A while back, I noticed the confusion some folks had when discussing free-martinism and hermaphroditism on one of the Internet goat lists. The following is a letter I wrote to one of the individuals seeking information. It occurs to me that this could make an informative "Tip of the Month".
There is as difference between a free martin and an hermaphrodite. The
hemaphroditism is related to the breeding of "polled to polled" and is
genetic. The gene, itself, is dominant, so a polled animal is heterozygous for the gene. Homozygosity for this gene results in a fatality. The symptoms are the presence of two sets of sex organs (an intersex animal). Does generally have a "bucky" appearance, and do not breed. The way to never have this problem in your herd is to always breed to a horned buck. He does not possess this gene, and hence cannot pass the condition to any of his progeny. In passing, I want to point out that a hornless buck is not necessarily polled - he may have been disbudded. Disbudded is good - naturally polled is not.
The freemartin is caused by an in-utero transfer of bloodcells from
male babies to female babies across the placenta. It can be thought of as
an environmental condition, as the male bloodcells retard the growth of the
female organs while the doe is developing in utero. Many years ago, I
purchased a lovely doe from a top breeder. This doeling was the only female
born in a set of quintuplets. She placed well in all the kid and dry
yearling classes under some top judges, so the condition was not easily
seen. But I could not get the doe bred. I was lucky. I had a friend who was
working at Oak Ridge Associated Universities and whose research project was
on free martinism. She had the technicians check the bloodcells of my lovely
doeling. Of 150 bloodcells that were counted, 148 were male. The blood had
been drawn by my veterinarian, so I didn't make any mistakes. My vet was
planning to write an article on the condition, but then she found an article
published before 1920 describing the condition in a goat, so my doe was the
second case of record. Hence, my vets article was never written. Free
martinism is exceedingly rare in dairy goats, but much more common in
cattle. Incidentally, the doe was posted, and her sex organs were all very
stunted - she never would have bred. The breeder from whom I bought the
doeling replaced her with another lovely doeling - without question, I might
add. It was no reflection upon the breeder. It was just a fluke of nature.
Hopefully, this information can help you recognize and eliminate some possible problems in a relatively painless manner.