Effect of cold storage of multivoltine silkworm eggs (TH14) on growth and survival rate
1995
Soisuda Nguankij
This experiment was to study the effect of cold storage of TH14 silkworm eggs maintained at 5 deg C, on the hatching percentage and the growth rate of silkworm. The experiment, however, was carried out for 6 consecutive generations. The preservation of silkworm eggs at the ages of 20 hours for 40 days, of 2 days for 30 days and of 9 days for 30 days in the cold storage resulted in the range of hatching percentage between 82.64-94.28 percent. The silkworm eggs preserved in the cold storage at for 6 generations showed that at 20 hours of ages they could be kept in the cold storage for 40-50 days. The hatching percentage decreased below 90 percent in the second and third generations. However, the hatching percentage in the fifth and sixth generations indicated higher performances at 93.02 and 93.79 percent respectively. The survival rate of silkworm ranged between 74.85-89.25 percent while the percentage of pupation ranged between 85.50-98.90 percent. Moreover, the shell percentage increased by 9.82 to 13.06 percent. The comparison of hatching percentage between the silkworm eggs rearing in the sixth generation to the normal silkworm eggs, the control, were rather similar, i.e., 93.79 and 95.43 percent respectively. On the contrary, the survival rate of the early larval stage was lower than the control, in the meantime the percentage of pupation did not differ. The quality of cocoon in the sixth generation differed significantly (from the control) in the fresh cocoon weight, the shell weight and the shell percentage.
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