-ROMs test (Diacron, s.r.l., Grosseto, Italy), respectively. The following biochemical serum parameters were also determined: triglycerides, cholesterol, alanine amino transferase (ALT) and albumin. Our results showed a decrease on broilers growth performances with increasing (P<0.05) amaranth inclusion level. Broilers fed diets containing 10% and 5% amaranth grain had a significantly higher serum antioxidant power compared to the control group (250 and 219 ?equivalents/l against 177 ?equivalents/l, respectively), and a lower level of serum lipid peroxidation compared to the control group (262 and 419 ?moles/l against 700 ?moles/l, respectively). Furthermore, the amaranth grain supplementation had a significant decrease (P<0.05) on cholesterol and triglycerides levels in comparison to broilers fed diet without amaranth grain. No differences were found for ALT and albumin levels among the three groups. In conclusion, a diet rich in PUFAs supplemented with amaranth grain determines a reduction of growth performances, but it may be effective in decreasing serum lipid peroxidation and in improving antioxidant defenses and some serum biochemical parameters in broilers.