Detailed Explanation of Female Induction Techniques in Bullfrog Farming

Female induction in wood frogs is an important measure for increasing frog oil yield and improving economic returns. So-called female induction, in plain terms, means adopting scientific methods during the frog egg incubation period and the tadpole rearing period to control more of the metamorphosing tadpoles to become female frogs, raising the proportion of female frogs.

There are mainly two methods of female induction in wood frogs: one is the temperature control method, and the other is the sex hormone induction method. (1) Temperature control method: because high temperatures lead to a higher proportion of wood frog gonads differentiating and developing toward the male direction, while low temperatures lead to a higher proportion differentiating and developing toward the female direction, therefore, during the tadpole growth and development period, especially during the slow growth stage and the metamorphosis stage, by adjusting water level and light and other methods, keeping the daily maximum water temperature at 13°C-18°C can induce the gonads to differentiate toward the female direction. If the water temperature exceeds 20°C, deep well water can be continuously injected into the pond during the daytime when the water temperature is high, while draining the water in the pond at the same time, to achieve the purpose of cooling. With this method, the female metamorphosis rate can generally reach more than 70%.

(2) Hormone induction method: because estrogen belongs to the sterol hormones and is insoluble in water, alcohol must be used to dissolve it when administering the drug. In addition, when administering the drug, attention must be paid to the dosage; too large a dosage will cause malformations in wood frog development, while an insufficient dosage will fail to produce an induction effect. The hormone can be thoroughly mixed with bait for feeding, or the drug can be dissolved and directly splashed into the pond.