Published online by Cambridge University Press: 09 March 2007
1. Two groups of ewes were fed on a cobalt-deficient diet throughout pregnancy; one group (group A) was given the diet from the beginning of pregnancy, whilst the other (group B) received the diet for 16 weeks before mating. The ewes in group A continued to receive the diet for 12 weeks post-partum.
2. The vitamin B12 content of serum was estimated on three occasions before parturition and, for group A ewes, at 12 weeks post partum. Urinary concentration of methylmalonic acid was also determined at intervals before the lambs were born.
3. Serum values for vitamin B12 indicated that the ewes in both groups were depleted of the vitamin, though those in group B were more severely affected, as was evidenced by the high incidence of perinatal mortality among the lambs born to these ewes. Perinatal mortality appeared to be associated with abnormally-high values for urinary concentration of methylmalonic acid.
4. Analysis of liver lipids and adipose tissue triacylglycerols of some of the vitamin B12-deprived lambs which died before, or within 1 d of, birth showed that, compared with the corresponding tissues of control lambs, these lipids contained unusually high proportions of odd-numbered fatty acids (mostly 15:0, 17:0 and 19:0). This observation is discussed in relation to the likelihood that, in vitmain B12-deprived lambs, propionate becomes available as a primer unit for fatty acid synthesis when the metabolism of its carboxylation product, methylmalonic acid, is impaired due to partlal lack of a vitamin B12-containing enzyme system.
To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.
To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.