German Shepherd Breeders: problems with Tieing during mating

I received the following question about unsuccessful ties:

GERMAN SHEPHERD BREEDERS QUESTION;  I guess the one question I have right now is that our oldest female GSD (five years old) that we purchased here in Suriname has been difficult to breed recently.  In the past, we bred her with our oldest male dog (also gotten locally),and he never had any problems mating with her.  We retired him last year, and we have had no success breeding Minx with another male GSD since then.  We tried with my parents’ male before they left the field, and then with our imported AKC registered male.  Although Minx would stand for them, and they would “try,” they never succeeded in penetrating her and “tying.”  We finally put our male Husky in with her, and he succeeded in a matter of minutes when we had been trying with the other dogs for several days.  (Some people like the GSD/Husky cross-breed, but the pups don’t sell for as much as the purebreds).  She doesn’t swell much (compared to our other females), so we don’t know if that is the problem?  Have you ever faced something like that?

DR. BANFE’S ANSWER:   (which may be of interest to German Shepherd Breeders:

It would be a pleasure to give you my take on this.  My website is at www.banffyhausgermanshepherds.com.  I am not sure what the problem is.  I have never had a problem mating a brood female if the timing were correct.  But sometimes when you are early (or late), and the scent is not right, the males will not tie correctly even though they appear to be trying.  I have had that problem before.  It is all by scent and they can smell when she is ready.  She may also not be completely receptive if the timing is wrong. So you may have tried too early but then been right on with the husky.  I use progesterone testing to get the right timing if I can’t leave her to have access to the male multiple times.

So I suspect that is the problem.  Also, I don’t know if you are assisting penetration.  That can make it more likely successful if you are a little early or late.  I have watched this but not done this as I have relied on a very experienced stud owner for this.