An earlier post on lamb evaluations elicited a question about halo hair, and in this post, I hope to clarify both the topic and why it is important to raising sheep. I should clarify first what halo hair is and is not. In my experience, halo hair is normally found in the birth coat of a lamb and is identified as the hair that typically extends above the level of the birth-coat wool. It is commonly found on the top of the head and may also appear in the britch (top of the rear legs) or on the back of the neck. The color of halo hair can be similar to the wool surrounding it, or it can be tan or reddish brown. These hairs are the vestiges of the dual coats that sheep wore centuries ago and are produced by the primary follicles in these areas.
True halo hair is only found in the birth coat and can be extensive, covering nearly the entire lamb. It is very distinct from what many breeders call “hairy britch,” but can look very similar if limited to the upper rear legs. The only way to be sure that one is looking at halo hair is to wait for all of it to fall out between two and eight months of age. In uncoated sheep this loss is obvious: the lamb looks to have a fleece of more uniform length and handle as it ages through these months. The halo hairs can remain trapped within the fleece of a coated sheep, but they can be easily removed by pinching and giving a slight tug or by rubbing the fleece with a damp hand.
When I first began raising sheep, I was told that a good breeder destroys all lambs who are born with halo hair — and so I culled many lambs in those first years, based solely on this old wives’ tale. Eventually I began to wonder whether we were scuttling many wonderful sheep in the process — and I wondered who, exactly, had originally determined that these lambs should go. When our girl Ireland was born covered in halo hair — the most I had ever seen — I decided to keep her and to find out what would happen to her fleece as she got older.
Due to the old wives’ tales, I was surprised when Ireland lost her halo hair in the first two or three months of life. I decided to keep her in the flock until her first shearing, just to see how her fiber would test at about one year of age. I had another surprise when her fiber tested among the finest of my flock at that time. There was no way I would cull her for fleece based on her test results! That was the beginning of many years of investigation into halo hair and fleece quality, and the work still continues today on a smaller scale. Ireland went on to win multiple awards for her beautiful fleece, so obviously I was not simply biased!
After Ireland, I began to keep more lambs with early halo hair. And in every case, if they lost their halo hair by fall, I would keep them in the flock until fiber testing. Overall they have been among the finest-fleeced members of our flock. I have found that halo hair tends to indicate a finer fiber-diameter fleece. The primary follicles seem to put out this coarse hair as they begin fiber production, probably to protect the lamb from the elements during its early life. When that need has passed, the hair breaks off and the primary follicles begin to produce a finer fiber for the remainder of the lamb’s life.
When I come across a lamb with halo hair during my evaluations, I mark this information in the appropriate column. If the halo hair is extensive — as in the case of Molly this year — I’ll write on that lamb’s evaluation line “do not breed” until the halo hair has all fallen out. We do not want to breed sheep who produce a hairy coat! Yet my experience is that halo hair is a temporary condition and, as in Molly’s case, is usually gone in a very short time.
For those of you dealing with halo hair, please know that when there is a lot of halo hair in the birth coat, evaluating crimp or handle becomes almost impossible. That’s one of the reasons why we mark them “do not breed” until they are older and the halo hair is gone.
In Molly’s case, her halo hair has been coming out in big clumps, like a dog’s undercoat in spring. This shedding is of the top coat, however — and that particular coat will not return during her lifetime. Halo hair lambs often grow up to produce their own babies with halo hair, so realize that once you start down this road, you are likely to see more of it as time goes on. Yet in my experience, there is no reason to shy away from a lovely lamb with halo hair. In a few weeks or months, no one will be any the wiser, and you will likely have a lovely, finer fleece from that particular flock member.