Evaluation of the Effects of Earthworm (Eisenia fetida) Meal and Ethanol Extract on Antioxidant Status, Liver Enzymes and some Blood Parameters in Western Azarbaijan Native Roosters

Oxidative stress is responsible for several health compromising conditions in livestock, resulting low performance, metabolic diseases, suppression of immune responses and fertility problems in males. It is known that the fatty acid composition of sperm membranes, especially their unsaturated components, determine their biophysical characteristics such as fluidity and flexibility as appropriate for their specific functions, including sperm motility and fertilizing capacity. The high levels of unsaturated fatty acids in the cell membranes made them susceptible to oxidation. Usually, the natural anti-oxidant defense of the birds needs fortification by dietary supplementation of antioxidants. Althoughsynthetic antioxidants are available and very effective, but health concerns are associated with their consumption. Researchers are seeking natural antioxidants to control the oxidation stress in birds. Natural antioxidants are substantially of plant origin. Antioxidants originated from animal kingdom are interesting, because they are natural, and protein rich feed ingredient with potentially functional properties. The vermiculture industry is a new and attractive agricultural activity and its main product is vermicompost which is applied in farm lands as a natural fertilizer. Earthworms are harvested as co-product and have the several applications. The purpose of this study was to investigate the antioxidant properties of earthworm meal (EM) and ethanol extract (EE), and effect of feeding earthworm meal and the extract on some oxidative parameters of native roosters.
In experiment 1, fresh earthworms (Eisenia fetida) were washed and air-dried in shadow and ground to produce the earthworm meal. Half of earthworm meals were soaked in 80 % (V/V) ethanol with continues shaking for 24 h. The extract was filtered and concentrated to produce the ethanol extract of earthworm meal. The proximate composition in content value of moisture, crude ash, crude protein, and crude fat was determined according to the methods of AOAC. The fatty acid profile of extracted lipid was determined by gas chromatography after methylation of fatty acids. The total phenolic compounds of earthworm meal were determined using folin ciocalteu method. Antioxidant activity of extract was measured by ferric ion reducing antioxidant power (FRAP) assay. In experiment two, 20 preselected Western Azarbaijan native roosters (34 weeks of age) were randomly allocated to 5 treatments and 4 blocks. Each rooster considered as an experimental unit and received 0 g EM or EE, 10 or 20 g/kg EM, and 5.65 or 11.30 g/kg EE for 13 consecutive weeks. At the end of experiment blood samples were collected form brachial vein of roosters, and birds were killed. The tissue samples were collected from the liver and testis after recording the organ weights. The biochemical parameters of blood including phosphorus, calcium, hemoglobin, albumin, uric acid, glucose, total protein, cholesterol and triglyceride was determined using spectrophotometer and commercial diagnostic kits. The activity of liver enzymes (lactate dehydrogenase, aspartate amino transferase, alkaline phosphatase and alanine amino transferase) in plasma was determined using spectrophotometer and commercial diagnostic kits. The malondialdehyde concentration was measured in blood plasma, liver tissue, and testis tissue of roosters as an indicator of lipid peroxidation using thiobarbituric acid method.
The results indicated that earthworm had 26 different fatty acids, which eicosapentanoic, stearic, and arachidonic acid had the highest percentages, respectively. The total phenolic compounds in earthworm were 169.72 mg/g of gallic acid equivalent. The results showed that FRAP was 242 μmol of Fe (II)/mg dry extract. The dry matter, crude fat, protein and ash of earthworm meal were determined 91, 1.7, 8.75 and 64.2 %, respectively.
The blood, liver and testis malondialdehyde concentration in all of earthworm and earthworm extract treated groups were significantly decreased (P