17 Methyltestosterone Estrogen Steroid Hormone MT Hormone Powder Tilapia

Recommendations

MT treatment in tilapia farming is considered to be entirely safe provided the following

recommended best practices are adopted by producers:

1. Restrict tilapia MT treatment to the early fry stages, specifically to the first month from

the time the fry are free-swimming/first-feeding.

2. Limit the dosage of MT used to a maximum of 50 mg MT/kg fry feed.

3. Rear MT treated tilapia fry to adult size for at least five months after hormone

treatment ends to ensure zero hormone residue remains in the fish.

4. As a precautionary measure, adopt safe handling protocols when preparing and

administering MT treated tilapia feed; use latex gloves and a protective face mask to

avoid dermal contact or inhalation of MT.

5. Keep a careful inventory of the amounts of MT supplied to and used in each tilapia

hatchery, and ensure that access to the hormone supply and record-keeping are controlled

by the farm manager or hatchery superviser.

6. Avoid direct release of hatchery water used for MT treatment of tilapia fry into the

environment. As a precautionary measure, tilapia hatcheries should utilize a gravel and

sand filter, plus a shallow vegetated pond or an enclosed wetland, to receive and hold the

hatchery wastewater for several days before discharge into the general environment.

General Conclusions

•  MT treatment of tilapia fry is the most simple and reliable way to produce allmale

tilapia stocks, which consistently grow to a larger/more uniform size than

mixed sex or all-female tilapias. It is highly effective on the Nile tilapia,

Oreochromic niloticus, the main species farmed commercially worldwide, thus

MT treatment has become the standard technique to produce all-male tilapias.

•  The quantities of MT used worldwide in aquaculute are not reported, but it can be

concluded that the great majority of tilapia products traded internationally

(including virtually all tilapia fillets) are derived from MT treated fish.

•  MT is a synthetic male hormone which closely mimics the naturally-produced

hormone testosterone.

Methyltestosterone Functions & Traits

Methyltestosterone is a pure testosterone hormone that has an added methyl group attached in order for the hormone to survive oral ingestion. However, due to the C17-aa alteration, its translating anabolic activity will be significantly less than most testosterone compounds. The methyl group is attached at the 17th carbon position officially classifying Methyltestosterone as a C17-aa anabolic androgenic steroid. Like all testosterone hormones, Methyltestosterone carries an anabolic rating of 100 as well as an androgenic rating of 100.