A homozygous suri has identical alleles for a single trait. It is important to try and use males that are homozygous. How do you know if he is? If your male covers 10 huacaya and the offspring are all suri this indicates that he is 99 per cent homozygous.
Australian breeders are using this method to prove if the stud is homozygous. The only way to guarantee you will never produce a huacaya from a suri -suri mating is to be certain that at least one of the parent animals is homozygous suri. It has been demonstrated that it is easier to prove a male homozygous due to the number of females that he may cover, whereas a female it may take several years to record if she is homozygous.
If a homozygous suri is mated to a heterozygous suri, 100 per cent of the offspring will be suri in appearance (or phenotype) but 50 per cent will be heterozygous and will carry the huacaya gene.
Using a homozygous male and huacaya female this mating will produce 100 per cent suri in appearance (or phenotype), but all offspring will be heterozygous as they all inherit a huacaya gene from the dam and a suri gene from the sire. These suri are known as “first-cross”, or “F1’s”.
Heterozygous Male If a heterozygous male is used in a breeding program it is incorrect to describe the offspring as BC1, BC2 etc as the huacaya gene is being reintroduced not eliminated.
If a heterozygous suri male covers a huacaya female only 50 per cent of the offspring will be born F1 suri; the other 50 per cent will be born huacaya, inheriting the huacaya gene from the dam together with the “recessive” huacaya gene being carried by the heterozygous suri sire - if you have a female return her to the huacaya breeding program, she is a homozygous huacaya, she does not carry the suri gene.
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Contact Cora or Tracy if you are interested in purchasing coloured suri.
