People have asked me at various times why I did a dual sired litter. I've seen all sorts of wild theories on the internet thrown about as to why a breeder would do this, from "they breed the bitch extra times to try to make as many pups as they can to make as much profit as possible" to "they were careless and let more than one male breed the bitch". Some people even accused the breeders of trying to pull a "fast one", although I've never been sure exactly what the con would be 🙂 On occasion someone actually realizes that some breeders do this as part of a well thought out plan.
In 2008 I did a dual sired litter, using Flip, Mac and Havok. I did it for a number of reasons. One reason is 2 litters for the "price" of one in terms of wear/tear on the female and down time from training. It also cuts the risk to the female in half, as she only has to go through one pregnancy and delivery. If the dam of the litter was primarily someone's competition dog, this would give them the chance to continue and maximize her genetic contributions, with the least amount of down time. Another reason was that I thought it would be an interesting blind study on what the two males produced. It's interesting to evaluate pups when you aren't sure who was sired by who, so there is no bias in terms of traits. I got lucky and my litter was half and half on the sires. And I was only about half and half on accuracy of guessing who was sired by each male. I know someone else who planned to do it because they had leased the bitch for just 1 litter, and really wanted to breed her to two different males. I could also see doing it if you had a female who was getting up there, who you felt should only be bred 1 more time but you wanted to breed her to more than one male. One other scenario which I have heard is a female that only has 1 breeding available, due to age, length of lease, etc and while the breeder really wanted pups from frozen semen, they wanted to make sure the female took. So they did an AI with the female, waited a few days to give it a chance to "take", then did a natural breeding after that. For my litter, since I owned both males, I was able to do the breedings back to back to maximize the chances of pups from each. Once Flip was ready to breed, I bred her to Havok, then after a short rest of about 10 minutes, I bred her to Mac. 2 days later, I bred her to Mac, then after a short rest, bred her to Havok. Skipped another day, then repeated with Havok first again. I have also heard of people who are doing a surgical AI with multiple sires having the vet inject the semen from each dog into different horns in the uterus to increase the chances of pups from both sires.
Dual sired litters are not cheap, with the DNA testing, extra registration expenses, etc so it's not something I think people get into just on a whim. After all the extra expenses, you also run the risk of getting a litter that actually only has one sire.
The down sides of this type of breeding was the timing of the DNA results, the pups were 8 weeks and ready to go to their new homes, but I still didn't have the DNA results back from AKC. And I had swabbed and mailed them off when the pups were 3 days old. Most of my homes didn't care which sire their pup was from, but a couple were hoping to get a pup from a specific sire so it threw a wrench in things. Especially when I finally got the DNA results back about 3 days after the pups went to their new homes, and a couple people did get pups from the "other sire". Finally it also added a good chunk to the overall cost, I believe the DNA, extra registration fees, etc was about $600.00. But I would do it again, in the right circumstances.
To keep the pups straight, I assigned each sire's pups a different litter letter.
Also the results of the DNA tests are listed below, along with how the decision was made regarding the sire of each pup.
Q/R DNA Results
The following are the DNA markers for the Q and R litters. The markers in black/bold are the markers which are unique to one specific sire, the other markers could have come from either sire. Two of the pups have a marker which does not specifically identify them with either sire, or doesn't agree with their other unique markers regarding parentage. Per AKC "in some instances, a pup will have an exclusion at only one marker. A single marker exclusion may be the result of a mutation event and, from a statistical standpoint, does not provide sufficient evidence to conclusively rule out parentage." These markers are indicated in red. "Parentage of a sire/dam is considered excluded when the alleles at two or more markers are excluded". Those markers are indicated in bold. Havok's pups are yellow, Mac's are green.