May 2, 2012

Seminar Notes On Reproduction


by Donald "Doc" Skinner, VMD

          I attended a symposium in Philadelphia and one of the lectures was on reproduction. The lecturer Shirley Johnston, DVM, PhD, DACT, has spent many years in reproductive research, during year 2001; she will become the first dean of the newest Veterinary School in Pomona, CA.  

All of her research was done using Radioactive Immune Assay to determine the progesterone  level.  This is much more effective than the color kit that is 86 percent.  Having an accurate progesterone level pinpoints the time of ovulation.  It takes two days for the egg to mature after ovulation.  Thus 3 to 5 days is the ideal time to breed after ovulation.  In a group of 50 pregnant bitches, all whelped  63  plus or minus one day from the time of ovulation.  Counting the time of gestation from the day of breeding  to be 63 days is inaccurate unless you made the breeding three days after ovulation. It is believed fresh sperm is capable of fertilization eight days after breeding. Therefore bitches are not early or late it all depends on when they were bred either before or after ovulation, remembering that all 50 of the research bitches whelped 63 days after ovulation. This observation would also lead to the conclusion that litter size has no bearing on the time of whelping.  Most bitches ovulate 12 days after the first sign of bleeding, when the progesterone level is 4 to 10 rngm. In the 50 bitches tested, ovulation varied from 7 to 22 days after the onset of bleeding.
          Frozen sperm can remain viable longer than the lifespan of everyone on the planet at this time.  One drawback that the lecturer mentioned was that fads change what is desirable with time in dogs more so than in food producing animals.  Oddly enough traditional brace people would not wish to incorporate the qualities of FC Yellow Creek Sport and SPOpeople would love it.  Frozen sperm from a bull can be used to inseminate many cows.  The sample from a dog is usually one on one.  Frozen sperm when properly handled and thawed and then placed into the vagina of the bitch has a 10 percent chance for success. The reason being sperm previously frozen has a poor chance of passing the cervical barrier. It is very difficult to catheterize the cervix.  However, when the sperm is injected directly into the uterus through a laparotomy incision the success rate is 90 percent. Obviously, breeding with the use of frozen semen is not for everyone.

         Chilled semen in the words of the lecturer is more user friendly. Synbiotics has a kit,‘Fresh Express’ that you do not have to be a rocket scientist to use. The sample is viable for four days. If it is shipped overnight delivery, time is not a factor. Artificial insemination with chilled semen is equally successful as using fresh semen. It is probably a lot easier to ship the semen than the bitch.
          The prostate surrounds the neck of the bladder and the urethra.  Benign prostatic  hypertrophy can cause bleeding;  this can lead to infection in the prostate, bladder, or even the testicles. All dogs by age 5 and humans by age 50 have some degree of BPH Prostatic infection can cause infertility.  Bacteria both aerobic and anaerobic and mycoplasms have been incriminated in prostatic infection leading to infertility. If culturing the semen is negative, BPH can be treated with Proscar.  Dogs showing blood in their semen were cleared after 4 months on Proscar at a dosage of 5 mg. per day.  The size of their prostate  was reduced by 22 percent and the volume by 40 percent. Proscar does not interfere with either libido or sperm production.  It is a very useful product for stud dogs.




NEXT EVENT

15 de Dezembro - 2012 - Póvoa de Varzim