Hypocholestremic effect of the polyherbal preparation containing Emblica officinalis (Amla), Ocimum sanctum (Tulsi), Withania somnifera (Ashwagandha) and Tinospora cordifolia (Giloy) was observed on a total of 72 healthy birds of 52 weeks including Kadaknath, White dwarf broiler and Coloured dwarf breed/lines in equal number. Yolk was collected from each egg for the extraction of lipids and lipids were analysed for the estimation of total lipids, cholesterol and triglycerides.
It was concluded from the present study that polyherbal preparation showed a significant hypocholestremic effect (P<0.05) and can be used effectively for reducing lipid contents in egg yolk for better human consumption and reducing the risk of Cardiovascular diseases.
Saturated fats have a profound hypercholesteremic effect, being a major risk factor for atherosclerosis and related occlusive vascular diseases. The normal level of blood cholesterol in human beings is 150-250mg/dl but when its level rises to more than 250mg/dl, it may lead to dangerous consequences like cardiovascular diseases. Increased serum cholesterol levels can be induced when animal fats (saturated fats) and food high in cholesterol, notably eggs, are consumed. Egg contains about 200-250mg of cholesterol (Griffin 1992) and is considered to be a major source of dietary cholesterol but it is also a rich source of all the essential amino acids, minerals and vitamins. The fatty acid composition of egg lipids in laying hens can be influenced predictably by the fatty acid composition of the diet (Van Elswyk et al 1992, Scott and Leo 1993, Farran et al 1995). It is also known that the intake of egg cholesterol contributes to elevation of serum cholesterol (Beynen and Katan 1989). Thus, it is considered relevant to explore ways for production of eggs low in cholesterol (Stewart 1988).
Several indigenous plants like Tulsi, Ashwagandha, Amla etc. have been claimed to possess hypolipidaemic, hypocholesteremic and immune stimulating properties that may be beneficial to reduce the risk of cardiovascular diseases. It is also observed that maximum lipid profile studies have been conducted on the serum but only a few studies have been conducted on eggs. Egg cholesterol remained the main focus of the studies while total lipids and triglycerides were neglected. So the present study was carried out to evaluate the combined effect of herbal plants on egg yolk lipid profile of various genotypes of birds.
The study was conducted on a total of 72 healthy birds of 52 weeks of age of Kadaknath, White dwarf broiler and Coloured dwarf breed/lines. Birds were procured from All India Coordinated Research Project (AICRP) on Poultry, Adhartal, Jabalpur. 24 birds from each breed were randomly divided into four groups with 6 birds in each group. The birds of different groups were kept separately in individual cages and maintained under similar managemental conditions. Group T1 was kept as control, consisting of basal diet without any herbal supplement while groups T2, T3 and T4, served as experimental ones whose diet was supplemented with polyherbal preparation at 250, 500 & 750mg/kg of diet respectively. The basal diet consisted of 2690 Kcal ME/kg and 17.92% protein.
Polyherbal preparation consisted of four plants- Ocimum sanctum, Emblica officinalis, Withania somnifera and Tinospora cordifolia. These plants were obtained from the Department of Aromatic and Medicinal Plants, Agriculture College, J.N.K.V.V, Jabalpur. The leaves of Ocimum sanctum, fruit of Emblica officinalis, roots of Withania somnifera and stem of Tinospora cordifolia were obtained, dried and crushed in mixer and grinder to obtain powder. These powders were then mixed in the ratio of 30:30:30:10 to obtain the polyherbal preparation.
Six eggs were collected from each group of birds on day 0, 14, 28 and 42 of the experiment. Yolk was collected from each egg for the extraction of lipids and lipids were analysed for the estimation of total lipids, cholesterol and triglycerides. Lipids were extracted from the egg yolk by the method using chloroform: methanol mixture in the ratio 2:1 v/v (Folch et al 1957) and total lipids were estimated by the standard method (Frings et al 1972) whereas cholesterol and triglycerides were estimated using diagnostic kits.
Data was analysed by 3 factorial complete randomized design by using fixed model. Significance of treatment effects and the interactions were assessed by the General Linear Model (GLM) and Compare Means options of Statistical Package for Social Sciences software (version 11.0) as per Steel and Torrie (1980).
Total lipid content of egg yolk in the control group in various breeds was found to be 30 % of the total egg yolk weight. This value corresponds with that reported by Cunningham and Lee (1978). No significant change was observed in control group whereas treatment group supplemented with 250 mg/kg feed showed significant (P<0.05) reduction on day 42 and treatment groups 500 mg/kg feed and 750 mg/kg feed showed significant (P<0.05) reduction on day 28 and 42 (Table 1).
The reduction in egg yolk total lipids on day 42 was calculated to be 6.31%, 10.23% and 17.96% respectively for three groups in case of Coloured dwarf when compared with day 42 of control group. In case of White dwarf reduction was 5.34%, 10.39% and 11.34% whereas it was 7.8%, 10.77% and 12.85% respectively for Kadaknath. Similar reduction in egg yolk total lipids (14%) was reported by El Bagir et al (2006) in White leghorn hens on supplementation of 1% black cumin seed. In contrary to this, De Schijver (1995) reported no significant change in egg yolk lipids of laying hens with supplementation of 2ppm clenbuterol.
Cholesterol concentration of egg yolk in the control group was 5% of the total lipids in yolk and was similar to the values obtained by Panada and Singh (1990), Van Elswyk et al (1991) and El Bagir et al (2006). Like total lipids, cholesterol content did not vary significantly in control group, whereas it varied significantly (P<0.05) on day 28 and 42 for groups supplemented with 250 and 500 mg/kg feed whereas group supplemented with 750 mg/kg feed varied on day 14, 28 and 42 (Table 2).
The percentage reduction in case Coloured dwarf was 2.64%, 3.54% and 11.34% for three treatment groups on day 42 when compared with day 42 of control group. Similarly reduction was 10.4%, 14.1% and 17.7% and 5.54%, 11.9% and 13.7% for White dwarf and Kadaknath respectively. Chowdhury et al (2002) found 5, 9, 14, 20 and 24% reduction in yolk cholesterol of laying hens on supplementation of 2, 4, 6, 8 or 10% garlic paste in diet. Elangovan et al (2004) found lower cholesterol levels in egg yolk levels of Japanese quails fed 1% garlic powder in diet. Mottaghitalab and Taraz (2004) reported a significant reduction (P<0.01) in yolk cholesterol content in laying hens when the diet was supplemented with 0.5, 1 and 1.5% garlic powder. Similarly significant reductions in blood and yolk cholesterol were also observed by Yigit et al (2000) by addition of vitamin C at the dose rate of 50,100 and 200 mg/kg to the laying hen diet. In contrary, Kim et al (2004) didn't find any significant difference in yolk cholesterol when lovastatin was fed at the dosage of 0.03, 0.06% while simvastatin and pravastatin at the same dosage resulted in significant reduction (20 and 9.7%) in yolk cholesterol content of laying hens.
The amount of triacylglycerols comprised about 55% of the egg yolk total lipid contents, which is similar to the values reported by Leskanish and Noble (1997). The control group of birds did not show any significant (P<0.05) change in triglyceride content of egg yolk, whereas treatment groups supplemented 250 and 500 mg/kg feed showed significant (P<0.05) reduction on day 28 and 42 while treatment group supplemented with 750 mg/kg feed showed significant (P<0.05) reduction on day 14, 28 and 42 (Table 3).
The reduction in egg yolk triglyceride values of Coloured dwarf on day 42 was 3.33%, 6.18% and 16.03% in three treatment groups respectively. The percent reduction was 5.65% in first treatment group whereas in other treatment groups, reduction calculated was 9.96% and 15.40% respectively on day 42 in White dwarf. The reduction in egg yolk triglyceride values of Kadaknath observed on 42 day was 4.95%, 8.53 % and 15.03% in three treatment groups respectively. El Bagir et al (2006) observed reduction of 13% and 20% in egg yolk triglycerides in White Leghorns on supplementation of black cumin at 1% and 3% inclusion level.
Polyherbal preparation showed a significant hypocholestremic effect (P<0.05) on dietary supplementation for a period of 42 days. It can be concluded that the polyherbal preparation prepared, at a dose rate of 750 mg/kg of feed was the most effective dose for reducing lipid contents and can be effectively used as a dietary supplement in poultry and is also beneficial in rural areas for backyard farming. Further research may focus on the identification of the active principle in these herbal plants. Knowledge of the chemical structure of the active principle could be important for the development of new hypocholesterolemic drugs and for studies on the mechanisms controlling cholesterol metabolism.
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