Key Technical Points for Overwintering Management in Bullfrog Farming

The bullfrog is a poikilothermic animal, and begins hibernation when the water temperature drops to 6-12 degrees. The following points should be noted in hibernation period management.

1. Prevent cold damage

Bullfrogs hibernate in two ways: lurking at the bottom of the water and in the ground. During the overwintering period, a 2 cm water layer must be maintained in the frog pond, and a cold-proof shed should be built over the water surface with branches or straw. Or use bamboo strips to make a semicircular shed frame above the pond, covered with straw curtains or plastic film. When the air temperature is above 6 degrees, part of the film should be lifted to facilitate ventilation and regulate the temperature inside the shed. At the same time, regularly check the freshness of the pond water and the stability of the water level, to prevent sudden weather changes and a drop in pond water temperature from causing cold injury to the bullfrogs.

2. Maintain body fat

Before overwintering, bullfrogs should be fed sufficient bait to let them eat their fill and grow strong, accumulating enough nutrients in the body to sustain the metabolic consumption during hibernation. If conditions permit, some fly maggots and loaches can be added to ensure the bullfrogs eat their fill and eat well, so as to store up the nutrients needed for hibernation, reduce mortality, and ensure farming benefits. At the same time, on sunny days at noon when the water temperature is above 10°C, feed some concentrated feed, such as small fish and shrimp, earthworms, etc.

3. Shelter from wind

For bullfrogs overwintering in caves, the caves should be dug in a place sheltered from the wind and facing the sun. The size of the caves depends on the scale of farming; generally the diameter is 15 cm, the depth is more than 1 m, and the length is variable. The caves should be both moist and protected from being submerged by pond water, and windbreak barriers should also be set up.

4. Prevent natural enemies

The main natural enemies of bullfrogs include water centipedes, rodents, ants, and so on, which should be removed or killed in time. Especially rats, which should be thoroughly eliminated.

5. Prevent pollution

The water quality of the overwintering pond requires a pH value of 5-9. Too high or too low will cause the death of bullfrogs. Therefore, attention should be paid to preventing water pollution. Oxygen consumption affecting water quality, pollution from pesticides, chemical fertilizers and domestic water, deterioration of leftover bait, and so on, should all be guarded against.