British English
Cattle Diseases
Cobalt Deficiency
Also known as: Vitamin B12 Deficiency
- Methylcobalamin which is involved in DNA synthesis (Kennedy et al., 1995)
- Deoxyadenosylcobalamin which is a key metabolite involved in utilization of propionic acid, a source of energy to ruminants (McDowell, 1985)
However, ruminants rely entirely on their rumen microbes to incorporate the cobalt into vitamin B12 (McDowell, 1985), therefore, the vitamin B12 status is not solely dependent on the level of cobalt in soil and diet (Paterson et al., 1989; Ried and Hovath, 1980). The efficiency at which cobalt is incorporated into vitamin B12 by the rumen microbes, the efficiency of absorption and the metabolic demands of the co-enzyme dependent functions are also important factors (Suttle, 1992). Dietary levels of cobalt below 0.05 mg/kg DM are regarded as inadequate.
Clinical Signs of Cobalt Deficiency
If your animals are deficient in cobalt you could use plants in the sward (e.g. legumes) that contain a higher levels of minerals
Cobalt deficiency largely manifests as failure to thrive, particularly in young stock (Ellison, 2002). Cattle are less susceptible to lack of cobalt than sheep (Kennedy et al., 1995), but when they succumb the clinical picture of a ‘pining’ or ‘wasting’ disease is the same. There is anorexia, loss of body condition, muscular wasting and an anemia that is both normochromic and normocytic (Suttle, 1992). Cobalt deficiency may also be responsible for reduced resistance to parasite and microbial infections (MacPherson et al., 1989).
Control and Prevention of Cobalt Deficiency
Cattle need a continuous supply of cobalt as the body’s capacity to store vitamin B12 is limited. Whether or not cobalt deficiency is the reason behind the animal’s poor performance can be attempted to be established by measuring the plasma B12 level of the animal in question. However, plasma B12 is not always very reliable as a measure of available B12 due to the strong binding of plasma proteins to B12, which may make it unavailable for detection in testing. Liver B12 may be a more useful measurement of B12 status if possible, where concentrations below 300nmol/kg FW are indicative of marginal cobalt status (Suttle, 2004). A diagnosis of cobalt deficiency may, in fact, only be made following a positive response to treatment in a group of animals. Splitting a group into a treatment and non-treatment group and recording liveweight gain in growing animals may be considered.
Forage and Soils
Most forages are a good source of cobalt with a range of 0.1-0.3 mg/kg DM, or ppm (Suttle, 2004). Poorly drained soils tend to lead to higher concentrations of cobalt in herbage grown on these soils (MacNaeidhe, 2001). Over-liming soils to increase the pH above 6.0 will reduce the availability of cobalt and may lead to deficiency. The use of leguminous plants, especially red and white clover and mixed grass species may improve the mineral content of the sward (MacNaeidhe, 2001). Furthermore, calves under low-input systems may grow slower than under conventional systems, and therefore have lower cobalt requirements.
Work on organic farms in Norway suggested that second-cut silages contained a higher content of cobalt compared to first-cut silage, although concentrations were low and herbage cobalt alone was insufficient to supply the livestock requirements on Norwegian farms (Govasmark et al., 2005). Although this type of work has not been undertaken elsewhere, the possibility of marginal cobalt status should be considered. However, of the trace element deficiencies discussed in Farm Health Online, cobalt deficiency is probably the most difficult one to prevent by methods of management. Farmers in areas where the soil is very deficient may have to import feedstuff from areas where cobalt deficiency is not a problem.
Method of supplying cobalt |
Pros / Cons |
|
Application of cobalt directly to pasture |
Often the use of fertilizer cobalt is impractical and uneconomical (McDowell, 1985) and is rarely effective because the soil conditions which have limited cobalt uptake by the herbage also lock up any added cobalt (Suttle, 2004). |
| Periodic oral drenching with cobalt | Oral drenching with cobalt sulfate solutions is a good alternative, but costly in terms of labor and impractical on many farms, as it needs to be repeated weekly or fortnightly. |
| Oral administration of cobalt slow-release pellets/boluses | Another method becoming increasingly popular is the use of slow release boluses containing several minerals including cobalt. These slowly dissolve in the reticulo-rumen and release cobalt on a continuous basis, which is the ideal situation for the rumen microorganisms’ requirements.The use of slow release boluses satisfy the need for cobalt better than any of the other methods mentioned by releasing it slowly, plus the need for animal handling would be minimal (Allan et al., 1993; Henry, 1995). |
| Supplementation of concentrate feeds | Cobalt supplementation via the drinking water can be practiced where there is a piped water supply (MacPherson, 1983).Heavy cobalt oxide pellets, given in pairs or singly with a ‘grinder’, improve the B12 status of growing and adult cattle for several months (Quirk and Norton, 1988). |
| Cobalt supplementation in salt licks/ free access minerals | Free access minerals are not a reliable method of supplying cobalt because of variable intakes (McDowell, 1996). |
Treating Cobalt Deficiency
Whether or not cobalt deficiency is the reason behind a group of animals’ poor performance should be considered only if more common conditions, such as gastrointestinal parasitism or liver fluke, have been eliminated. Diagnosis should be attempted with liver B12, (possibly) plasma B12 or by response to treatment. The most immediate response to symptoms of cobalt deficiency will be obtained by injecting cyanocobalamin which is found in a number of multivitamin products Vet advice should be sought. The meat withdrawal period should be checked and the appropriate organic sector body standards applied. One should be able to avoid the use of more than one injection by changing to other methods of prevention, like the use of mineral supplements of cobalt in feed or the use of boluses. Treatment by oral dosing with cobalt gives a dramatic increase in the vitamin B12 synthesis of the rumen microbes and doses of 35 – 70 mg cobalt per week are highly effective (Suttle, 1992).
Good Practice Based on Current Knowledge
- Establish whether the soil is deficient in cobalt
- Try to establish whether cobalt deficiency is the reason why the calves/cows are not doing well after elimination of other causes of ill-thrift
- Use plants in the sward (e.g. legumes) that contain a higher level of minerals, including cobalt
- Use slower growing breeds of cattle
- If necessary, control and prevent cobalt deficiency in the animals with a cobalt-containing bolus, in-feed minerals, drenching or mineral licks as part of the Herd Health Plan
- Treat severely affected animals with a single cyanocobalamin injection
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