Method of Improving Liveability of Poultry

The present invention is in the general field of poultry farming and relates particularly to the feeding of laying fowl or layers.

The demand for poultry eggs, especially chicken eggs has expanded considerably over the last decade. The poultry industry has grown from a home industry to a large scale manufacturing industry in which tens of thousands of eggs are produced daily at single farms or egg laying installations. Some eggs are produced for eating and some eggs are produced for hatching. One problem with such large scale egg producing is the mortality of laying hens during their egg laying life. As with most animals, the mortality rate of laying poultry increases with age.

It is therefore an important object of the present invention to provide a means for increasing the liveability of egg producing poultry or laying hens, i.e. decreasing the mortality rate thereof or increasing the egg productive life thereof.

Another object of the invention is to extend the productive life of a laying hen or increase the total period of time that a laying hen can effectively produce eggs.

Various types of zeolites, mainly naturally occurring zeolites or those found in nature, have been fed to a variety of animals, in various amounts, including chickens, for a variety of reasons and with various results, mostly unfavorable.

An article by C. Y. Chung et al from Nongsa Sihom Youngu Pogo 1978, 20 (Livestock) pp. 77-83, discusses the effects of cation exchange capacity and particle size of zeolites on the growth, feed efficiency and feed materials utilizability of broilers or broiling size chickens. Supplementing the feed of the broilers with naturally occurring zeolites, such as clinoptilolite, some increase in body weight gain was determined. Chung et al also reported that earlier results at the Livestock Experiment Station (1974, 1975, 1976 --Suweon, Korea) showed that no significant difference was observed when 1.5, 3, and 4.5 percent zeolite was added to chicken layer diets.

U.S. Pat. No. 3,836,676 issued to Chukei Komakine in 1974 discloses the use of zeolites as an absorbent for adhesion moisture of ferrous sulfate crystals in an odorless chicken feed comprising such crystals and chicken droppings. The results were said to be no less than those in the case where chickens were raised with ordinary feed.

Experiments have been in progress in Japan since 1965 on the use of natural zeolite minerals as dietary supplements for poultry, swine and cattle. Significant increases in body weight per unit of feed consumed and in the general health of the animals was reported (Minato, Hideo, Koatsugasu 5:536, 1968). Reductions in malodor were also noted.

Using clinoptilolite and mordenite from northern Japan, Onagi, T. (Rept. Yamagata Stock Raising Inst. 7, 1966) found that Leghorn chickens required less food and water and gained as much weight in a two-week trial as birds receiving a control diet. No adverse effects on health or mortality were noted. The foregoing Japanese experiments were reported by F. A. Mumpton and P. H. Fishman in the Journal of Animal Science, Volume 45, No. 5 (1977), pp. 1188-1203.

Canadian Pat. No. 939,186 issued to White et al in 1974 discloses the use of zeolites having exchangeable cations as a feed component in the feeding of urea or biuret non-protein (NPR) compounds to ruminants, such as cattle, sheep and goats. Natural and synthetic as well as crystalline and non-crystalline zeolites are disclosed. Zeolites tested included natural zeolites, chabazite and clinoptilolite and synthetic zeolites X, Y, F, J, M, Z, and A. Zeolite F was by far the most outstanding and zeolite A was substantially ineffective.

In a recent study at the University of Georgia, both broilers and layers were fed small amounts (about 2%) of clinoptilolite, a naturally occurring zeolite from Tilden, Tex. The egg shells from the hens receiving zeolite were slightly more flexible as measured by deformation, slightly less strong as measured by Instron breaking strength, and had a slightly lower specific gravity. The differences in egg shell quality were very small. This type of zeolite was ineffective in producing a stronger egg shell. An article written by Larry Vest and John Shutze entitled "The Influence of Feeding Zeolites to Poultry Under Field Conditions" summarizing the studies was presented at Zeo-Agriculture '82.

A study by H. S. Nakaue of feeding White Leghorn layers clinoptilolite, reported in 1981 Poultry Science 60:944-949, disclosed no significant differences in egg shell strength between hens receiving the zeolite and hens not receiving the zeolite.

Zeolites are crystalline, hydrated aluminosilicates of alkali and alkaline earth cations, having infinite, three-dimensional structures.

Zeolites consist basically of a three-dimensional framework of SiO.sub.4 and AlO.sub.4 tetrahedra. The tetradra are cross-linked by the sharing of oxygen atoms so that the ratio of oxygen atoms to the total of the aluminum and silicon atoms is equal to two or O/(Al+Si)=2. The electrovalence of each tetrahedra containing aluminum is balanced by the inclusion in the crystal of a cation, for example, a sodium ion. This balance may be expressed by the formula Al/Na=1. The spaces between the tetrahedra are occupied by water molecules prior to dehydration.

There are a number of different types of zeolites. Some zeolites are found in nature and are made synthetically. Zeolite A is not found in nature and is made only synthetically. The present invention relates only to the use of zeolite A.

Zeolite A may be distinguished from other zeolites and silicates on the basis of their composition and X-ray powder diffraction patterns and certain physical characteristics. The X-ray patterns for these zeolites are described below. The composition and density are among the characteristics which have been found to be important in identifying these zeolites.

The basic formula for all crystalline sodium zeolites may be represented as follows:

In general, a particular crystalline zeolite will have values for "x" and "y" that fall in a definite range. The value "x" for a particular zeolite will vary somewhat since the aluminum atoms and the silicon atoms occupy essentially equivalent positions in the lattice. Minor variations in the relative number of these atoms do not significantly alter the crystal structure or physical properties of the zeolite. For zeolite A, the "x" value normally falls within the range 1.85.+-.0.5.

The value for "y" is not necessarily an invariant for all samples of zeolites. This is true because various exchangeable ions are of different size, and, since there is no major change in the crystal lattice dimensions upon ion exchange, the space available in the pores of the zeolite to accommodate water molecules varies.

The average value for "y" for zeolite A is 5.1. The formula for zeolite A may be written as follows:

In the formula, "y" may be any value up to 6.

An ideal zeolite A has the following formula:

Among the ways of identifying zeolites and distinguishing them from other zeolites and other crystalline substances, the X-ray powder diffraction pattern has been found to be a useful tool. In obtaining the X-ray powder diffraction patterns, standard techniques are employed. The radiation is the K.alpha. doublet of copper and a Geiger counter spectrometer with a strip chart pen recorder is used. The peak heights, I, and the positions as a function of 2.theta. where .theta. is the Bragg angle, are read from a spectrometer chart. From these, the relative intensities, 100 I/I.sub.o, where I.sub.o is the intensity of the strongest line or peak and d the interplanar spacing in angstroms corresponding to the recorded lines are calculated.

X-ray powder diffraction data for a sodium zeolite A are given in Table I.

Occasionally, additional lines not belonging to the pattern for the zeolite appear in a pattern along with the X-ray lines characteristic of that zeolite. This is an indication that one or more additional crystalline materials are mixed with the zeolite in the sample being tested. Small changes in line positions may also occur under these conditions. Such changes in no way hinder the identification of the X-ray patterns as belonging to the zeolite.

The particular X-ray technique and/or apparatus employed, the humidity, the temperature, the orientation of the powder crystals and other variables, all of which are well known and understood to those skilled in the art of X-ray crystallography or diffraction can cause some variations in the intensities and positions of the lines. These changes, even in those few instances where they become large, pose no problem to the skilled X-ray crystallographer in establishing identities. Thus, the X-ray data given herein to identify the lattice for a zeolite, are not to exclude those materials which, due to some variable mentioned or otherwise known to those skilled in the art, fail to show all of the lines, or show a few extra ones that are permissible in the cubic system of that zeolite, or show a slight shift in position of the lines, so as to give a slightly larger or smaller lattice.

A simpler test described in "American Mineralogist," Volume 28, page 545, 1943, permits a quick check of the silicon to aluminum ratio of the zeolite. According to the description of the test, zeolite minerals with a three-dimensional network that contains aluminum and silicon atoms in an atomic ratio of Al/Si=2/3=0.67, or greater, produce a gel when treated with hydrochloric acid. Zeolites having smaller aluminum to silicon ratios disintegrate in the presence of hydrochloric acid and precipitate silica. These tests were developed with natural zeolites and may vary slightly when applied to synthetic types.

U.S. Pat. No. 2,882,243 describes a process for making zeolite A comprising preparing a sodium-aluminum-silicate water mixture having an SiO.sub.2 :Al.sub.2 O.sub.3 mole ratio of from 0.5:1 to 1.5:1, and Na.sub.2 O/SiO.sub.2 mole ratio of from 0.8:1 to 3:1, and an H.sub.2 O/Na.sub.2 O mole ratio of from 35:1 to 200:1, maintaining the mixture at a temperature of from 20.degree. C. to 175.degree. C. until zeolite A is formed, and separating the zeolite A from the mother liquor.

It is an important object of the present invention to increase the liveability of laying poultry or layers by feeding a feed to the laying poultry or layers which contains a small effective amount of zeolite A.

It is another object of the invention to provide a longer egg producing life feed by feeding the poultry a feed containing a small amount of zeolite A sufficient to extend the egg producing life of the poultry.

Another object of the invention is to provide an improved process for increasing the effective egg producing period of laying poultry wherein an effective amount of zeolite A is added to the diet of the laying poultry.

Still another object of the invention is to cost effectively decrease the mortality rate of laying poultry.

Other objects and advantages of the invention will be more fully understood from a reading of the description and claims hereinafter.

The present invention relates to a method of improving the liveability, i.e. increasing the egg producing life of layers or laying poultry wherein a small amount of zeolite A is added to the feed of the layers.

The drawing illustrates the effectiveness of the present invention showing a comparison of the mortality rate of laying poultry fed zeolite A and laying poultry similarly fed without zeolite A.

It has been discovered that the addition of a relatively small amount of zeolite A to a regular or standard feed for laying chickens or hens effectively increases the liveability or decreases the mortality rate of laying poultry with no significant changes in egg production, egg weight or feed consumption. Zeolite A is added in amounts of from about 0.25 percent to about 4.00 percent of weight of the total feed and more preferably in amounts of about 0.75 to 3.5 weight percent.

A typical feed preparation for large scale laying hen operations comprises the following by weight percent:

Zeolite A is added to such feed formulation in small amounts by weight percent of up to about four. Greater amounts may be used, but may deprive the layers of the desired amount of nutrients. Greater amounts are also likely to be cost ineffective. A particularly preferred amount of zeolite A is from about one-half to about two percent by weight of the total feed formulation. A most preferred amount of zeolite A is about 0.75 to about 1.50 weight percent of the total feed formulation.

The most convenient means of measuring egg shell strength is by measuring the specific gravity of the egg. This is simply done by immersing the egg in solutions of salt water of varying strengths. It is well known in the art that specific gravity correlates with egg shell strength. As specific gravity of the egg is raised, the strength of the egg shell is increased.

Using Ethyl EZA.RTM. zeolite, a commercially available sodium zeolite A, a number of tests were conducted to determine the effect of zeolite on egg shell quality.

Procedure: 480 hens (Dekalb XL pullets) were divided into eight equal groups and fed one of the following dietary treatments for a minimum of six weeks:

The diet fed to the hens consisted principally of corn supplemented with a soybean meal (SBM) and limestone. Smaller amounts of alfalfa meal, dicalcium phosphate (DiCalP), a synthetic amino acid (DL-methionine), salt, a commercial vitamin and mineral supplement for layers (Micro-Mix). Sand and/or hydrochloric acid (HCl) were added to some diets. Each diet assured that the hens received all of the required nutrients and minerals.

Diets 1-4 contained 1,238 calories per pound, 16% protein, 0.55% total sulfur amino acids, 4% calcium and 0.70% total phosphorous.

Diets 5-8 contained 1,292 calories per pound, 16% protein, 0.55% total sulfur amino acids, 2.75% calcium and 0.70% phosphorous.

All diets were isocaloric and isonitrogenous within treatments and are detailed in Table A.

The results are summarized in Tables B, C, D, E, F and G as follows:

A review of the test data in Table B shows that zeolite A provides a definite benefit on shell quality, and had no significant effect on the other qualities studied except possibly for shell weight. Two concentrations (0.75%, 1.5%) were evaluated because of sodium limitations and for those levels, the data showed a linear relationship with concentration.

In Table C zeolite A had no significant effect on production (% hen day). However, there is some indication that a slight reduction occurred, particularly with Diet 8 in the 2.75% Ca series (i.e. low-Ca).

In Table D there appears to be an indication of some benefits from zeolite A.

Previous indications that feed consumption was reduced without any reduction in egg or body weight or in egg production could not be substantiated by the statistical data. As shown in Table E 1.5% zeolite A reduced feed consumption, relative to baseline, at both Ca levels in Weeks 1 and 4. However, this did not occur in the other six weeks of the trial. Thus, if we look at the results for the 8th week:

The reduced value is most likely attributable to a palatability consideration. Laying hens usually eat more than they need. Any factor, such as feed dustiness, can reduce intake by up to 5% without an adverse effect.

Tables F and G show no significant benefits for body and egg weights.

The foregoing tests were conducted by Dr. David A. Roland, Senior Alumni Professor of Poultry Nutrition. Under the carefully controlled university conditions and with the scale tested, no significant effects on mortality of the laying hens was noted. Subsequent tests by Dr. Roland on a similar scale produced similar results.

A large scale field trial was conducted on a commercial farm under the supervision of Dr. David A. Roland, Senior Alumni Professor of Poultry Nutrition, at Auburn University. The feeding trial utilized two identical poultry houses having a capacity of 15,000 birds or laying hens, and designated House "R" and House "H". Each house contained approximately 14,500 hens. The hens were in their 11th month of egg production. Each house was attended by an experienced employee. About 51/2 hours per day were required to attend each house, each day. The bulk of the time was spent in manual egg collection of approximately 850 to 1,000 dozen eggs each day. Older hens usually produce less eggs. The eggs were loaded on stackable "filler flats". Each flat holds three dozen eggs, with 10 flats to a case and 18 cases to a rack. The rack was a wheeled cart about six feet tall and had a capacity of 5,400 eggs. The eggs were transported in a rack to a processing plant and kept until graded. Daily production records were kept at the laying houses.

House "R" was the control house and House "H" was the test house. The same regular commercial feed blend was used in each house, except that the blend fed to the birds in House "H" during the zeolite testing period contained 0.75 weight percent zeolite A which had been carefully uniformly blended into the feed.

The field trial was conducted over a period of eleven weeks. The zeolite testing period was for six weeks, commencing on the first day of the fourth week and ending on the last day of the ninth week. Mortality data was collected on both houses during the entire eleven week test period.

Referring to the drawing, mortality versus time curves based on a compilation of raw data are shown for House "R", the control house, wherein none of the hens were fed feed containing zeolite A and for House "H", the test house, wherein the hens were fed a feed containing 0.75 weight percent zeolite A during six weeks of the eleven week test period. It is readily seen that the mortality rate of the hens on the zeolite free diet in House "R" was substantially greater than the mortality rate of the hens on the zeolite test feeding program in House "H". It appears from the curves that the effects on mortality of the zeolite fed hens were cumulative and even more effective after the zeolite was removed from the diet of the hens.

The commercial field trial of the feeding of zeolite A to the hens was conducted during winter months. The trial was divided into three periods, pretreatment, treatment and post treatment. A number of problems were concentrated in the zeolite fed house and occurred during a two week period. There was a mite infestation, interruption of water twice and malfunction of the automatic feeder. An unusually severe winter had its effect on each house. Even with the additional stress in the zeolite fed house, the mortality rate of the hens declined. The study suggests that the addition of zeolite A to the hens' regular feed ration extends the hens' economically useful period of production by several months.

In a preliminary study of a relatively few laying hens with one percent zeolite in the diet it was indicated that the relative ranks of zeolites in improving shell strength were as follows:

In shell strength, the controls were inferior to or equal to the poorest of all the zeolites.

The term poultry includes all domestic fowl, namely chickens, turkeys, ducks, geese, and the like.

Corn is the principal diet for most laying poultry. A feed formulation comprising by weight percent the following is desirable:

Calcium carbonate is usually in the form of natural limestone ground to a suitable particle size, but sometimes oyster shells which have also been suitably ground are used.

It can be appreciated that a wide variety of nutrients or foods may be included in the diets of layers or poultry laying hens. In a controlled environment, the hens are only exposed to desired foods or food products. A typical laying ration composition contains the following:

The foregoing composition is obtained from or included the following ingredients:

Grain and processed grain by-products. Includes corn, corn hominy, corn germ meal, barley, millet, oats, rice, rice hulls, rye, sorghum, wheat and wheat shorts. These are among the energy ingredients, mostly carbohydrates with some proteins.

Plant protein products. Includes soybean oil meal, barley malt sprouts, coconut meal, corn distillers grain, corn gluten meal, cottonseed meal, pea seed, potato meal, peanut meal, rape seed meal, sunflower meal, wheat germ meal, brewers' yeast. All of these are protein sources.

Roughage or fiber. Includes dehydrated alfalfa, alfalfa hay, alfalfa leaf meal and pasture grasses. These are all fiber sources.

Animal and fish by-products. Includes blood meal, blood flour, dried buttermilk, dried whey, dried casein, fish meal, dried fish solubles, liver meal, meat meal, meat meal tankage, bone meal and dried skim milk. Anchovies, herring and menhaden are sources of fish meal.

Minerals and synthetic trace ingredients. Includes vitamins such as B-12, A, pantothenate, niacin, riboflavin, K, etc., DL methionine, choline chloride, folic acid, dicalcium phosphate, magnesium sulfonate, potassium sulfate, calcium carbonate (limestone, oyster shells), salt, sodium selenite, manganous oxide, calcium iodate, copper oxide, zinc oxide and D activated animal sterol.

Molasses and animal fats are added to improve palatability and to increase or balance the energy levels.

Preservatives are also added such as, Ethoxyquin and sodium sulfite.

In general, a feed composition for poultry laying hens should preferably contain by weight percent the following:

The foregoing disclosure and description of the invention is illustrative and explanatory and various changes in the illustrated process may be made within the scope of the appended claims without departing from the spirit of the invention.