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 AZA Wildlife Contraception Center in collaboration with Purina Mills LLC/Mazuri brand.  The goal of the study is to obtain approval for use of MGA-treated feed as a contraceptive method for exotic hoofstock species.  However, at this time the feed must be considered experimental, and all participants must adhere to strict protocols for data collection and reporting as dictated by the Food and Drug Administration (FDA).  The AZA Wildlife Contraception Center is responsible for maintaining data collected by study participants and, in conjunction with Purina Mills LLC, submits regular reports to the FDA.

 

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 AZA Wildlife Contraception Center and Purina Mills LLC until such time as it is approved by the FDA for general manufacture and feeding.

 

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 Jan Dempsey, Nutritionist, Nestle Purina, at Janet.Dempsey@purina.nestle.com or 314-982-2875.

 

REPORTING REQUIRED FROM INSTITUTIONS USING MGA FEED

All institutions using MGA feed must submit an annual report to the AZA Wildlife Contraception Center with the following information: species and number of animals treated during the preceding year, including scientific name, common name, ISIS #, birth date, sex, feed product code, amount of feed offered per day, date started, date ended, presence of male in herd, estrous behavior observed, birth dates of any offspring born, abortions, date of death if individual dies and any possibly deleterious effects that might have been due to product use.

 

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 Contraception Advisory Group Survey.  The resulting data will form the basis of FDA reports and of Contraceptive Advisory Group Recommendations.  Failure to submit the annual survey will result in suspension from the trials.  Each spring a survey form is mailed to every institution requesting information from the previous year.  Completed reports should be returned to:

 

Sally Boutelle

Program Coordinator

AZA Wildlife Contraception Center

Saint Louis Zoo

1 Government Drive

St. Louis, MO 63110 USA

Contraception@stlzoo.org

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

University of California

Dept VM‑PMI,1126 Haring Hall

1 Shields Ave

Davis, CA 95616

lmunson@ucdavis.edu

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. Joan Bauman, Saint Louis Zoo Endocrinologist, at jbauman@stlzoo.org or 314-646-4762. 

 

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

            Saint Louis Zoo

            1 Government Drive

            St. Louis, MO  63110

 

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 Joan Bauman (314-646-4762) when samples are being shipped to ensure someone is on hand to accept shipment.

 

Feed Consumption Study

If you are interested in participating in a feed consumption study, please contact Jan Dempsey, Nutritionist, at Janet.Dempsey@purina.nestle.com  314-982-2875.

 

 

TO PURCHASE MGA FEED

Before placing your first order, you must register with the Wildlife Contraception Center using the following form.  BE SURE TO SIGN THE AGREEMENT AND SEND BY POSTAL MAIL.  You may email the form, but the Center requires the original form with a signature for compliance with FDA.  Once your information is received, the Center will then notify Purina Mills, LLC, that you are an approved buyer.  You will then be able to make the purchase through your regular Purina product dealer.

 


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:

 

Species

 

Number and Gender* of Animals

ID or ISIS#

Product Code

(5ZA4, 5ZA5, etc,)

lbs. of feed/animal/day

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

            * 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 Contraception Center Survey every 6 months with information on animals treated during the preceding year, including scientific name, common name, ISIS #, birth date, sex, feed product code, amount of feed offered per day, date started, date ended, presence of male in herd, estrous behavior observed, birth dates of any offspring born, abortions, date of death if applicable, and any possibly deleterious effects that might have been due to product use.  If any adverse effects are noted, a detailed report must be submitted.  Any animals participating in this study will not be used for food purposes.

 

 

Veterinarian Signature (required):_____________________________________________________

 

Mail MGA Feed Registration Form to:

Sally Boutelle

Program Coordinator

AZA Wildlife Contraception Center

Saint Louis Zoo

1 Government Drive

St. Louis, MO 63110

Contraception@stlzoo.org