UTILIZATION OF POULTRY BY –PRODUCT ( EGG SHELL) FOR SUSTAINABLE POULTRY FARMING IN INDIA
Post no 1368 Dt 23rd August 2019
Compiled & shared by- DR RAJESH KUMAR SINGH, JAMSHEDPUR,9431309542,rajeshsinghvet@gmail.com.
The poultry sector of India is now a days passing through critical phase. Poultry entrepreneurs are hardly making money due to higher cost of production of the poultry produce. So it has become very important to think of the sources from where the poultry farmers can adjust and make up their losses. Keeping this in mind to make the poultry farming sustainable ,our poultry farmers must think of the most neglected area , the utilization of egg shell for profit making.
The poultry industry produces large amounts of hatchery waste which includes solid waste and wastewater. The solid hatchery waste comprises empty shells, infertile eggs, dead embryos, late hatchings and dead chickens and a viscous liquid from eggs and decaying tissue. The wastewater comes from water used to wash down incubators, hatchers and chick handling areas. The sustainability of the poultry industry including hatcheries is at risk. Seepage of effluent from livestock industries into the ground water or run off into streams and rivers is one of the causes of increasing concentration of nitrates and phosphates in drinking water.
Traditional disposal methods for solid hatchery waste include land fill, composting, rendering, and incineration . Most of the hatchery waste is sent to land fill or composting, which costs the chicken meat industry millions of rupees each year in disposal costs . Some of the hatchery waste is rendered. The methods for wastewater disposal include sending it to land fill, using it for irrigation, disposing it directly into the sewer or into a wastewater lagoon. Some hatcheries use a wastewater treatment system. Land fill hatchery waste will break down naturally and produce methane which escapes to the atmosphere. Capturing and using the methane to prevent its release to air is beneficial to environment since methane has 21 times more global warming capacity than CO2 .
Hatchery waste is a high protein waste with 43-71% moisture . Dried hatchery waste contains 33.1% crude protein (CP), 29.0% ether extract, 12.1% crude fibre, 21.5% ash and 28.8 MJ/kg of gross
energy . Apparent metabolisable energy (AME) of the hatchery waste by-product meal is 23.9 MJ/kg and the apparent amino acid availability of the hatchery waste by-product meal is 73.5% . Hatchery waste could be developed into high protein feedstuffs, other value added products or utilised as an organic fertiliser after appropriate treatment.
If large amounts of wastes from animal production are directly applied into the soil, it pollutes the environment, including the ground water .
The egg consists of nine different items, which are egg shell (the outer covering of the egg), air cell (the pocket of air at the end of an egg), shell membrane, thin albumen, thick albumen, chalazae (anchor yolk) vitteline membrane, germinal disk and egg yolk. An eggshell is the outermost covering of an egg. The shell color of an egg is representative of the breed of hen that produces the egg. White hens produce white eggs and brown hens produce brown eggs.In an average laying hen the process of shell formation takes around 20 hours. Eggshell serves to protect the egg against damage and microbial contamination, prevention of desiccation, regulation of gas and water exchange for the growing embryo and provides calcium for embryogenesis. The shell makes up 9-12 percent of an egg’s total weight. It contains 27 essential microelements. Shell contains calcium carbonate(94%), magnesium carbonate (1%), calcium phosphate (1%) and organic matter (4%). It also contains trace amounts of sodium, potassium, zinc, manganese, iron, copper, sulphur, water, protein, crudefat, ash, alanine, arginine, asparticacid, cystine, histidine, leucine, lysine, isoleucine, tyrosine, valine , phenylalanine, proline, serine and threonine. India ranks fifth in the world with annual egg production of 1.61 million tones. Andhra Pradesh with Telengana is the largest egg producing state in India. Eggshell acts as a waste material from different domestic sources such as poultry farms, egg producing factories, hatcheries, homes and restaurant and results in increases pollution problems. Most eggshell waste is discarded without further processing by sending to landfill at a very high cost which is a very big issue. It is necessary to find an alternative method which would transform the waste eggshells into a valuable item, giving financial benefits to the competitive egg processing industry, apart from giving manufacturers a new profit stream. Egg shell can be used in variety of ways. Egg shells are used to enhance the soil fertility as it quickly decomposes and adds valuable calcium and other minerals to the soil. Crushed eggshell is scattered around the plants and flowers, which protect it from plant eating slugs, snails and cutworms, without using eco-unfriendly pesticides. Biodegradable eggshell halves are filled with potting soil and one or two seeds are added to each shell to start seedlings for the garden. It is one of the simple way to start a seedling in shells. When the seedlings are big enough for transplanting outside, the shells are cracked at the bottom and seedlings are planted. Eggshells contain 95% calcium, and hens need calcium to lay eggs that have those strong shells. If shells have been sterilized to kill bacteria they can be fed to laying hens. Egg shells are used as a coating pigments for inkjet printing paper and are also used for various decorative purposes by using paint. It can be used as food additive in coffee in the filter which reduce the bitterness in coffee. It can also be used as a nontoxic abrasive on pots and pans. It acts as a natural drain cleaner. A couple of crushed eggshells can be kept in kitchen sink strainer. At all times it traps additional solids and they gradually break up and help to naturally clean pipes on their way down the drain. Egg shells also act as laundry whitener. These if scattered in areas most prone to cats,also help in keeping cats away. Eggshell particles are used in toothpaste as an anti-tartar agent. Egg shell is having important medicinal uses such as healing cuts, treating ingrown toenails, skin irritations, itchy skin, skin-tightening and facial. Eggshells are dissolved in a small jar of apple cider vinegar (takes about two days) and the mixture is used to treat minor skin irritations. It also acts as a facial in which dried egg shells are ground with the help of mortar and pestle, mixed with egg white and the mixture is applied on face and then rinsed.
Egg shell is used as pet food. Dry eggshells are taken in oven at 2500 C, for 30 minutes and then put in a plastic zipper bag, sealed and the shells are crushed with a rolling pin until they are a fine powder. This is added in to dog’s food as a great calcium supplement to help in its bones and teeth growth. In addition, calcium carbonate from eggshell has an advantage for not containing toxic elements like calcium carbonate from oyster shells, which contains lead as well as other potential toxic elements such as aluminum, cadmium and mercury. Because of this property egg shell is used as a source of calcium supplement in animal and human. This supplement leads to increased bone density, less arthritic pain and even stimulates cartilage growth in man and animals. Egg shells are also used in as a calcium supplement in orange juice. Eggshell consumption helps stop bone loss in postmenopausal women. Applications of eggshells in the form of calcium lactate has been used as a firming agent, a flavor enhancer, a flavoring agent, a leavening agent, a nutrient supplement, a stabilizer and thickener. Eggshells have thus nearly as many uses as the eggs themselves. Egg shells can thus be used in such a way which may help to overcome the global eggshell waste problem, high disposal costs and Uenvironmental concerns.
Eggshell: Ideal Source for Hydroxyapatite———
A study has suggested that the recycling of chicken eggshells is a way of improving the ecosphere; it reduces the need of management of waste and the eggshells can serve as useful raw materials for nanomaterials . Fresh eggshell consists of a typically three-layered structure; the foamy cuticle layer on the outer surface resembles a ceramic; the middle layer is spongy; the inner layer consists of lamellar layers. It represents almost 11% of the egg total weight . Calcium carbonate (calcite) is the main component in eggshells and is the major inorganic substance found in an egg and it makes up about 94% of chemical composition of eggshell. This makes it an essential material for hydroxyapatite production . Others are organic matter which makes up 4%, magnesium carbonate (1%), and calcium phosphate (1%) as well as insoluble proteins . The calcite is the most stable form of calcium carbonate; it forms elongated structures called columns, palisades, or crystallite. Calcification of eggshell is regarded as one of the most rapid known processes of biomineralization and the bulk of mineral found within the eggshell is calcite with a needle like hydroxyapatite in small amounts found in the inner cuticle . The large presence of calcite contributed to the better mechanical properties and strength of eggshell based HAp.
Methods of Hydroxyapatite Production from Eggshell——–
There are several methods for the production of eggshell based hydroxyapatite. One of these methods is the hydrothermal method.
Hydrothermal method is the most widely reported method of HAp production from eggshell. It has been proven to be the most convenient method of HAp production . This method of synthesizing HAp from eggshells in a phosphate solution at a high temperature is a novel way for producing useful biomedical materials . In this method, fine hydroxyapatite single crystals are synthesized by a hydrothermal method with Ca(OH)2 and CaHPO4·2H2O as starting materials.
Handling of Hatchery Waste ———–
In developed countries the majority of hatcheries use a vacuum extraction system to transfer the waste into bins. Some hatcheries store the waste in a cool room and then place the waste into a Bio-Bin. Other hatcheries will crush the waste first, then use a vacuum or auger system to transfer waste into the bin. In the USA, one
disposal option is to transport the hatchery waste to a facility that separates the liquids from the solids by using a centrifuge . The liquid is refrigerated and transported to a pet food manufacturing plant. The solids are sent to land fill.
Separation of Waste at the Hatchery———–
Hatchery waste can be separated into solid and liquid components and then treated separately. For example the liquid in hatchery waste can be separated from the solid hatchery waste by spinning. In addition inclined screens, followed by the use of belt or filter presses can be used for separation of solid and liquid portions of the waste. These methods produce about 45% of solid materials . In other industries a flexible multi-layer filter can be used to separate liquid wastes from sludge wastes.
The principle of this process relies on liquid waste passing through the liner into the container by gravity . Another system for separating liquid and solid waste is to use a conveyor with an upper and lower conveyor roller and an endless conveyor belt extending around the conveyor rollers. A waste deflector extends above and along the lowest portion of the upper run. Liquid and solid wastes are separated and placed in collectors which are located near the upper and lower rollers.
Separating egg shells from hatchery waste ————–
A powerful suction vacuum is used to only remove the dry, very light shells from the hatchery waste, leaving the heavier infertile eggs. The shell and non-shell materials can also be separated by using a vibrating or shaking device (e.g., a shaker-sieve belt), which can separate lighter parts from heavier parts in the hatchery waste. A stream of gas (such as a cyclone forced-air separator) also can
be used to separate lighter materials from heavier materials in hatchery waste. After hatching, live chicks and unhatched chicks or clear eggs from the hatching tray are placed on a moving belt with
fixed gaps that only allow chicks to slide through, while shells and unhatched eggs are retained on the belt. Then the shell is vacuumed up for further separation, with the dead embryos being disposed into a separate container .
Methods to recycle egg shells —————
Eggs shells can be composted with other organic materials to increase the mineral content of the compost. Other minor uses for crushed egg shells include;
1) spread around plants to deter slugs and snails,
2) mixed with garden soil for use as a fertiliser;
3) fine pieces of crushed egg shell mixed with seeds for use as a feed for aviary birds;
4) added to cement to increase its strength;
5) used by artists to make mosaics and;
6) to make textured paint for 3D effects in artwork. These are small niche uses and not suited to industrial volumes of egg shells .
Complete separation of the membrane and the shell increases the value of the resulting products. One method is to use a meat processing machine to grind egg shells into a powder, and then mix the powder with water to separate the membrane. The shell sinks and the membrane stays suspended in the
water. Another method is to place the egg shells into a tank containing a fluid mixture and use cavitation (vapour bubbles in a flowing liquid) in the fluid mixture to separate the shell membrane. The fluid mixture is ideally recirculated to continue the separation process . Egg shell membrane contains about 10% collagen, which can be used in medicine. Collagen glue is used as a filling in corneal wounds. It can be also used for skin grafts, dental implants, angioplasty sleeves, plastic surgery and treatment of osteoporosis and in pharmaceuticals as well as food casings and film emulsions. The pure shell powder can be used in the paper industry, or as a lime substitute or calcium supplement in agriculture .
Other uses of egg shell membrane include:
Use as a component of biodegradable plastic.
Alter food-borne bacterial pathogen heat resistance with an egg shell membrane bacteriolytic enzyme.
Adsorbent for the removal of reactive dyes from coloured waste effluents.
Eliminate heavy metal ions from a dilute waste solution
Products that can be developed from shell include; ———
increase the mineral content of compost
spread around plants to deter slugs and snails
mixed with garden soil for use as a fertiliser
mixed with seeds for use as a feed for aviary birds
added to cement to increase its strength
used by artists to make mosaics
to make textured paint for 3D effects in artwork
produce collagen from the egg shell membrane.
Methods which can be used for treating the solid waste include the following; ———
Use of a furnace to heat the waste to produce steam to run a turbine generator and produce electricity
Rendered, autoclaved, extruded, boiled, ensiled, enzyme treated to produce pet or livestock feed or composted to produce fertiliser
On site stabilisation of product by using an in-line composter.
The most effective method for treating hatchery waste on site is to establish an anaerobic digester system. It is by far the most popular process used to treat organic wastes in all other organic waste industries. It has the advantage of being a high efficiency process and produces biogas which can be used for heating or generating power. The biosolids remaining after the digester process can be used as a high quality fertiliser.
Off the shelf digester systems for purchase by hatcheries are not available and need to be designed by engineers and built specifically to the requirements of each hatchery. Hatcheries disposing wastewater into lagoons could adopt the integrated aquaculture approach to produce water suitable for irrigation and other potential products such as ornamental fish; a multi-billion industry worldwide. The ideal system in a hatchery would incorporate separation and handling equipment to separate waste into its various components for further treatment. This would save disposal costs, produce biogas to reduce power costs at plants and produce a range of value added products.
In India the Dhopeshwar Engineerings has come up with innovation in Handling and Treatment of Poultry Hatchery Waste in a sustainable way.
He can be contacted on-www.dhopeshwar.in
