Antilipemic effect of Moringa oleifera leaf powder on blood serum cholesterol fractions in broiler finishers

The effects of using Moringa leaf powder (MLP) as feed additive on the differential cholesterol profile of broiler chickens at finisher phase was investigated in view of the scientific urge to find means of reducing fatty compounds in common meat products. One hundred and twenty,4-weeks old Abor acre broilers were used for this experiment and allotted to four different treatment groups (T1-T4). The control group; T1 was without MLP inclusion, T2 with 0.40% (of the total diet on dry matter basis) MLP inclusion, T3 with 0.80% MLP inclusion and T4 with 0.40% Liver fit powder (LVP-commercial product). Each group had three replicates with 10 chickens in a completely randomized design. The experiment lasted four weeks at the end of which blood samples were collected for the serum lipid fractions analysis. Parameters investigated were Total Cholesterol (TC), Triglycerides (TG), Low Density Lipoprotein (LDL), Very Low Density Lipoprotein (VLDL) and High Density Lipoprotein (HDL). Data generated were subjected to statistical analysis of variance. The results revealed that TC, TG, LDL and VLDL fractions of the serum cholesterol got reduced significantly (p<0.05) in birds on T3 and T4 while HDL got increased significantly with inclusion of MLP. These results suggest that MLP is hypocholesterolemic in nature. Consequently, MLP inclusions compared favorably well with LVP and therefore can be used for reducing bad lipid fractions of serum of broilers at finisher phase to reduce the risk of high fat related diseases among the consumers.


INTRODUCTION
It has been clinically proven that human requires a balanced diet in order to survive (Stadelman, 1994). One of the essential requirements for this balanced diet is protein, which is supplied by meat (Oyewole et al., 2003). Broilers are white meat producing chickens that grow and ready for table after forty-two days of rearing with good management (Adesehinwa and Iyayi, 2010). Their feed is concentrated with energy and protein content (Nworgu et al., 1999). Their growth pattern can be divided into two phases namely broiler starter which is between the first to fourth week, while the finisher is from fifth week to harvest (Oluyemi, 2010). Broiler starter requires high metabolic energy of about 3240 kcalkg -1 and 24% of protein while finisher requires between 21 and 24% protein and energy content of 2900 to 3000 kcalkg -1 (Low, 2004).
Fatty broilers meat has been linked to prolonged consumption of high energy diets by broiler chickens  (Ayssiwede et al., 2011) and this makes such meat to be undesirable for the fear of high dietary cholesterol levels on the part of the consumers to avoid escalated blood cholesterol levels which can predispose them to heart related diseases (Grundy, 1990). The desire of meat consumers is highly geared towards healthier products with very low level of cholesterol (Basmacioglu and Ergul, 2005).
Broiler chicken has a good feed conversion ratio ranging from 1:1.5 to 1:2.5 kg. This implies that for every 1.5 to 2.5 kg of feed consumed, broilers will gain 1 kg of meat. This efficiency is often affected by environmental, temperature, disease, nature of the feed, nutrient supplements and availability of water (Adeyemi, 2002). An animal needs sufficient levels of some vitamins, minerals, proteins and other nutrients for its physical development and well-being. Vitamins are usually given to the non-ruminant either as feed base premix or as oral therapy against vitamins deficiency or as immune suppressors during stressful conditions such as vaccination, transportation, weighing and so on (Portugaliza and Fernandez, 2012).
Several vegetables and plant species abound in Nigeria as condiments or spices in human diets or as supplementary feeds to livestock such as rabbits, poultry, swine and cattle (Adeogun, 1994). Feed additives are non-nutritive materials which when added to the feed improves the performance of birds, but while absent from the feed does not constitute a deficiency situation (Atteh, 2004). Additives used in poultry feeding includes enzymes, antibiotics and grit, those that are used to produce more desirable consumer product like marigold petal, algae meal, ripe pawpaw, those that alter metabolism like growth promoters. Other additives include antifungal agents, coccidiostats, antihelmintic drugs and at times tranquiling drug (Klasing and Leshchinsky, 2000).
As a result of high costs of these commercial additives animal nutritionists are exploring locally available plants; shrubs and herbs are used as feed additives to reduce the cost of production. Among of these plants is Moringa oleifera, which is a fast growing drought resistant tree of the family Moringaceae and contain wealth of essential disease preventing nutrients. M. oleifera, or the horseradish tree, is a pan-tropical species (Anderson et al., 2004). Over the past two decades, many reports have appeared in mainstream scientific journals describing its nutritional and medicinal properties. Its utility as a nonfood product has also been extensively described (e.g. lumber, charcoal, fencing, water clarification, lubricating oil). As with many reports of the nutritional or medicinal value of a natural product, there are an alarming number of purveyors of "healthful" food who are now promoting M. oleifera as a panacea (Foidl et al., 2001).
M. oleifera is a native of Indian sub-continent and naturalize in tropical and sub-tropical area around the world. M. oleifera among other twelve varieties of moringa species have been found to contain all essential amino acids, which is unusual for a plant source. It has also proven to be good cure for diseases like skin infection, intestinal worms, glandular swelling in countries like Malaysia, Guatemala, Pueto Rico, Philippines (Fuglie, 2001).
The fear of fatty meat and high dietary cholesterol which may be dangerous to human health is of great concern to broilers meat consumers. In order to reduce this fat intake and alleviate the fear of heart and other related diseases, many commercial products reported to be liver enhancers have been introduced to the poultry feed industry with good results in respect of detoxification and hypocholesteromic effects. However, these products are not always available to the poultry farmers at affordable prices hence the need to investigate ways of reducing cholesterol level in meats with the use of organic materials that are locally available. Therefore, integration of M. oleifera as feed additive in broiler nutrition is a new dimension worth investigating. The objective of this work is to establish the effect of inclusion of M. oleifera leaf powder on serum lipid component concentrations of broiler chickens at finisher phase of production.

MATERIALS AND METHODS
M. oleifera leaves were harvested fresh from matured trees. The fresh leaves were sundried for about five days until complete dryness. Dried leaves were thoroughly pounded with wooden mortar. The resulting powder was stored in an airtight bottle and preserved under room temperature for subsequent usage as feed additive for the experimental birds.
One hundred and twenty day old Abor Acre broiler chicks purchased from a reputable farm in Ibadan, Oyo State, Nigeria was used for this investigation. At four weeks of age with an average live weight of 425 g, they were randomly allotted into treatment groups with three (3) replicates each. Thirty birds were allotted to each treatment group (10 birds per replicate) in a completely randomized design. The treatment groups (T1-T4) are the control group, T1 without MLP inclusion, T2 with 0.40% (of the total diet on dry matter basis) MLP inclusion, T3 with 0.80% MLP inclusion and T4 with 0.40% liver fit powder (LVP-commercial product).
The birds were reared on a closed deep litter system. Routine management practices in term of medication and vaccination were strictly observed while feed and water were given to them ad libitum. At the end of the eighth week, blood samples were taken from the wing web veins of twelve birds from each treatment group to determine the serum concentrations for total cholesterol, highdensity lipoproteins (HDL), low-density lipoproteins (LDL), very low-  density lipoproteins (VLDL) and triglyceride using the procedures earlier described by Julian (2001) and Kwiterovich (2005). Data collected were subjected to statistical analysis using the Statistical Package for Social Science (SPSS 17 Evolution) and treatments were separated with Duncan's option of the same software. Table 1 shows the gross compositions of broiler finisher mash fed the experimental birds.

RESULTS AND DISCUSSION
The calculated values for the nutrients conformed to the recommendations for broilers at both phases (Onifade, 1997). The diets were isocaloric and isonitrogeneous. The metabolizable energy was 2800.50 and crude protein content was 22.50% across board. Table 2 shows the effects of Moringa leaf meal inclusion on serum total cholesterol and differential lipids of the broilers.
Some levels of significant differences were observed among the cholesterol fractions investigated. Although, no significant (p>0.05) difference was observed for TC between birds on T1 and T2, and also between T3 andT4, the pairs significantly (p<0.05) differed with the latter having the lower values. The same trend was observed for TG and LDL. Also, birds on T3 and T4 had higher values of HDL significantly (p<0.05) than those on T1 and T2. However, the VLDL of T1 and T2 were not significantly (p>0.05) different but it significantly differed from others (p<0.05) with the least value of 70.45 mg/dl for T4 group. Meanwhile, birds on 0.80% MLP and LVP additives had significantly higher values of HDL as compared to the birds in T2 and T1 group.
The results of the TC and other lipid fractions in this experiment agree with the findings of Booth andWickens (1998), Fahey et al. (2001) and Bennett et al. (2003) that Moringa leaves have antioxidant properties which is useful for the proper functioning of the liver in blood lipid regulations. Ghasi et al. (2000) established the fact that blood cholesterol got reduced significantly with the inclusion of crude extract of leaf of M. oleifera in high fat fed Wistar rats. Also, Olugbemi et al. (2010) earlier reported that Moringa leaf meal is hypocholesterolemic in its actions on egg yolk and albumen when added to laying hens diets.

Conclusion
High fat deposition among broiler chickens is not desirable and the antilipemic activities of Moringa leaf powder have been validated by the results of this investigation. Inclusion of MLP at 800 g/ton (0.80%) as additive in the diets of broiler chickens at finisher phase will reduce the TC, LDL and VLDL which is a good indication of fat reduction for safe consumption.