Note: Descriptions are shown in the official language in which they were submitted.
~1 3~3~7~
Case 5061-F-Plus
ZEOI~TES IN POULIRY ~ ING
me present m venti~n is in the gen`~ral field of poultry
farmlng and relates to the feeding of poultry.
m e demand for poultry has expanded considerably sver
the last decade. m e poultry indNstry has yrown frcm a hcme
industry to a large scale manufacturing industry in which tens of
thousands of chickens, turkeys and other birds are fed daily at
single farms or poultry installations. This increased interest
10 in the poultry industry concerns not only the demand for eggs,
especially chicken eygs, but also the demand for poultry meat
such as t~rrke~s and chickens. For this reason there has been an
increased interest in imprcving the quality of poultry and
poultry products by means of modification in the poultry feed.
In our earlier work in this area of paultry feed, it was
discovered that the inclusion of small amounts of zeolite A in a
regular feeding program of poultry, such as chickens, increased
the egg shell strength and this is described in U. S. patent
4,556,564. A related discovery is describe~ in U. S. 4,610,8B2
and consists of the use of small amounts of zeolite in the fe0d
to improive the feed utilization efficiency and result in larger
egg size.
Another beneficial effect found by the use of zeolite A
in the feed is decreased mortality rate of poultry and this is
described in U. S. patent 4,610,883.
.
~311 3~71
-- 2
Continued mvestigatio~ of the effects of zeolite A in
poultry feed has resulted in the discovery of the follc~ing
beneficial effects and positive results by the regular feeding of
small amc~mts of zeolite A:
1. Calmer birds, reduced ac~ivity resulting in
decreased production of body c~ecked eggs (layers)
2. Ex~ended lay cycle duration (layers and broiler
breeders)
3. Reduced condemnation (broilers)
4. Improved feathering (broilers)
5. Improved resistance to hea~ stress (all poultry,
but especially layers)
; 6. Increased male aggressiveness in breeding activity
(breeders)
~he advantages of larger eggs, extended lay cycles and
reduced condemnations are self-evident. Calmer birds produce
more, less deformel eggs and lay with greater regularity. Stress
in layers, as with most animals is a highly negative factor.
Imprc~ed feathering c~rrelates with healthier and stronger birds.
More recently, o~r studies have discovered that the
inclusion of zeolite A in the feed of b milers r~ ts in improv-
mg the lean/fat ratio in the edible carcassO With the increased
desirability of less fat in a human diet, it has becc~e more and
more important that ~he meat of poultry raised for food have a
; 25 high lean conten~ and a low fat content.
An article by CO 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
13~ 3~7~l
growth, feed efficiency and feed materials utilizability of
broilers or broiling size chickens. Supplementm g the feed of
the broilers with naturally occurring zeolites, such as clinop-
tilolite, some increase in body wei~ht gain ~as determined.
Chung et al also reported that earlier results at the Livestcck
Experiment Station (1974, 1975, 1976 - Suweon, Korea) showed that
no significant difference was observed when 1.5, 3,and 4.5 per-
cent zeolite was added to chicken layer diets.
U.S~ Patent 3,836,676 issued to Chukei Ko~aXine in 1974
discloses the use of zeolites as an absorbent for adhesion mois-
ture of ferrous sulfate crystals in an odorless chicken feed com-
prising such crystals and chicken droppings. I'he results were
said to be no less than those m the case where chickPns 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 ani-
mals 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
IÆghorn chickens required less fcod and water and gained as ~uch
weight in a two-week trial as birds receiving a control diet. No
adverse effects on health or mortality were note1. m e foregoing
Japanese experiments were reported by F. A. Mumpton and P. H.
Fishman in the Journal of Animal Science, ~ol. 45, No. 5 (1977)
pp. 1188-1203.
~3~3~1
Canadian Patent 939,186 issued ~o 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)
c~mp~unds 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, chaba-
zite and clinoptilolite and synthetic zeolites X, Y, F, J, M, 7.,
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, U.S.A.,
both broilers and layers were fed small amounts (about 2%) of
clinoptilolite, a naturally occurring zeolite from Tilden,
Tex~as. An article written by Larry Vest and John Shutze entitled
"The Influence of Feeding Zeolites to Poultry Under Field
conditions" summariz mg the studies was presented at
Zeo-Agriculture '82.
A study by H. S. Nakaue of feeding White Ieghorn layers
clinoptilolite, reported in 19~1 Poultry Science 60:944-949, dis-
closed no significant differenc~s in eggshell stren~th between
he~s receiving the natural zeolite and hens not receiving the
natural zeolite.
In general zeolites are crystalline, hydrated alumlno-
silicates of alkali and alkaline earth cations, having infinite,
three dimensional structures. There are a wide variety of
tyE~s. Scme types are naturally occurring and some of these
types are made synthetically. Other types are made only syn-
~hetically.
~313~7~
Zeolites consist basically of a three-dimensional frame-
wor~ of SiO4 and Al04 tetrahedra. m e tetrahedra æ e cross-
linked by the sharing of oxygen atom~s so that the ratio of o~ygen
atoms to the total of the alumlnum and silicon atoms is equal to
5 two or 0/(A1 + Si) = 2. 1`he electrovalence of each te~rahedra
containLng aluminum is balanced by the inclusion in the crystal
of a cation, for example, a sodium ion. m is balance may be ex-
pressed by the formula Al/Na = l. The spaces between the tetra-
hedra are occupied by water molecules prior to dehydration.
Zeolite A, which is not found in nature, is made
synthetlcally, and may be distinguished from other zeolites and
silicates on the basis of composition, X-ray powder diffraction
patterns, and cer*ain physical c~laracteristics. m e X-ray
patterns for these zeolites æe described below. Composition and
15 density are among the characteristics which have been found to be
important in identifying these zeolites.
The ~2sic formula for all crystalline sodium zeolites
may be represented as follows:
Na20 A1203 xSiO2 YH2o
In general, a particul æ crystalline zeolite will hcave
values for "x" and "y" that fall in a definite r~ngs. The value
"x" for a particular zeolite will v~ry somewhat since ~he alum-
inum atoms and the silicon atoms occupy essentially equivalent
positions in the lattice. Minor variations in the relative num-
25 ber of these atoms do not significantly alter the crystal struc-
ture or ph~sical properties of the zeolite. For zeolite A, the
"x" value normally f~lls within the range 1.85 ~ 0.5.
- 6 -3
The value for "y" is ~t necessarily an invariant for
all samples of zeolites. This is true because various ~xc~ange-
able ions are of different size, and, since there is no major
rha~e in the crystal lattice dimensions u~n ion exchange, the
S space available in the pores of the zeolite to accommodate w~t~r
molecules varies.
The average value for "y" for zeolite A is 5.I. The
formula for zeolite A may be written as follows
l.O ~ 0.2 Na2O A12O3 1.85 ~ 0.5 sio2 yH2O
10 In the formula, "y" may be any value up to 6.
An ideal zeolite A has the following formula:
(Na~lSiO4)12 27~I20
Among the ways of identifying zeolites and distinguish-
ing them from other zeolites and other crystalline substanr~c,
15 the X-ray pcwder diffraction pattern has been found to be a use-
ful tool. In obtaining ~he X-ray pcwder diffraction patterns,
standard techni~ues are employed. m e radiation is the K doub-
let of copper and a Geiger~ccunter spec~rometer or suitable
radiation detector with a strip chart pen r~corder is used. The
20 peak heights, I, and the positions as a function of 2i where i is
the Bragg angle, are read from a spectrometer chart or accumu-
lated in computer memory. From thess, ~he relative mtensities,
lOO VIol where Io is the intensity of the strongest line or
peak and d the interplanar spacing in angstroms corresponding to
25 the recorded lines are calcNlated.
X-ray powder diffraction data for a sodium zeolite A are
given in Table I.
~LP *trade-m~rk
~3~ 3~7~
TABLE I
X-R~Y DIFFRACTION ~ATTEKN FOR Z~OI~TE A
100
h2 + k2 + 12 - (A) Io
1 12.29 100
2 8.71 70
3 7.11 35
4 6.15 2
5.51 25
6 5.03 2
8 4.36 6
9 4.107 35
3.895 2
11 3.714 50
13 3.417 16
14 3.293 45
16 3.078 2
17 2.987 55
1~ 2.904 10
2.754 12
21 2.6~8 4
22 2.626 20
24 2.515 6
2.464 4
26 2.414 >1
27 2.371 3
29 2.289
2.249 3
32 2.177 7
33 2.144 10
34 2.113 3
2.083 4
36 2.053 9
41 1.924 7
42 1.901 4
44 2.858 2
1.837 3
49 1.759 2
1.743 13
53 1.692 6
54 1.676 2
1.661 2
57 1.632 4
59 1.604 6
13~3~7~
The most significant d values for zeolite A are given in
Table IIo
TABLE II
MOST SIGNIFIC~NT d VPIUES FOR ZEOIITE A
5d Value of Reflection_in A
12.2 + 0.2
8.7 + 0.2
7.10 * 0.15
5.50 + 0.10
4.10 + 0.10
3.70 + 0.07
3.40 + 0.06
3~29 + 0.05
2.98 + 0.05
2.62 + 0.05
Cccasionally, additional lines not belonging to the pat-
tern 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 muxed with the
zeolite in the sample being testel. Small changes in line posi-
tions may also occur under these conditions. Such changes in no
way hinder the identification of the X-ray patterns as belonging
to the zeoliteO
The particular X-ray techni~ue and/or apparatus em-
ployed, the humidity, the temperature, the orientation of the
powder crystals and other variables, all of which are well known
and understocd to those skilled Ln ~he art of X-ray crystallog-
raphy or diffraction can cause some variations in the intensities
and positions of the lines~ These changes, even in those few in-
stances where they become large, pose no problem to the skilled
X-ray crystallographer in establishing identities. mus, the
`'~ '
. . .
~3~ 3~
X-ray data given herein to identify the lattice for a zeolite,
are not to exclude those ma~erials which, due to some variable
mentioned or otherwise known to those skillecl in the art, fail to
show all of the lines, or shcw a few extra ones that are permis-
S sible in the cubic system of that zeolite, or show a slight shiftin position of the lines, so as to give a slightly larger or
smaller lattice parameter.
A simpler test describecl in "American Mineralogist,"
Vol. 28, page 545, 1943, permits a quick check of the silicon to
10 aluminum ratio of the zeolite. Accord 3 to the description of
the test, zeolite minerals with a three-dimensional network that
contains aluminum and silicon atoms in an atc~ic ratio of Al/Si =
2/3 = 0.67, or greater, produce a gel when treated with hydro-
chloric acid. Zeolites having smaller c~luminum to silicon ratios
15 disintegrate in the presence of hydrochloric acid ancl precipitate
silica. These tests were develo~ed with natural zeolites and may
vary slightly when applied to synthetic types.
U. S. Patent No. 2,882,243 describes a process for mak-
ing zeolite A ccmprising preparing a sodium-aluminum-silicate
20 water mLxture having an SiO2:A1203 mole ratio oE from 0.5:1
to 1.5:1, and Na20/SiO2 le ratio of Erom 0.8:1 to 3:1, and
an H2O/Na20 mole ra~io of from 35:1 to 200:1, maintaining the
mixture at a temperatuxe of from 20C. to 175C. until zeolite A
is form0d, and separating the zeolite A frcm the mother liquor.
It is an important object of the present invention to
provide an improved feed formulation for broilers which contains
a small amount, i.e., up to four weigh~ percent of th~ feed, of
zeolite A.
~3~3~7~
It is a principal object of the invention to prcvide a
broiler feed containing zeolit A which impxoves the lean/fat
ratio of the broilexs withou~ causing a deleterious ef~ect on the
broilers.
Still another object of the invention is ts cost effec-
tively increase broiler production.
Other objects and advantages of the invention will be
more fully understood from a reading of the description and
claims hereinafter.
It has been discovered that the addition of a relatively
snkall amount of zeolite ~ to a regular or standard feed for
broiling poultry, especially broiler chickens, effectively im-
proves the lear~fat ratio of the broiler poultry with no signif-
icant changes in feed consumption. Zeolite A is preferably added
15 in amounts of frcm 0.25 percent to 4.00 percent, arld more
preferably less than 3.5 percent by weight of the total feed.
Broilers ar~ normally fed several different rations dur-
ing their grcw~h period.
A typical feed preparation for large scale broiler poul-
try operations broadly comprises the following by weight percent:
Corn 55-75
Soy Bean Meal 16-30
Limestone 0.5-1.0
Phosphates 0.6-2.0
25 Fat 2.0-7.0
Vitamins, Amino Acids
Salt an~ Other Minerals 0.5-1.0
ll3~3~7~
A typical feeding scherne for broiler poultry includes a
starter ration, a grower ration, a finisher ration and a with-
dra~iL ration. mese rations will vary in cor~osition to match
or othe~wise agree with the poultry's nutritional requirements as
the poultry grow to maturity. m e withdrawal ration is free of
antibiotics and the like so as not to leave any undesir~ble
residue in the final meat product.
Zeolite A is added to each of such feed formulations or
rations in small amounts by weight percent of up to four weight
percent with less than 3.5 weight percent beir~ preferred.
Greater amounts r~y be used, but r~y deprive the broiLer pouLtry
of the desired amount of nutrients. Greater amo~mts are also not
likely to be cost effective. A preferred amount of zeolite A is
frcm one-half to two percent by weight of the total feed formu-
lation. A most preferred amount of zeolite A is about 0.25 toabout l.00 weight percent of the total feed for~ulation.
Using EIHACALTMfeed component, a ccmmercially availabLe
sodium zeolite A, a number of tests were conducted to determine
the effect of zeolites on the lean/fat ratio in broiler poultry.
20 Eq~AC~L feed component has the following typical characteris-
tics:
Form Free flowin~ powder
Color White
Bulk Density, lb/ft3 23-29
Mean Particle Size, microns 3.0
Theoretical Xon Exchan~e Capacity,
millie~livalents per gr~m (al~drou~s) 7.0
.~.... .. .
~ 3 ~ 3 ~ 7 :~
- 12 -
A typical chemical analysis is as follows.
E~r %
Sodium (Na) 12.6
Alumininum (Al) 14.8
Silicon (Si) 15.3
Oxygen (O) 35.1
Water of hydration (H20) 22.2
Heavy Metals less than 10 PPM
(Food Chemicals Codex Method)
10 Lead less than lO PPM
(Food Chemicals Codes Method)
Ihe diet fed to the broilers consisted principally of
corn supplemented with a soybean meal (S~M) and limestone.
Smaller amounts of fish m~al, dicalcium phosphate (DiCalP), a
15 syn~hetic amuno acid (DI,methionine), salt, a ~ cial vitamin
and mlneral supplement for broilers (Micro-Mix~ were also added.
Each diet assured that the broilers received all of the required
nutrients and minerals reccmmended by the Subc~nnittee on Poultry
Nutrition of the National Research Council of the U.S.A.
Female broilers have a much higher tendency than males
tGward excess fat deposits in their carcassesO It is therefore
of utmost importance that fat be reduced, since females comprise
a significant portion of ~he broiler meat consumed. Analysis of
very low density lipoproteins (VIDL) in the blood correlates with
25 the lean/fat ratio o~ the OECaSS in broiler chickens. Studies
of zeolite A diets compared wi~h conirols, i.e. similar diets not
containLng zeolite A, are shown in ~he following table:
. .... : -~ : , ,
~L3 ~ 3~
- 13 -
Wei~ht PercentAveraqe Parts_~er Million VIDL in Blood
Zeolite A m DietM~les _ Females
n 24.1 2~.4
0.25 25.1 25.7
0.50 24.5 24.8
It can readily be seen that in female broilers, where
fat is deposited more quantitatively the higher level of zeolite
A in the diet results in lower VIaL le~els in the blood. Higher
levels of zeolite A in broiler diets (1.0 weight perce~lt) have
10 been shcwn to give be~ter performance in weight gain and feecl
eeficiency and should be expected to give added benefit with the
lean/fat parameter also.
me term poultry includes all domestic fowl, namely
chickens, turkeys, d~lcks, geese, an~ the like.
It can be appreciated that a wide variety of nutrients
or foods may be included in the diets of broiler poultry. In a
controlled envLronment, the poultry are only exposed to desired
foods or food products. A typical ration progra-m for broiler
poultry contains the following:
Starter Diet - Fed to Broilers 0-21 Days of Aqe
Weiqht Percent
Crude Protein 21.22
Calcium 0.86
Available Phosphorus 0.45
25 Synthetic Lysine 1 18
Me~hionine and Cystine 0.~7
Sodium 0.20
Pot3ssium 0.82
Chloride 0.31
30 Metabolizable Energy in K cal/lb 1440
~ 3 i 3~
Grower Diet - Fed to Broilers 21-43 Days of ~qe
Wei~ht Percent
C~lde Protein 19.27
Calci~n O.80
Available Phosphorus 0.41
Synthetic Lys me 1.04
Methionine and Cyst me 0.82
Sodium 0.20
P~t ssium 0.74
10 Chloride 0.31
Metabolizable Energy in K cal/lb 1460
Withdrawa _ iet - Fed to Broilers ~3-50 Dk~ys of Aqe
Weiaht Percent
CXude Protein 16.85
15 Calci~n 0.60
Available Phosphorus 0.32
Synthetic Lysine 0.86
Methionine and Cystine 0.72
Sodium 0.20
20 Potassium 0.63
Chloride 0.32
Metabolizable Energy in K cal/lb 1480
The foregoing comEositions æe obtained from or include
many of the following ingredie~ts-
Grain and Processed ~rain bv-~roducts. Includes corn,
corn hcminy, corn germ meal, barley, millet, oats, rice, rice
hulls, rye, sorghum, wheat and wheat shorts. These are among the
energy mgredients, mostly carbohydrates with s~ne proteins.
Plant ~rotein products. Includes soybe m oil mÆal,
30 barley malt sprouts, cocDnut meal, corn distillers grain, corn
~l 3 ~ 3 ~
- 15 -
glu~.en meal, cottonseed meal, pe~ seed, potato meal, peanut meal,
rape seed m~al, sunflower meal, wheat germ meal, brewers' yeast.
All of these are protein sources.
Rouqhaqe or fiber. Includes dehydrated alfalfa, alfalfa
5 hay, alfalfa leaf meal and pasture grasses. These are all fiber
sources.
Animal and fish by-~roducts. Includes blood meal, blood
flour, dried huttermilk, dried whey, dried casein, fish meal,
dried fish solubles, liver meal, meat meal, meat meal tank~age,
10 bone meal and dried s]um milk. Anchovies, herring and menhaden
are sources of fish meal.
Minerals and svnthetic trace inq_edients. Includes
vitamins such as B~12, A, pantothenate, niacin, riboflavin, K,
e~c., DLrmethionine, choline chloride, folic acid, dicalciurn
phosphate, magnesium sulfonate, potassium sulfate, calcium
carbonate ~limestone, oyster shells), salt, scdium selenite,
manganous oxide, calcium iodate, copper oxide, zinc oxide and D
activated animal sterol.
Molasses and animal fats are added to improve palat-
20 ability and to increase or balance the energy levels.
Preservatives are also added such as, Ethoxyquin andsodium sulfite.
In general, a Eeed composition for broilers or broiler
poultry should preferably contain by weigh~ percent the follow-
25 ing:
16 ~ 3~3~
Weiqht Percen~
crude protein - at least about 14
crude fat - at least about 2
crude fiber - not more than about: 7
S calcium - about 0.5 to 1.0
phosphorous - at least about 0.2
iodine ~ at least 0.0001
sodium - about 0.1 to 0.4
chlorine - about 0.1 to 0.5
zeolite A - about 0.25 to 4.0
~ s mentioned above, there are other beneficial effects
which result from including a small amount of zeolite A in the
poultry feed. For example, heat stress trials were conducted at
University houses under controlled conditions of temperature.
15 Ihe first trial was aborted when the temperature went out of
control and caused high mortality.
A second trial was conducted with 84 birds. The birds
were 68 week old commercial laying hens of the white leghorn
breed. m e birds were equally divided into two groups of 42
20 bir~s each. One group was fed a diet including zeolite A. The
other group, the control group, was ~ed the same diet, but with-
out any zeolite A. me group of birds fed zeolite A maintained
production rate, shell quality and liveability when subjected to
heat stress temperatures of 92-94F for .our weeks while the 42
control birds had reduced production rates, poorer shell quality
~L3~3~
- 17 -
and increased mortality. All three of the parameters were sig-
nificantly different at a 95 percent co~Eide~ce level.
During two days of the final week of` a broiler chicken
test conducted at another uni~ersity, the ten~erature in the
broiler experimen~al house rose abc~e 98,F. Morkality among the
broilers increased significantly during such two day period.
After the data was analyzed, it was found that the mortality rate
among the control birds was 2.5 times that oE the birds being fed
zeolite A in their diets. The followLng table summarizes the
10 mortality.
Weight Percent E~C,~LTM Percent Mortality During Iwo
Feed Component in Diet Day Hiqh ~leat Stress Period
o 2.00 tl-
0.25 0 75
0.50 0.~,8
0.75 0.75
In another heat stress study, 168 birds (30 week old,
young, mature laying hens) were divided into groups oE 84 birds
each, with one group being fed 1.5 weight percent ETHACAL feed
20 component in an environmentally controlled room in which daytime
and nighttime temperatures were held at ~5F and 85F, re~pec-
tively during weekdays and held at a constant 85F on weekends.
m e other group (control group,~ was similarly fed, but without
any ETH~CAL feed component in the diet. The most dramatic
25 result was the mor'cality difference. m irty of 'che control birds
died dur mg the tests and only three of the ETHAC~L feed compo-
nent fed birds diedO
~3~3~7~
- 18 -
~ s another example of a heneficial effect, ~sm~
ETHACAL feed ccmponent, a commercially available sodium zeolite
A, a number of tests were conducted to determine the effect of
zeolites on male aggressiveness.
Calcium Zeolite A Salt
Diet (Wt. %) (Wt. %~ (Wt. %~
1 2.50 0 0.21
2 2.50 0.5 0.15
3 2.50 1.0 0.09
l~e &alt in the diets was adju~sted to equal sodium
levels to compensate for the sodium contained in the zeolite A.
The diet fed to the poultry consisted principally of
corn ~upplemented with a soybean meal (SEM) and limestone. It
also contained smaller amounts of alfalfa m~al, dicalcium phos-
15 phate (DiCalP), a synthetic amino acid (DLrmethionine), salt, acommercial vitamin and mineral supplement for layer~s (Micro-
Mix). Each diet assured that the broiler breeders received all
of the required nutrients and m merals recommended by the
National Research Council of the U.S. Subccmmittee on Poultry
20 Nutrition.
Diets contained normal amounts of calories per pound,
protein, sulfur amino acids, calcium and phosphorous.
Data with regard to male aggressiveness ~as acquired by
observing ~he behavior of the males as the ~arm workRr entered
each pen. It i5 well known thkat male roosters will defend their
te~ritory (the pen of hens) by attacXing any intruders into the
pen, even human workers. It is also well known that the more
1313~
- 19 -
aggressive males have generally higher sperm counts than the more
docile males and will inseminate more females and fertilize more
eggs. Gver a two week period the workers recorded the pen num-
bers m which ~hey were attacked by the males. m e pens were
S rc~ndomly distributed in a lar~e poultry house. m e following
table gives the average results for the 2 week period.
Percent Ethacal FeedPercent of Aggressive
Ccmpone t in DietAttacks
'O O
0.5 33
1.0 60
m e data clearly show a linear response with zeolite
concentration in the diet.
Again using Ethyl EZA~ zeolite, a commercially ~vailable
15 sodium zeolite A, a number of tests were conducted to determ me
the effect of zeolites on production of body-checked eggs.
Two large poultry houses having identical hen popula-
tions of 15,000 62 week old hens each were used. The diets fed
to these old hens in the two houses were identical in every wa~
20 except that 0.75% zeolite A was added to the diet of the hens of
o~e of the houses for a period of six weeks. Data was taken for
three weeks prior to addition of the zeolite and again for two
weeks after the six week test period. A summary of the data is
shown in the following table:
- 20 - ~3~3~ ~ ~
Averaae Percenta~e of BodY-ChecXs
% Zeolite Pretreatment l~eatment Posttreatment
in Diet Period _ Period Perio~ _
0 23.51 16.7~ 18.74
0.75 22.10 12.2~ 25.15
The data shcw that during ~he pretreatment period the
percent of body-checks was cibout equal in th8 two houses. During
the treatment period the percent of body-checXs had drcpped
almost 50 percent in the house in which the hens were fed zeolite
10 A in their diets; and during the posttreatment period when the
zeolite A had been removed frcm the diet the percent of body-
checks was again as high as they had been in the pretreatment
period.
In another feeding test with 32,000 hens at a difEere~t
15 location the percentage of body-check eggs during the treatment
period with 0.75% zeoli~e A in the diet was 44 percent lower than
the pretreatment period and 57 percent lower than the posttreat-
m~nt period.
