This is the right approach, Lena -- to look at spinal fusion by vertebral
category.
In my own experience, in both cattle and horses, the sacral segments are
co-fused (along with the intervening plates) before birth or at latest,
within the first six months. Then the lumbar plates begin fusing, starting
at or just before age 2. The thoracics begin fusing, from back to front,
at three to four years of age.
The atlas and the anterior axis fuse at age 2, but the rest of the
cervicals are much slower; most don't complete until 4 years of age, and
the posteriormost two or three may not fuse (in large, long-necked
domestic horses) until age eight. They are in any case the last of all the
postcranial bones to fuse -- in cattle at age four, in horses no earlier
than age 5 1/2. I would acknowledge a six-month plus-or-minus margin of
error, especially with the later-fusing elements; and entire males
typically lag six months behind females, i.e. so that last fusion of C6 or
C7 in a colt/stallion would not be before age six. Gelding still further
delays maturation, though I don't have enough data on that to give you
more than a plus-or-minus two months additional, i.e. a steer might not
fuse the lowest two neck vertebrae until age 5.
Note that I have troubled to get this information through repeated
observation because with horses, it is crucially important to the owner's
decision as to when riding/weightbearing of their young horse is ethical,
wise, and/or best-practice. In the next issue of "The Eclectic Horseman"
magazine you will find a two-part miniseries on growth and development in
the horse which begins with embryology and includes a summary, with good
illustrations, of what I know about skeletal fusion. See
www.eclectichorseman.com. Cheers -- Deb Bennett
> Well, Silver just states [horse and cattle vertebrae] "bodies fuse with
> epiphyses at 5 years" (p.285), and the lack of detail and lack of source
> makes me a bit wary about using Silver.
>
> Habermehl (1975, 99-102) is more detailed on vertebral fusion, and
> yesterday I tried to translate his (potentially a bit out of date)
> terminology. Luckily my google skills were better today. Habermehl quotes
> Keusch and Grätz (1955), saying that at 1-6 years of age the endplates are
> unfused to fusing. At 7 years the fusion line disappears first at the
> lumbar vertebrae and at 9 years at latest all endplates are fully fused to
> the vertebrae. (p.101-102). On the other hand, Schriener (1966) could not
> find anything for age estimation in his study of Fränkischen Vleckvieh
> (p.102), so I guess there is some inter-breed variation going on.
>
> /Lena
>
>
> ----- Original Message -----
> From: "Haskel Greenfield" <[log in to unmask]>
> To: "Lena Strid" <[log in to unmask]>
> Cc: [log in to unmask]
> Sent: Monday, 15 February, 2016 11:48:23 PM
> Subject: Re: [ZOOARCH] Fusion age of cattle vertebrae
>
> My memory is that Silver includes this in his 1969 summary. It is a
> classic.
> Best
> Haskel
>
> Haskel Greenfield
> Sent from my iPhone
>
>> On Feb 15, 2016, at 3:50 PM, Lena Strid <[log in to unmask]>
>> wrote:
>>
>> Dear all,
>>
>> Is there any information on when the endplates of cattle vertebrae fuse
>> to the vertebral body? Ideally detailed down to cervical/thoracic/lumbar
>> groups. I have from a single Iron Age pit at least four articulated
>> spines (atlas - sacrum) in various stage of fusion* and I would like to
>> age them better than "sub-adult - adult".
>>
>> With thanks,
>> Lena
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>
> Files attached to this email may be in ISO 26300 format (OASIS Open
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>
>
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