Managing trace element status of your weaning lambs
Care must be taken to provide adequate levels of trace elements to lambs as they transition from milk to pasture to avoid any drop in
growth rates.
At weaning, many farmers often report a dip in growth rates but may put it down to other factors. Pat Grace, Agrimin’s Sale Manager says: “How many times have I heard a farmer tell me that growth rates have stopped at weaning – often followed by a phrase like ‘it’s just a poor season’ and a shrug of the shoulders.”
The phrase does encompass some of the difficulties when trying to manage trace element status as it can be a complicated picture, changing from year to year. Other factors that influence trace elements include:
- Land conditions- plains and lowlands generally being better than moorlands and uplands
- Plant species- some plants and grasses are better than others in terms of trace element content
- Weather conditions - will impact grass growth rates and their trace element content
- Feed regimes- some common feeds can create trace element problems – rape, roots and other brassicas can inhibit iodine absorption and cereal supplements are generally lower in trace elements.
Severe trace element shortfalls will show themselves in some clinical conditions.
- Selenium deficiency can present as white muscle disease. Signs include sudden onset stiffness, with lambs reluctant to move, such that they are easily caught. After one or two days, affected lambs are unable to rise
- Cobalt deficiency can show as “Pine.” Signs include lethargy, reduced appetite, poor quality wool with an open fleece, small size and poor body condition. There may be tear staining of the cheeks, and pale mucous membranes (eyes) develop after several months. In severe cases, lambs present with nervous signs including depression, head pressing and aimless wandering.
Both are damaging conditions for the animal, though fortunately not that common.
In most cases, it is the subclinical effects that affect a flock the most.
"Cobalt is essential for lamb growth", says Animal Scientist, Annie Williams of Agrimin. "It forms part of vitamin B12. Even at slightly low levels it can cause poor growth rates. Unfortunately it is only picked up by producers who keep good records of weight gains."
"Selenium shortfalls can impact the immune system, with all the knock-on effects that can bring in terms of the lamb's ability to ward off other diseases and parasites," she adds.
Managing trace element status
With a varying picture of trace element status, it is always a good idea to regularly test pasture and blood levels to build a trace element supplementation plan into your routine healthcare management.
The options for managing trace element status are many and varied – they all come with their advantages and disadvantages. They range from in-feed additives, buckets and licks, drenches, injections and boluses. It is a balance between consistency of supply and how long the intervention will last – and of course cost.
Pat adds: “As a rule of thumb, if you’ve identified a trace element shortfall through blood tests, forage analysis or from your productive records, then you will want a secure way of managing long-term consistency and status. Boluses are the best and most cost-efficient way of achieving that,” he says.
On-farm productivity tests carried out across the whole country show the benefits of bolusing lambs.
Pat says: “We carry out quite a few on-farm tests where we measure the impact of our lamb bolus on a control group of lambs, compared to a non-bolused group. We measure blood levels at the start and finish, but in the end, the producer is more interested in the actual benefits measured such as daily liveweight gain.
“Trials show bolused lambs finish either earlier than non-bolused animals, or at a higher weight. The price gains at market significantly exceed bolus costs,” he says.
Agrimin’s lamb bolus works out at less than 50p per animal and will provide cobalt, selenium and iodine cover for 120 days, with no withdrawal issues.
