Udder Health Part Two - Supernumerary Teats in Goats
Udders are fascinating but sometimes an udder has issues, whether an odd physical trait or a temporary ailment. Arguably the most common of physical abnormality is some sort of extra teat. Terms vary from association and producer, but for the sake of simplicity, we’re calling any teat-like growth with an orifice an extra teat and any growth on the teat or udder without an orifice a “spur.” To better visualize and understand some terms, there are few good sources on udder anatomy, including this one at the Goat Biology website - https://goatbiology.com/animations/lactationanat.html
There are many, many types of extra teats. Lumped together, they’re called supernumeraries. Some will interfere with both kids nursing and milking and some will be so small and out of the way they are not a problem as far as function. For an extremely detailed graphic of possible extra teat types check out this link from the American Boer Goat Association. https://abga.org/wp-content/uploads/2013/11/01-01-2017-Teat-Chart.png
Extra teats may or may not produce milk – meaning they are functional or nonfunctional. A blind teat has an orifice but doesn’t have a streak canal so that the milk can enter the teat. A functional extra teat might be connected to the udder half and produce milk. In the case of some Boer and Boer crosses, the goat might actually have udder quarters instead of udder halves so that the extra teats are not only fully functional but attached to their own mammary glands.
A common type of extra teat is a “split” or “fishtail” teat where the teat and the extra teat are fused either less than 50% of their length or their entire length, respectively. These might also be called “forked” teats. No matter the term or type of supernumerary teat, any extra teat or spur is undesirable in Kinder goats. According to the breed standard, any teat abnormality including: “More or less than two, multiple orifice, bifurcated, double, or extra teats” and “spurs, supernumerary, blind, abnormal and/or deformed” teats are a disqualifying fault, and the animal should not be registered. With the miniature LaMancha goats, the MDGA classifies supernumerary teats as a "slight to serious fault, with a double orifice or extra teat being serious in does. A disqualification is a double orifice or extra teat on a buck. Interestingly, an extra teat on a doe is a disqualification only if it make the doe difficult to milk. https://miniaturedairygoats.net/live-show/mdga-fault-matrix/
Where do supernumeraries come from? According to a large study conducted on dairy goats, found here - https://www.sciencedirect.com/science/article/pii/S0022030216305562 - supernumeraries are likely heritable. That same study (as well as anecdotal evidence) suggests the environment might be a factor too – “Environmental factors predisposing for SNT are still not well known but a role of intrauterine hormones has been suggested (Brka et al., 2002). As SNT are formed during embryogenesis, the environmental effects result from the intrauterine environment and, more broadly, from the dam’s environment.” It is worth mentioning that the authors of the study discuss too that “the phenotype needs better defined” since the study only noted the absence or presence of the supernumerary teat, not the placement, number, or functionality of the extra teat(s).
Perhaps these unknowns are why herds without a history of teat issues suddenly have a crop of kids with supernumeraries or perhaps more study could confirm anecdotal evidence among breeders suggesting that the unwanted trait might be “hidden” for generations before occurring when two specific lines cross – more studies are always needed when it comes to goats!
My Experiences with Supernumerary Teats
I own goats with supernumerary teats. Two Boer X Nubian does I've since sold had clean 2x2 teats. In 2020, those does kidded with doelings, sired by Kinder bucks. Three of the four doelings also had clean 2x2 teats, just like their dams. The other had no teat abnormalities. I kept 2 of those 2x2 teat doelings for my mutt herd - Billie Jean and Sherry. I recently attempted to get photos of the extras for this article. Imagine my surprise when those yearlings now only have 3 teats instead of 4! You can watch the full video here - https://www.facebook.com/heftygoathollerfarm/videos/1212640819208962 I had absolutely no idea an extra teat could disappear without being manually removed (a procedure I refuse to do for a variety of reasons). This raises SO many questions and makes me wonder - can the genes for a supernumerary teat be there without expressing at all? How often does this happen? Will they reappear, even as a small spur or the like, when those girls freshen? I don't know! Typically speaking, all of the breeders I've purchased from avoid any teat abnormalities like the plague and have a long history of normal teats in their herds. (At least to their knowledge by my new found knowledge that extras can disappear makes me question everything!) Here in this herd, I have NO Kinders with teat abnormalities. I've had none. I've had no teat abnormalities in the miniature LaMancha herd with the exception of Verbena and her tiny teat spur. Since her parents have normal teats, and since it has never cropped up again, neither in her full siblings, half siblings, or in her first kids - I am calling it a fluke. Definitely not something I want in my minis but I refuse to toss away a wonderful, promising young doe over something that doesn't negatively affect her function and has not yet been proven to be hereditary in this particular line/cross - this makes me think it is more likely the result of an environmental factor. Domino (unregistered mutt, likely Nubian cross) is another interesting situation. Her teats are normal. She's been bred to three different bucks over the years, and several of her kids have had supernumerary teats, usually a 2x2, sometimes even forked or fishtailed. Usually she has bucklings that go for meat, so this hasn't been an issue. Because she has been the common factor in the extras appearing, I am guessing that is where the gene came from. It is also possible she had a supernumerary teat that was removed, but I have no way of finding this out. Her retained doeling this year has normal teats. As I said earlier, while I do NOT want extra teats in my herd, I am not willing to cull those aforementioned does because of them because they simply don't cause an issue except for the occasional newborn latching onto the wrong teat like newborn Strawberry here with her Boer X dam, Charlie. Of the two does, Charlie had the largest extras. Poppy (pictured on the cover photo of this blog) had much smaller extra teats. One of Charlie's extras was functional but the orifice was smaller. Strawberry learned quickly which was the "good" teat.
The kids of said does are either normal-teated, staying in my herd or being sold unregistered, or going for meat anyway. Almost all of my bucklings get wethered, anyway. Absolutely no teat abnormalities would be tolerated in any buckling prospect. Any registrable doelings that crop up with an issue (like Verbena) - well that depends on the breed. A Kinder won't be registered, in accordance with the rules. If a mini doe, then I will decide if it is a doe I am retaining (in which case I would register according to the fault matrix) or sold. If sold, then she would not be registered. This is just my herd. Different breeders will have a wide variety of opinions on this issue, sometimes very strong opinions. Follow any registry rules and do what works for your herd.
I am curious to see on my Boer X lines how long it takes to breed it out. Or if the extras on Billie Jean or Sherry disappear entirely... or reappear! I am also curious in my Domino line if it will ever pop back up in her grandkids. Goats sure make you ponder...
Sources - Diseases of the Mammary Gland
Paul J. Plummer, Cassandra Plummer
Dairy Goat Herd Health:
Udder Abnormalities and Mastitis
Lionel Dawson, Oklahoma State University
Michael Lane, University of California – Davis
Martin P, Palhière I, Tosser-Klopp G, Rupp R. Heritability and genome-wide association mapping for supernumerary teats in French Alpine and Saanen dairy goats. J Dairy Sci. 2016 Nov;99(11):8891-8900. doi: 10.3168/jds.2016-11210. Epub 2016 Aug 17. PMID: 27544860.