Comparative Studies on Fatty Acid Composition of Domestic and Hybrid Chickens and Their Effect on Blood Parameters in Experimental Rats

Abstract

Chicken meat is generally thought to be health friendly due to its favorable fatty acid composition leading to an antiatherogenic lipidemic status. Beneficial effect of the chicken oil on hyperglycemia has also been claimed through its effect on oxidative stress and insulin resistance. To further explore the potential benefits, the effects of the oil, extracted from domestic and hybrid chicken for their fatty acid composition as well as for their effects on glycemic and lipidemic status in diabetic model rats were studied. The macro and micronutrient contents of these two chicken species (10 chickens of each species) were also compared. All macronutrients such as ash, moisture, total protein, total carbohydrate and total lipid were found to be high for the hybrid chicken. Lipid content was significantly higher (around 40%) in hybrid chicken than that of domestic chicken. Except for potassium and manganese which were found to be high in hybrid chicken (127.8 μg/kg and 9.74 μg/kg respectively) than domestic chicken (86.83 μg/kg and 6.83 μ/kg respectively), all other micronutrients such as iron, calcium, zinc and lead were higher for domestic chicken. Zinc content of hybrid chicken was significantly lower (around 50%) than that of domestic chicken. The average amount of oil content of two species were extracted with soxhlet apparatus using n-hexane as an extracting solvent and it was found to be 3.54% for domestic chicken and 4.84% for hybrid chicken. Chemical characteristics of the extracted oil were investigated by analyzing various parameters such as iodine value, saponification value, acid value, peroxide value and percentage free fatty acid. Iodine value and unsaponifiable matter were higher for hybrid chicken (77.92% and 11.14% respectively) than those of domestic chicken (60.56% and 3.5% respectively). Again saponification value, acid value, peroxide value and percentage free fatty acid were higher for domestic chicken than hybrid chicken. Lipid and protein content of different meat portion (Breast, Thigh, Drumstick and Wings) of chicken were analyzed and compared. Lipid content was higher in thigh meat (3.65±0.57 and 5.43±0.9 for domestic and hybrid chicken) and protein content was higher in breast meat (16.54±1.5 and 19.27±1.3) for both of the chickens. An interventional design was used to evaluate the hypoglycemic and hypolipidemic effects. Seven groups of rats (n=6 in each group) were studied: Group: NCD - normal ( non-diabetic rats ), DC- Diabetic Control (Alloxan induced diabetic rat without treatment), DG- Diabetic + Glibenclamide, DDODiabetic + Domestic chicken oil (1% of total diet), DHO- Diabetic + Hybrid chicken oil (1% of total diet), DDF- Diabetic + Domestic chicken flesh(1% of total diet), DHF- Diabetic + Hybrid chicken flesh (1% of total diet). Diabetes was induced in Wister adult rats with alloxan (55 mg/kg bw) and fasting blood glucose above 11.5 mmol/L after three days were considered as diabetic. The rats were fed for 21 days with a dose for glibenclamide as 0.6 mg/ kg body weight, for chicken oil as 1% of total diet and an amount of dried flesh of chicken equivalent to 1% of chicken oil (calculated from oil content, Table 4.4). End point (21th day) was compared with baseline (7th day) of the study. Blood glucose level was significantly decreased for DDO and DHO group. There were significantly lower blood glucose value in DG and DDO groups at endpoint compared to baseline (mmol/l, mean ± SD, Baseline vs Endpoint, 16.0 ± 1.12 vs 10.9 ± 0.08; P< 0.001 and 15.06 ± 1.09 vs 11.9 ± 0.7 ; P<0.001, for the DG and DHO groups at Endpoint compared to Baseline (mmol/l, mean ± SD, Baseline vs Endpoint, 16.0 ± 1.12 vs 10.9 ± 0.08; P< 0.001 and 16.11 ± 0.71 vs 12.8 ± 0.56; P< 0.001). There were also significant effect on body weight was observed for DDO and DHF group. For DG and DDO groups at Endpoint compared to Baseline (gm, mean ± SD, Baseline vs Endpoint, 94.54 ± 0.54 vs 117.9 ± 0.63; P< 0.001 and 94.49 ± 2.98 vs 113.52 ± 2.64; P< 0.05, for DG and DHF groups at Endpoint compared to Baseline (gm, mean ± SD, Baseline vs Endpoint, 94.54 ± 0.54 vs 117.9 ± 0.63; P< 0.001 and 94.16 ± 1.63 vs 114.56 ± 2.54; P< 0.05). Chicken oil also showed hypolipidemic effects. A significant decrease in cholesterol level had seen for DDO and DHO treatment group. 69% and 82% reduction of cholesterol level were observed for domestic and hybrid chickens oil treatment respectively in diabetic rats whereas 44% and 62% reduction were seen for domestic and hybrid chicken flesh. In case of glibenclamide, it was 89%. LDL level was reduced significantly for DDO and DHO treatment group by 65% and 71%, for DG group, it was 77%. HDL level was increased significantly for DHO and DHF treatment group by 70% and 62%. Triglyceride level was reduced significantly for DHO group by 30%, Whereas Triglyceride level was reduced by 86% for glibenclamide treatment. A significant reduction of Uric acid level was observed for DHO group by 56% compared with control group. Serum urea levels were reduced significantly for DDO and DHO treatment group by 45% and 54%. Creatinine level was also reduced significantly for DDO and DHO by 41% and 62%. Administration of chicken oil and flesh also maintained SGPT and SGOT level. A significant reduction was found in SGPT level for DHO and DHF treatment group by 60% and 51% respectively. Similar effect had seen for SGOT level. The level was decreased significantly by 43% and 42% for DHO and DHF. So, both types of chicken oils have a beneficial impact on liver function test. The antiatherogenic fatty acid content in the domestic chicken oil was as follows: arachidonic acid (1.7%), oleic acid (75%) and stearic acid (1.84%). ln contrast the proatherogenic fatty acids were as follows: myristic acid (0.24%), palmitic acid (19%) and behenic acid (0.85%). On the other hand, the antiatherogenic fatty acid content in the hybrid chicken oil was as follows: arachidonic acid (0.5%), oleic acid (48%), palmitoleic acid (28%) and stearic acid (4.7%). In contrast, the proatherogenic fatty acids were as follows: myristic acid (0.34%), palmitic acid (17%) and behenic acid (0.2%). Both, the domestic and hybrid chicken oils contain predominant amount of MUFAs and PUFAs. Chicken meat and flesh seem to have hypoglycemic and hypolipidemic effects on experimental diabetic rats. So, consumption of chicken might be more beneficial to human health.