I saw at the butcher's shop today that they sold the head of the lamb, cut in half down the middle. I became really interested because the brain was fresh, and I believed it to be really nutritious. However, when I told my family about it, they were rather freaked out. They argued that the brain portion could contain BSE (mad cow's disease), and that eating the head is inhumane. I have no idea whether the BSE part is true, and if it is, whether or not cooking will remove the BSE. I'm interested in a way to properly cook a lamb's head (ie boiled in soup, broiled, or something else), and convince my family to try it out. Thanks in advance.
My understanding is that no cooking method helps with BSE and that seems to be backed up by a U.S. Department of Agriculture fact sheet that states:
Current scientific research indicates that cooking will not kill the BSE agent
However having a look around at a few references like BSE in sheep from the UK department of Agriculture and Rural Development while there's a theoretical risk of sheep contracting the disease it's never actually been detected. There is a related disease in sheep called Scrapie but from that Wikipedia page:
Scrapie has been known since 1732, and does not appear to be transmissible to humans
I've never cooked a whole lamb's head but have cooked lamb brains and one word of caution is that they do cook quickly. Most recipes I've used seem to involve poaching for only five to ten minutes so it may be worth considering removing the brain while cooking the head and adding back late in the cooking process. Another idea might be to make two courses as a common theme, maybe a soup using the head and some crumbed brains.
All of the prion-based brain diseases - mad cow, BSE, chronic wasting disease (deer), CJD (humans) all come from the misshaped protein (prion) that collects in nervous system tissues - brains, spinal cord, nerve tissue sheathing - so, yes, if it's going to be passed, it will generally be much more likely to get contracted from eating brains or spinal chord. Obviously, that's not the only place it can show up, since we saw transmissions from eating beef from tainted cows, but since it attacks the nervous system, you have much higher concentrations there in afflicted animals or humans.
Heat can destroy prions, but not at any kind of temperature approached by cooking. They destroy deer carcasses in my state in specialized blast furnaces because those prions are pretty darn close to indestructible.
When stating that government regulatory agencies state that there's no proof of transmission, keep in mind also that those agencies are not the neutral arbiters of safety one would hope for. They are heavily invested in and influenced by considerations of market success for their industry.
With Mad Cow there were complete denials that it was possible, or that it was happening. In the USA, it was dismissed as a UK/Europe thing even though the method of concentration/transmission (animal proteins from rendered carcasses of same or similar species put back into feed) was used in the USA. Then, when more publicity happened, our regulatory agencies claimed it would not happen here because we "banned" those feed practices, while not noting that the ban was strictly optional and not widely followed. Then, when we saw cases, it was blamed on the cattle being "Canadian," even though both of our countries had identical feed practices.
If you feel it's not a risk, then carry on. If you feel it might be, or have others you are feeding that feel it might be, nothing in the food preparation you do could have any impact on the risk or non-risk.
When John Stauber first wrote "Mad Cow USA," where he correctly predicted we'd see cases here, he was decried in a concerted industry PR smear campaign as a nut-job, a charlatan, a fear-monger, a Luddite, etc. Then, when it happened, everyone wanted to interview him on TV and radio. Here's his excellent book, in its entirety -