ANIMAL HEALTH Tailing
To B12 or not B12 at tailing BY: ANDREW ROE
W
ith tailing/docking just around the corner in most regions, a common question being posed by our sheep farming clients is “Should I give my lambs B12 at tailing?” As is the case with anything to do with cobalt (the mineral essential for the production of vitamin B12), the answer is not simple. Unlike selenium, where vast areas of the country are known to have deficient soils, cobalt deficiency is a bit more patchy. A study by Scott Knowles et al (published in 2014) reported that only 54% of NZ’s pastures contained enough cobalt to meet the requirements of our grazing livestock. The most severe soil deficiencies have been found in parts of the central North Island and the upper Westland/ Nelson areas, while marginal to moderate deficiencies have been documented in parts of the lower North Island, Canterbury,
Country-Wide
October 2021
There is no simple answer to whether or not to give lambs B12 at tailing.
South Otago and Southland. Soil cobalt levels are strongly linked to the parent rock of the soil concerned, so it is common for neighbouring properties, and even different parts of the same farm, to have quite different soil cobalt levels. On top of that there is a seasonal element to cobalt availability in our pastures; levels typically start to fall later in spring and bottom out over the summer months, before lifting again in the autumn. Cobalt requirements of our livestock also vary, with growing lambs requiring a lot more than ewes, especially when grazing high quality forages after weaning. Getting back to the original question; when you consider the above factors, there will be relatively few sheep farms where the lambs have already become vitamin B12 deficient by tailing time. Sure, there have been reports of properties with more severe deficiencies, where supplementation of their ewes helped prevent deficiency in young lambs. But for most farms cobalt intake is generally
adequate over winter and ewes have lower dietary cobalt requirements than young, growing lambs. So their colostrum and milk will be meeting the B12 needs of their young offspring. Therefore any B12 supplementation given to lambs at this time of year is designed more to protect against an upcoming shortfall in dietary cobalt, rather than to correct an existing deficiency. For this to be effective the choice of product is important. When it comes to injectable B12 products most are short-acting, lifting tissue B12 levels for about four weeks. So they are of dubious use at docking time on all but the most severely cobalt-deficient properties. By the time pasture cobalt levels are falling into the deficient zone (typically late October/early November onwards) any benefits gained from these products are likely to have almost worn off. Of more use for those farmers looking to supplement their lambs at tailing is the long acting injectable product, SmartShotB12 as this will not only correct a deficiency,
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