The causes of abortions are really really complex. There can be many many issues that go into that. It could be management, it could be stress, it could be feeding, but this time we discussed that apparently over the last couple of quarters we've seen, at the laboratories, a lower proportion of submissions came up with an organism.
The reason for that is you should definitely keep sending materials from abortions to the laboratories because what they can do is either confirm that there's an infectious agent or organism that causes the abortion.
That could be for instance PRRS or it can rule out that there are specific organisms that cause the abortions and then you have to go to the management factors to figure out what is going on in abortions.
Source : Farmscape