In this table, P stands for Polled. It is a dominant gene, ie you only have to have one copy of it to look polled (each goat has two copies of each gene, one from mum, one from dad. So PP, Pp and pP are all polled and you can't tell which genes they've got by looking at them. p is the recessive version of the gene, which is horned. A horned goat must be pp.
h is the gene for hermaphrodism and is recessive, ie you have to have two copies to be hermaphrodite, ie hh. But a normal goat can 'carry' the hermaphrodite gene, ie it could be Hh or hH.
The way I see it, normal horned goats are the last line in the table. There is no reason to breed for lines where hermaphrodism crops up, so in horned goats the h gene has been bred out.
BUT, in polled goats you've got a reason to keep the hermaphrodite gene, since it is linked to the polled gene, which you're deliberately keeping. In theory it would be possible to breed for polled, normal goats (PP hh) but because the hermaphrodite gene is recessive, and so a normal goat can carry it, you would have to have a long pedigree before you knew that you had no h genes in it, since you can't tell by looking.
And this is only if the hermaphrodite condition is a single recessive gene and it's highly likely that it is not - sex determination is affected by a whole host of genes.
Ph PH Ph PH
Ph PH Ph PH
ph pH ph pH
ph pH ph pH
| Ph Ph PH PH
ph ph pH pH
Ph Ph PH PH
ph ph pH pH
| Polled, hermaphrodite Polled, normal, carries hermaphrodite gene Polled, normal, carries hermaphrodite gene Polled, normal, no hermaphrodite gene
Polled, hermaphrodite Polled, normal, carries hermaphrodite gene Polled, normal, carries hermaphrodite gene Polled, normal, no hermaphrodite gene
Polled, hermaphrodite Polled, normal, carries hermaphrodite gene Polled, normal, carries hermaphrodite gene Polled, normal, no hermaphrodite gene
Horned, hermaphrodite Horned, carries the hermaphrodite gene Horned, carries the hermaphrodite gene Horned, no hermaphrodite gene
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