Suckler beef producers whose cows are part-way through gestation are reminded to review the micronutrient status of their feeds.
Many in-calf cows are said to be deficient in essential minerals and vitamins, which can potentially have serious consequences, ranging from retained cleansings and metritis to poor foetal development and growth. They can also be one of the biggest causes of stillbirths.
Tom Butler, technical manager at the Denis Brinicombe Group, says winter forages, especially straw, contain poor levels of micronutrients compared with grass grazed in spring.
“High forage diets in late gestation are important in the control of the dry cow’s body condition. However, because they’re likely to be fed with little or no concentrate – which tends to supply a base level of micronutrients – they’re likely to be deficient in vitamins and minerals,” he explains.
This step-down in minerals is said to come at exactly the time the cow most needs an adequate supply.
He says for many spring calving herds it is not too late to address the situation and recommends producers review the mineral status of their cows’ diets, which are often only balanced for protein and energy.
“Inconsistencies and deficiencies in micronutrients would ideally be balanced on a farm-by-farm basis, but this isn’t always practical.”
Instead, he says it is important to find a source of trace minerals and vitamins which can be reliably delivered in a sustained and consistent manner to ensure the animal’s base requirements are met.
This has proved a challenge to the feed additives industry and most delivery systems – whether bucket, loose minerals or bolus – have some limitations.
“The challenge has always been that we require just milligrams of each essential trace mineral and vitamin and we need them supplied in a constant trickle of the same quantity every day,” he says.
Using a rumen bolus is said to be a reliable way of achieving this, although Mr Butler adds some provisos.
“To get the real value from a bolus it’s important it delivers a consistent flow of essential micronutrients, while minimising the risk of regurgitation before it has fully released its mineral supply.”
Manufacturer, Rumbol Products – who has developed the EnduraBol® range with the Denis Brinicombe Group – has overcome this problem. The boluses erode only from the top, rather than leaching or eroding from their entire surface area.
“This original, patented technology ensures the same amount of micronutrients are delivered from the same surface area every day – a bit like a candle burning down at a constant rate,” he says.
“Once it’s completely used, the inert weight, which has prevented regurgitation through the life of the bolus, is now exposed to rumen fluids and simply dissolves.”
The same manufacturing company has also cracked a second problem, which is how to include vitamins in the bolus.
“Vitamins are denatured by heat, which is typical in bolus manufacturing, but Rumbol has perfected a cold-pressed process. This means they can reliably deliver both essential trace elements and vitamins in one bolus,” he says.
The EnduraBol® High Iodine bolus contains six trace elements and three vitamins and will deliver the base daily essentials of micronutrients for six months.
According to Mr Butler, a couple of months pre-calving is a good time to administer them. “This will cover micronutrient requirements around calving and well into lactation, helping set the cow up to get back in calf.”