Study

Hormonal priming, induction of ovulation and in-vitro fertilization of the endangered Wyoming toad (Bufo baxteri)

  • Published source details Browne R.K., Seratt J., Vance C. & Kouba A. (2006) Hormonal priming, induction of ovulation and in-vitro fertilization of the endangered Wyoming toad (Bufo baxteri). Reproductive Biology Endocrinology, 4, 34

Actions

This study is summarised as evidence for the following.

Action Category

Use artificial fertilization in captive breeding

Action Link
Amphibian Conservation

Use hormone treatment to induce sperm and egg release during captive breeding

Action Link
Amphibian Conservation
  1. Use artificial fertilization in captive breeding

    A replicated study in 2005 of captive Wyoming toad Bufo baxteri in the USA (Browne et al. 2006b) found that the proportion of eggs that became fertilized artificially was similar following one or two priming dose of hormones, but two priming doses resulted in higher numbers of viable eggs. Females given two priming doses produced significantly more tadpoles than those given one priming dose (2,300 vs 84). Toads were housed in 45 l tanks. Ten females were primed with 500 IU human chorionic gonadotrophin and 4 µg lutenizing hormone-releasing hormone (LHRHa). After 72 hours, the 10 females and an additional 10 females were given 100 IU human chorionic gonadotrophin and 0.8 µg LHRHa, followed 96 hours later by 500 IU human chorionic gonadotrophin and 4 µg LHRHa. Eggs produced during the fertile period (12–18 hours after hormone treatment) were fertilized in a dish with spermic urine.

     

  2. Use hormone treatment to induce sperm and egg release during captive breeding

    A replicated study in 2005 of captive Wyoming toad Bufo baxteri in the USA (Browne et al. 2006b) found that one or two priming doses of hormones were required to induce egg production, but not sperm production. Eight of 10 males receiving a single dose of 300 IU human chorionic gonadotrophin (hCG) produced spermic urine within five hours. Females given a single dose of hCG plus lutenizing hormone-releasing hormone-a (LHRHa) produced no eggs. Compared to one priming dose, two priming doses resulted in a greater proportion of females spawning (70 vs 88%) and significantly higher average number of eggs produced (1,647 vs 3,280) and numbers produced/female at a given time (4 vs 7). The total number of eggs/female did not differ with treatment. Toads were housed in 45 l tanks. Ten females were primed with 500 IU hCG and 4 µg LHRHa. After 72 hours, the 10 females and an additional 10 females were given 100 IU hCG and 0.8 µg LHRHa, followed 96 hours later by 500 IU hCG and 4 µg LHRHa.

     

Output references

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