Daily Testing Methods and Key Points During the Shrimp Grow-Out Period

@#@234@#@Technicians should patrol the pond once in the early morning and once in the evening each day, carefully observing changes in the pond environment, water color, and the safety of shrimp activity, and keep records. The main testing contents are as follows:

1. During the grow-out period, viral pathogen testing should be carried out frequently, using methods such as T-E staining, nucleic acid probes, and PCR.

2. Remove crabs and rodents around the shrimp pond. Strictly prevent the introduction of dead shrimp from other shrimp ponds and water discharged from diseased shrimp ponds.

3. Measure water quality factors such as water temperature and dissolved oxygen. Measure the lowest water temperature and the highest water temperature before sunrise and at 16:00 each day. Measure dissolved oxygen and pH value in the pond. Measure transparency once a day, measure changes in pond water salinity at irregular intervals, frequently test changes in the types and quantities of plankton in the pond, and where conditions permit, test changes in other water quality factors such as ammonia nitrogen.

4. Observe shrimp activity and distribution.

5. Pay attention to discovering diseased and dead shrimp, and promptly remove diseased and dead shrimp. Check the cause of death; where conditions permit, frequently test changes in the number of pathogenic Vibrio in the pond.

6. Measure shrimp growth every 5-10 days. You can measure shrimp body length or body weight. Shrimp body length refers to the length from the base of the eyestalk to the end of the last abdominal segment; each measurement should randomly sample no fewer than 50 shrimp. To measure body weight, scoop up no fewer than 50 shrimp, weigh the total weight at one time, then calculate the average weight per shrimp.

7. Observe shrimp feeding and feed utilization.

8. Regularly estimate the number of shrimp in the pond. For small shrimp of 3-6 cm, a small lift net of known area can be used to lift shrimp multiple times at multiple locations in the pond, and estimate the number remaining in the pond based on experience. For shrimp with a body length above 6 cm, a cast net can be used for quantification. Cast the net at multiple points in the pond and sample according to the distribution of shrimp in the pond. Based on the number of shrimp caught, use the following formula to calculate the total number of shrimp in the pond.

9. Pay attention to the safety of gates, ditches, and pond dikes. Check whether the aerator is operating normally, and pay attention to electrical safety during thunderstorms.