This invention relates generally to the injection of eggs, referred to as xe2x80x9cin ovoxe2x80x9d injection, and more particularly concerns an apparatus and method for the automated injection of various substances into eggs, especially for the control of disease in avian flocks.
There are a number of reasons in the fields of both medicine and poultry husbandry, among others, for the injection of a range of substances into various types of eggs. For example, in the field of medicine, fertile, or embryonated, eggs are used to incubate and harvest biologicals which have medical applications, such as certain vaccines. Eggs provide an appropriate environment for the growth of the vaccines.
Another reason for the injection of eggs is to add substances to the embryo or to the environment around the embryo. The purpose is to induce beneficial effects in the subsequently hatched chicks. The substances which may be added include antimicrobials such as antibiotics, bactericides and sulfonamides; vitamins; enzymes; nutrients; organic salts; hormones; adjuvants; immune stimulators and vaccines. This technique can, for example, lead to an increased percentage of hatch. The chicks from eggs that are injected prior to hatch may retain a sufficient amount of the injected substance so there is no need to inject the hatched bird. The chicks may grow faster and larger and experience improvement in other physical characteristics.
In ovo injection has also proven effective as a means for disease prevention. A significant problem in the poultry industry is a high incidence of infectious diseases which increases the cull rate and causes a high rate of mortality during the growing stage of young birds. An example is Marek""s disease, which is a widespread herpes virus-induced lymphoproliferative disease of chickens. It is standard practice in commercial hatchery operations to immunize birds post-hatch against diseases like Marek""s prior to placing them in brooder houses. This is a very labor-intensive process. With the advent of in ovo injection, certain types of vaccination, such as Marek""s, which in the past had been carried out on hatched poultry are now successfully performed on embryonated eggs.
In general, the in ovo injection technique involves delivering a substance in fluid form to the interior of an egg using a needle. Occasionally, the needle is used to both penetrate the egg shell and deliver the fluid substances. However, fine needles, which are preferred when precise fluid delivery is required, may not be rigid enough to penetrate an egg shell. On the other hand, needles large enough and rigid enough to penetrate the egg shell may not provide suitable fluid delivery, both in terms of location and amount, which more delicate needles can provide. Furthermore, the penetrating process quickly dulls or plugs the needle. Therefore, a drill or punch is typically used to make a hole in the egg. Once the drill or punch has penetrated the egg shell, the needle is inserted into the interior of the egg for delivering the fluid substance.
An important parameter in in ovo injection is the location of the needle injection port within the egg at the time of fluid injection. Eggs are comprised of a brittle exterior shell and two flexible interior membranes. An outer membrane adheres to the interior of the shell and an inner membrane encases the fluid contents of the egg, including the allantois, amnion and yolk sac. At the time the egg is first laid, the two membranes are substantially coextensive. However, as the fertile egg is incubated, the inner membrane separates from the outer membrane, thereby forming an air cell between the two membranes, usually at the large end of the egg.
The egg can be injected at any location, and even into the embryo itself. The suitability of a particular location depends on the purpose for which the egg is being injected and the fluid substance delivered; since some substances must be delivered to a particular location within the egg in order to be effective. The problem with locating the needle at the appropriate injection point is that eggs vary in size. The resulting differences in distance between the shell and the location at which delivery of the fluid substance is desired complicates the task of consistently locating the injection point.
The amount of fluid delivered is also an important parameter. Typically, it is necessary that a sufficient amount of fluid be introduced into the egg to produce the desired effect, For example, in the case of bactericides, the amount of material introduced into the eggs must be sufficiently great to cause an appreciable increase in the percentage, of hatch, but must not be so great that it kills or injures the embryos.
Automated apparatus and methods for injecting eggs are available. Generally, in such devices the eggs are brought under a bank of injectors housing needles and punches. First, the punches open a hole in the shell. Then the needle is inserted into the egg, followed by injection of fluid. A primary goal of automated in ovo injection is to be able to handle a high egg volume in a short period of time while consistently maintaining the amount and location of the fluid substance delivered within each of the eggs.
An automated device for injecting eggs must address the fact that eggs are not identical in size. Some devices include means for permitting vertical travel of the injectors relative to the apparatus to accommodate eggs of different sizes. However, another problem related to xe2x80x9cin ovoxe2x80x9d injection in commercial hatcheries is that the eggs are typically carried in setting trays, or xe2x80x9cegg flats.xe2x80x9d Conventional egg flats comprise anywhere from 36 to 168 depressions for receiving the smaller end of the egg. Because the depressions are designed to accommodate the varying sizes of eggs, the eggs are free to wobble in the depression. As a result, the eggs may be slightly tilted with respect to the injectors. The capacity to accurately and precisely control the travel of a needle within the egg is diminished when the egg is tilted, even where the relative vertical travel between the egg and the needle is carefully controlled to account for differences in egg height.
Methods for dealing with the tilted eggs include lifting the eggs free of the flat in a suction cup integral with the injector to properly orient the eggs with respect to the needles or allowing the injectors to translate through an arc to properly orient the injectors to the tilted eggs. The former is impractical and has never seen commercial application. The latter method is somewhat effective, but can fail in practice when an injector translates improperly, becoming so angled with respect to an egg that the needle will glance off the egg shell, completely missing the egg. Therefore, fluid delivery location still remains a problem for automated in ovo injection devices.
Another problem with existing in ovo injection machines is that the pump mechanisms for delivering the substances may produce excessive sheer and compressive forces on the substance. In the case of Marek""s disease vaccine, which is commonly presented as a whole-cell suspension, these forces can rupture the cells and thereby render the vaccine virus inside the cells much less effective.
Another consideration in egg injection is that it must be done in as clean an environment as is possible so that there is reduced probability of bacteria or mold entering the egg during or after puncture. Since the same needle is used repetitively, there exists the possibility of cross-contamination. Accordingly, the needle must be sanitized periodically. The magnitude of this problem is exacerbated in the automated apparatus where the same needle is used to inject hundreds of eggs.
For the foregoing reasons there is a need for an automated egg injection apparatus and method which is less labor-intensive than known systems. The apparatus should handle a high volume of eggs with a high level of precision with respect to both the location and quantity delivered. Ideally, the injection needle should be capable of functioning as both the penetrating and fluid delivery means. Fluid delivery should be gentle and precise so as not to damage live vaccine cells. The overall operation should be sanitary so as to minimize, if not eliminate, cross-contamination. The machine design should facilitate both manufacture and operation, thus reducing manufacturing and operating costs as compared to known devices and methods.
The present invention comprises an apparatus and method for in ovo injection that satisfies these needs.
An apparatus for injecting fluid substances into eggs, having features of the present invention, comprises a plurality of injectors, disposed within each of the injectors are needles moveable between a retracted position and an extended injecting position with respect to the injectors; means for positioning the plurality of injectors in alignment with a corresponding plurality of eggs; means for advancing the injectors into engagement with the eggs; means for advancing the needles from the retracted position to the extended position into the eggs; means for producing pulses of fluid substance through the needles; and means for retracting the needles from the eggs.
A feature of the egg injection apparatus is an injection assembly comprising one or more substantially horizontally-oriented plates with openings therethrough for holding the injectors substantially vertically in the openings in the plates, a lower portion of the injector depending downwardly below the plates and an upper portion of the injector resting at or above the plates. The openings in the plates are slightly larger than the cross-section of the injectors for permitting the injectors to move vertically within the openings in the plates with respect to the plates. An egg nesting cup is pivotally secured to the lower end of each injector. Means for raising and lowering the plates and the injectors are provided so that when the plates are lowered and the lower portion of the injector contacts an egg to be injected, the nesting cup seats against the egg and, while the plates proceed downwardly, the injector moves vertically upward with respect to the plate and the nesting cup is free to move independently of the injector body to seat around the egg. One of the plates may be horizontally moveable relative to the other plates after the plates have reached the limit of their downward movement for securing the injectors against movement.
An injector for use with an egg injecting apparatus is also provided, comprising an injector body, a needle disposed within the injector body, the needle moveable between a retracted position and an extended injecting position with respect to the injector body, an articulating cup pivotally secured to the end of the injector body, the articulating cup adapted for receiving the upper portions of the eggs, means for driving needle into the egg with sufficient force to pierce the egg shell, means for supplying fluid to the needle for delivery into the eggs after penetration to a predetermined distance, and means for retracting the needle from the egg. The relationship defined by the seated position of the articulating cup against the shell of an egg and the injecting position of the needle is consistently reproducible so that the penetration and injection location of the needle within an egg is consistent regardless of the size and orientation of the egg. A fastener pivotally secures the cup to the injector, the fastener having a sanitizing fluid reservoir defined by an annular recess at the upper end of the fastener.
A needle for use in the injector comprises a beveled, solid tip for penetration of the egg shell, and a radial opening adjacent the tip for delivery of fluid. The needle tip may be coated with titanium and beveled at an angle of from about 20 degrees to about 45 degrees.
Fluid delivery is accomplished via a pressurized fluid source, tubing carrying fluid from the pressurized fluid source to the needle, a first contacting member adapted to be rigidly connected to the egg injection apparatus and a second contacting member reciprocally connected to the first contacting member, wherein the tubing passes between the members for pinching the tubing closed when the contacting members are together and allowing fluid to flow through the tubing when the contacting members are apart. The volume of fluid delivered is controlled by the fluid pressure and the amount of time the contacting members are apart.
A spray assembly for applying sanitizing solution to the injectors and needles is provided, comprising a pan, a spray shield extending upwardly from the sides of the pan, the spray shield adapted to receive the injector assembly of the egg injection device, a plurality of spray nozzles in the pan, means for supplying sanitizing fluid to the spray nozzles, and means for moving the spray nozzles back and forth across the pan during spraying for uniform coverage of the injector assembly.
A method for injecting fluid substances into eggs having features of the present invention comprises providing an injectable fluid substance, arranging a plurality of eggs in an egg flat, placing the egg flat containing eggs into an egg-receiving assembly in alignment with a plurality of injectors, each of the injectors housing a fluid delivery needle, vertically aligning the beveled delivery tip of each needle with an egg, positioning a plurality of injectors, including an articulating cup, in seating relation against portions of the shell of each egg, initiating vertical needle movement, moving the needle between a retracted position and an extended position with respect to the cup, the extended position piercing the egg through the shell and defining an injecting position within the egg, delivering a predetermined amount of fluid at the end of the needle stroke through the needle into the egg in measured amounts; and withdrawing the needles from the eggs.
The method may further comprise the step of positioning the injectors in a sanitizing shower following the step of injection and extending and retracting the delivery tips of the needles at least once during the sterilizing shower, and then repeating steps above.
Accordingly, it is an object of the present invention to provide a new apparatus and method for in ovo injection having one or more of the novel features of this invention as set forth above or hereinafter shown or described.
Similarly an object of this invention is to provide an automated apparatus and method for in ovo injection which is capable of injecting a high volume of eggs in a short time period.
It is an object of this invention to provide for the control of disease in avian flocks. Therefore, in one of its aspects, it is an object of this invention to inject beneficial substances into the embryo or to the environment around the embryo to improve the hatch rate and to induce beneficial effects in the subsequently-hatched chicks.
Another object of this invention is to provide a needle for use in in ovo injection which is sufficiently rigid and durable to repeatedly penetrate an egg shell and which provides appropriate substance delivery location and amount.
Still another object of this invention is to provide an in ovo injection apparatus and method for consistently and accurately controlling the location of the substance delivery needle at a predetermined injection point in the egg, regardless of the size of the egg or the tilt of the egg when in a conventional egg flat.
Further, an object of this invention is to so control the amount of material injected so as to provide the maximum amount of beneficial substances without damage.
Yet another object of this invention is provide gentle delivery of fluid substances to minimize damage to whole-cell suspensions, such as Marek""s vaccine.
A still further object of this invention is to provide an in ovo injection apparatus and method which reduces labor and minimizes manufacturing and operation costs.
Finally, an object of this invention is to provide for a sterile environment for in ovo injection so as to minimize cross-contamination.
The apparatus of the present invention provides a method for automatically injecting eggs with a desired fluid at a predetermined location within the egg. The vertically-movable injector further including an egg nesting cup accommodates the varying sizes of eggs and the slight tilt encountered with respect to vertical due to the design of egg flats. The injector is positioned with respect to the egg so that the same injection location is achieved despite the size and orientation of the egg. The present invention is capable of accurately controlling the travel of the needle within the egg. A solid-tipped needle can be used for egg shell penetration and injection thereby eliminating the need for a separate punch. Radial outlet ports on the needle prevent direct fluid impingement on the embryo. The preferred fluid delivery method also eliminates the pumping of fluids through conventional fluid-handling systems and offers both precise and cell-safe fluid delivery. Few live cells are destroyed in the delivery, ensuring that an effective quantity of vaccine titer reaches the egg. A clean injection environment is maintained since all egg contacting surfaces are sanitized after each injection cycle. This minimizes the potential for cross-contamination of the eggs. The egg injection apparatus of the present invention is simple to manufacture and operate. Labor is reduced from known methods and devices while at the same time improving output.