Techniques for Improving Reproductive Efficiency in Tursiops
IAAAM Archive
J. P. Schroeder, DVM
Naval Ocean Systems Center, Hawaii Laboratory, Kailua, Hawaii

The development and application of management tools such as ovulation induction, artificial insemination, and early pregnancy diagnosis have been important to the success of modern domestic animal breeding programs.  We have been conducting research aimed at applying these basic tools to dolphin breeding and some progress can be reported in each of these areas.

  • Ovulation Induction: It is difficult to detect estrus in a dolphin and most have long periods of anestrus between seasons, during lactation, or because of some pathology. We have induced ovulation using injections of pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG).  Ovulation is confirmed by serum progesterone levels greater than 3 ng/ml, and total estrogen levels of at least .6 ng/ml. The following procedure has been successful.  PMSG,1,200.00 units are injected intramuscularly on day one to initiate folliculogenesis, 400 units are injected on day three to prevent regression and 1,000 units of HCG on day seven to cause ovulation.  Potential benefits of induced ovulation include decreasing the interval between births, thereby increasing the numbers of offspring per dam, if successful breeding occurs.
  • Artificial Insemination: With the ability to induce ovulation, artificial insemination of the female becomes more feasible.  However, healthy semen is required to complete the process.  We have trained a mature male Tursiops truncatus to ejaculate into a collection bag so that fresh semen can be collected, evaluated, and frozen for future use.  Sperm production was seasonal -- counts ranged from zero to 62.98 x 109 (mean 6.03 x 109 ) (N=131). The peak in serum testosterone preceded the peak in sperm production by two to three months.  When maximum sperm production was reached in September, the testosterone level had declined to 3 ng/ml as compared to 55 ng/ml in June.
  • Pregnancy Diagnosis: We have routinely used radioimmunoassay of progesterone (P) levels in dolphin serum as indicators of ovulation or pregnancy.  A P level of over 3 ng/ml on at least two successive tests six weeks apart has been indicative of pregnancy, but a third test could be necessary under certain conditions.  A P level below 1 ng/ml on any sample has been a definite negative test.  Using this multiple test technique gives an accurate diagnosis and will indicate the need to separate, rebreed or cull a specific female.
Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)

J. Pete Schroeder, DVM
NOSC
Kaneohe, HI


MAIN : 1983 : Reproductive Efficiency
Powered By VIN
SAID=27