MGA MILLED IN FEED: PRODUCT INFORMATION
Mazuri ADF-16 Herbivore
pellet with MGA provides an alternative contraceptive method particularly for
ungulates housed and fed in mixed species/mixed sex herds. Two MGA concentrations are offered to allow
for delivery of the appropriate MGA dose.
This product is considered suitable for bovids, giraffes, cervids,
camelids and hippos, but is not effective in suids or equids.
The product is available
only as part of an experimental trial coordinated by the
The FDA requires all medicated diets be manufactured
under an INAD (New Animal Drugs for Investigational Use, 21 CFR 511.1(a)). Purina Mills LLC was granted permission to
manufacture MGA-treated herbivore pellet for use in this project under their
existing INAD on file with the FDA.
Therefore, all participating institutions must obtain the experimental
MGA feed through the
SAFETY OF MGA FEED TO HUMANS
When used as directed, this product poses no health
risk to humans. Domestic cattle are 240
times more sensitive to MGA than are humans, i.e., a human would have to ingest
a dose 240 times higher than that ingested by cattle to have the same
effect. The doses being recommended for
exotic ungulates are within the range used for cattle. Purina Mills, Inc. believes it is not
hazardous materials according to the OSHA Hazard Communications Standard, 29
CFR 1910.1200 or the EPA Community Right-to-Know regulations. Questions about the Purina Mills MSDS program
should be directed to Mr. Paul Luther at 314-768-4630.
SAFETY OF MGA FEED TO TREATED ANIMALS
MGA has been fed to domestic cattle for decades
without untoward effects, which suggests that it should be generally safe for
ruminants. However, exotic species have
not been treated for more than 5 years, so possible long term effects are not
known. Also, species differences may
apply.
RECOMMENDED DOSES OF MGA FEED
The two concentrations are:
Mazuri ADF-16 0.1MA (5ZA4) containing 0.1 mg MGA/lb,
and Mazuri ADF-16 0.5MA (5ZA5) containing 0.5 mg MGA/lb. Either concentration alone or in combination
may be used to achieve the recommended daily MGA dose/animal for your
individual feeding program. The following daily MGA doses are recommended:
0.5 mg MGA/day/animal for species with body size
smaller than an adult, female banteng (about 800 lb).
1.0 mg MGA/day/animal - for species with body size
similar to or larger than an adult, female banteng.
2.0 mg MGA/day/animal - for hippos and giraffe (some
giraffe have needed as much as 3.0 mg/day to suppress estrous behavior).
NOTE: The
maximum safe dose is considered to be more than 3 times that recommended here.
The amount of pellet and choice of concentration
depends on the species, the body size and on your particular feeding
program. The MGA herbivore pellet is
intended to replace the regular herbivore pellet in your current diets. The pellet should still be fed in conjunction
with hay, in an amount that meets the recommended minimum daily MGA dose while
still meeting the nutritional needs of the animals.
In general, ruminant herbivores have a daily diet
intake of 1.5 – 4.0% body mass (BM), with larger species consuming food at a
smaller percentage of BM than medium or small species. The amount of herbivore pellet to feed is
based largely on the quality of hay fed, and the pellet is intended to correct
the nutrient imbalances or deficits that might occur on a diet of only
hay. Regular analysis of the nutrient
content of your hay is highly recommended.
It may be necessary to make adjustments in your current feeding regimens
in order to deliver the appropriate dose of MGA via the new herbivore
products. Current recommendations from
zoo nutritionists suggest that medium to large size ruminant herbivores should
receive 30-40% of the diet (by weight, as fed basis) as a nutritionally
complete herbivore pellet and 60-70% of the diet (by weight, as fed basis) as
hay. The type of hay(s) used (i.e.,
legume or grass hay, species of hay) in the diet is dependent on the nutrient
content of the hay, the species being fed and hay types available in your area.
If you would like assistance in determining an
appropriate feeding plan, please contact
REPORTING REQUIRED FROM INSTITUTIONS USING MGA FEED
All institutions using MGA feed must submit an annual
report to the AZA Wildlife
LATENCY TO EFFECT
As with implants and injections, separation or
alternative contraception should be used for 1-2 weeks.
ESTROUS CYCLES DURING CONTRACEPTIVE TREATMENT
MGA in feed, like other synthetic progestins, allows
for contraception by blocking ovulation, causing thickening of cervical mucus,
slowing ovum transport, and/or interfering with fertilization or
implantation. However, follicle growth
may continue and sometimes be accompanied by estrogen production sufficient to
cause estrous behavior. Ovulation may
occur even though pregnancy does not ensue.
Higher progestin doses may be preferred so that estrous behavior is
blocked, but may not be effective in completely suppressing follicle growth and
estradiol production.
DURATION OF EFFICACY
Duration of efficacy may not be much more than one
day, so must be administered daily.
REVERSIBILITY
Time to reversal can vary for many reasons. The most basic measure of reversal is when
the concentration of the contraceptive compound in the body drop below the
level of efficacy. However, it is often
not possible to measure this event, so confirmation that reversibility has been
successful must depend on documentation that ovulatory cycles have resumed or
diagnosis of pregnancy or birth of young.
Many factors other than contraceptives affect ovulation and
conception. These include reproductive
history, age, health, body weight (very thin or obese animals may not ovulate
or conceive) and, of course, fertility of the partner. Circulating MGA clears very rapidly following
cessation of treatment, so ovulation and conception may occur within days,
although actual latency is usually longer and will depend on the individual.
CONTRACEPTION FOR SEASONAL BREEDERS
Treatment should begin at least one month before the
anticipated onset of the breeding season.
CONTRACEPTION DURING PREGNANCY
MGA in feed, like other synthetic progestins, is not
recommended in pregnant animals because of the possibility of prolonged
gestation, stillbirth, abortion, etc. in some species, although the effect may
depend on dose.
CONTRACEPTION DURING LACTATION
MGA in feed, like other synthetic progestins, is
considered generally safe for nursing infants.
PRE-PUBERTAL CONTRACEPTION
MGA in feed has been shown not to affect pre-pubertal
female domestic cattle.
WEIGHT GAIN
Like all synthetic progestins, MGA in feed probably
causes weight gain in all species.
CONTRACEPTION DATABASE SURVEY
Because all contraceptives used in exotic species
must be considered experimental, it is critical that records be kept on each
method used, dose, date started, date ended, presence of opposite-sex in group,
signs of estrous behavior, birth dates of any offspring born, abortions, date of
death if an individual dies during treatment, and any other pertinent
observations, especially pathology that might be related to contraceptive
use. Records must be included annually
in the
Sally Boutelle
Program Coordinator
314-646-4595; Fax:314-646-5534
CONTRACEPTION ADVISORY GROUP SAFETY STUDY (AZA Contraceptive Pathology Survey)
Dr. Linda Munson continues to conduct comprehensive
pathologic examinations on reproductive tracts to detect deleterious effects
associated with contraceptives. The
results of these analyses become part of the AZA Contraceptive Advisory Group
Pathology Database and provide important information about contraceptive safety
that is used to make informed decisions for our annual recommendations. Complete reproductive tracts are needed from
BOTH CONTRACEPTED AND NON-CONTRACEPTED females (and MGA -fed males), so that we
can determine if diseases are spontaneous in a species or caused by the
contraceptive. Complete reproductive
tracts and liver samples from treated animals, including tissue collected by
ovariohysterectomy or at necropsy are appropriate.
Instructions for Submission of Tissue
Reproductive tracts can be fixed in buffered formalin
by immersion of the entire tract for 72 hrs if a small incision is made in each
uterine horn, making sure there is a ratio of 1 part tissue to 10 part
formalin. If sending the entire tract is
impractical, send a description (or
photos) of necropsy results, samples of all lesions, 2 endometrial samples (be
sure to include both caruncles and inter‑caruncular areas) and both
ovaries. Liver samples also should be
fixed in buffered formalin. Submission
forms can be found at www.stlzoo.org/contraception. A brief summary of the reproductive history
of each animal should be included.
Pathology evaluations will be conducted free of charge and a report will
be sent to the contributing institution for the animal’s medical records. For institutions with their own pathologist,
please contact Linda concerning the sharing of tissues for this study. Send tissue and reports to:
Linda Munson, DVM, PhD
Dept VM‑PMI,1126 Haring Hall
530- 754‑7567; Fax 530‑752‑3349
RESEARCH OPPORTUNITIES
Fecal Sample Collection to Monitor Ovulation
If your institution can collect feces weekly from
known individuals and wish for hormone analysis, please contact Dr.
Collection of Fecal Samples:
1. Collect sample as fresh as possible.
2. Scoop up about a spoonful (inexpensive plastic
coffee spoons are convenient for this).
3. Place in small zip-lock bag. Do not overfill bag. Make sure it is well sealed.
4. Using permanent black marker (Sharpie), clearly
label bag with animal ID and date of collection.
5. Freeze immediately, at -70EC if
possible.
6. Ship on dry ice by overnight courier to:
Joan
E. Bauman, Ph.D.
Research
Department
7. Mark box “Frozen Specimens”. Include information in the box clearly identifying species, what assays are requested (i.e.: progesterone for cycle monitoring), and contact information for the sender.
8. Notify
Feed Consumption Study
If you are interested in participating in a feed
consumption study, please contact
TO PURCHASE MGA FEED
Before placing your first order, you must register
with the
REGISTRATION FOR PARTICIPATION IN AZA WILDLIFE
CONTRACEPTION CENTER TRIALS OF MAZURI ADF-16 HERBIVORE PELLET WITH MELENGESTROL
ACETATE (MGA) FOR CONTRACEPTION OF BOVIDS, CERVIDS, CAMELIDS, GIRAFFES, AND
HIPPOS
Contact person (responsible for reporting): Date:
Phone/E-mail address:
Institution:
Address:
City/State/Zip:
Purina Mills dealer/phone:
Species and Proposed Feeding Regimen:
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Species |
Number and Gender* of Animals |
ID or ISIS# |
Product Code (5ZA4,
5ZA5, etc,) |
lbs. of feed/animal/day |
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*
reported as number of males.number of females (i.e. 1.1 = 1 male, 1 female)
By this application, the participating institution
agrees to feed the contraceptive product only to approved species at the
recommended dosage, and also agrees to submit the Wildlife
Veterinarian Signature (required):_____________________________________________________
Mail MGA Feed Registration Form to:
Sally Boutelle
Program Coordinator