How does it work?
For this example, we will choose rex to work with. You have a rabbit with amazing fur (D027 - sire) and another with amazing type (CC2 - dam) that are unrelated. We breed them together and get a mix of kits. Some have great fur, others great type, and a few with both great fur AND type. While all these kits can be used, most breeders who practice line-breeding will cull all but the kits with both traits (fur and type).
The male kits with great fur and be bred back to the dam. Likewise, the female kits with great type can be bred back to the sire. You'll end up with the same result as the first breeding, some have one trait, some have both traits.
The ideal match is a kit with both traits (BONBON) mating back to the parent (D027). The result will be more kits with both traits, and kits starting to become more uniform.
In the following pedigree, a full sibling mating did occur. We learned quickly that the particular line worked with reaches sexual maturity very early. For rex, the average is 6-8 months old before first reproduction is possible. In the case of our foundation stock, and consequently the kits produced from the BONBON x D027 mating, sexual maturity was reached just prior to 4 months of age. The litter was not separated at this point, and the siblings (BT1 x BT4) successfully mated.
The resulting litter showed more uniform in type and coat quality, however recessive colors began to pop up. The pedigree shown below outlines the matings and the colors of each rabbit. While all rabbits in the past were castor, the most recent litter contained castors, reds, and a black otter.
This pattern of breeding offspring back to parents can be continued, but it is encouraged to out-cross or bring in new genetic lines every couple of generations. This helps to prevent negative inbreeding effects (See The Risks)
For this example, we will choose rex to work with. You have a rabbit with amazing fur (D027 - sire) and another with amazing type (CC2 - dam) that are unrelated. We breed them together and get a mix of kits. Some have great fur, others great type, and a few with both great fur AND type. While all these kits can be used, most breeders who practice line-breeding will cull all but the kits with both traits (fur and type).
The male kits with great fur and be bred back to the dam. Likewise, the female kits with great type can be bred back to the sire. You'll end up with the same result as the first breeding, some have one trait, some have both traits.
The ideal match is a kit with both traits (BONBON) mating back to the parent (D027). The result will be more kits with both traits, and kits starting to become more uniform.
In the following pedigree, a full sibling mating did occur. We learned quickly that the particular line worked with reaches sexual maturity very early. For rex, the average is 6-8 months old before first reproduction is possible. In the case of our foundation stock, and consequently the kits produced from the BONBON x D027 mating, sexual maturity was reached just prior to 4 months of age. The litter was not separated at this point, and the siblings (BT1 x BT4) successfully mated.
The resulting litter showed more uniform in type and coat quality, however recessive colors began to pop up. The pedigree shown below outlines the matings and the colors of each rabbit. While all rabbits in the past were castor, the most recent litter contained castors, reds, and a black otter.
This pattern of breeding offspring back to parents can be continued, but it is encouraged to out-cross or bring in new genetic lines every couple of generations. This helps to prevent negative inbreeding effects (See The Risks)
Did we see any negative effects?
The short answer is no. We looked at mature weight (at least 9 months old to allow new Sr.s to reach a 'truer' mature weight), overall type (on a scale of 1 to 10 for comparative purposes, based off the ARBA Standard of Perfection), and reproductive success (kits/litter).
The short answer is no. We looked at mature weight (at least 9 months old to allow new Sr.s to reach a 'truer' mature weight), overall type (on a scale of 1 to 10 for comparative purposes, based off the ARBA Standard of Perfection), and reproductive success (kits/litter).
It should be noted that the 37.5% inbred rabbits were at the 9 month age mark, so a lower mature weight may be biased because of that. The rabbits that preformed the best were 25% inbred (BT1 and litter mates in the pedigree above) while many of the new genetic lines bought for out-crossing purposes and original foundation stock were lighter, had less than optimal type, and one had very poor reproductive success (at 3 kits/litter).
We did not experience any still born kits or malformations causing serious issues with even 37.5% inbred rabbits. To prevent any potential negative effects, out-crossing is the next step for the next generation.
We did not experience any still born kits or malformations causing serious issues with even 37.5% inbred rabbits. To prevent any potential negative effects, out-crossing is the next step for the next generation.